.net vs Task c SHA-512 Mismatch

Question

I am trying to write a function to create a sha512 string in an object from a .net function that

public static string GetSHA512(string strPlain) { UnicodeEncoding UE = new UnicodeEncoding(); byte[] HashValue = null; byte[] MessageBytes = UE.GetBytes(strPlain); System.Security.Cryptography.SHA512Managed SHhash = new System.Security.Cryptography.SHA512Managed(); string strHex = string.Empty; HashValue = SHhash.ComputeHash(MessageBytes); foreach (byte b in HashValue) { strHex += String.Format("{0:x2}", b); } return strHex; } 

This gives the result as

 input : pass123 output: 2a6353744cc2914c602265f50d2e413d0561368775756392517abb340ef75d52ee0c5d3623ddd1826fd768a13dca8961f5957c75df0d793b9d7537aabe050705 

What I tried looks like this

 -(NSString *)createSHA512:(NSString *)string { const char *cstr = [string cStringUsingEncoding:NSUTF8StringEncoding]; NSData *data = [NSData dataWithBytes:cstr length:string.length]; uint8_t digest[CC_SHA512_DIGEST_LENGTH]; CC_SHA512(data.bytes, data.length, digest); NSMutableString* output = [NSMutableString stringWithCapacity:CC_SHA512_DIGEST_LENGTH]; for(int i = 0; i < CC_SHA512_DIGEST_LENGTH; i++) [output appendFormat:@"%02x", digest[i]]; return output; } 

which gives the result below

 input : pass123 output: fd37ca5ca8763ae077a5e9740212319591603c42a08a60dcc91d12e7e457b024f6bdfdc10cdc1383e1602ff2092b4bc1bb8cac9306a9965eb352435f5dfe8bb0 

Can anyone suggest what I am doing wrong?

Why are these two meanings different?

Please correct my mistakes.

EDIT

Medium While I tried to change the encoding to NSUTF16StringEncoding and NSUnicodeStringEncoding , the results of which are still different and as it should

 input : pass123 output: 514331e3f7ca0a295539347ebccc4e4f095fe5f3c1df10d43b4d550144c7b30ba9507831893ea63ea22e62e993be529b0d14be7800a90aa0de199d6be62a5f1b 

Answer 1

A small part of the trial and error in the function and the search for a compatible encoding version found here help me solve the problem.

There was no need to convert the function to const char, so it was deleted and directly converted to data using the default method.

 -(NSString *)createSHA512:(NSString *)string { NSData *data = [string dataUsingEncoding:NSUTF16LittleEndianStringEncoding]; uint8_t digest[CC_SHA512_DIGEST_LENGTH]; CC_SHA512(data.bytes, data.length, digest); NSMutableString* output = [NSMutableString stringWithCapacity:CC_SHA512_DIGEST_LENGTH]; for(int i = 0; i < CC_SHA512_DIGEST_LENGTH; i++) [output appendFormat:@"%02x", digest[i]]; return output; } 

Answer 2

In Objective-C version, you convert text to binary using UTF-8. In the .NET version, you are using UTF-16. This may not be the only difference, but it is certainly relevant.

I would rewrite your .NET method as:

 public static string GetSHA512(string text) { byte[] messageBytes = Encoding.UTF8.GetBytes(text); byte[] hash; using (SHA512 hashAlgorithm = SHA512.Create()) { hash = hashAlgorithm.ComputeHash(messageBytes); } StringBuilder builder = new StringBuilder(); foreach (byte b in hash) { builder.AppendFormat("{0:x2}", b); } return builder.ToString(); } 

Answer 3

For base64encoded string:

 -(NSString *)createSHA512Net:(NSString *)string { NSData *data = [string dataUsingEncoding:NSUTF16LittleEndianStringEncoding]; uint8_t digest[CC_SHA512_DIGEST_LENGTH]; CC_SHA512(data.bytes, data.length, digest); NSData *out = [NSData dataWithBytes:digest length:CC_SHA512_DIGEST_LENGTH]; NSString *str = [out base64EncodedStringWithOptions:kNilOptions]; return str; }