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supremeuppityone · 5 years ago

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This was written for Klaroline Bingo @klaroline-events.

You can read Part 2 here.

Prompt: Zombies.

It was supposed to be a routine scouting mission for supplies, but the second wave of the virus changed the world and now nothing was routine.

Warning: Angst

Remains

“The fair face of nature was deformed as with the ravages of some loathsome disease” ― Edgar Allan Poe, The Colloquy of Monos and Una

She didn’t dream anymore. No, that was a lie. Nightmares were still dreams. The infected changed the world, but perhaps Caroline should be grateful. Once the second wave of the virus spread, she was a new person. She became a survivor. Caroline impatiently pushed back the greasy strands that escaped her sloppy braid, snorting as she recalled a time when frizzy split ends like these would’ve led to instant banishment from her social circle. Right before the world died, she’d been posting tutorials on marble and tortoiseshell manicures and the best smudge-proof lipsticks to wear with face masks. And now she could field strip a Glock in under a minute. But there was no use mourning the remains of her old life.

She was crouched behind a stack of old tires when she spied Klaus’ rally signal, indicating the all-clear to their group. The arrogant Brit in all of his alpha male glory easily had become the leader of their group of castoffs; some were intrigued by the brooding mystique he cultivated and others comforted by his confident, charismatic leadership. Caroline was still suspicious of his intentions, knowing better than to be swayed by those innocent dimples and playful smirk.

Caroline shook her head in irritation, refusing to get distracted. They were at a landfill about eight miles outside of camp, searching for salvageable materials. The mission was what mattered. Survivors had grown desperate, swallowing their distaste at sifting through the remains of the world. She wrinkled her nose as she passed by a river of brown sludge, the smells of rotten eggs, motor oil and bleach making her stomach turn.

“Nothing there for us; keep looking,” Klaus barked at her sharply, making her scowl. She recalled how furious Klaus had been on that first scouting mission to a landfill; shouting until he was hoarse when he realized how quickly food waste decomposed even in the mild spring. After the first wave of the virus, the grocery stores were raided; the second wave saw the residential areas ransacked. The zombie hordes had been timid at first, as though viewing the immune as the predators. But humanity was fragile, and soon they became prey.

“I know,” Caroline snarled, feeling the need to bare her teeth when he held up his hands in mock surrender. She jerked her head toward a heap of milk-white containers in one of the mounds in the distance, telling him, “Those might be plastic jugs we could repurpose. You should be over there investigating instead of wasting time waiting on me to screw up.”

Anger registered on his handsome face before his expression went carefully blank. “Time spent with you is never a waste,” he muttered, quietly stalking away to signal Enzo, Bonnie and Tyler to follow him to the area she’d indicated.

That was weird. Klaus always seemed irritated by her presence; he grumbled at her questions and mocked the efficiency protocols she’d established around camp. Plus, during his daily combat drills, Klaus always made her train harder than anyone else, running through every fight sequence over and over until her muscles shrieked. Between her explosive temper and his wild mood swings, they’d had some epic screaming matches, but ultimately a begrudging respect had formed and she was startled to realize she’d come to trust him implicitly with their group’s safety. So, why was he messing with her now?

Irritated that their asshat leader’s antics were so distracting, Caroline carefully stepped around broken glass, leaning forward to examine an overturned metal rowboat. Even with the streaks of rust, the hull was intact and they could take it out on the lake to fish.

“You’ve got that look on your face, little bird,” Kol drawled, startling her with his close proximity. He grinned cheekily at her glare, adding, “The one where you’re planning to boast how you’ve scored the most useful haul on our mission. Tsk, tsk — you know what a sore loser Nik can be.”

“Klaus is a grumpy asshat regardless. Pretty sure he came out of the womb with that smirky-scowl of his.”

His brother snorted, kicking aside a dented oil pump that scattered several crank seals across the trash heap. “You didn’t know him from before, little bird. Trust me — Nik is almost downright cheerful these days.” His brown eyes twinkled mischievously as he mused, “I wonder why that is?”

She ignored him, rooting around the edge of the rowboat to see if they could break it free from the black silt and thick sludge that she did her best not to identify. She impatiently pushed away some rusted-out tractor parts that likely belonged to the same pile Kol was kicking around. Actually, it was thanks to Klaus she even could identify tractor parts. He’d pulled her off of game hunting duty to help him work on the tractor they’d found in the woods behind the campgrounds. He taught her the different parts and tools used to free up the seized engine.

“Oil down the cylinders,” he’d commanded, showing her how to neatly coat the spark plug holes in a manner that she absolutely refused to find erotic. Tractors weren’t sexy. British asshats who knew how to tune up carburetors were not sexy, damn it!

She flicked her eyes up, skin prickling as she had the sensation of being watched. Klaus was watching her. Again. Was he seriously that concerned she’d screw up this scouting mission? Asshat. With a huff of annoyance, she turned her back, stooping a bit to inspect something shiny that had caught the sun’s rays. She checked to make sure she couldn’t identify any solvents or other chemicals before she touched it — a lesson they all learned last week when Enzo came back from a scouting mission with a nasty rash. He could’ve died. But they all could, at any time. They were stuck in this terrible world where everything kept trying to kill them.

Her heart gave an unfamiliar tweak as she uncovered an old charm bracelet with several silver butterflies and cheap glass beads linked together. It looked nothing like the platinum and diamond butterfly one her father had given her as a child, but it was the last thing he’d gifted her before he died. Once the infected had swarmed her property, she’d had no choice but to leave it behind. She hadn’t cried when her childhood friend, Elena, succumbed to the virus and transformed, but she’d wept a river over losing that damn bracelet. She was fucked up long before the world ended.

She was focused on unwinding the bracelet from where it had caught on the hinge of a splintered cabinet door, and she didn’t hear Klaus’ piercing whistle until it was too late. Decayed arms grabbed at her long braid, yanking her back with surprising strength.

“Fucking zombies!” Kol bellowed, bashing a skull in with the butt of his rifle as two more clawed at him.

Caroline’s body reacted of its own accord, muscle memory executing a fluid elbow strike as she reached for her gun. She hardly felt the recoil as the bullet messily severed the zombie’s brittle neck.

Kol gestured wildly, shouting at her to run, but she stubbornly kept trying to free the bracelet, paying no mind to the splinters from the door shredding the back of her hands. She couldn’t explain, but she needed it. A connection. Another creature reached for her, gnashing its rotted teeth, but she paid it no mind as she swung the cabinet door, gouging out strips of its festering cheeks.

The door broke just as Klaus reached her, his gray eyes feral as he jerked her arm, yelling, “Leave it! It’s not worth your life!”

Caroline stubbornly shook her head, angry tears in her eyes as another group of infected raced toward them. Too many. Defeated, she left the bracelet where it had fallen and finally allowed Klaus to spirit her away with the rest of their team.

________________________________

Klaus was a caged animal as he paced the short length of the small cabin Caroline shared with Bonnie, whirling around to face her with his blazing stare. “You could’ve died, Caroline!”

“Yes.”

Caroline’s simple answer seemed to spark something in him, and his voice grew dangerously quiet as he harshly said, “You jeopardized the safety of our people over trivial nonsense. My brother was nearly killed. How could you be so stupid? So utterly selfish?!”

Fuck. It wasn’t anything she hadn’t heard before, but somehow those words felt different coming from Klaus. “Because I needed it!” The raw emotion tore at her throat, and she’d never felt so small and weak. “You don’t have tell me I’m stupid and selfish — I already know. I’ve heard it my whole useless life.”

She wasn’t sure when she started crying, but she didn’t duck her head in shame. Instead, she straightened her spine and looked him in the eye. She wanted him to understand. “I was always stupid and shallow and no one ever loved me as much as I loved them, but my dad gave me a bracelet with butterflies on it and I needed that connection to him!”

Klaus opened his mouth to speak, a rare look of uncertainty in his gaze as he studied her. Shaking her head, she felt the fight leave her as she brokenly confessed, “It’s all I have left. And even if no one cared about who I was before, it’s all that remains of my humanity.”

The silence between them was nothing but jagged edges that made Caroline want to curl away from him. Suddenly, Klaus was so close she could feel his breath on her cheek, something unrecognizable flashing in her gaze. He kissed her roughly, clutching at her back as his lips moved over hers. Dominating. Possessing.

The fiery kiss was over far too quickly, leaving her reeling from the heat of his touch. As she raised trembling fingers to touch her lips, Klaus wordlessly stormed away, his jaw tight. What the fuck just happened?

________________________________

Hours later, a heavy banging on the warped wooden door woke her. Bleary eyed, Caroline stumbled out of her bedroll, flicking the safety off of her Glock. Her heart sped up when she spied Klaus standing at her doorstep with his fists clenched.

“Um,” she stuttered inelegantly, unsure of what to say.

“Here,” Klaus said gruffly, thrusting something at her and storming off again before she could speak.

Caroline looked down at her hand, immediately tearing up when she saw it was the old charm bracelet from the landfill.

#kcbingo2020 #klaroline fanfic #uppity bitch fanfic #klaroline #klaroline aesthetic #aesthetic #kc does zombies #just working through my quarantine feelings

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raymondsecurityadventures · 6 years ago

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Spot The Fake

Something that’s been recently faked

I live in the American gardens building on West 81st St on the 11th floor. My name is Raymond Li, I am 21 years old. I believe in taking care of myself and a balanced diet and a rigorous exercise routine. If in the morning my face is a little puffy, I put on an icepack and wear it while I do my stomach crunches. I can do 1000 now. After I remove the icepack I use a deep pore cleanser lotion. In the shower I use a water activated gel cleanser, then a honey almond body scrub. And on the face: an exfoliating gel scrub. Then I apply an herb mint facial mask which I leave on for 10 minutes while I prepare the rest of my routine. I always use an aftershave lotion with little or no alcohol, because alcohol dries your face out and makes you look older. Then moisturiser. Then an anti ageing eye-balm followed by a final moisturising protective lotion.

There is definitely an idea of a Raymond Li. Some kind of abstraction. But there is no real me - only an entity, something illusory. And though I can hide my cold gaze and you can shake my hand and feel flesh gripping yours and maybe you can even sense our lifestyles are even comparable: I simply am not there.*

Detection

You too can be like this and someone who is someone they are not can be quite difficult to detect, as mentioned in week 2′s tutorial whereupon spies in deep-cover were used to discuss identity and its comprising elements, as the mask will inevitably stop being the mask and become your real face. That being said, someone who is inexperienced in playing their mask will, of course, bear signs of rigidity, an uncomfortableness in their role and perhaps other more telltale signs as issues with physical appearance and action. A good example is Scarlett Johansson in Ghost in the Shell (2016?), that bald white kid who plays Aang in The Last Airbender (2011?) and more recently, the showrunners of Game of Thrones pretending they could write a fucking script.

Something that could be easily faked:

Ear cavity biometric scanning. A Japanese firm, NEC, has developed a technology that works similarly to sonar in that it fires a sound wave toward your eardrum and reads the returned signal. This signal will have had to pass through your ear cavity (the hole leading to your eardrum), which will have interfered with the signal in such a way that the machine is capable of translating said signal into the pattern of the ridges (yes there are ridges in your ear) of your ear cavity. This machine is essentially a fat earphone hooked up to a computer that is capable of transmitting sound as well as listening to it. And while it sounds silly, it’s pertinent to remember that audio based imaging techniques such as ultrasound have become incredibly advanced and are capable of generating fairly high resolution images of your belly, or in this case, your ear cavity.

