The other day I was writing an ETL where I expected duplicate data to be accidentally sent over quite often so I needed an SHA-256 function to guarantee that a set of incoming rows were unique (notice I said the set of rows, not individual rows so that rules out using an index to prevent duplicates). SQL Server 2012 has it but for this project I was stuck on SQL Server 2008 R2 which only has an SHA-1 function (obviously not good enough).
So here’s an SHA-256 stored procedure I wrote for SQL Server 2008…
using System; using System.Data; using System.Data.SqlClient; using System.Data.SqlTypes; using System.Text; using Microsoft.SqlServer.Server; using System.Security.Cryptography; public partial class StoredProcedures { [Microsoft.SqlServer.Server.SqlProcedure] public static void usp_SHA256( String strIn, out String strOut) { SqlPipe sp; sp = SqlContext.Pipe; ASCIIEncoding AE = new ASCIIEncoding(); byte[] pBytes = AE.GetBytes(strIn); SHA256Managed hashvalue = new SHA256Managed(); byte[] cHash = hashvalue.ComputeHash(pBytes); string hashedStr = System.Text.ASCIIEncoding .ASCII.GetString(cHash); strOut = hashedStr; sp.Send(hashedStr); } };