本文实例讲述了JavaScript实现SHA-1加密算法的方法。分享给大家供大家参考。具体实现方法如下:
调用方法:hex_sha1即可。
/* * * A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined * in FIPS PUB 180-1 * * By lizq * * 2006-11-11 * */ /* * * Configurable 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 sha1_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) // 每次处理512位 16*32 { var olda = a; var oldb = b; var oldc = c; var oldd = d; var olde = e; for (var j = 0; j < 80; j++) // 对每个512位进行80步操作 { 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(safe_add(rol(a, 5), sha1_ft(j, b, c, d)), safe_add(safe_add(e, w[j]), sha1_kt(j))); e = d; d = c; c = rol(b, 30); b = a; 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 * * 返回对应F函数的值 * */ 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 * * 返回对应的Kt值 * */ 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 bugs in some JS interpreters. * * 将32位数拆成高16位和低16位分别进行相加,从而实现 MOD 2^32 的加法 * */ function safe_add(x, y){ var lsw = (x & 0xFFFF) + (y & 0xFFFF); var msw = (x >> 16) + (y >> 16) + (lsw >> 16); return (msw << 16) | (lsw & 0xFFFF); } /* * * Bitwise rotate a 32-bit number to the left. * * 32位二进制数循环左移 * */ 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 ? "0123456789ABCDEF" : "0123456789abcdef"; 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; }
希望本文所述对大家的javascript程序设计有所帮助。
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