With this in mind, we now look to overcoming this system, and ‘authenticating’ ourselves as someone else using this tech. We could:

Obtain a wax mould of someone’s ear and artificially reconstruct an ear cavity by casting said mould onto a material of similar intensity reflection coefficient as skin to create a hollow earplug of sorts. Reflection coefficient refers to the speed that sound travels through a particular medium. To bypass an authentication protocol that utilised this machine, we could have our infiltrator simply wear this earplug. Alternatively, have the infiltrator carry a replica of the ear around that was built around the reconstructed ear cavity

Replicate the signal that the machine would expect to hear. After all, it is expecting only a sound byte and thus would be very susceptible to a replay attack. The issue would be obtaining said signal but there could perhaps be ways to steal it, such as implanting a similar device into their earphones. This would be the less likely to be successful however, as the broadcast sound, and hence the expected return signal, could probably be vary easily varied

*it’s a quote from the movie American Psycho. Don’t worry I’m not actually a murderous psychopath masquerading as a normie; I AM an anime watching, body pillow hugging normie.

#cyka-blyat #secs #analysis

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commodorez · 7 years ago

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What's a good starting point for learning this stuff? Most of my computer knowledge is being able to assemble the parts together, doing network and and system diagnostics, and just fiddling with OSes. (And the one time I used Backtrack + Reaver to hack my friend's wifi lol.) But Idk how to write code (I've tried tutorials but they never seem to stick.) or figure out how the actual circuitry itself works.

That actually is how many people get started.

As for writing code? I was taught how in school. There are many different approaches here, from picking it up through python on a linux command line environment, to playing with BASIC on a 8-bit microcomputer from the 1980s, to messing with C. There really isn’t one right answer, and I’m sure my followers have a variety of suggestions for how best to approach that.

Circuitry... if you haven’t figured it out by now, I approach this stuff from a vintage computer angle, which ends up having a similar approach to a microcontroller if you separated the chip out into the various components within: CPU, RAM, ROM, graphics, serial/parallel I/O controllers, etc. This user port on a C64 can feel similar to the digital I/O on an arduino for example. There was a time when a Radio Shack 100-in-One style kit would be a great answer to this, but times have changed, and most people don’t build analog circuits from scratch any more. I still do but that’s just how I roll.

We live in an era where arduinos are incredibly inexpensive, and provide a mix between a C-like language and simple circuitry where you can learn the hardware and software aspects hand in hand. Plus, you can learn the newer device control protocols beyond just serial, like I2C and SPI, and really put some cool stuff together that ends up being practical with not all that much effort as it used to require. Not to mention, once you find yourself restrained by the limitations of the arduino IDE, you can always leave it behind for higher performance options that grant you greater fine control over your microcontroller. Then Parallax Propellers, ARM Cortex M0′s, ESP32′s, etc. all become options depending on the type of performance you need to achieve.

I hope that answers your question in a helpful way.

#arduino #Anonymous

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swarupkumarnath07 · 2 years ago

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Basic Understanding of SPI Communication Protocol

SPI Communication Protocol

Hello and welcome to my blog! Today I’m going to share with you some basics of SPI communication protocol. SPI stands for Serial Peripheral Interface and it is a way of transferring data between devices using a master-slave configuration. SPI uses four wires: SCLK (serial clock), MOSI (master out slave in), MISO (master in slave out) and SS (slave select). The master device generates the clock signal and selects which slave device to communicate with by pulling the SS line low. The master and slave then exchange data by shifting bits on the MOSI and MISO lines in sync with the clock. SPI is a fast, simple and reliable protocol that can be used for many applications such as sensors, memory chips, LCD displays and more.

If you are interested to understand more about the SPI Protocol, then you can go through the PiEmbSysTech SPI Protocol Tutorial Blog. If you have any questions or query, that you need to get answer or you have any idea to share it with the community, you can use Piest Forum.

I hope you enjoyed this brief introduction to SPI communication protocol. Stay tuned for more posts on electronics and programming. Thanks for reading!

#embeddedsystems

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cbonline · 3 years ago

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Usb spi programmer jtag xbox

It will now be recognized as "Memory Access", this time use the driver in "Driver for the Flasher", it will then be recognized as LibUSB.Ĭonnect it to the xbox mainboard and use nandpro. 28 Liteon Switch (Patch) 29 TIAO XBOX 360 USB SPI Solderless Adapter. The Glitch360Spi 3.0 rev b is a HiSpeed USB2 SPI programmer, it can use any existing protocols (SPI, JTAG, BitBang, etc) If you want. Unplug the flasher from the PC and plug it in again. 25 FTDI based USB JTAG is coming soon 26 Liteon Switch Tutorial is Published. Start PDFSUSB and flash PICFLASH.hex to it. Solder it together, plug it in by USB, it will be recognized as Custom USB device, use the driver in "Driver for PDFSUSB". Some connectors for USB, the jumper and the SPI output/input (thanks to DarkstarTM, cory1492, Straßenkampf and all others who were involved) Remove the both hooks from invert in the configuration, before programming. You need an external 5V supply, for this you can use a USB cable, cut it.ĭownload PicPGM, plug the PIC onto the programmer, plug it in and use PicPGM to flash PicXBoot.hex Schematics for the Programmer and programming the PIC The easiest to build programmer is ART2003.Īnother programmer is the TAIT Classic Programmer. The flasher is built with PIC 18F2550, which is the cheapest out there.īefore you can build the flasher you need to program the PIC. I am not sure if the program "PDFSUSB" is freeware/shareware so i removed it.

But you can use a pci-lpt-card, which normally doesnt work with nandpro. Unfortunatly if you dont have a LPT-port you wont be able to program the PIC, which is used in the flasher. It is very easy to build and costs about 25€. With this Flasher you can read or write the xbox 360's nand. Programmers and Debuggers AVR JTAGICE mkII USER GUIDE The Atmel AVR JTAGICE mkII Debugger The Atmel® AVR® JTAGICE mkII supports On-Chip Debugging and programming on all Atmel AVR 8- and 32-bit microcontrollers and processors with On-Chip Debug capability.

3.2.2 Schematics for the Programmer and programming the PIC.

#Usb spi programmer jtag xbox

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craftloading57 · 4 years ago

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Neo4j Python

要通过python来操作Neo4j，首先需要安装py2neo，可以直接使用pip安装。 pip install py2neo 在完成安装之后，在python中调用py2neo即可，常用的有Graph,Node,Relationship。 from py2neo import Graph,Node,Relationship 连接Neo4j的方法很简单：. The Python Driver 1.7 supports older versions of python, Neo4j 4.1 will work in fallback mode with that driver. Neo4j Cypher Tutorial With Python. In this course student will learn what is graph database, how it is different from traditional relational database, why graph database is important today, what is neo4j, why neo4j is the best graph database available in the market, students will also get the idea about cypher query and uses of cypher query(all CRUD operations and complete sets of uses cases.

Neo4j Python Book

Neo4jDeveloper(s)Neo4jInitial release2007; 14 years ago(1)Stable releaseRepositoryWritten inJavaTypeGraph databaseLicense

Source code:GPLv3 and AGPLv3

Binaries:Freemiumregisterware

Websiteneo4j.com

Neo4j (Network Exploration and Optimization 4 Java) is a graph database management system developed by Neo4j, Inc. Described by its developers as an ACID-compliant transactional database with native graph storage and processing,(3) Neo4j is available in a GPL3-licensed open-source 'community edition', with online backup and high availability extensions licensed under a closed-source commercial license.(4) Neo also licenses Neo4j with these extensions under closed-source commercial terms.(5)

Neo4j is implemented in Java and accessible from software written in other languages using the Cypher query language through a transactional HTTP endpoint, or through the binary 'bolt' protocol.(6)(7)(8)(9)

History(edit)

Version 1.0 was released in February 2010.(10)

Neo4j version 2.0 was released in December 2013.(11)

Neo4j version 3.0 was released in April 2016.(12)

In November 2016 Neo4j successfully secured $36M in Series D Funding led by Greenbridge Partners Ltd.(13)

In November 2018 Neo4j successfully secured $80M in Series E Funding led by One Peak Partners and Morgan Stanley Expansion Capital, with participation from other investors including Creandum, Eight Roads and Greenbridge Partners.(14)

Release history(edit)

Release historyReleaseFirst release(15)Latest

minor version(16)

Latest release(16)End of Support Date(15)Milestones1.02010-02-23Old version, no longer maintained: 1.0N/A2011-08-23Kernel, Index, Remote-graphdb, Shell(17)1.12010-07-30Old version, no longer maintained: 1.1N/A2012-01-30Graph-algo, Online-backup(17)1.22010-12-29Old version, no longer maintained: 1.2N/A2012-06-29Server including Web Admin, High Availability, Usage Data Collection(17)1.32011-04-12Old version, no longer maintained: 1.3N/A2012-09-12Neo4j Community now licensed under GPL, 256 Billion database primitives, Gremlin 0.8(17)1.42011-07-08Old version, no longer maintained: 1.4N/A2013-01-08The first iteration of the Cypher Query Language, Experimental support for batch operations in REST1.52011-11-09Old version, no longer maintained: 1.5N/A2013-03-09Store Format Change, Added DISTINCT to all aggregate functions in Cypher,

New layout of the property store(s), Upgraded to Lucene version 3.5(17)

1.62012-01-22Old version, no longer maintained: 1.6N/A2013-07-22Cypher allShortestPaths, management bean for the diagnostics logging SPI, gremlin 1.4(17)1.72012-04-18Old version, no longer maintained: 1.7N/A2013-10-18Moved BatchInserter to a different package, lock free atomic array cache, GC monitor(17)1.82012-09-28Old version, no longer maintained: 1.8N/A2014-03-28Bidirectional traversals, Multiple start nodes(17)1.92013-05-21Old version, no longer maintained: 1.9.92014-10-132014-11-21Performance improvement on initial loading of relationship types during startup,

Pulled out Gremlin as separate plugin to support different versions(17)

2.02013-12-11Old version, no longer maintained: 2.0.42014-07-082015-06-11Extending model to “labeled” property graph and introduced visual IDE(17)(18)2.12014-05-29Old version, no longer maintained: 2.1.82015-04-012015-11-29Cypher new cost based planner, Fixes issue in ReferenceCache, potential omission, potential lock leak(17)2.22015-03-25Old version, no longer maintained: 2.2.102016-06-162016-09-25Massive Write Scalability, Massive Read Scalability, Cost-based query optimizer,

Query plan visualization(19)

2.32015-10-21Old version, no longer maintained: 2.3.122017-12-122017-04-21Break free of JVM-imposed limitations by moving the database cache off-heap,

Spring Data Neo4j 4.0, Neo4j-Docker Image, Windows Powershell Support, Mac Installer, and Launcher(20)

3.02016-04-16Old version, no longer maintained: 3.0.122017-10-032017-10-31user-defined/stored procedures called APOC (Awesome Procedures on Cypher),

Bolt binary protocol, in-house language drivers for Java, .NET, JavaScript and Python(21)(18)

3.12016-12-13Old version, no longer maintained: 3.1.92018-06-052018-06-13Causal Clustering, Enterprise-Class Security and Control, User-Defined Functions,

Neo4j IBM POWER8 CAPI Flash, User and role-based security and directory integrations(22)(18)

3.22017-05-11Old version, no longer maintained: 3.2.142019-02-262018-11-31Multi-Data Center Support, Causal Clustering API, Compiled Cypher Runtime, Node Keys,

Query Monitoring, Kerberos Encryption, Clustering on CAPI Flash, Schema constraints,

new indexes and new Cypher editor with syntax highlights and autocompletion(23)(18)

3.32017-10-24Old version, no longer maintained: 3.3.92018-11-022019-04-28Write performance is 55% faster than Neo4j 3.2, Neo4j Data Lake Integrator toolkit, Neo4j ETL(24)3.42018-05-17Old version, no longer maintained: 3.4.172019-11-192020-03-31Multi-Clustering, New Data Types for Space and Time, Performance Improvements(25)3.52018-11-29Older version, yet still maintained: 3.5.282021-04-202021-11-28Native indexing, Full-text search, The recommended index provider to use is native-btree-1.0(26)4.02020-01-15Older version, yet still maintained: 4.0.112021-01-112021-07-14Java 11 is required, Multiple databases, Internal metadata repository “system” database,

