SHA1 Generated Hashes Do Not Match (JS and C#)

I am trying to create the .NET equivalent of Javascript code below. I've tried what I've shared in the ".NET SHA1" section but it generated different hash outputs. I tried translating javascript code into C# (which I've shared as well) which doesn't work either. What am I doing wrong, how can I get the same hash value generated by javascript function in C# ?

.NET SHA1 Hash:

public string CreateHash(string a, string b, string c)
{
    string concatenation = string.Concat(a, b, c);

    SHA1 sha = new SHA1CryptoServiceProvider();
    byte[] byt = Encoding.GetEncoding(0).GetBytes(concatenation);
    byte[] hash = sha.ComputeHash(byt);
    return Convert.ToBase64String(hash);
}

Javascript Code:

function createHash()
{
    var hashdata = somestringconcat;

    m.digest.value = encode64(sha1Hash(hashdata));

    return 0;
}


var keyStr = "ABCDEFGHIJKLMNOP" +
             "QRSTUVWXYZabcdef" +
             "ghijklmnopqrstuv" +
             "wxyz0123456789+/" +
             "=";

function encode64(input) {
   var output = "";
   var chr1, chr2, chr3 = "";
   var enc1, enc2, enc3, enc4 = "";
   var i = 0;

   do {
       chr1 = eval('0x' + input.charAt(i++) + input.charAt(i++));
       if (i<input.length)
            chr2 = eval('0x' + input.charAt(i++) + input.charAt(i++));
       else 
            i=i+2;
       if (i<input.length) 
            chr3 = eval('0x' + input.charAt(i++) + input.charAt(i++));
       else 
            i=i+2;

       enc1 = chr1 >> 2;
       enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
       enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
       enc4 = chr3 & 63;

       if (i == input.length + 4) {
          enc3 = enc4 = 64;
       } else if (i == input.length + 2) {
          enc4 = 64;
       } 

       output = output + 
          keyStr.charAt(enc1) + 
          keyStr.charAt(enc2) + 
          keyStr.charAt(enc3) + 
          keyStr.charAt(enc4);
       chr1 = chr2 = chr3 = "";
       enc1 = enc2 = enc3 = enc4 = "";
    } while (i < input.length);

    return output;
}


function sha1Hash(msg)
{
    // constants [4.2.1]
    var K = [0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6];

    // PREPROCESSING 

    msg += String.fromCharCode(0x80); // add trailing '1' bit to string [5.1.1]

    // convert string msg into 512-bit/16-integer blocks arrays of ints [5.2.1]
    var l = Math.ceil(msg.length/4) + 2;  // long enough to contain msg plus 2-word length
    var N = Math.ceil(l/16);              // in N 16-int blocks
    var M = new Array(N);
    for (var i=0; i<N; i++) {
        M[i] = new Array(16);
        for (var j=0; j<16; j++) {  // encode 4 chars per integer, big-endian encoding
            M[i][j] = (msg.charCodeAt(i*64+j*4)<<24) | (msg.charCodeAt(i*64+j*4+1)<<16) | 
                      (msg.charCodeAt(i*64+j*4+2)<<8) | (msg.charCodeAt(i*64+j*4+3));
        }
    }
    // add length (in bits) into final pair of 32-bit integers (big-endian) [5.1.1]
    // note: most significant word would be ((len-1)*8 >>> 32, but since JS converts
    // bitwise-op args to 32 bits, we need to simulate this by arithmetic operators
    M[N-1][14] = ((msg.length-1)*8) / Math.pow(2, 32); M[N-1][14] = Math.floor(M[N-1][14])
    M[N-1][15] = ((msg.length-1)*8) & 0xffffffff;

    // set initial hash value [5.3.1]
    var H0 = 0x67452301;
    var H1 = 0xefcdab89;
    var H2 = 0x98badcfe;
    var H3 = 0x10325476;
    var H4 = 0xc3d2e1f0;

    // HASH COMPUTATION [6.1.2]

    var W = new Array(80); var a, b, c, d, e;
    for (var i=0; i<N; i++) {

        // 1 - prepare message schedule 'W'
        for (var t=0;  t<16; t++) W[t] = M[i][t];
        for (var t=16; t<80; t++) W[t] = ROTL(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16], 1);

        // 2 - initialise five working variables a, b, c, d, e with previous hash value
        a = H0; b = H1; c = H2; d = H3; e = H4;

        // 3 - main loop
        for (var t=0; t<80; t++) {
            var s = Math.floor(t/20); // seq for blocks of 'f' functions and 'K' constants
            var T = (ROTL(a,5) + f(s,b,c,d) + e + K[s] + W[t]) & 0xffffffff;
            e = d;
            d = c;
            c = ROTL(b, 30);
            b = a;
            a = T;
        }

        // 4 - compute the new intermediate hash value
        H0 = (H0+a) & 0xffffffff;  // note 'addition modulo 2^32'
        H1 = (H1+b) & 0xffffffff; 
        H2 = (H2+c) & 0xffffffff; 
        H3 = (H3+d) & 0xffffffff; 
        H4 = (H4+e) & 0xffffffff;
    }

    return H0.toHexStr() + H1.toHexStr() + H2.toHexStr() + H3.toHexStr() + H4.toHexStr();
}

//
// function 'f' [4.1.1]
//
function f(s, x, y, z) 
{
    switch (s) {
    case 0: return (x & y) ^ (~x & z);
    case 1: return x ^ y ^ z;
    case 2: return (x & y) ^ (x & z) ^ (y & z);
    case 3: return x ^ y ^ z;
    }
}

