IOS sha1 wrong output

Question

Im trying to make same Sha1 out put in IOS but the result aren't the same.

Due to this answer SO it should be fine and same result

this is my C# Code :

    using (SHA1 sha1Hash = SHA1.Create())
     {
            string hash1 = GetSHA1Hash(sha1Hash, "8390495498");
     }

    static string GetSHA1Hash(SHA1 sha1Hash, string input)
    { 
        byte[] data = sha1_Hash.ComputeHash(Encoding.UTF8.GetBytes(input));
        StringBuilder sBuilder = new StringBuilder();
        for (int i = 0; i < data.Length; i++)
        {
            sBuilder.Append(data[i].ToString("x2"));
        }
        return sBuilder.ToString();
    }

the result is : d763bd0b5b346a3c95eb4f2912be40c2ce6f0a41

And my Objective C code :

   [sh1obj sha1:@"8390495498"]
- (NSString *)sha1:(NSString *)str {
    NSData *data = [str dataUsingEncoding:NSUnicodeStringEncoding];

    NSString *unicodePassword = [[NSString alloc] initWithData:data encoding:NSUnicodeStringEncoding];
    data = [unicodePassword dataUsingEncoding:NSUnicodeStringEncoding];
    data = [NSData dataWithBytes:[data bytes] + 2 length:[data length] - 2];

    unsigned char hash[CC_SHA1_DIGEST_LENGTH];
    CC_SHA1([data bytes], [data length], hash);
    NSData *result = [NSData dataWithBytes:hash length:CC_SHA1_DIGEST_LENGTH];
    NSLog(@"Result: %@",result);

    return result;
}

the result is : <241cdda1 6867aaad cb69faed d0975579 f6ec3a07>

i even tried this one too :

  [sh1obj sha1:@"8390495498"]
- (NSString *)sha1:(NSString *)str {

    const char *cStr = [str UTF8String];
    unsigned char result[CC_SHA1_DIGEST_LENGTH];
    CC_SHA1(cStr, strlen(cStr), result);
    NSString *s = [NSString  stringWithFormat:
                   @"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
                   result[0], result[1], result[2], result[3], result[4],
                   result[5], result[6], result[7],
                   result[8], result[9], result[10], result[11], result[12],
                   result[13], result[14], result[15],
                   result[16], result[17], result[18], result[19]
                   ];
    NSLog(@"Result: %@",s);
    return s;
}

and the result was : cbdb5d7936ac9a56846cabad5e9d41942a08b49c

What does the +2 do in dataWithBytes? And have you tried NSUTF8StringEncoding? — Thilo, Oct 23 '14 at 07:36
And why do you put the NSData back into an NSString and then decode it again? — Thilo, Oct 23 '14 at 07:37
I'm trying to remove BOM with "+2". after i changed to NSUTF8StringEncoding it gives me the result of third method. if i remove the "+2" method it gives me another sha1 : 0e225a4e 22393d01 a85a44b4 8d5f3ed3 72515a7d at this moment don't know what to do :( — Ahad Porkar, Oct 23 '14 at 07:42

Thilo · Accepted Answer · 2014-10-23T07:59:15.127

1

I think the Objective-C code is correct:

$ echo -n 8390495498 | openssl sha1  
cbdb5d7936ac9a56846cabad5e9d41942a08b49c

edited Oct 23 '14 at 07:59

answered Oct 23 '14 at 07:33

Thilo

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IOS sha1 wrong output

1 Answers1