Schema-based security and Role-Based Access Control, Role and user management capabilities,

Sharding and federated access, A new neo4j:// scheme(27)(28)

4.12020-06-23Older version, yet still maintained: 4.1.82021-03-192021-12-23Graph privileges in Role-Based Access Control (RBAC) security, Database privileges for transaction management, Database management privileges, PUBLIC built-in role, Cluster Leadership Control, Cluster Leadership Balancing, Cypher Query Replanning Option, Cypher PIPELINED Runtime operators, Automatic routing of administration commands(29)4.22020-11-17Current stable version:4.2.5 2021-04-092022-05-16(Administration) ALIGNED store format, Procedures to observe the internal scheduler, Dynamic settings at startup, WAIT/NOWAIT in Database Management, Index and constraint administration commands, Filtering in SHOW commands, Backup/Restore improvements, Compress metrics on rotation, Database namespace for metrics, neo4j-admin improvements, HTTP port selective settings (Causal Cluster) Run/Pause Read Replicas, Database quarantine (Cypher) Planner improvements, Octal literals (Functions and Procedures) round() function, dbms.functions() procedure (Security) Procedures and user defined function privileges, Role-Based Access Control Default graph, PLAINTEXT and ENCRYPTED password in user creation, SHOW CURRENT USER, SHOW PRIVILEGES as commands, OCSP stapling support for Java driver(30)

Old version

Latest version

Future release

Licensing and editions(edit)

Neo4j comes in 2 editions: Community and Enterprise. It is dual-licensed: GPL v3 and a commercial license. The Community Edition is free but is limited to running on one node only due to the lack of clustering and is without hot backups.(31)

The Enterprise Edition unlocks these limitations, allowing for clustering, hot backups, and monitoring. The Enterprise Edition is available under a closed-source Commercial license.

Data structure(edit)

In Neo4j, everything is stored in the form of an edge, node, or attribute. Each node and edge can have any number of attributes. Both nodes and edges can be labelled. Labels can be used to narrow searches. As of version 2.0, indexing was added to Cypher with the introduction of schemas.(32) Previously, indexes were supported separately from Cypher.(33)

Neo4j, Inc.(edit)

Neo4j is developed by Neo4j, Inc., based in the San Francisco Bay Area, United States, and also in Malmö, Sweden. The Neo4j, Inc. board of directors consists of Michael Treskow (Eight Roads), Emmanuel Lang (Greenbridge), Christian Jepsen, Denise Persson (CMO of Snowflake), David Klein (One Peak), and Emil Eifrem (CEO of Neo4j).(34)

See also(edit)

References(edit)

^Neubauer, Peter (@peterneubauer) (17 Feb 2010). '@sarkkine #Neo4j was developed as part of a CMS SaaS 2000-2007, became released OSS 2007 when Neo Technology spun out' (Tweet) – via Twitter.

^https://neo4j.com/release-notes/neo4j-4-2-5/.

^Neo Technology. 'Neo4j Graph Database'. Retrieved 2015-11-04.

^Philip Rathle (November 15, 2018). 'Simplicity Wins: We're Shifting to an Open Core Licensing Model for Neo4j Enterprise Edition'. Retrieved 2019-01-16.

^Emil Eifrem (April 13, 2011). 'Graph Databases, Licensing and MySQL'. Archived from the original on 2011-04-26. Retrieved 2011-04-29.

^'Bolt Protocol'.

^Todd Hoff (June 13, 2009). 'Neo4j - a Graph Database that Kicks Buttox'. High Scalability. Possibility Outpost. Retrieved 2010-02-17.

^Gavin Terrill (June 5, 2008). 'Neo4j - an Embedded, Network Database'. InfoQ. C4Media Inc. Retrieved 2010-02-17.

^'5.1. Transactional Cypher HTTP endpoint'. Retrieved 2015-11-04.

^'The top 10 ways to get to know Neo4j'. Neo4j Blog. February 16, 2010. Retrieved 2010-02-17.

^'Neo4j 2.0 GA - Graphs for Everyone'. Neo4j Blog. December 11, 2013. Retrieved 2014-01-10.

^'Neo4j 3.0.0 - Neo4j Graph Database Platform'. Release Date. April 26, 2016. Retrieved 2020-04-23.

^'Neo Technology closes $36 million in funding as graph database adoption soars'. SiliconANGLE. Retrieved 2016-11-21.

^'Graph database platform Neo4j locks in $80 mln Series E'. PE Hub Wire. Archived from the original on 2019-04-26. Retrieved 2018-11-01.

^ ab'Neo4j Supported Versions'. Neo4j Graph Database Platform. Retrieved 2020-11-26.

^ ab'Release Notes Archive'. Neo4j Graph Database Platform. Retrieved 2021-04-20.

^ abcdefghijk'neo4j/neo4j'. GitHub. Retrieved 2020-01-28.

^ abcd'Neo4j Open Source Project'. Neo4j Graph Database Platform. Retrieved 2020-01-28.

^'Neo4j 2.2.0'. Neo4j Graph Database Platform. Retrieved 2020-01-28.

^'Neo4j 2.3.0'. Neo4j Graph Database Platform. Retrieved 2020-01-28.

^'Neo4j 3.0.0'. Neo4j Graph Database Platform. Retrieved 2020-01-28.

^'Neo4j 3.1.0'. Neo4j Graph Database Platform. Retrieved 2020-01-28.

^'Neo4j 3.2.0'. Neo4j Graph Database Platform. Retrieved 2020-01-28.

^'Neo4j 3.3.0'. Neo4j Graph Database Platform. Retrieved 2020-01-28.

^'Neo4j 3.4.0'. Neo4j Graph Database Platform. Retrieved 2020-01-28.

^'Neo4j 3.5.0'. Neo4j Graph Database Platform. Retrieved 2020-01-28.

^'Neo4j 4.0.0'. Neo4j Graph Database Platform. Retrieved 2020-01-28.

^'2.1. System requirements - Chapter 2. Installation'. neo4j.com. Retrieved 2020-01-28.

^'Neo4j 4.1.0'. Neo4j Graph Database Platform. Retrieved 2020-06-23.

^'Neo4j 4.2.0'. Neo4j Graph Database Platform. Retrieved 2020-11-26.

^'The Neo4j Editions'.

^'The Neo4j Manual v2.1.5'.

^'The Neo4j Manual v1.8.3'.

^Neo4j. 'Staff - Neo4j Graph Database'. Retrieved 2020-06-19.

External links(edit)

Official website

Neo4j Python Book

Retrieved from 'https://en.wikipedia.org/w/index.php?title=Neo4j&oldid=1020554218'

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emertxeseo · 1 year ago

Text

Mastering Embedded Systems: A Comprehensive Online Course Overview

Embarking on the journey to master embedded systems can open doors to exciting career opportunities and allow you to contribute to innovative technologies shaping our world. With the convenience and flexibility of online learning, you can now access comprehensive courses that delve deep into the intricacies of embedded systems. In this blog, we'll provide an overview of what to expect from a comprehensive online course in embedded systems, guiding you through the path to mastering this dynamic field.

Understanding Embedded Systems

Before diving into the specifics of an online course, let's briefly recap what embedded systems are. Embedded systems are specialized computing systems designed to perform specific tasks within larger systems or devices. They are ubiquitous in modern technology, powering everything from smartphones and smart appliances to automobiles and industrial machinery.

The Importance of a Comprehensive Course

A comprehensive online course in embedded systems goes beyond surface-level knowledge, providing you with a deep understanding of the underlying principles and practical skills needed to excel in this field. Such a course covers a wide range of topics, including:

Embedded Hardware Design: Understanding the architecture and components of embedded systems, including microcontrollers, sensors, and actuators.

Microcontroller Programming: Learning programming languages such as C and assembly language to write code for embedded systems.

Real-Time Operating Systems (RTOS): Exploring the concepts of multitasking, scheduling, and resource management in real-time embedded systems.

Embedded Software Development: Developing software applications for embedded systems, including device drivers, firmware, and middleware.

Communication Protocols: Understanding protocols such as UART, SPI, I2C, Ethernet, and CAN bus for inter-device communication.

Embedded System Debugging and Testing: Learning techniques and tools for debugging, testing, and troubleshooting embedded systems.

Course Format and Delivery

A comprehensive online course in embedded systems typically offers a variety of learning resources and formats to cater to different learning styles. These may include:

Video Lectures: Engaging video lectures presented by experienced instructors, covering key concepts and practical demonstrations.

Interactive Tutorials: Hands-on tutorials and exercises to reinforce learning and apply theoretical concepts to real-world scenarios.

Practical Projects: Opportunities to work on real-world projects, designing and implementing embedded systems solutions from start to finish.

Quizzes and Assessments: Regular quizzes and assessments to gauge your understanding of the material and track your progress.

Discussion Forums: Online forums for asking questions, sharing insights, and collaborating with fellow students and instructors.

Instructor Expertise and Support

One of the key factors that distinguish a comprehensive online course is the expertise and support provided by the instructors. Look for courses taught by experienced professionals with a deep understanding of embedded systems and relevant industry experience. Instructors should be accessible and responsive, providing guidance and support throughout your learning journey.

Student Success and Testimonials

Before enrolling in an online course, take the time to research student success stories and testimonials. Look for reviews and testimonials from past students who have completed the course and achieved success in their careers. Positive feedback and success stories can provide valuable insights into the quality and effectiveness of the course.

Conclusion

Mastering embedded systems requires dedication, commitment, and access to comprehensive learning resources. With a comprehensive embedded systems course online, you can gain the knowledge, skills, and confidence needed to excel in this dynamic field. By choosing a course that covers a wide range of topics, offers diverse learning formats, is taught by experienced instructors, and has a track record of student success, you'll be well on your way to mastering embedded systems and unlocking endless possibilities in your career.

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foxdoctors309 · 4 years ago

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Maker Cardarduino

Arduino Code Maker

Online Arduino Schematic Maker

Create Arduino

Just a quick walk through how to use the SD card module with Arduino. It is the same for Micro SD card modules. The Arduino official site provide a library for this purpose, and I will describe how I used this library and explain what each function does.

The SD card module communicates with the Arduino over the serial peripheral interface (SPI) communication protocol. It can be simply connected to the Arduino’s hardware SPI pins. LCD with I2C Module to the Arduino As the name implies, the LCD module communicates with Arduino through I2C communication. After a week of research, brainstorming and studying we ended up making, the SD-CARD (social distancing icard). The SD-CARD consists of an Arduino Nano which is connected with a buzzer, an ultrasonic sensor and 2 LEDs. The ultrasonic sensor calculates the distance between the person wearing it and people near him/her.

Buy the Arduino from: Banggood | Amazon

Buy SD Card Module from: Amazon | Banggood

I have not tested this library with all the SD card modules, but I think it should work for majority of them, unless you are told by the seller that you should use a different library.

The Library uses standard SPI interface for communication, which hasSPI buses, MISO, MOSI, SCK (CLK) and a chip select signal pin, CS.

(pic)

** MOSI – pin 11 ** MISO – pin 12 ** SCK (CLK) – pin 13 ** CS – pin 4

The default Arduino library for SD card is huge! With the example read/write sketch, when compiled it’s 13690 Bytes which is half of the available flash space on an Arduino pro mini!

So if you are tight in sketch space, it’s a good idea to find a smaller library. Depends on the SD cards you have and the format you want to use, you have these options.

FAT32 Format (larger than 2GB)

Adafruit SD (almost the same as Arduino SD, except a few optimization on SRAM memory)

FAT16 Format (smaller than 2GB)

I haven’t tested all of these libraries, so do your research and test them before using it. Here I will show you how to use the Arduino SD library.

