diff options
Diffstat (limited to 'src/IOL.Helpers/CryptographyHelpers.cs')
| -rw-r--r-- | src/IOL.Helpers/CryptographyHelpers.cs | 160 |
1 files changed, 85 insertions, 75 deletions
diff --git a/src/IOL.Helpers/CryptographyHelpers.cs b/src/IOL.Helpers/CryptographyHelpers.cs index df53055..237116b 100644 --- a/src/IOL.Helpers/CryptographyHelpers.cs +++ b/src/IOL.Helpers/CryptographyHelpers.cs @@ -7,8 +7,6 @@ namespace IOL.Helpers; public static class CryptographyHelpers { - // https://github.com/DuendeSoftware/IdentityServer/blob/main/src/IdentityServer/Extensions/HashExtensions.cs - private const int AES_BLOCK_BYTE_SIZE = 128 / 8; private static readonly RandomNumberGenerator _random = RandomNumberGenerator.Create(); @@ -16,15 +14,25 @@ public static class CryptographyHelpers /// Creates a MD5 hash of the specified input. /// </summary> /// <returns>A hash</returns> - public static string Md5(this string input, string salt = default) { - if (input.IsNullOrWhiteSpace()) return string.Empty; + public static byte[] AsMD5Hash(this string input, string salt = default) { + if (input.IsNullOrWhiteSpace()) { + return default; + } var hmacMd5 = salt.HasValue() ? new HMACMD5(Encoding.UTF8.GetBytes(salt ?? "")) : new HMACMD5(); - var saltedHash = hmacMd5.ComputeHash(Encoding.UTF8.GetBytes(input)); - return Convert.ToBase64String(saltedHash); + return hmacMd5.ComputeHash(Encoding.UTF8.GetBytes(input)); } + public static byte[] AsMD5Hash(this byte[] input, string salt = default) { + if (input == null) { + return default; + } + + var hmacMd5 = salt.HasValue() ? new HMACMD5(Encoding.UTF8.GetBytes(salt ?? "")) : new HMACMD5(); + return hmacMd5.ComputeHash(input); + } + // https://stackoverflow.com/a/13026595/253938 /// <summary> /// Method to perform a very simple (and classical) encryption for a string. This is NOT at /// all secure, it is only intended to make the string value non-obvious at a first glance. @@ -32,16 +40,17 @@ public static class CryptographyHelpers /// The shiftOrUnshift argument is an arbitrary "key value", and must be a non-zero integer /// between -65535 and 65535 (inclusive). To decrypt the encrypted string you use the negative /// value. For example, if you encrypt with -42, then you decrypt with +42, or vice-versa. - /// - /// This is inspired by, and largely based on, this: - /// https://stackoverflow.com/a/13026595/253938 /// </summary> - /// <param name="inputString">string to be encrypted or decrypted, must not be null</param> + /// <param name="input">string to be encrypted or decrypted, must not be null</param> /// <param name="shiftOrUnshift">see above</param> /// <returns>encrypted or decrypted string</returns> - public static string CaesarCipher(string inputString, int shiftOrUnshift) { + public static string CaesarCipher(this string input, int shiftOrUnshift) { + if (input.IsNullOrWhiteSpace()) { + return default; + } + const int C64_K = ushort.MaxValue + 1; - if (inputString == null) throw new ArgumentException("Must not be null.", nameof(inputString)); + if (input == null) throw new ArgumentException("Must not be null.", nameof(input)); switch (shiftOrUnshift) { case 0: throw new ArgumentException("Must not be zero.", nameof(shiftOrUnshift)); case <= -C64_K: @@ -49,26 +58,43 @@ public static class CryptographyHelpers } // Perform the Caesar cipher shifting, using modulo operator to provide wrap-around - var charArray = new char[inputString.Length]; - for (var i = 0; i < inputString.Length; i++) { - charArray[i] = - Convert.ToChar((Convert.ToInt32(inputString[i]) + shiftOrUnshift + C64_K) % C64_K); + var charArray = new char[input.Length]; + for (var i = 0; i < input.Length; i++) { + charArray[i] = Convert.ToChar((Convert.ToInt32(input[i]) + shiftOrUnshift + C64_K) % C64_K); } return new string(charArray); } //https://tomrucki.com/posts/aes-encryption-in-csharp/ - public static string EncryptWithAes(this string toEncrypt, string password) { - var key = GetKey(password); + /// <summary> + /// Encrypts a string input with aes encryption + /// </summary> + /// <param name="input">The string to encrypt</param> + /// <param name="encryptionKey">The key to encrypt the input with</param> + /// <returns>A base 64 encoded string of the encrypted input</returns> + /// <exception cref="ArgumentNullException">Throws null if encryptionKey is empty or null</exception> + public static string EncryptWithAes(this string input, string encryptionKey) { + if (input.IsNullOrWhiteSpace()) { + return default; + } + + if (encryptionKey.IsNullOrWhiteSpace()) { + throw new ArgumentNullException(nameof(encryptionKey)); + } + + var key = encryptionKey.AsMD5Hash(); + + using var aes = Aes.Create(); + aes.Mode = CipherMode.CBC; + aes.Padding = PaddingMode.PKCS7; - using var aes = CreateAes(); - var iv = GenerateRandomBytes(AES_BLOCK_BYTE_SIZE); - var plainText = Encoding.UTF8.GetBytes(toEncrypt); + var iv = new byte[AES_BLOCK_BYTE_SIZE]; + _random.GetBytes(iv); + var plainText = Encoding.UTF8.GetBytes(input); using var encryptor = aes.CreateEncryptor(key, iv); - var cipherText = encryptor - .TransformFinalBlock(plainText, 0, plainText.Length); + var cipherText = encryptor.TransformFinalBlock(plainText, 0, plainText.Length); var result = new byte[iv.Length + cipherText.Length]; iv.CopyTo(result, 0); @@ -77,65 +103,54 @@ public static class CryptographyHelpers return Convert.ToBase64String(result); } - private static Aes CreateAes() { - var aes = Aes.Create(); - aes.Mode = CipherMode.CBC; - aes.Padding = PaddingMode.PKCS7; - return aes; - } + /// <summary> + /// Decrypts a string input with aes encryption + /// </summary> + /// <param name="input">The base 64 encoded string to decrypt</param> + /// <param name="encryptionKey">The key to decrypt the input with</param> + /// <returns>A string of the decrypted input</returns> + /// <exception cref="ArgumentNullException">Throws null if encryptionKey is empty or null</exception> + public static string DecryptWithAes(this string input, string encryptionKey) { + if (input.IsNullOrWhiteSpace()) { + return default; + } - public static string DecryptWithAes(this string input, string password) { - var key = GetKey(password); - var encryptedData = Convert.FromBase64String(input); + if (encryptionKey.IsNullOrWhiteSpace()) { + throw new ArgumentNullException(nameof(encryptionKey)); + } - using var aes = CreateAes(); + var key = encryptionKey.AsMD5Hash(); + var encryptedData = Convert.FromBase64String(input); + using var aes = Aes.Create(); + aes.Mode = CipherMode.CBC; + aes.Padding = PaddingMode.PKCS7; var iv = encryptedData.Take(AES_BLOCK_BYTE_SIZE).ToArray(); var cipherText = encryptedData.Skip(AES_BLOCK_BYTE_SIZE).ToArray(); - using var decryptor = aes.CreateDecryptor(key, iv); - var decryptedBytes = decryptor - .TransformFinalBlock(cipherText, 0, cipherText.Length); + var decryptedBytes = decryptor.TransformFinalBlock(cipherText, 0, cipherText.Length); return Encoding.UTF8.GetString(decryptedBytes); } - private static byte[] GetKey(string password) { - var keyBytes = Encoding.UTF8.GetBytes(password); - using var md5 = MD5.Create(); - return md5.ComputeHash(keyBytes); - } - - private static byte[] GenerateRandomBytes(int numberOfBytes) { - var randomBytes = new byte[numberOfBytes]; - _random.GetBytes(randomBytes); - return randomBytes; - } - - /// <summary> /// Creates a SHA256 hash of the specified input. /// </summary> - /// <param name="input">The input.</param> - /// <returns>A hash</returns> - public static string Sha256(this string input) { - if (input.IsNullOrWhiteSpace()) return string.Empty; - + /// <param name="input">The input</param> + /// <returns>A base 64 encoded hash string of the input</returns> + public static string AsSHA256Hash(this string input) { + if (input.IsNullOrWhiteSpace()) return default; using var sha = SHA256.Create(); var bytes = Encoding.UTF8.GetBytes(input); var hash = sha.ComputeHash(bytes); - return Convert.ToBase64String(hash); } /// <summary> /// Creates a SHA256 hash of the specified input. /// </summary> - /// <param name="input">The input.</param> - /// <returns>A hash.</returns> - public static byte[] Sha256(this byte[] input) { - if (input == null) { - return null; - } - + /// <param name="input">The input</param> + /// <returns>A byte array containing the hash of the input</returns> + public static byte[] AsSHA256Hash(this byte[] input) { + if (input == null) return default; using var sha = SHA256.Create(); return sha.ComputeHash(input); } @@ -143,28 +158,23 @@ public static class CryptographyHelpers /// <summary> /// Creates a SHA512 hash of the specified input. /// </summary> - /// <param name="input">The input.</param> - /// <returns>A hash</returns> - public static string Sha512(this string input) { - if (input.IsNullOrWhiteSpace()) return string.Empty; - + /// <param name="input">The input</param> + /// <returns>A base 64 encoded hash string of the input</returns> + public static string AsSHA512(this string input) { + if (input.IsNullOrWhiteSpace()) return default; using var sha = SHA512.Create(); var bytes = Encoding.UTF8.GetBytes(input); var hash = sha.ComputeHash(bytes); - return Convert.ToBase64String(hash); } /// <summary> /// Creates a SHA256 hash of the specified input. /// </summary> - /// <param name="input">The input.</param> - /// <returns>A hash.</returns> - public static byte[] Sha512(this byte[] input) { - if (input == null) { - return null; - } - + /// <param name="input">The input</param> + /// <returns>A byte array containing the hash of the input</returns> + public static byte[] AsSHA512(this byte[] input) { + if (input == null) return default; using var sha = SHA512.Create(); return sha.ComputeHash(input); } |