The iteration count is the number of times that the password is hashed during the derivation of the symmetric key. The higher number, the more difficult it is to validate a password guess and then derive the correct key. It is used together with the salt which is used to prevent against attacks using rainbow … Read more
First, let’s point out that SHA-256 does not accept all possible binary strings as input. As defined by FIPS 180-3, SHA-256 accepts as input any sequence of bits of length lower than 2^64 bits (i.e. no more than 18446744073709551615 bits). This is very common; all hash functions are somehow limited in formal input length. One … Read more
The flag has a default of true and it will be set to false if the detection fails, so you can simply use +PrintFlagsFinal to see if it is used: My Laptop without AES-NI: C:\>”C:\Program Files\Java\jdk1.7.0_51\bin\java” -XX:+PrintFlagsFinal -version | find “UseAES” bool UseAES = false {product} bool UseAESIntrinsics = false {product} java version “1.7.0_51” Java(TM) … Read more
I have presented that move in “Why doesn’t Git use more modern SHA?” in Aug. 2018 The reasons were discussed here by Brian M. Carlson: I’ve implemented and tested the following algorithms, all of which are 256-bit (in alphabetical order): BLAKE2b (libb2) BLAKE2bp (libb2) KangarooTwelve (imported from the Keccak Code Package) SHA-256 (OpenSSL) SHA-512/256 (OpenSSL) … Read more
Unlike the java.util.Random class, the java.security.SecureRandom class must produce non-deterministic output on each call. What that means is, in case of java.util.Random, if you were to recreate an instance with the same seed each time you needed a new random number, you would essentially get the same result every time. However, SecureRandom is guaranteed to … Read more
Answer All passwords need to be salted in order to hash them securely. In this case, however, you are correct; System.Web.Helpers.Crypto takes care of creating a salt for you. You don’t need to create one. It is stored in the string returned by Crypto.HashPassword(). Example All you need to do is something like this. using … Read more
Here’s how to do it properly in CBC mode, including PKCS#7 padding: import base64 from Crypto.Cipher import AES from Crypto.Hash import SHA256 from Crypto import Random def encrypt(key, source, encode=True): key = SHA256.new(key).digest() # use SHA-256 over our key to get a proper-sized AES key IV = Random.new().read(AES.block_size) # generate IV encryptor = AES.new(key, AES.MODE_CBC, … Read more
Use the MessageDigest class and supply data piece by piece. The example below ignores details like turning byte[] into string and closing the file, but should give you the general idea. public byte[] createSha1(File file) throws Exception { MessageDigest digest = MessageDigest.getInstance(“SHA-1”); InputStream fis = new FileInputStream(file); int n = 0; byte[] buffer = new … Read more
IMHO, the easiest way to generate a random number in a [min..max] range with window.crypto.getRandomValues() is described here. An ECMAScript 2015-syntax code, in case the link is TL;TR: function getRandomIntInclusive(min, max) { const randomBuffer = new Uint32Array(1); window.crypto.getRandomValues(randomBuffer); let randomNumber = randomBuffer[0] / (0xffffffff + 1); min = Math.ceil(min); max = Math.floor(max); return Math.floor(randomNumber * … Read more
Using java.security.MessageDigest is the simplest way import java.math.BigInteger import java.security.MessageDigest fun md5(input:String): String { val md = MessageDigest.getInstance(“MD5”) return BigInteger(1, md.digest(input.toByteArray())).toString(16).padStart(32, ‘0’) }