The SD library comes with the Arduino IDE, so you don’t need to download it. It needs to be include at the beginning of the sketch.

Including `SD.h` automatically creates a global “SD” object which can be interacted within a similar manner to other standard global objects like “Serial”.

Read from SD card

First you need top open the file first.

It will return false if it fails to open the file, so check dataFile before using it. The “read” function reads the file line by line, so you will have to use a while loop, until it fail to reach the end of the file. Now you can write to the file using this.

Note that you need to close the file after finished reading it. Also, you can only open one file at a time, if you want to read the next file, you need to close the current file first.

Write to SD card

First you need to open the file you want to write to with “FILE_WRITE” parameter.

The “open” function takes two parameters, file location and mode (only required for “Write”, if missing by default it opens the file in Read-Only mode). It will return false if it fails to open the file, so check dataFile before using it. Now you can write to the file using this.

Note that you need to close the file after writing to it. Also, you can only open one file at a time, if you want to open the next file, you need to close the current file first.

Check if a File Exists

Create a Text File on SD Card

There isn’t a function for this purposes, but you can open a file with “FILE_WRITE” mode to create a file, if this file doesn’t exist.

Delete a File on SD card

List All the files on SD card

There isn’t a function for this in the library, but we can create a custom function to achieve this purpose. This function is from the example sketch in the Library. It prints the file directory to serial monitor.

Testing SD card or Get SD Card Information

Track ME is a 'small' GPS, SD Card, and GSM Shield controlled by an Arduino Mega.Call me and get my location.

Track ME

Arduino Code Maker

Project tutorial by Hugo Gomes

57,633 views

32 comments

94 respects

In this tutorial, you’ll learn how to use SD and micro SD cards with Arduino in a simple project to measure the environment temperature.

SD Card Module with Arduino: How to Read/Write Data

by ElectroPeak

104,338 views

12 comments

24 respects

This project describes of a low-cost GPS data logger for RC planes. In a previous project I described how to build a GPS data logger.

RC LOGGERSTATION - GPS Data Logger for RC Plane

Project tutorial by yvesmorele

5,044 views

2 comments

14 respects

Make your kid's battery-operated electric bike more fun with Arduino!

Electric Bike

Project tutorial by ifeghali

4,665 views

2 comments

13 respects

An Arduino based MP3 player with 30 levels of volume adjustment, 5 levels of EQ adjustment, and a pretty cool retro looking UI.

Arduino Retro Style MP3 Player!

Project tutorial by Neutrino

11,344 views

0 comments

23 respects

This project will play sound from Arduino and work the same as Google Assistant with limited commands. voice-controlled automation.

Talkative Automation || Audio from Arduino || HC-05 || Voice

Project tutorial by Vishalsoniindia

5,831 views

0 comments

9 respects

A small device that can be placed in a car's console to serve various functions such as temperature, time, date, etc.

Car Console Computer

Project showcase by Bie

4,761 views

0 comments

5 respects

Doorbell plays sound from microSD card and Arduino.

SD Card Doorbell

Project tutorial by Projecter

4,429 views

0 comments

10 respects

Connect Ultrasonic Ranger and MicroSD to Arduino, and program it to record the distance - Quick and Easy!

Measure Distance With Sonic Ranger And Record It On MicroSD

Project tutorial by Boian Mitov

4,263 views

0 comments

21 respects

Aim of this project is to improve the experience of the visually challenged, while making cashless transactions in public.

Online Arduino Schematic Maker

Payment Terminal for the Visually Challenged

Project tutorial by Paarth Arkadi

3,636 views

1 comment

8 respects

This project uses a micro SD card to store a text file and print it out to a 16x2 liquid crystal display.

Reading Text Files From an SD Card (Arduino)

Project tutorial by millerman4487

2,815 views

1 comment

4 respects

This is an Arduino base, preset keyboard emulation (HID-human interface device), with SD card file reader and AES 128 encryption.

Create Arduino

Arduino Programmed Keyboard Strikes

Project in progress by Sam

2,295 views

0 comments

1 respect

Retrieve data from speed and cadence sensor in a bike trainer. Display info in LCD screen and log in a SD Card

Bike trainer logger

by cimanes

913 views

0 comments

1 respect

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qvault · 5 years ago

Text

BitBanged SPI in Go, An Explanation

I’m going to focus mostly on some design decisions and how I went about writing an SPI interface using Go on a Raspberry Pi. I assume my readers have a basic understanding of what a Raspberry Pi is, and how basic electronics work. If not, read on anyway and I will be sure to include some valuable resources below.

Why Go?

In a past life, I worked on hardware interfacing software, and the first thing I can tell you is that I hate C. Don’t get me wrong, I understand the appeal of having lightning-fast code and the ability to manipulate memory and low-level functions. I also understand the headache of writing concurrent C code, and anyone familiar with Go knows that this is where it shines.

https://www.raspberrypi.org/blog/compute-module-3-launch/

The project that first got me interested in using Go for embedded applications was one where we decided to use a Raspberry Pi Compute Module 3 to interact with ADC (analog to digital converter) components, and collect data using several of these components.

I quickly threw together a prototype in Python using the standard Python GPIO library, and was satisfied with the initial results. It was apparent however that for a more industrial solution we needed an application that was:

Faster — Able to support more operations per second at lower memory and CPU usage.

Compiled — We didn’t want anyone to be able to pop out the Compute Module and steal our source code.

Maintainable — We had a very small team, and none of us were very experienced with firmware so we wanted to abstract up a bit if possible.

I considered C++ at first. C++ is about as fast as it gets, and is a compiled language. I’m quite comfortable in C++ and have written many applications using it, but we ultimately decided on Go instead for the simple fact the concurrent programming in Go is as easy as it gets. C++ may run a bit faster, but we knew that if we wrote this particular program in Go, it would likely be about half the size (in lines of code) and we were more confident in our ability to keep the code clean and maintainable.

It is important to note that the program in question was doing a lot more than just the data collection via SPI interface with an ADC component. There were user inputs, data displays, etc. It was to be a highly concurrent program.

What is SPI?

http://www.circuitbasics.com/basics-of-the-spi-communication-protocol/

SPI stands for serial peripheral interface. I don’t want to get too far off track, but basically it is just a protocol for a master (your program) to communicate with the hardware (like a thermometer or analog to digital converter). If you want to learn more check out the link in the picture’s caption.

My Environment

Device: Raspberry Pi 3B (We used the compute module for production)

IDE: VS Code

Remote Editing: Check out this tutorial to edit code on the pi using VS Code remotely

Hardware: Breadboard, jumper wires, an ADC that uses an SPI interface

OS: Raspbian

Implementation

First things first, I needed a great GPIO package. For this project, we built the code to be able to use any of the GPIO pins on the Pi. I used Dave Cheney’s library: https://github.com/davecheney/gpio

The code below should build and run. Please keep in mind that if you are going to use this code, you will need to change the pin numbers to match the pins you used to connect your GPIOs to your ADC.

package main import ( "fmt" "time" "github.com/davecheney/gpio" ) // AdcRead represents the data needed to perform a read operation on the ADC component type AdcRead struct { Cs gpio.Pin Clock gpio.Pin Miso gpio.Pin NumBits int ResultsChan chan uint32 } // Exec reads the current value stored in the ADC register func (reader AdcRead) Exec() { // Start the CS Low to begin the read reader.Cs.Clear() // Initialize an impty uint32 to store the value we are reading var result uint32 // Loop over each bit the the component sends back (The number depends varies from // component to component, read the datasheet) for i := 0; i < reader.NumBits; i++ { // Set the clock to logic high reader.Clock.Set() // Read 1 bit in, if it is high, then add a "1" to our rightmost bit bit := reader.Miso.Get() if bit { result |= 0x1 } // Shift Left to get to the next bit to be read if i != reader.NumBits-1 { result <<= 1 } // The clock will pulse low, then high again to get the next bit reader.Clock.Clear() } // Set chip select low to end the read reader.Cs.Set() // Send the result back through the channel to whatever part of our // application cares about it reader.ResultsChan <- result } func main() { // Open necessary pins. The numbers here are examples, they should be changed based // on which pins you use const csPinNumber = 5 const clockPinNumber = 6 const misoPinNumber = 7 csPin, err := gpio.OpenPin(csPinNumber, gpio.ModeOutput) if err != nil { fmt.Printf("Error opening cs pin: %v\n", err) } clockPin, err := gpio.OpenPin(clockPinNumber, gpio.ModeOutput) if err != nil { fmt.Printf("Error opening clock pin: %v\n", err) } misoPin, err := gpio.OpenPin(misoPinNumber, gpio.ModeInput) if err != nil { fmt.Printf("Error opening miso pin: %v\n", err) } resultsChan := make(chan uint32, 1) adcReader := AdcRead{ Cs: csPin, Clock: clockPin, Miso: misoPin, NumBits: 32, // Our ADC component sends a 32 bit value ResultsChan: resultsChan, } // Execute each read at 10 Hz c := time.Tick(time.Duration(100) * time.Millisecond) go func() { for range c { adcReader.Exec() } }() // Print everything that comes through the results channel for true { result := <-resultsChan fmt.Println(result) } }

View repository: https://github.com/lane-c-wagner/spi

Thanks For Reading

Lane on Twitter: @wagslane

Lane on Dev.to: wagslane

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The post BitBanged SPI in Go, An Explanation appeared first on Qvault.

