Method of implementing SHA-1 Encryption Algorithm in JavaScript, javascriptsha-1

Method of implementing SHA-1 Encryption Algorithm in JavaScript, javascriptsha-1

This example describes how to implement the SHA-1 Encryption Algorithm in JavaScript. Share it with you for your reference. The specific implementation method is as follows:

Call method: hex_sha1.
Copy codeThe Code is as follows :/*
*
* A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined
* In fips pub 180-1
*
* By lizq
*
* 2006-11-
*
*/
/*
*
* Retriable variables.
*
*/
Var hexcase = 0;/* hex output format. 0-lowercase; 1-uppercase */
Var chrsz = 8;/* bits per input character. 8-ASCII; 16-Unicode */
/*
*
* The main function to calculate message digest
*
*/
Function hex_sha1 (s ){
Return binb2hex (core_sha1 (AlignSHA1 (s )));
}
/*
*
* Perform a simple self-test to see if the VM is working
*
*/
Function shaw.vm_test (){
Return hex_sha1 ("abc") = "a9993e364706816aba3e25717850c26c9cd0d89d ";
}
/*
*
* Calculate the SHA-1 of an array of big-endian words, and a bit length
*
*/
Function core_sha1 (blockArray ){
Var x = blockArray; // append padding
Var w = Array (80 );
Var a = 1732584193;
Var B =-271733879;
Var c =-1732584194;
Var d = 271733878;
Var e =-1009589776;
For (var I = 0; I <x. length; I + = 16) // 512-bit 16*32
{
Var olda =;
Var oldb = B;
Var oldc = c;
Var oldd = d;
Var olde = e;
For (var j = 0; j <80; j ++) // perform step 80 for each 512 bits
{
If (j <16)
W [j] = x [I + j];
Else
W [j] = rol (w [j-3] ^ w [j-8] ^ w [j-14] ^ w [j-16], 1 );
Var t = safe_add (rol (a, 5), sha1_ft (j, B, c, d), safe_add (e, w [j]), shaw.kt (j )));
E = d;
D = c;
C = rol (B, 30 );
B =;
A = t;
}
A = safe_add (a, olda );
B = safe_add (B, oldb );
C = safe_add (c, oldc );
D = safe_add (d, oldd );
E = safe_add (e, olde );
}
Return new Array (a, B, c, d, e );
}
/*
*
* Perform the appropriate triplet combination function for the current
* Iteration
*
* Returns the value of the corresponding F function.
*
*/
Function sha1_ft (t, B, c, d ){
If (t <20)
Return (B & c) | ((~ B) & d );
If (t <40)
Return B ^ c ^ d;
If (t <60)
Return (B & c) | (B & d) | (c & d );
Return B ^ c ^ d; // t <80
}
/*
*
* Determine the appropriate additive constant for the current iteration
*
* Returns the corresponding Kt value.
*
*/
Function sha1_kt (t ){
Return (t <20 )? 1518500249: (t <40 )? 1859775393: (t <60 )? -1894007588:-899497514;
}
/*
*
* Add integers, wrapping at 2 ^ 32. This uses 16-bit operations internally
*
* To work around und bugs in some JS interpreters.
*
* Divide the 32-bit values into 16-bit high and 16-bit low, respectively, to add MOD 2 ^ 32.
*
*/
Function safe_add (x, y ){
Var lsw = (x & 0 xFFFF) + (y & 0 xFFFF );
Var msw = (x> 16) + (y> 16) + (lsw> 16 );
Return (msw <16) | (lsw & 0 xFFFF );
}
/*
*
* Bitwise rotate a 32-bit number to the left.
*
* 32-bit binary number shifts left
*
*/
Function rol (num, cnt ){
Return (num <cnt) | (num >>> (32-cnt ));
}
/*
*
* The standard SHA1 needs the input string to fit into a block
*
* This function align the input string to meet the requirement
*
*/
Function AlignSHA1 (str ){
Var nblk = (str. length + 8)> 6) + 1, blks = new Array (nblk * 16 );
For (var I = 0; I <nblk * 16; I ++)
Blks [I] = 0;
For (I = 0; I <str. length; I ++)
Blks [I> 2] | = str. charCodeAt (I) <(24-(I & 3) * 8 );
Blks [I> 2] | = 0x80 <(24-(I & 3) * 8 );
Blks [nblk * 16-1] = str. length * 8;
Return blks;
}
/*
*
* Convert an array of big-endian words to a hex string.
*
*/
Function binb2hex (binarray ){
Var hex_tab = hexcase? "0123456789 ABCDEF": "0123456789 abcdef ";
Var str = "";
For (var I = 0; I <binarray. length * 4; I ++ ){
Str + = hex_tab.charAt (binarray [I> 2]> (3-I % 4) * 8 + 4) & 0xF) +
Hex_tab.charAt (binarray [I> 2]> (3-I % 4) * 8) & 0xF );
}
Return str;
}
/*
*
* Calculate MessageDigest accord to source message that inputted
*
*/
Function calcDigest (){
Var digestM = hex_sha1 (document. SHAForm. SourceMessage. value );
Document. SHAForm. MessageDigest. value = digestM;
}

I hope this article will help you design javascript programs.