AdaptiveCrypt

A future-proof extensible hashing/encryption library.

Usage example:

var acs = new AdaptiveCryptService("sha1", 10, 8, new Sha512HashingService(Encoding.UTF8.GetBytes("secret-hash-key-1")),
                                   "aes1", 10, 8, new AesEncryptionService(Encoding.UTF8.GetBytes("secret-encryption-key-1")));

Hashing a password

ModularCrypt hash = acs.Hash(Encoding.UTF8.GetBytes("password"));
string hashAsString = hash.ToString(); // $sha1$10$base64-salt$base64-hash

Validating a password

var prevHash = new ModularCrypt(hashAsString);
ModularCrypt testHash = acs.Hash(Encoding.UTF8.GetBytes("password"), prevHash);
bool isValidPassword = testHash == prevHash;

Encrypting an email

ModularCrypt encrypted = acs.Encrypt(Encoding.UTF8.GetBytes("foobar@example.com"));
string encryptedAsString = encrypted.ToString(); // $aes1$10$base64-salt$base64-cipher

Decrypting an email

var prevEncrypt = new ModularCrypt(encryptedAsString);
byte[] emailAsBytes = acs.Decrypt(prevEncrypt);
string email = Encoding.UTF8.GetString(emailAsBytes); // foobar@example.com

Configure new settings to increase computation cost

acs = new AdaptiveCryptService("sha2", 11, 8, new Sha512HashingService(Encoding.UTF8.GetBytes("secret-hash-key-2")),
                               "aes2", 11, 8, new AesEncryptionService(Encoding.UTF8.GetBytes("secret-encryption-key-2")));

// Add previous settings to support previous records ####
acs.AddHashingService("sha1", new Sha512HashingService(Encoding.UTF8.GetBytes("secret-hash-key-1")));
acs.AddEncryptionService("aes1", new AesEncryptionService(Encoding.UTF8.GetBytes("secret-encryption-key-1")));

// Compute new hash for existing password (e.g. when user authenticates successfully)
prevHash = new ModularCrypt(hashAsString);
testHash = acs.Hash(Encoding.UTF8.GetBytes("password"), prevHash);
if (testHash == prevHash)
{
    // Authenticate success, compute new hash with increased computation costs
    ModularCrypt newHash = acs.Hash(Encoding.UTF8.GetBytes("password"));
    string newHashAsString = newHash.ToString(); // $sha2$11$base64-salt$base64-hash
}

// Re-encrypt an email
prevEncrypt = new ModularCrypt(encryptedAsString);
Console.WriteLine(encryptedAsString);
Console.WriteLine(prevEncrypt);
emailAsBytes = acs.Decrypt(prevEncrypt);
ModularCrypt newEncrypted = acs.Encrypt(emailAsBytes);
string newEncryptedAsString = encrypted.ToString(); // $aes2$11$base64-salt$base64-cipher