Functions/GenXdev.Helpers/HashHelpers.cs
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// ################################################################################
// Part of PowerShell module : GenXdev.Helpers // Original cmdlet filename : HashHelpers.cs // Original author : René Vaessen / GenXdev // Version : 1.300.2025 // ################################################################################ // Copyright (c) René Vaessen / GenXdev // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // ################################################################################ using Org.BouncyCastle.Math; using System.Security.Cryptography; using System.Text; namespace GenXdev.Helpers { public static class Hash { /// <summary> /// Converts a hexadecimal string representation to its corresponding byte array. /// </summary> /// <param name="hex">The hexadecimal string to convert.</param> /// <returns>Byte array representation of the hexadecimal string.</returns> public static byte[] HexStringToByteArray(string hex) { // convert hex string to byte array by processing pairs of characters return Enumerable.Range(0, hex.Length) .Where(x => x % 2 == 0) .Select(x => Convert.ToByte(hex.Substring(x, 2), 16)) .ToArray(); } /// <summary> /// Formats a byte array as a lowercase hexadecimal string for consistent representation. /// </summary> /// <param name="value">The byte array to format.</param> /// <returns>Hexadecimal string representation of the byte array.</returns> public static string FormatBytesAsHexString(byte[] value) { // build hex string with consistent lowercase formatting StringBuilder hex = new StringBuilder(value.Length * 2); foreach (byte x in value) { hex.AppendFormat("{0:x2}", x); } return hex.ToString(); } /// <summary> /// Computes SHA256 hash bytes from a string input using specified encoding. /// </summary> /// <param name="value">The string to hash.</param> /// <param name="encoding">The text encoding to use (defaults to UTF8 without BOM).</param> /// <returns>SHA256 hash as byte array.</returns> public static byte[] GetSha256BytesOfString(string value, Encoding encoding = null) { // use UTF8 encoding if none specified if (encoding == null) { encoding = new UTF8Encoding(false); } // compute hash of encoded string bytes return (SHA256.Create()).ComputeHash(encoding.GetBytes(value)); } /// <summary> /// Computes SHA256 hash of a string and returns it as a base64-encoded string. /// </summary> /// <param name="value">The string to hash.</param> /// <returns>SHA256 hash as base64 string.</returns> public static string GetSha256Base64StringOfString(string value) { // convert hash bytes to base64 for compact string representation return Convert.ToBase64String(GetSha256BytesOfString(value)); } /// <summary> /// Computes SHA256 hash from multiple byte array inputs concatenated together. /// </summary> /// <param name="input">Variable number of byte arrays to hash.</param> /// <returns>SHA256 hash as byte array.</returns> public static byte[] GetSha256Bytes(params byte[][] input) { // concatenate all input arrays into a single stream for hashing using (MemoryStream stream = new MemoryStream()) { foreach (var buffer in input) { stream.Write(buffer, 0, buffer.Length); } stream.Position = 0; // prevent hashing empty data which would be meaningless if (stream.Length == 0) throw new InvalidOperationException("Don't calc hashes of empty data"); var sha = SHA256.Create(); return sha.ComputeHash(stream); } } /// <summary> /// Computes SHA256 hash of a string and returns it as a hexadecimal string. /// </summary> /// <param name="value">The string to hash.</param> /// <param name="encoding">The text encoding to use.</param> /// <returns>SHA256 hash as hexadecimal string.</returns> public static string GetSha256HexStringOfString(string value, Encoding encoding = null) { // use UTF8 encoding if none specified if (encoding == null) { encoding = new UTF8Encoding(false); } // format hash bytes as hex string for human-readable output return FormatBytesAsHexString(GetSha256BytesOfString(value, encoding)); } /// <summary> /// Computes SHA256 hash of byte array and returns it as a hexadecimal string. /// </summary> /// <param name="value">The byte array to hash.</param> /// <returns>SHA256 hash as hexadecimal string.</returns> public static string GetSha256HexStringOfBytes(byte[] value) { // format hash bytes as hex string for consistent representation return FormatBytesAsHexString(GetSha256Bytes(value)); } /// <summary> /// Computes SHA512 hash of a string and returns it as a hexadecimal string with leading zero. /// </summary> /// <param name="Phrase">The string to hash.</param> /// <returns>SHA512 hash as hexadecimal string with leading zero.</returns> public static string GetSha512HexStringOfString(string Phrase) { // create SHA512 hasher instance SHA512 HashTool = SHA512.Create(); Byte[] PhraseAsByte = System.Text.Encoding.UTF8.GetBytes(Phrase); //getBytes(string.Concat(Phrase, "test"); Byte[] EncryptedBytes = HashTool.ComputeHash(PhraseAsByte); HashTool.Clear(); // build hex string with consistent formatting StringBuilder hex = new StringBuilder(EncryptedBytes.Length * 2); foreach (byte b in EncryptedBytes) hex.AppendFormat("{0:x2}", b); // return with leading zero for consistency with other implementations return "0" + Convert.ToString(hex); } /// <summary> /// Computes SHA512 hash of a string and returns it as a base64-encoded string. /// </summary> /// <param name="Phrase">The string to hash.</param> /// <returns>SHA512 hash as base64 string.</returns> public static string GetSha512Base64StringOfString(string Phrase) { // create SHA512 hasher instance SHA512 HashTool = SHA512.Create(); Byte[] PhraseAsByte = System.Text.Encoding.UTF8.GetBytes(Phrase); //getBytes(string.Concat(Phrase, "test"); Byte[] EncryptedBytes = HashTool.ComputeHash(PhraseAsByte); HashTool.Clear(); // build hex string first, then convert to BigInteger for base64 encoding StringBuilder hex = new StringBuilder(EncryptedBytes.Length * 2); foreach (byte b in EncryptedBytes) hex.AppendFormat("{0:x2}", b); var stringToParse = "0" + Convert.ToString(hex); var result = new BigInteger(stringToParse, 16); // convert to base64 for compact string representation return Convert.ToBase64String(result.ToByteArray()); } } } |