HashAlgorithm.ComputeHash Method (System.Security.Cryptography) (2024)

Source:

HashAlgorithm.cs

Source:

HashAlgorithm.cs

Source:

HashAlgorithm.cs

public: cli::array <System::Byte> ^ ComputeHash(cli::array <System::Byte> ^ buffer);

public byte[] ComputeHash (byte[] buffer);

member this.ComputeHash : byte[] -> byte[]

Public Function ComputeHash (buffer As Byte()) As Byte()

Parameters

Returns

The computed hash code.

Exceptions

Examples

The following example computes the SHA256 hash value of a string and returns the hash as a 64-character, hexadecimal-formatted string. The hash string created by this code example is compatible with any SHA256 hash function (on any platform) that creates a 64-character, hexadecimal-formatted hash string.

using System;using System.Security.Cryptography;using System.Text;public class Program{ public static void Main() { string source = "Hello World!"; using (SHA256 sha256Hash = SHA256.Create()) { string hash = GetHash(sha256Hash, source); Console.WriteLine($"The SHA256 hash of {source} is: {hash}."); Console.WriteLine("Verifying the hash..."); if (VerifyHash(sha256Hash, source, hash)) { Console.WriteLine("The hashes are the same."); } else { Console.WriteLine("The hashes are not same."); } } } private static string GetHash(HashAlgorithm hashAlgorithm, string input) { // Convert the input string to a byte array and compute the hash. byte[] data = hashAlgorithm.ComputeHash(Encoding.UTF8.GetBytes(input)); // Create a new Stringbuilder to collect the bytes // and create a string. var sBuilder = new StringBuilder(); // Loop through each byte of the hashed data // and format each one as a hexadecimal string. for (int i = 0; i < data.Length; i++) { sBuilder.Append(data[i].ToString("x2")); } // Return the hexadecimal string. return sBuilder.ToString(); } // Verify a hash against a string. private static bool VerifyHash(HashAlgorithm hashAlgorithm, string input, string hash) { // Hash the input. var hashOfInput = GetHash(hashAlgorithm, input); // Create a StringComparer an compare the hashes. StringComparer comparer = StringComparer.OrdinalIgnoreCase; return comparer.Compare(hashOfInput, hash) == 0; }}// The example displays the following output:// The SHA256 hash of Hello World! is: 7f83b1657ff1fc53b92dc18148a1d65dfc2d4b1fa3d677284addd200126d9069.// Verifying the hash...// The hashes are the same.

Imports System.Security.CryptographyImports System.TextPublic Module Program Public Sub Main() Dim source As String = "Hello World!" Using sha256Hash As SHA256 = SHA256.Create() Dim hash As String = GetHash(sha256Hash, source) Console.WriteLine($"The SHA256 hash of {source} is: {hash}.") Console.WriteLine("Verifying the hash...") If VerifyHash(sha256Hash, source, hash) Then Console.WriteLine("The hashes are the same.") Else Console.WriteLine("The hashes are not same.") End If End Using End Sub Private Function GetHash(ByVal hashAlgorithm As HashAlgorithm, ByVal input As String) As String ' Convert the input string to a byte array and compute the hash. Dim data As Byte() = hashAlgorithm.ComputeHash(Encoding.UTF8.GetBytes(input)) ' Create a new Stringbuilder to collect the bytes ' and create a string. Dim sBuilder As New StringBuilder() ' Loop through each byte of the hashed data ' and format each one as a hexadecimal string. For i As Integer = 0 To data.Length - 1 sBuilder.Append(data(i).ToString("x2")) Next ' Return the hexadecimal string. Return sBuilder.ToString() End Function ' Verify a hash against a string. Private Function VerifyHash(hashAlgorithm As HashAlgorithm, input As String, hash As String) As Boolean ' Hash the input. Dim hashOfInput As String = GetHash(hashAlgorithm, input) ' Create a StringComparer an compare the hashes. Dim comparer As StringComparer = StringComparer.OrdinalIgnoreCase Return comparer.Compare(hashOfInput, hash) = 0 End FunctionEnd Module' The example displays the following output:' The SHA256 hash of Hello World! is: 7f83b1657ff1fc53b92dc18148a1d65dfc2d4b1fa3d677284addd200126d9069.' Verifying the hash...' The hashes are the same.