//
// rotate left (circular left shift) value x by n positions [3.2.5]
//
function ROTL(x, n)
{
    return (x<<n) | (x>>>(32-n));
}

//
// extend Number class with a tailored hex-string method 
//   (note toString(16) is implementation-dependant, and 
//   in IE returns signed numbers when used on full words)
//
Number.prototype.toHexStr = function()
{
    var s="", v;
    for (var i=7; i>=0; i--) { v = (this>>>(i*4)) & 0xf; s += v.toString(16); }
    return s;
}

C# Translation Attempt:

string Sha1Hash(string msg)
{
    // constants [4.2.1]
    uint[] K = new uint[] { 0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6 };

    // PREPROCESSING 
    msg += Convert.ToChar(0x80); // add trailing '1' bit to string [5.1.1]

    // convert string msg into 512-bit/16-integer blocks arrays of ints [5.2.1]
    uint l = (uint)Math.Ceiling(msg.Length / 4d) + 2;  // long enough to contain msg plus 2-word length
    uint N = (uint)Math.Ceiling(l / 16d);              // in N 16-int blocks

    uint[][] M = new uint[N][];
    for (int i = 0; i < N; i++)
    {
        M[i] = new uint[16];
        for (int j = 0; j < 16; j++)
        {  // encode 4 chars per integer, big-endian encoding
            M[i][j] = (uint)((Convert.ToChar(i * 64 + j * 4) << 24) | (Convert.ToChar(i * 64 + j * 4 + 1) << 16) |
                      (Convert.ToChar(i * 64 + j * 4 + 2) << 8) | (Convert.ToChar(i * 64 + j * 4 + 3)));
        }
    }
    // add length (in bits) into final pair of 32-bit integers (big-endian) [5.1.1]
    // note: most significant word would be ((len-1)*8 >>> 32, but since JS converts
    // bitwise-op args to 32 bits, we need to simulate this by arithmetic operators
    M[N - 1][14] =  (uint)Math.Floor(((msg.Length - 1) * 8) / Math.Pow(2, 32));
    M[N - 1][15] = (uint)((msg.Length - 1) * 8) & 0xffffffff;

    // set initial hash value [5.3.1]
    ulong H0 = 0x67452301;
    ulong H1 = 0xefcdab89;
    ulong H2 = 0x98badcfe;
    ulong H3 = 0x10325476;
    ulong H4 = 0xc3d2e1f0;

    // HASH COMPUTATION [6.1.2]
    ulong[] W = new ulong[80];
    ulong a, b, c, d, e;

    for (int i = 0; i < N; i++)
    {

        // 1 - prepare message schedule 'W'
        for (int t = 0; t < 16; t++) W[t] = M[i][t];
        for (int t = 16; t < 80; t++) W[t] = ROTL(W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16], 1);

        // 2 - initialise five working variables a, b, c, d, e with previous hash value
        a = H0; b = H1; c = H2; d = H3; e = H4;

        // 3 - main loop
        for (int t = 0; t < 80; t++)
        {
            ulong s = (ulong)Math.Floor(t / 20d); // seq for blocks of 'f' functions and 'K' constants
            var T = (ROTL(a, 5) + F(s, b, c, d) + e + K[s] + W[t]) & 0xffffffff;
            e = d;
            d = c;
            c = ROTL(b, 30);
            b = a;
            a = T;
        }

        // 4 - compute the new intermediate hash value
        H0 = (H0 + a) & 0xffffffff;  // note 'addition modulo 2^32'
        H1 = (H1 + b) & 0xffffffff;
        H2 = (H2 + c) & 0xffffffff;
        H3 = (H3 + d) & 0xffffffff;
        H4 = (H4 + e) & 0xffffffff;
    }

    return string.Concat(ToHexStr(H0), ToHexStr(H1), ToHexStr(H2), ToHexStr(H3), ToHexStr(H4));
}

ulong ROTL(ulong x, int n)
{
    return ((x << n) | (x >> (32 - n)));
}

string ToHexStr(ulong param)
{
    return ""; //
}

ulong F(ulong s, ulong x, ulong y, ulong z)
{
    switch (s)
    {
        case 0: return (x & y) ^ (~x & z);
        case 1: return x ^ y ^ z;
        case 2: return (x & y) ^ (x & z) ^ (y & z);
        case 3: return x ^ y ^ z;
    }
    return 0;
}

const string keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

string Encode64(string input)
{
    string output = "";

    int chr1 = 0;
    int chr2 = 0;
    int chr3 = 0;
    int enc1, enc2, enc3, enc4 = 0;
    var i = 0;

    do
    {
        chr1 = Convert.ToInt32(("0x" + input[i++] + input[i++]), 16);

        if (i < input.Length)
            chr2 = Convert.ToInt32(("0x" + input[i++] + input[i++]), 16);
        else
            i = i + 2;
        if (i < input.Length)
            chr3 = Convert.ToInt32(("0x" + input[i++] + input[i++]), 16);
        else
            i = i + 2;

        enc1 = chr1 >> 2;
        enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
        enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
        enc4 = chr3 & 63;

        if (i == input.Length + 4)
        {
            enc3 = enc4 = 64;
        }
        else if (i == input.Length + 2)
        {
            enc4 = 64;
        }

        output = output +
           keyStr[enc1] +
           keyStr[enc2] +
           keyStr[enc3] +
           keyStr[enc4];

        chr1 = chr2 = chr3 = 0;
        enc1 = enc2 = enc3 = enc4 = 0;
    } while (i < input.Length);

    return output;
}