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tak4hir0 · 6 years ago

Link

この記事は Java Advent Calendar 2018 の 9 日目のエントリーです。流行をとらえた話題が多いなか、10~15年前感のあるコンテンツです。化石です。しかし化石とはいえ、よく使う技術ではあります。ということで、何気なく使ってたけど改めて勉強し直しました。検証バージョン java 1.8.0_181 JDBCドライバ postgresql 42.2.5 PostgreSQL 10.5 自前ビルド検証環境 Java動作環境 Windows 10 Pro ver.1803 CPU 4コア(Hyper-Vと共用) RAM 16GB(うち、Hyper-Vへ8GB割り当て) Intel Core i5-4690 CPU 3.50GHz SSD PostgreSQL動作環境 Hyper-V 仮想インスタンス CentOS Linux release 7.1.1503 (Core) CPU 4コア(ホストと共用) RAM 8GB JDBCとは Javaからデータベースにアクセスするための標準API。引用元 TECHSCORE 1. JDBC API ドライバには様々なタイプが存在するが、今回は一番メジャーなタイプ4(全てJavaで実装されているドライバ)の話に絞る。引用元 TECHSCORE 1. JDBC API データベースアクセスの流れ大まかな流れは以下のようになる。 ConnectionクラスでDBとの接続を確立する Statementクラスで実行したいSQLを定義して実行する ResultSetクラスでSQLの実行結果にアクセスするコードは以下のようになる。(close()処理をさぼってるので注意) public static void main(String[] args) throws SQLException { Connection conn = DriverManager.getConnection("jdbc:postgresql://192.168.11.116:5432/sampledb", "kimura", "test"); PreparedStatement pstmt = conn.prepareStatement("SELECT name,price FROM product"); pstmt.setFetchSize(2); ResultSet rs = pstmt.executeQuery(); while (rs.next()) { System.out.println(rs.getString(1)); System.out.println(rs.getInt(2)); } } fetchSize SQLの実行結果を一括でJava側に取得すると、全データがメモリ上に確保されることになる。過度なインスタンス生成はOutOfMemoryErrorにつながるため、データを分割して取ってくる仕組みがある。1回に取ってくるデータサイズがfetchSize。処理速度とメモリ利用量のトレードオフを考慮して決めることになる。検証する 30万程度のレコードをfetchSize=0 と fetchSize=1000で取得してみる。 SELECT count(*) FROM sample; count --------- 3294112 (1 row) PostgreSQL JDBC Driver の場合はfetchSizeを有効にするには以下の条件がある。 conn.setAutoCommit(false)を忘れずに実行する。 The connection to the server must be using the V3 protocol. This is the default for (and is only supported by) server versions 7.4 and later. The Connection must not be in autocommit mode. The backend closes cursors at the end of transactions, so in autocommit mode the backend will have closed the cursor before anything can be fetched from it. *The Statement must be created with a ResultSet type of ResultSet.TYPE_FORWARD_ONLY. This is the default, so no code will need to be rewritten to take advantage of this, but it also means that you cannot scroll backwards or otherwise jump around in the ResultSet. The query given must be a single statement, not multiple statements strung together with semicolons. Chapter 5. Issuing a Query and Processing the Result public static void main(String[] args) throws SQLException, InterruptedException { Connection conn = DriverManager.getConnection("jdbc:postgresql://192.168.11.116:5432/postgres", "kimura", "test"); conn.setAutoCommit(false); PreparedStatement pstmt = conn.prepareStatement("SELECT * FROM sample"); // 0と1000で試行する pstmt.setFetchSize(0); // この間にjconsoleをつなぐ TimeUnit.SECONDS.sleep(15); ResultSet rs = pstmt.executeQuery(); while (rs.next()) { System.out.println(rs.getString(1)); } } fetchSize=0 だと、メモリ利用量が多いが、実行時間は短い。 fetchSize=1000 だと、メモリ利用量が少ないが、実行時間は長い。 SPI ConnectionやStatementやResultSetはすべてインタフェースである。なぜインタフェースを通してプログラミングするだけでいいのか。実装クラスをnewする必要はないのか。これは、SPIという仕組みを利用している。参考 Java Service Provider Interface これによって、MyBatisなどの3thパーティのライブラリがJDBC APIを利用してコーディングしておけば、ライブラリの利用者側で好きなJDBC実装と組み合わせて使える。 PreparedStatement ユーザ文字列をもとにSQLを組み立てるときに、ただの文字列として処理するとSQLインジェクションという脆弱性を生む可能性がある。PreparedStatementを使うと、この問題を防ぐことができる。参考 Wikipedia SQLインジェクション訴訟問題に発展する可能性もあるので、しっかりと対策したい。参考 SQLインジェクション対策もれの責任を開発会社に問う判決検証するまず、SQLインジェクションの脆弱性がある残念なコードを作る。 public static void main(String[] args) throws Exception { Connection conn = DriverManager.getConnection("jdbc:postgresql://192.168.11.116:5432/sampledb", "kimura", "test"); Statement pstmt = conn.createStatement(); String userInput = "alice"; ResultSet rs = pstmt.executeQuery("SELECT name, password FROM users WHERE name = '" + userInput + "'"); while (rs.next()) { System.out.println("name: " + rs.getString("name") + ", password: " + rs.getString("password")); } 実行結果は以下のとおり。String userInput = "alice"に従った内容だけが取得できるので、特に問題ないように見える。 name: alice, password: secret1 次に、ユーザからの入力部分を String userInput = "alice' OR '1' = '1"; に変えて実行してみる。すると、他のユーザの情報にもアクセスできている。 name: bob, password: secret2 name: alice, password: secret1 ここの問題点は、意図せずにSQLの構造を変化させられていること。こんなときに、PreparedStatementを使う。 public static void main(String[] args) throws Exception { Connection conn = DriverManager.getConnection("jdbc:postgresql://192.168.11.116:5432/sampledb?loggerLevel=DEBUG", "kimura", "test"); PreparedStatement pstmt = conn.prepareStatement("SELECT name, password FROM users WHERE name = ?"); String userInput = "alice' OR '1' = '1"; pstmt.setString(1, userInput); ResultSet rs = pstmt.executeQuery(); while (rs.next()) { System.out.println("name: " + rs.getString("name") + ", password: " + rs.getString("password")); } } 実行結果は以下の通り。先ほどのように、別のユーザ情報にアクセスできない。 PreparedStatementを利用すると、バインド変数部分が一つの文字列として解釈される。そのため、nameがalice' OR '1' = '1のものを探すことになる。意図せずにSQLの構造を変更させられることがないので、SQLインジェクション対策になる。 SQLException DBまわりのエラーはSQLExceptionという型でスローされる。 getMessage()でエラー文言が、getSQLState()でエラーコードが取得できる。参考 SQLException Javadoc 参考 The Java? Tutorials Handling SQLExceptions PostgreSQLであれば、SQLStateは以下に詳細に定義されている。 PostgreSQL 10.5 付録A PostgreSQLエラーコードまたJDBC4からSQLExceptionに階層が定義されている。例えば、シンタックスエラーを表すSQLSyntaxErrorExceptionといった具合に。しかし、PostgreSQL JDBC Driverでは対応していない様子。 Github Issue 『Support for JDBC 4.0 exception hierarchy』 PSQLExceptionさえあればいいんや！…というのは冗談としても、実際にWEBアプリケーションを組む場合はフレームワークが独自の階層を持った例外クラスに変換してくれることが多い。なので、実害はないように思う。例えばSpring Frameworkであれば、2.1. Consistent Exception Hierarchyに記載されているような例外の型階層に変換してくれる。検証する構文として問題のあるSQLを実行し、SQLExceptionの中身を表示する。 public static void main(String[] args) throws Exception { Connection conn = DriverManager.getConnection("jdbc:postgresql://192.168.11.116:5432/sampledb", "kimura", "test"); conn.setAutoCommit(false); try { // FROM のtypo PreparedStatement pstmt = conn.prepareStatement("SELECT * FORM sample"); pstmt.executeQuery(); } catch (SQLException e) { System.out.println(e.getErrorCode()); System.out.println(e.getSQLState()); System.out.println(e.getMessage()); } } 実行結果は以下の通り。 0 // PostgreSQL JDBC Driverの場合は常に0 42601 ERROR: syntax error at or near "FORM" 位置: 10 ISOLATION_LEVEL Connection#setTransactionIsolationメソッドでトランザクションの隔離性を設定できる。AutoCommitがtrueになっているとSQL実行ごとに自動でトランザクションがコミットされるため、Connection#setAutoCommit(false)と組み合わせることが多い。 ISOLATION_LEVELの詳細は、データベースの知識なので割愛する。ここらへんは以前に調べた。参考 PostgreSQL Isolation について JDBCコネクションプール先述したConnectionをSQL実行の度にオープン/クローズすると、接続コスト(TCPコネクション確立～DBの認証）がその都度かかる。そのため、コネクションを使いまわすのがJavaの世界では一般的であり、この仕組みをコネクションプールと呼ぶ。引用元 IBM Developer 第3回「JDBCとデータベース接続」コネクションプールの実装によるが、以下のパラメータはたいてい存在する。コネクションプール関連コネクションのバリデーション関連 JDBC Driverのパラメータ操作関連特に、コネクションプールの最大数を超えた要求が来た場合、要求スレッドはコネクションが返却されるのを待つことになる。最悪はタイムアウトして例外が発生することになるので、頻繁にタイムアウトが発生しないように注意する。コネクションプールのメリット・デメリットは以下が詳しい。また、コネクションプール以外のデータベース接続アーキテクチャも記載されているので、ぜひとも一読するべき。参考 Webシステムにおけるデータベース接続アーキテクチャ概論 AP視点のメリット DriverManager#getConnectionしたときのパケットをWireSharkでキャプチャすると、クライアント~サーバ間で複数回の通信が行われていることがわかる。コネクションをプールすることで、上記のやり取りを省略できる。検証する以下の3つで、どれくらい接続コストが違うのかを確かめる。単純にコネクションを使いまわした場合コネクションプールライブラリを使った場合都度接続した場合なお、PostgreSQLは同一ホストの仮想環境に立っているので、ネットワーク的な遅延が低い状況である。単純にコネクションを使いまわした場合 private static final int LOOP_COUNT = 10000; public static void main(String[] args) throws SQLException, InterruptedException { long start = System.currentTimeMillis(); Connection conn = DriverManager.getConnection("jdbc:postgresql://192.168.11.116:5432/postgres", "kimura", "test"); for (int i = 0; i < LOOP_COUNT; i++) { PreparedStatement pstmt = conn.prepareStatement("SELECT 1"); ResultSet rs = pstmt.executeQuery(); while (rs.next()) { } rs.close(); pstmt.close(); } conn.close(); long end = System.currentTimeMillis(); System.out.println("time: " + (end - start)); } コネクションプールライブラリを使った場合 private static final int LOOP_COUNT = 10000; public static void main(String[] args) throws Exception { HikariConfig config = new HikariConfig(); config.setUsername("kimura"); config.setPassword("secret"); config.setJdbcUrl("jdbc:postgresql://192.168.11.116:5432/sampledb"); config.setMaximumPoolSize(2); long start = System.currentTimeMillis(); HikariDataSource ds = new HikariDataSource(config); for (int i = 0; i < LOOP_COUNT; i++) { Connection conn = ds.getConnection(); PreparedStatement pstmt = conn.prepareStatement("SELECT 1"); ResultSet rs = pstmt.executeQuery(); while (rs.next()) { } rs.close(); pstmt.close(); conn.close(); } long end = System.currentTimeMillis(); System.out.println("time: " + (end - start)); } 都度接続した場合 private static final int LOOP_COUNT = 10000; public static void main(String[] args) throws SQLException, InterruptedException { long start = System.currentTimeMillis(); for (int i = 0; i < LOOP_COUNT; i++) { Connection conn = DriverManager.getConnection("jdbc:postgresql://192.168.11.116:5432/postgres", "kimura", "test"); PreparedStatement pstmt = conn.prepareStatement("SELECT 1"); ResultSet rs = pstmt.executeQuery(); while (rs.next()) { } rs.close(); pstmt.close(); conn.close(); } long end = System.currentTimeMillis(); System.out.println("time: " + (end - start)); } 実行結果は以下の通り。コネクション使いまわしコネクションプールライブラリ(HikariCP) 都度接続 1回目 2124 2522 42304 2回目 2363 2538 42890 3回目 2352 2593 41420 4回目 2275 2594 43021 5回目 2291 2280 43948 平均(ms) 2281 2505.4 42716.6 接続コスト(TCPコネクション確立～DBの認証)はそれなりにかかる、ということがわかった。 JDBCコネクションプール(DB視点) PostgreSQLはコネクションごとにpostgresプロセスをforkする。 PostgreSQL 10.5 第50章 PostgreSQL内部の概要 The Internals of PostgreSQL Process and Memory Architecture 引用元 The Internals of PostgreSQL Process and Memory Architecture そのため、同時接続数分だけプロセスを生成することになる。例えば、コネクションプール=3のときのPostgreSQLのプロセスは以下のようになる。 ]$ ps -ef | grep postgres kimura 1721 61604 0 13:21 ? 00:00:00 postgres: kimura sampledb 192.168.11.104(61246) idle kimura 1730 61604 0 13:22 ? 00:00:00 postgres: kimura sampledb 192.168.11.104(61251) idle kimura 1734 61604 0 13:22 ? 00:00:00 postgres: kimura sampledb 192.168.11.104(61253) idle ... 以下の理由から、コネクションプールを利用すると安定運用しやすい。都度プロセスを生成するとコストが高い同時接続数が決まるので、リソース使用量を見積もりやすい検証する都度プロセスを生成するのは、どのくらいコストが高いのかを確かめる。以下のコードを10秒間実行し、sarコマンドでCPU使用状況の平均を取る。 