I have a C# function as below:

string stringvalue = "530500480530490480530480480520570480520510500490";
var encodedvalue= Encoding.Unicode.GetBytes(stringvalue);
using (HashAlgorithm ssp = System.Security.Cryptography.HashAlgorithm.Create("SHA256"))
        {

            var digest = ssp.ComputeHash(encodedvalue);

            return BitConverter.ToString(digest); 

        }

I need to create a javascript function that match the code above so that the end result for both C# and JS is the same.

Currently in my JS code, I'm using this:

var hash = CryptoJS.SHA256("530500480530490480530480480520570480520510500490");
var hexhash = hash.toString(CryptoJS.enc.hex);

This is the result of my hexhash:

d956678c8f12c65299daf35019a9a1eb3e6eb9855fd850aeb5aafe46057d179e

But in my C# code, this line of var digest = ssp.ComputeHash(bPass); return the following array:

I don't know much about encoding. Please tell me what type of result is being populated in the c# code above? If I'm not mistaken, the ComputeHash is returning bytes but I need lots of reading to confirm that which is another long hour of studying

I tried many different ways of converting the JS Sha256 code but no luck. I'm stuck at this particular line for almost a day.

Please help. Thanks

EDIT: Sorry for the code error. I had updated the C# code. ComputeHash accept an array

I have a C# function as below:

string stringvalue = "530500480530490480530480480520570480520510500490";
var encodedvalue= Encoding.Unicode.GetBytes(stringvalue);
using (HashAlgorithm ssp = System.Security.Cryptography.HashAlgorithm.Create("SHA256"))
        {

            var digest = ssp.ComputeHash(encodedvalue);

            return BitConverter.ToString(digest); 

        }

I need to create a javascript function that match the code above so that the end result for both C# and JS is the same.

Currently in my JS code, I'm using this:

var hash = CryptoJS.SHA256("530500480530490480530480480520570480520510500490");
var hexhash = hash.toString(CryptoJS.enc.hex);

This is the result of my hexhash:

d956678c8f12c65299daf35019a9a1eb3e6eb9855fd850aeb5aafe46057d179e

But in my C# code, this line of var digest = ssp.ComputeHash(bPass); return the following array:

I don't know much about encoding. Please tell me what type of result is being populated in the c# code above? If I'm not mistaken, the ComputeHash is returning bytes but I need lots of reading to confirm that which is another long hour of studying

I tried many different ways of converting the JS Sha256 code but no luck. I'm stuck at this particular line for almost a day.

Please help. Thanks

EDIT: Sorry for the code error. I had updated the C# code. ComputeHash accept an array

• javascript
• c#
• encoding
• cryptojs

• That ComputeHash doesn't directly accept a string parameter. The code won't even compile. – xanatos Commented Mar 14, 2016 at 9:54

6 Answers 6

In my example I am using System.Security.Cryptography.SHA256Managed to get SHA256 in C#.

The method SHA256Managed.ComputeHash takes a byte array as a parameter and return another byte array. Now we need to convert back your byte array to a string.

The following code return the same result a Javascript SHA-256.

 byte[] bytes = Encoding.UTF8.GetBytes("530500480530490480530480480520570480520510500490");
 SHA256Managed hashstring = new SHA256Managed();
 byte[] hash = hashstring.ComputeHash(bytes);
 string hashString = string.Empty;
 foreach (byte x in hash)
 {
     hashString += String.Format("{0:x2}", x);
 }
 return(hashString);

Just to explain : String.Format("{0:x2}", x)

• X means Hexadecimal format.
• 2 means 2 characters.

I finally found the answer after uncountable hours of trial and error.

The C# code var digest = ssp.ComputeHash(encodedvalue) is returning byte array from the result of var encodedvalue= Encoding.Unicode.GetBytes(stringvalue); as Jean replied. In order to create the function in Javascript, I need to ensure that the encodedvalue is producing the correct encoding format and size just like the one in C#.

Using only CryptoJS, I manage to get the matching result from below

function GetHexFromString() {
var stringVal = '8563A578-7402-4567-A6CE-4DE4E0825B021234';
// Convert the string to UTF 16 little-endian
// Result: 560530540510650530550560450550520480500450520530540550450650540670690450520680690520690480560500530660480500490500510520
var utf16le = CryptoJS.enc.Utf16LE.parse(stringVal);  

// Convert to Sha256 format and get the word array
var utf16Sha256 = CryptoJS.SHA256(utf16le);
// Convert the Sha256 word array to Uint8Array to get the 32 byte array just to see the result to ensure it match with the C# function
// Result: 94,203,69,29,35,202,209,149,121,144,44,6,98,250,141,161,102,7,238,35,228,117,111,236,118,115,51,113,134,72,52,69
var utf16sha256Array = convertWordArrayToUint8Array(utf16Sha256); 

// Convert the Sha256 to hex (if i'm not mistaken, it's base 16) format
var hexSha256 = utf16Sha256.toString(CryptoJS.enc.hex);

