How do I do a SHA1 File Checksum in C#?
49,517
Solution 1
With the ComputeHash method. See here:
Example snippet:
using(var cryptoProvider = new SHA1CryptoServiceProvider())
{
string hash = BitConverter
.ToString(cryptoProvider.ComputeHash(buffer));
//do something with hash
}
Where buffer is the contents of your file.
Solution 2
If you are already reading the file as a stream, then the following technique calculates the hash as you read it. The only caveat is that you need to consume the whole stream.
class Program
{
static void Main(string[] args)
{
String sourceFileName = "C:\\test.txt";
Byte[] shaHash;
//Use Sha1Managed if you really want sha1
using (var shaForStream = new SHA256Managed())
using (Stream sourceFileStream = File.Open(sourceFileName, FileMode.Open))
using (Stream sourceStream = new CryptoStream(sourceFileStream, shaForStream, CryptoStreamMode.Read))
{
//Do something with the sourceStream
//NOTE You need to read all the bytes, otherwise you'll get an exception ({"Hash must be finalized before the hash value is retrieved."})
while(sourceStream.ReadByte() != -1);
shaHash = shaForStream.Hash;
}
Console.WriteLine(Convert.ToBase64String(shaHash));
}
}
Solution 3
Also you can try:
FileStream fop = File.OpenRead(@"C:\test.bin");
string chksum = BitConverter.ToString(System.Security.Cryptography.SHA1.Create().ComputeHash(fop));
Author by
Admin
Updated on June 27, 2020Comments
-
Admin almost 4 years
How do I use the
SHA1CryptoServiceProvider()
on a file to create a SHA1 Checksum of the file?