PostgreSQLの同時接続数は10と仮定する。コネクション使いまわし(同時接続10) public static void main(String[] args) throws Exception { ExecutorService service = Executors.newFixedThreadPool(10); for (int j = 0; j < 10 { Connection conn = DriverManager.getConnection("jdbc:postgresql://192.168.11.116:5432/postgres", "kimura", "test");; while (true) { try { PreparedStatement pstmt = conn.prepareStatement("SELECT 1"); ResultSet rs = pstmt.executeQuery(); while (rs.next()) { } rs.close(); pstmt.close(); } catch (SQLException e) { e.printStackTrace(); } } }); } } 都度接続(同時接続10) public static void main(String[] args) throws Exception { ExecutorService service = Executors.newFixedThreadPool(10); for (int j = 0; j < 10 { while (true) { try { Connection conn = DriverManager.getConnection("jdbc:postgresql://192.168.11.116:5432/postgres", "kimura", "test"); PreparedStatement pstmt = conn.prepareStatement("SELECT 1"); ResultSet rs = pstmt.executeQuery(); while (rs.next()) { } rs.close(); pstmt.close(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } } }); } } 1つめがコネクション使いまわし、2つめが都度接続。 CPU %user %nice %system %iowait %steal %idle 平均値: all 4.09 0.00 33.13 0.00 0.00 62.78 平均値: all 14.24 0.00 61.06 0.03 0.00 24.68 (かなりアバウトかつDB負荷が高い条件ではあるけど)コネクションを使いまわしたほうが、DBとしても負荷が低いことがわかった。 workerプロセスごとにメモリをどれくらい使うのかコネクションプールした状態だと、どの位メモリを消費するかを確認する。都度接続のコードでConnection#close()せずに、10000本コネクションを張る。テスト実行の前にキャッシュを捨てる。 /proc/sys/vm/drop_caches サーバ全体のメモリ状況は、検証前後で以下のようになった。 ]$ free total used free shared buff/cache available Mem: 10391784 5721584 4118352 370328 551848 4194024 Swap: 2097148 0 2097148 // 10000本コネクションを張る ]$ free total used free shared buff/cache available Mem: 10391784 6269028 3277516 372400 845240 3357384 Swap: 2097148 0 2097148 次に、workerプロセスに絞ったメモリ利用量は以下のようになった。 ]$ ps aux | grep "postgres: kimura postgres" | grep -v grep | awk '{print $2}' | xargs -i% cat /proc/%/smaps | awk '/^Pss/{sum += $2}END{print sum}' 2367442 (kb) PSSは物理メモリの使用量(共有メモリ分は、プロセス数で割った値を使う)のこと。参考プロセス毎のメモリ消費量を調べたい時に使えるコマンド PostgreSQLは共有メモリにディスクから取得したデータをキャッシュするので、RSSで見るとメモリ利用量を過大評価したことになるため。参考 The Internals of PostgreSQL Buffer Manager 実行中のworkerの場合はwork_memやtemp_buffersなどが上乗せされるので、最終的にはメモリ利用量はもっと増えるはず。 PreparedStatementのキャッシュ DBCP2などのコネクションプールライブラリは、PrepatedStatementインスタンスを破棄せずに内部でキャッシュする。これによって、インスタンス生成コストが抑えられる。ただし最近流行りのHikariCPでは、この機能を提供しておらず、次に示すサーバサイドステートメントキャッシュのみを提供している。 Many connection pools, including Apache DBCP, Vibur, c3p0 and others offer PreparedStatement caching. HikariCP does not. HikariCP README 検証する DBCP2を利用して、PreparedStatementがキャッシュされるのを確認する。 Apache Common DBCP2 BasicDataSource Configuration Parameters PreparedStatementがキャッシュされるのを確認する public static void main(String[] args) throws Exception { Properties props = new Properties(); props.setProperty("username", "kimura"); props.setProperty("password", "secret"); props.setProperty("url", "jdbc:postgresql://192.168.11.116:5432/sampledb"); props.setProperty("driverClassName", "org.postgresql.Driver"); props.setProperty("poolPreparedStatements", "true"); DataSource ds = BasicDataSourceFactory.createDataSource(props); while (true) { Connection conn = ds.getConnection(); PreparedStatement pstmt = conn.prepareStatement("SELECT 1"); Object pgstmt = pstmt.unwrap(DelegatingStatement.class) .getDelegate() .unwrap(DelegatingPreparedStatement.class).getDelegate() .unwrap(PoolablePreparedStatement.class).getDelegate(); System.out.println(pgstmt.getClass() + " " + pgstmt.hashCode()); pstmt.close(); conn.close(); } } 実行結果は以下の通り。 class org.postgresql.jdbc.PgPreparedStatement 627150481 class org.postgresql.jdbc.PgPreparedStatement 627150481 class org.postgresql.jdbc.PgPreparedStatement 627150481 class org.postgresql.jdbc.PgPreparedStatement 627150481 class org.postgresql.jdbc.PgPreparedStatement 627150481 class org.postgresql.jdbc.PgPreparedStatement 627150481 PreparedStatementインスタンスがキャッシュされていることがわかる。次に、どれくらい性能が上がるかを調べる。 private static final int LOOP_COUNT = 10000; public static void main(String[] args) throws Exception { Properties props = new Properties(); props.setProperty("username", "kimura"); props.setProperty("password", "secret"); props.setProperty("url", "jdbc:postgresql://192.168.11.116:5432/sampledb"); props.setProperty("driverClassName", "org.postgresql.Driver"); // trueとfalseで比較する props.setProperty("poolPreparedStatements", "false"); long start = System.currentTimeMillis(); DataSource ds = BasicDataSourceFactory.createDataSource(props); for (int i = 0; i < LOOP_COUNT; i++) { Connection conn = ds.getConnection(); PreparedStatement pstmt = conn.prepareStatement("SELECT 1"); ResultSet rs = pstmt.executeQuery(); while (rs.next()) { } rs.close(); pstmt.close(); conn.close(); } long end = System.currentTimeMillis(); System.out.println("time: " + (end - start)); } 結果は以下の通り。キャッシュありキャッシュなし 1回目 3689 4013 2回目 3485 3571 3回目 3741 3805 4回目 3957 4026 5回目 3674 3894 平均(ms) 3709.2 3861.8 PreparedStatementの��ャッシュだけではあんまり差がでない。DBCP2的にも poolPreparedStatements はデフォルトでfalse。まあ、そういうことなんだろう。サーバサイドステートメントキャッシュ JDBCドライバがサーバ側のプリペアド機能を利用して実現するキャッシュ。 PostgreSQLでは、同一コネクションで同じSQLが複数(デフォルトでは5回)発行されると、サーバサイドステートメントキャッシュが有効になる。バックエンドは複数のプリペアド文とポータルの経過を追うことができます（しかし、1つのセッション内でのみ存在可能です。複数のセッションで共有することはできません）。 PostgreSQL 10.5 第52章フロントエンド/バックエンドプロトコルプリペアド文が利用されるとDB側の構文解析や実行計画といったフェーズがスキップできるため、DB側の処理が削減される。引用元 The Internals of PostgreSQL Query Processing また、JDBCドライバとしても、通信時にヘッダー情報を要求しなくなる、といった通信プロトコルレベルの最適化を実施する。しかし、プリペアド文を利用すると、コネクションごとに構文解析したクエリやカーソルが保持される。メモリ消費を制限するための上限を設定するパラメータとして、preparedStatementCacheQueries(デフォルト 256) や preparedStatementCacheSizeMiB(デフォルト 5) がある。参考 PostgreSQL JDBC Driver hapter 9. PostgreSQL? Extensions to the JDBC API 検証するサーバサイドステートメントキャッシュの性能差を比較する。 PgConnection#setPrepareThresholdでサーバサイドステートメントキャッシュのしきい値を設定する。 private static final int LOOP_COUNT = 10000; public static void main(String[] args) throws SQLException, InterruptedException { Connection conn = DriverManager.getConnection("jdbc:postgresql://192.168.11.116:5432/postgres", "kimura", "test"); PGConnection pgconn = conn.unwrap(PGConnection.class); // 有効のときは 1 を設定。無効のときは LOOP_COUNT + 1 を設定 pgconn.setPrepareThreshold(LOOP_COUNT + 1); conn.setAutoCommit(false); PreparedStatement pstmt = conn.prepareStatement("SELECT * from sample WHERE id = ?"); long start = System.currentTimeMillis(); for (int i = 0; i < LOOP_COUNT; i++) { pstmt.setInt(1, i); ResultSet rs = pstmt.executeQuery(); while (rs.next()) { } } long end = System.currentTimeMillis(); System.out.println("time: " + (end - start)); } 実行結果は以下の通り。 prepareThresholdが有効 prepareThresholdが無効 1回目 2165 3207 2回目 2222 3177 3回目 2146 3170 4回目 2447 3230 5回目 1944 3076 平均(ms) 2184.8 3172 PrepareThresholdが効いているほうが、けっこう早く終わることがわかった。リクエストの最適化通常のリクエスト。だいたい5ステップある。 ... PostgreSQL Type: Parse // 構文解析 Length: 54 Statement: Query: SELECT id, price FROM sample WHERE id = $1 Parameters: 1 Type OID: 23 PostgreSQL Type: Bind // $1の変数の値をセット Length: 22 Portal: Statement: Parameter formats: 1 Format: Binary (1) Parameter values: 1 Column length: 4 Data: 00000002 Result formats: 0 PostgreSQL Type: Describe // レスポンスにヘッダー情報付与 Length: 6 Portal: PostgreSQL Type: Execute // SQL実行 Length: 9 Portal: Returns: all rows PostgreSQL Type: Sync // お決まりのやつらしい Length: 4 ステートメントキャッシュ開始時点のリクエスト。 ... PostgreSQL Type: Parse // プリペアド文の要求 Length: 57 Statement: S_1 Query: SELECT id, price FROM sample WHERE id = $1 Parameters: 1 Type OID: 23 PostgreSQL Type: Bind // $1の変数の値をセット Length: 25 Portal: Statement: S_1 Parameter formats: 1 Format: Binary (1) Parameter values: 1 Column length: 4 Data: 00000002 Result formats: 0 PostgreSQL Type: Describe // レスポンスにヘッダー情報付与 Length: 6 Portal: PostgreSQL Type: Execute // SQL実行 Length: 9 Portal: Returns: all rows PostgreSQL Type: Sync // お決まりのやつらしい Length: 4 ステートメントキャッシュが有効になったあとのリクエスト。 Parseが無くなっている Describeがなくなっている ... PostgreSQL Type: Bind Length: 29 Portal: Statement: S_1 Parameter formats: 1 Format: Binary (1) Parameter values: 1 Column length: 4 Data: 00000002 Result formats: 2 Format: Binary (1) Format: Binary (1) PostgreSQL Type: Execute Length: 9 Portal: Returns: all rows PostgreSQL Type: Sync Length: 4 レスポンスの最適化通常のレスポンス。 ... PostgreSQL Type: Parse completion //構文解析完了 Length: 4 PostgreSQL Type: Bind completion // $1の変数の値をセットが完了 Length: 4 PostgreSQL Type: Row description // Describe要求に対応 Length: 51 Field count: 2 Column name: id Table OID: 24576 Column index: 1 Type OID: 23 Column length: 4 Type modifier: -1 Format: Text (0) Column name: price Table OID: 24576 Column index: 2 Type OID: 23 Column length: 4 Type modifier: -1 Format: Text (0) PostgreSQL Type: Data row // データ行 Length: 18 Field count: 2 Column length: 1 Data: 32 Column length: 3 Data: 323030 PostgreSQL Type: Command completion //コマンド完了 Length: 13 Tag: SELECT 1 PostgreSQL Type: Ready for query // 次の要求待ち Length: 5 Status: Idle (73) ステートメントキャッシュが有効になった状態のレスポンス。テーブルヘッダ情報がない Data row にも型情報がない ... PostgreSQL Type: Bind completion // $1の変数の値をセットが完了 Length: 4 PostgreSQL Type: Data row // データ行 Length: 22 Field count: 2 Column length: 4 Data: 00000002 Column length: 4 Data: 000000c8 PostgreSQL Type: Command completion //コマンド完了 Length: 13 Tag: SELECT 1 PostgreSQL Type: Ready for query // 次の要求待ち Length: 5 Status: Idle (73) 異なるPreparedStatementインスタンスでもキャッシュが効くか同一コネクションから生成されたPreparedStatementインスタンスであれば、各インスタンスをまたいでキャッシュが効くことを確認する。 public static void main(String[] args) throws Exception { Connection conn = DriverManager.getConnection("jdbc:postgresql://192.168.11.116:5432/sampledb", "kimura", "test"); PGConnection pgconn = conn.unwrap(PGConnection.class); pgconn.setPrepareThreshold(2); for (int i = 0; i < 2; i++) { PreparedStatement pstmt = conn.prepareStatement("SELECT 1"); PGStatement pgStatement = pstmt.unwrap(PGStatement.class); System.out.println(pgStatement.isUseServerPrepare()); pstmt.executeQuery(); pstmt.close(); } } 実行結果は以下の通り。 false true 同一Connecionであれば、PreparedStatementが違ってもキャッシュされることがわかった。ソースコードでいうと、以下のあたりが該当箇所だった。 PgPreparedStatement#executeInternal QueryExecutorImpl#sendParse 最後に JDBCドライバは断片的な知識をもとにググりながら使うことが多かったので、全体的に学び直すことでいい勉強になった。