 // Insert a dash in between 2 characters in the string
 hexSha256 = hexSha256.replace(/(\S{2})/g, "$1-");
 // Remove the last dash in the string
 hexSha256 = hexSha256.replace(/-$/, "");

// Final Result: 5E-CB-45-1D-23-CA-D1-95-79-90-2C-06-62-FA-8D-A1-66-07-EE-23-E4-75-6F-EC-76-73-33-71-86-48-34-45
return hexSha256.toUpperCase();
}

function convertWordArrayToUint8Array(wordArray) {
        var len = wordArray.words.length,
            u8_array = new Uint8Array(len << 2),
            offset = 0, word, i
        ;
        for (i = 0; i < len; i++) {
            var word = wordArray.words[i];                

            u8_array[offset++] = word >> 24;
            u8_array[offset++] = (word >> 16) & 0xff;
            u8_array[offset++] = (word >> 8) & 0xff;
            u8_array[offset++] = word & 0xff;                                              
        }
        return u8_array;
    }

Hope it help whoever that need such method

An alternative to Koo SengSeng's answer (if you don't want to use CryptoJS library).
SHA256 function is from here, the arrToUintArr function is from Koo SengSeng's answer.

var SHA256=function a(b){function c(a,b){return a>>>b|a<<32-b}for(var d,e,f=Math.pow,g=f(2,32),h="length",i="",j=[],k=8*b[h],l=a.h=a.h||[],m=a.k=a.k||[],n=m[h],o={},p=2;64>n;p++)if(!o[p]){for(d=0;313>d;d+=p)o[d]=p;l[n]=f(p,.5)*g|0,m[n++]=f(p,1/3)*g|0}for(b+="\x80";b[h]%64-56;)b+="\x00";for(d=0;d<b[h];d++){if(e=b.charCodeAt(d),e>>8)return;j[d>>2]|=e<<(3-d)%4*8}for(j[j[h]]=k/g|0,j[j[h]]=k,e=0;e<j[h];){var q=j.slice(e,e+=16),r=l;for(l=l.slice(0,8),d=0;64>d;d++){var s=q[d-15],t=q[d-2],u=l[0],v=l[4],w=l[7]+(c(v,6)^c(v,11)^c(v,25))+(v&l[5]^~v&l[6])+m[d]+(q[d]=16>d?q[d]:q[d-16]+(c(s,7)^c(s,18)^s>>>3)+q[d-7]+(c(t,17)^c(t,19)^t>>>10)|0),x=(c(u,2)^c(u,13)^c(u,22))+(u&l[1]^u&l[2]^l[1]&l[2]);l=[w+x|0].concat(l),l[4]=l[4]+w|0}for(d=0;8>d;d++)l[d]=l[d]+r[d]|0}for(d=0;8>d;d++)for(e=3;e+1;e--){var y=l[d]>>8*e&255;i+=(16>y?0:"")+y.toString(16)}return i};
var arrToUintArr=function(a){for(var l=a.length,b=new Uint8Array(l<<2),o=0,w,i=0;i<l;i++) w=a[i],b[o++]=w>>24,b[o++]=(w>>16)&0xff,b[o++]=(w>>8)&0xff,b[o++]=w&0xff;return b;}
var computeHash=function(k){for(var a=[],s=SHA256(k),i=0;i<8;i++) a.push(parseInt(s.substr(i*8,8),16));return arrToUintArr(a);}

computeHash(k) will return an array of numbers representing bytes.

This is equal to below code in C#:

new System.Security.Cryptography.SHA256CryptoServiceProvider().ComputeHash(Encoding.UTF8.GetBytes(k));

Try

var digest = ssp.ComputeHash(Encoding.UTF8.GetBytes(stringvalue))

return BitConverter.ToString(digest)
                   .Replace("-", string.Empty)
                   .ToLowerInvariant();

That js library is converting the string to UTF8 before calculating its hash.

typescript code:

private computeHash(text: string): string {
    return CryptoJS.SHA256(text).toString();
}

c# equivalent:

private string ComputeHash(string text)
{
    using (var sha256 = SHA256.Create())
    {
       var bytes = Encoding.UTF8.GetBytes(text);
       var hash = sha256.ComputeHash(bytes);
       return hash.Aggregate(string.Empty, (current, x) => current + $"{x:x2}");
    }
}

after two days of research it works perfectly! Two different codes give the same result.

js

const sha1 = require('sha1');    
const getHash = str =>{
    const hashingBytes = Buffer.from(sha1(str), "hex");
    const base64Value = Buffer.from(hashingBytes).toString('base64');
    return base64Value;
}

c#

 System.Security.Cryptography.SHA1 sha = new System.Security.Cryptography.SHA1CryptoServiceProvider();
        byte[] bytes = System.Text.Encoding.ASCII.GetBytes(str);
        byte[] hashingbytes = sha.ComputeHash(bytes);
        var hash = Convert.ToBase64String(hashingbytes);