curl Usage
HTTP request method:-X POST-X PUTHTTP request Content-Type header-H "Content-Type: application/x-www-form-urlencoded"-H "Content-Type: application/json"HTTP request body/dataform urlencoded: -d...
View ArticleApache Directory GUI Tool for Managing LDAP Server
Apache Directory is good GUI tool for managing general LDAP server, but it is particularly designed for ApacheDS.http://directory.apache.org/studio/
View ArticleDogtag Certificate System 10 pkispawn Configuraiton file
IntroductionReference from pki_default.cfg(5) that ships with pki-server version 10.# man 5 pki_default.cfgpki_default.cfg(5) PKI Default Instance Configuration pki_default.cfg(5)NAME pki_default.cfg -...
View ArticleGetting Started with Python on Ubuntu 16.04
PrerequisiteUbuntu 16.04$ lsb_release -aNo LSB modules are available.Distributor ID: UbuntuDescription: Ubuntu 16.04.3 LTSRelease: 16.04Codename: xenialInteractive Mode$ pythonPython 2.7.12 (default,...
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Ubuntu 16.04 Disk Usage Analyzer
To be able to scan your entire file system you need to start the Disk Usage Analyzer with sudo.$ sudo baobab
View ArticleCryptographically Secure Pseudo-Random Number Generator (CSPRNG) in Linux and...
IntroductionWhat is random? Example is the below bits randomly generated?0100 1101 1101 0011The probability for that is 1/2^16.And to measure the uncertainty we introduce the notion entropy. And in...
View ArticleRandom in Linux
Syscall available since kernel 3.17Only blocks at initialization if insufficient entropy$ man 2 getrandomGETRANDOM(2) Linux Programmer's Manual GETRANDOM(2)NAME getrandom - obtain a series of random...
View ArticleHow to Test Randomness (Entropy)
You can use ent http://www.fourmilab.ch/random/. On Ubuntu you can install via$ sudo apt-get install ent$ man entent(1) ent(1)NAME ent - pseudorandom number sequence testSYNOPSIS ent [options]...
View ArticleRNG/DRBG/PRNG Cheat Sheet
RNG (Random Number Generator) produces random bitsnon-deterministicuses external analog sourceDRBG (Deterministic Random Bit Generator) produces pseudorandom bitsdeterministicfrom a seed (taken from...
View ArticleHash Functions Cheat Sheet
In previous blog I wrote about Deterministic Random Bit Generator, DRBG that makes arbitrary output from a short fixed length seed.And the inverse of that is Hash FunctionINPUT: arbitrarily long...
View ArticleBlock Cipher - Encrypt More Than 1 Block
If you are going to encrypt (cipher) more than one block, you need a mode of operation for that.For example the preferred cipher AES (Advanced Encryption Standard) usesKey sizes 128, 192 or 256...
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Symmetric Authenticated Encryption (AE) or Authenticated Encryption with...
You can do more in Symmetric Encryption (Cipher) and that is Symmetric Authenticated Encryption (AE) or Authenticated Encryption with Associated Data (AEAD) which simultaneously provides...
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Asymetric RSA Trapdoor Permutation
The RSA algorithm works the followingPublic Key: a large number n and exponent ePrivate Key: primes p and q such that n = p * q.The RSA trapdoor permutation: x -> xe mod n = ySo the strength in RSA...
View ArticleAsymmetric Encryption with RSA and OAEP (Optimal Asymmetric Encryption Padding)
The preferred padding with RSA cipher algorithm is OAEP (Optimal Asymmetric Encryption Padding).Java Example:First generate public and private RSA keys with some length, here we use 2048...
View ArticleDiffie–Hellman key exchange (DH)
"Diffie–Hellman key exchange (DH)[nb 1] is a method of securely exchanging cryptographic keys" [1]"Although Diffie–Hellman key agreement itself is a non-authenticated key-agreement protocol, it...
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Comparing Elliptic-Curve Cryptography (ECC) and RSA
Reference: https://www.researchgate.net/publication/255970113_A_Survey_of_the_Elliptic_Curve_Integrated_Encryption_SchemeUse standard curves only.Curve25519Curve448
View ArticleCrypto Attacks Side-Channel Attacks
Timing Leaks - attacks based on measuring how much time various computations takes. For example algorithm known and start to guess key, if return fast the first bytes wrong if reply takes, you know...
View ArticleCrypt Libraries
LibraryWebsiteWritten inLibgcryptgnupg.org/related_software/libgcrypt/CGnuTLSgnutls.orgCcryptlibcryptlib.comCBotanbotan.randombit.netC++Crypto++® Library 5.6.5cryptopp.comC++Microsoft...
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SSL/TLS Attacks
Padding oracles in CBC mode CompressionVaudenay 2002Boneh/Brumley 2003BEAST 2011Lucky13 2013POODLE 2014Lucky Microseconds 2015RSA PKCS1-1.5Bleichenbacher 1998Jager 2015DROWN 2016MD5 & SHA1CA...
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