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darkweblink · 6 years ago

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Dark Web Tools and Services That Present Enterprise Risk

Dark Web Definition

Deep Web is the major part of the internet which consists of 90% of the internet. The other two parts comprises the internet world is the surface web and the Dark Web. The Dark Web is sometimes also referred to it as the Darknet. To understand all the three layers of the internet that consists of all the three layers mentioned above, the image that mostly resembles is the picture of an iceberg that is afloat.

The top most part of the iceberg that is visible from the outside can be understood as the surface web. The crust of the iceberg is also known as the visible web. The visible web comprises of web pages, websites that are listed in the search engines. Search engines like Google, Bing and Wikipedia have all the web pages in their directories. All the search results a user makes are tracked monitored and listed by the traditional search engines.

The dark web is accessed by using special software and web servers called centralized computers hosting webpage’s. The most common of these special software are TOR [The Onion Router] and I2P [Invisible Internet Project], says J. Eduardo Campos, formerly a cyber security advisor for a major tech company and currently co-founder of the consulting firm Embedded knowledge.

Dark Web Tools and Services That Present Enterprise Risk

The web tools and services that affect an organization which pose as a threat in the form of network breach or data comprise when the system gains access to Deep Web directories which is accessed with the help of Tor .onion urls directories.

· Infection or attacks, including malware, distributed denial of service (DDoS) and botnets

· Access, including remote access Trojans (RATs), key loggers and exploits

· Espionage, including services, customization and targeting

· Support services such as tutorials

· Credentials

· Phishing

· Refunds

· Customer data

· Operational data

· Financial data

· Intellectual property/trade secret

· Other emerging threats

Malware:

The Dark Web Links play a vital role in the spreading communities of malware developers; the principal Darknet are privileged environments for malware authors and botmasters. The numerous black marketplaces are excellent points of aggregation for malware developers and crooks that intend to pay for malicious code and command and control infrastructures. The use of Darknet represents a design choice for malware developers that use them to hide the command and control servers.

The list of malicious malware that were exploiting both the Tor network and I2P dark net to hide their command and control servers are as follows:

i) Malware Using C&C In The Darknet:

Many types of malware are directly controlled by servers hosted on both Tor and I2P, and it is quite easy to find Ransom-as-a-Service (RaaS) in the Darknets. Below just a few examples of malware that were discovered in the last 12 months leveraging Darknets for their operations:

· 2017 – MACSPY – Remote Access Trojan as a service on Dark web

· 2017 – MacRansom is the first Mac ransomware offered as a RaaS Service.

· 2017 – Karmen Ransomware RaaS

· 2017 –Ransomware-as-a-Service dubbed Shifr RaaS that allows creating ransomware compiling 3 form fields.

ii) Shifr RaaS Control Panel

Malware authors use to hide C&C servers in the Darknet to make botnets resilient against operations run by law enforcement and security firms. The principal advantages of Tor .onion urls directories based botnets are:

· Availability of Authenticated Hidden Services.

· Availability Private Tor Networks

· Possibility of Exit Node Flooding

Security researcher use traffic analysis to determine to detect botnet activities and have proposed different options to eradicate it

· Obscuration of the IP addresses assigned to the C&C server

· Cleaning of C&C servers and of the infected hosts

· Domain name revoke

· Hosting provider de-peered

Remote Access Trojans (RAT):

It is a malware that infects remote computers and allows a remote attacker to control the computer for malicious purposes. They disguise as a legitimate program or file. After infecting a target device the threat actor gets accessed to the victim’s computer.

How to Prevent RAT from Vicious Attack:

Steps To Avoid Remote Access Trojans

a) Do not click suspicious links and do not download emails sent by unknown users.

b) Keep your computer updated with trusted anti-malware programs and make sure you update them regularly.

c) Configure your firewall in your computer regularly. If a malware infects a computer, it should not spread to other system in the network so easily.

d) Keep your operating system updated with recent patches and if possible use a virtual machine to access the internet.

Espionage (Targeting and Customization):

Intelligence on competitors gathered in a legal way can give a leg up in the fight for market share. But sometimes it’s not enough. Competitors send spies to gather information more often than you would think, judging by the news. Industrial espionage embraces illegal and unethical methods of collecting corporate data. It involves stealing intellectual property and trade secrets to use them for a competitive advantage. The theft of economic information sponsored by foreign states is called economic espionage. It’s done not just for profit but for strategic reasons. Usual targets of industrial espionage are:

· Trade Secrets: While definition of “trade secret” varies from country to country, it generally means protected information about existing products or products in development. This information may help your rivals make their products more competitive or even bring a similar product to the market faster than you can.

·Client Information: Data of your clients, including their financial information, can be used to steal business or can be leaked to damage the reputation of your company.

·Financial Information: Financial information about your company can be used to offer better deals to your clients and partners, win bids, and even make better offers to your valuable employees.

·Marketing Information: This will allow your competitors to prepare a timely answer for your marketing campaigns, which, in turn, may render them ineffective.

Steps to help avoid trouble with the Dark Web

Once data ends up on the Dark Web Links Hidden Wiki there's very little that can be done about it. It's best to avoid this from happening to your company, employee or customer data. The following best practices can help.

1. Prohibit employees from using Tor .onion url directories

If employees are allowed to access the TOR network, they can easily expose your company to damaging material and/or malware. This would be particularly detrimental to your corporate network, says Wagner. Provide clear guidance in employee manuals and train employees on 'clean' internet use, advises cyber security attorney Braden Perry, a partner with Kennyhertz Perry. Use software to block TOR. Make it clear that corporate investigations will be initiated if management suspects that this rule is being broken.

2. Educate employees on security protocols.

The end user is the weakest link in your protective measures for your network, says Campos. This means it's important to teach all employees about cyber security measures and compliance with your company's policies, he says. The more aware and trained your employees, the better. He went on to add.

3. Limit employee access to sensitive data. It's a good idea to operate on a need-to-know basis when it comes to company data. The fewer employees who have access to company and client sensitive data, the less likely your company is to experience a breach.

#darkweb #deepweb #darkweblink #deepweblink

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tecezeposts · 5 years ago

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Why WordPress sites get hacked? How to protect it?

Recently, legion WordPress site has been hacked it’s frustrating to seek out out that your WordPress site has been hacked. during this article, we are going to share the highest reasons why WordPress site gets hacked, so you’ll be able to avoid these mistakes and protect your site.

Why is WordPress Targeted by Hackers?

First, it’s not just WordPress. All websites on the web are prone to hacking attempts.

The reason why WordPress sites are a typical target is that WordPress is the world’s preferred website builder. It powers over 31% of all websites meaning many legion websites across the world.

This immense popularity gives hackers a straightforward thanks to finding websites that are less secure, in order that they can exploit it.

Hackers have different types of motives to hack a web site. Some are beginners who are just learning to use less secure sites.

Some hackers have malicious intents like distributing malware, employing a site to attack other websites or spamming the web.

With that said, let’s take a glance at a number of the highest causes of WordPress sites getting hacked, and the way to forestall your website from getting hacked.

1. Insecure Web Hosting

Like all websites, WordPress sites are hosted on an internet server. Some hosting companies don’t properly secure their hosting platform. This makes all websites hosted on their servers prone to hacking attempts.

This can be easily avoided by choosing the most effective WordPress hosting provider for your website. It ensures that your site is hosted on a secure platform. Properly secure servers can block many of the foremost common attacks on WordPress sites.

If you would like to require extra precautions, then we recommend employing a managed WordPress hosting provider.

2. Using Weak Passwords

Using weak passwords

Passwords are the keys to your WordPress site. you would like to create sure that you’re employing a strong unique password for every one of the subsequent accounts because they will all provide a hacker complete access to your website.

Your WordPress admin account Web hosting control board account FTP accounts MySQL database used for your WordPress site Email accounts used for WordPress admin or hosting account All these accounts are protected by passwords. Using weak passwords makes it easier for hackers to crack passwords using some basic hacking tools.

You can easily avoid this by using unique and powerful passwords for every account. See our guide the most effective thanks to managing passwords for WordPress beginners to find out a way to manage all those strong passwords.

3. Unprotected Access to WordPress Admin

The WordPress admin area gives the user access to perform different actions on your WordPress site. it’s also the foremost commonly attacked area of a WordPress site.

Leaving it unprotected allows hackers to undertake different approaches to crack your website. you’ll be able to make it difficult for them by adding layers of authentication to your WordPress admin directory.

First, you must password protect your WordPress admin area. This adds an additional security layer, and anyone trying to access the WordPress admin will provide an additional password.

If you run a multi-author or multi-user WordPress site, then you’ll be able to enforce strong passwords for all users on your site. you’ll be able to also add two-factor authentication to create it even harder for hackers to enter your WordPress admin area.

4. Incorrect File Permissions

File permissions

File permissions are a collection of rules employed by your web server. These permissions help your web server control access to files on your site. Incorrect file permissions can provide the hacker access to write down and alter these files.

All your WordPress files should have 644 value as file permission. All folders on your WordPress site should have 755 as their file permission.

See our guide a way to fix the image upload issue in WordPress to find out a way to apply for these file permissions.

5. Not Updating WordPress

Some WordPress users are petrified of updating their WordPress sites. They fear that doing so would break their website.

Each recreates of WordPress fixes bugs and security vulnerabilities. If you’re not updating WordPress, then you’re intentionally leaving your site vulnerable.

If you’re afraid that an update will break your website, then you’ll be able to create an entire WordPress backup before running an update. This way, if something doesn’t work, then you’ll be able to easily revert back to the previous version.

6. Not Updating Plugins or Theme

Just like the core WordPress software, updating your theme and plugins is equally important. Using an outdated plugin or theme can make your site vulnerable.

Security flaws and bugs are often discovered in WordPress plugins and themes. Usually, theme and plugin authors are quick to mend them up. However, if a user doesn’t update their theme or plugin, then there’s nothing they will do about it.

Make sure you retain your WordPress theme and plugins up to date.

7. Using Plain FTP rather than SFTP/SSH

SFTP rather than FTP

FTP accounts are wont to upload files to your web server using an FTP client. Most hosting providers support FTP connections using different protocols. you’ll be able to connect using plain FTP, SFTP, or SSH.

When you connect with your site using plain FTP, your password is distributed to the server unencrypted. It is spied upon and simply stolen. rather than using FTP, you must always use SFTP or SSH.

You wouldn’t change your FTP client. Most FTP clients can connect with your website on SFTP yet as SSH. you simply must change the protocol to ‘SFTP – SSH’ when connecting to your website.

8. Using Admin as WordPress Username

Using ‘admin’ as your WordPress username isn’t recommended. If your administrator username is admin, then you must immediately change that to a distinct username.

For detailed instructions take a look at our tutorial on a way to change your WordPress username.

9. Nulled Themes and Plugins

Malware

There are many websites on the web that distribute paid WordPress plugins and themes free. Sometimes it’s easy to urge tempted to use those nulled plugins and themes on your site.

Downloading WordPress themes and plugins from unreliable sources is incredibly dangerous. Not only they’ll compromise the safety of your website, but they’ll even be wont to steal sensitive information.

You should always download WordPress plugins and themes from reliable sources like the plugin/theme developers website or official WordPress repositories.

If you can not afford or don’t want to shop for a premium plugin or theme, then there are always free alternatives available for those products. These free plugins might not be pretty much as good as their paid counterparts, but they’ll get the task done and most significantly keep your website safe.

You can also find discounts for several of the favored WordPress products within the deals section on our website.

10. Not Securing WordPress Configuration wp-config.php File

WordPress configuration file wp-config.php contains your WordPress database login credentials. If it’s compromised, then it’ll reveal information that might provide a hacker complete access to your website.

You can add an additional layer of protection by denying access to the wp-config file using .htaccess. Simply add this small code to your .htaccess file.

<files wp-config.php> order allow, deny deny from all </files>

11. Not Changing WordPress Table Prefix

Many experts recommend that you simply should change the default WordPress table prefix. By default, WordPress uses wp_ as a prefix for the tables it creates in your database. You get a choice to change it during the installation.

It is recommended that you simply use a prefix that’s a bit more complicated. this can make it harder for hackers to guess your database table names.

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topfygad · 5 years ago

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How to find the best VPN for Saudi Arabia in 2020

With the liberalization of the visa regime in 2019, increasingly individuals are touring to the Kingdom of Saudi Arabia (KSA) to find the wonders of what was once one of the secretive nations on the planet.

Saudi Arabia is, very step by step, altering for the higher.

Nevertheless, foreigners must know that they’ll’t behave like they’d do again house and, most significantly, they want to pay attention to one factor:

In Saudi, there isn’t any freedom of speech and the web is censored, which implies that some web sites are blocked.

And, if you wish to navigate safely and entry these censored websites, you will have to have one thing known as a VPN.

On this tutorial, I’ll clarify to you what it’s and find out how to discover the proper VPN for Saudi.

In case you are touring to the nation, don’t neglect to examine my journey information to Saudi Arabia

On this tutorial, you’ll discover:

Why you want a VPN

Finest VPNs

VPN and the regulation The right way to use a VPN Free VPN

Why do you want a VPN in Saudi Arabia?

There are 2 issues you should find out about Saudi Arabia and the web:

The web is censored, which implies that some web sites are blocked.

The Authorities reserves the proper to regulate and monitor anybody accessing the web, which implies that you could possibly be spied on at any time.

Because of this, as a way to navigate extra safely, privately and to entry all blocked web sites, you will have to be in possession of a Digital Non-public Community (VPN), which is one thing that lets you connect with a server from a unique location, so your connection can be utterly nameless and neither hackers nor the Saudi authorities will have the ability to see what you might be doing.

Instance:

Let’s assume you wish to go to X web site, which turns to be blocked in Saudi.

In Saudi, there’s a firewall that forestalls you from accessing the positioning and, since you might be connecting from a server situated within the nation, you gained’t have the ability to entry it.

Nevertheless, whenever you connect with a VPN in Saudi, you possibly can choose the nation you wish to join from and, if you choose Germany for instance, it is possible for you to to entry that X web site as a result of, in Germany, it isn’t blocked.

As well as, your connection can be nameless, therefore utterly secure.

Which web sites are blocked in Saudi Arabia?

Usually, something that has to do with:

Pornography

Any web site which will trigger controversy with the regime

Playing

Drug-related websites

Whereas the above websites appear apparent and, more than likely, chances are you’ll not even be eager about accessing them, there are different websites and web providers extra generally used which can be abruptly blocked for various causes:

In 2006, Google Translate was blocked as a result of it was used to bypass the firewall by translating the content material from blocked web sites.

Some Wikipedia pages could also be blocked.

VoIP web sites (Voice over Web Protocol) web sites, that are free calling web providers resembling Skype or WhatsApp. In 2017, they determined to dam these providers in concern that activists would use them.

A few of the above pages and providers aren’t blocked anymore however VoIP providers, for instance, work terribly gradual in KSA and throughout my journey, I wasn’t in a position to make use of WhatsApp Name till I linked to ExpressVPN.

And there are extra causes to make use of a VPN service in Saudi Arabia:

To entry video streaming providers resembling Netflix or HBO.

They aren’t blocked in Saudi however, as chances are you’ll know, the content material in each nation varies, so some TV exhibits and flicks which can be found in your house nation won’t be out there within the Kingdom.

By connecting to a VPN, it is possible for you to to observe the content material out there in your required location.

One of the best VPNs for Saudi

These are the most effective VPNs in KSA.

Quickest VPN for Saudi – Categorical VPN

Finest finances VPN for Saudi – NordVPN

Finest SUPER finances VPN for Saudi – PrivateVPN

IMPORTANT! – Do not forget that VPN web sites could also be blocked, so your wisest transfer could be to get your VPN earlier than you go to the nation

Finest VPN providers for Saudi Arabia: what to search for in a VPN

In case you examine tech-related blogs, you will notice that they classify the completely different VPNs in keeping with very difficult phrases resembling DNS queries, PPTP protocols and incomprehensible stuff like that.

Let me inform you one thing:

I take advantage of a VPN day by day, but, I don’t perceive any of that.

I don’t as a result of, such as you, I simply need it to entry blocked websites and navigate safely so, for touring functions – or if you’re only a common expat – you don’t must know any of that.

For normal individuals or vacationers, the one components that matter when selecting a VPN software program for Saudi Arabia are the next:

Worth

Safety

Velocity (a VPN will decelerate your connectivity)

Variety of nations and servers it could possibly connect with

These are the principle advantages I search for in a VPN and, on this article, these are the factors I take advantage of to categorise the most effective VPNs for KSA

Then again, all of the VPNs I like to recommend are good, reliable and verified, so all of them have the next options as effectively:

Tremendous user-friendly – Anybody can use it

Supply a 30-day money-back assure

Can be utilized for each desktop and cell

Can be found for each Android and iPhone

Are suitable with Netflix (Word that Netflix is actually good at detecting VPNs and proxies and relying on the server you strive to connect with, it might not work, however this occurs with all VPNs)

The quickest and finest VPN for Saudi Arabia – Categorical VPN

Worth for 1 month – 12.95USD

Worth for six months – 9.99USD a month

Worth for 1 yr – 8.32USD a month

Categorical VPN is the most effective VPN available in the market.

This can be very quick, has the strongest encryption and may join 2,000 servers from 94 completely different nations.

I’ve used fairly a couple of VPNs and, after making an attempt ExpressVPN, I noticed that there isn’t a greater one, so this could the most effective VPN for Saudi.

By default, my laptop computer at all times connects to it when switching on my laptop and it’s so quick, that I have a tendency to not do not forget that I’m truly linked to a VPN.

PROS:

One of the best VPN out there available in the market, for the straightforward cause that there isn’t a quicker one, plus it’s tremendous safe.

CONS:

You get what you pay for, so ExpressVPN has a better worth than different VPNs.

SPECIAL OFFER via MY hyperlink – GET Three MONTHS FOR FREE! CLICK HERE TO CLAIM YOUR ExpressVPN DEAL!

One of the best finances VPN for Saudi Arabia – NordVPN

Worth for 1 month – 11.95USD

Worth for 1 yr – 6.99USD a month

Worth for two years – 4.99USD

Worth for Three years – 3.49USD a month

Earlier than getting ExpressVPN, I used to have NordVPN and it was nice.

In line with web consultants, it has some kind of double encryption which makes it significantly safe, plus you possibly can choose 64 nations to attach from.

It’s positively cheaper than ExpressVPN, particularly should you get the long-term plan, however the cause why it’s cheaper is that it’s slower, primarily whenever you connect with a not very quick public Wi-Fi community.

Since I really want a robust web for my sort of labor, I assumed it will be wiser to maneuver to a quicker VPN resembling ExpressVPN.

Nevertheless, NordVPN is the second-best VPN I’ve ever used so, should you simply need it for normal looking, this is likely to be the one for you, particularly as a result of their long-term plans are tremendous low-cost.

PROS:

Quicker than common VPNs

In case you purchase a long run plan, it will get tremendous low-cost

CONS vs ExpressVPN:

64 nations to attach from (ExpressVPN has 94)

In case you solely need it for 1 month, the worth is nearly the identical as ExpressVPN

It’s not the quickest and, should you don’t have a robust Wi-Fi connection, your Skype video is probably not of the very best quality

SPECIAL OFFER – SAVE 70%! CLICK HERE TO CLAIM YOUR NordVPN DEAL!

One of the best SUPER finances VPN for Saudi – PrivateVPN

Worth for 1 month – 7.12USD

Worth for Three months – 4.20USD a month

Worth for 24 months – 1.95USD a month

PrivateVPN is kind of a brand new supplier primarily based in northern Europe and, with lower than 100 servers, it’s by far, the most effective excessive finances VPN out there available in the market.

At this worth, you possibly can’t discover something higher and, in keeping with VPN consultants, it presents an excellent stage of safety, with robust encryption options, in addition to leak safety.

When it comes to velocity, Non-public VPN can also be very quick, typically even quicker than different premium VPNs resembling NordVPN or ExpressVPN, however the greatest draw back is that it’s kind of inconsistent, that means that sooner or later it is likely to be extraordinarily quick however the subsequent day chances are you’ll be watching a Breaking Unhealthy episode via a pixelated display screen.

In the long run, you get what you pay for however, at this worth, you possibly can’t get a greater deal.

PROS:

Probably the most finances VPN. At this worth, you gained’t discover something higher

CONS vs ExpressVPN

The velocity is inconsistent

No 24/7 assist dwell chat

SPECIAL OFFER –SAVE 65% + 1 MONTH CLICK HERE TO GET YOUR PrivateVPN DEAL

Is it authorized to make use of a VPN in Saudi Arabia?

Utilizing a VPN in KSA goes in opposition to the regulation however significantly, everybody and his mom use it.

Stories say that round 30% of web customers in Saudi at all times use a VPN.

Is it secure then?

Effectively, so long as you aren’t an activist who makes use of it to arrange protests or create content material in opposition to the Authorities, they won’t care, particularly if you’re a foreigner.

How to connect with a VPN in Three simple steps and connect with blocked websites in Saudi

Step 1 – Enter ExpressVPN web site via this hyperlink and select your plan

Step 2 – Obtain Categorical VPN to your desktop or get the App on Google Play or Apple Retailer.

Step 3 – Select a location from the checklist and join – It’s so simple!

CLICK HERE TO GET YOUR EXCLUSIVE DISCOUNT with ExpressVPN

Why you need to by no means use a free VPN for Saudi Arabia

These are the the explanation why it’s not beneficial:

Low velocity

Usually, gained’t work on a desktop

Not safe in any respect, which implies much less anonymity

Loads of advertisements

You possibly can’t choose your required nation

Don’t take the chance. Premium VPNs are the best way to go and I like to recommend ExpressVPN.

CLICK HERE TO GET your low cost with ExpressVPN!

Extra content material about Saudi Arabia

Saudi Arabia journey information 2-week itinerary for Saudi Issues to do in Riyadh Is it moral to go to Saudi? Feminine journey in Saudi

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#IFTTT #Cheapr Travels

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