From 6dd00e11439ff129826f413dcb6818e4b1301be7 Mon Sep 17 00:00:00 2001 From: Benjamin Auder Date: Tue, 23 Jan 2018 01:15:25 +0100 Subject: [PATCH 1/1] First commit --- README.md | 7 +++ sha1.js | 126 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 133 insertions(+) create mode 100644 README.md create mode 100644 sha1.js diff --git a/README.md b/README.md new file mode 100644 index 0000000..97d6a30 --- /dev/null +++ b/README.md @@ -0,0 +1,7 @@ +# sha1.js + +Just a few lines of javascript code to compute the Sha-1 sum, which +I often use to validate some secret string on a website. + +It's actually limited to "not-too-long" messages: as far as you don't +hash a big file everything should be fine. diff --git a/sha1.js b/sha1.js new file mode 100644 index 0000000..cc352d0 --- /dev/null +++ b/sha1.js @@ -0,0 +1,126 @@ +var Sha1 = {}; // SHA-1 namespace + +// SHA-1 algorithm as described at http://en.wikipedia.org/wiki/SHA-1 +// The implementation follows http://fr.wikipedia.org/wiki/Sp%C3%A9cifications_SHA-1 (in french). +// SHA-1 implementation of Chris Veness 2002-2010 [www.movable-type.co.uk] helped a lot for debugging, +// and for hacks like toHexStr(). See his script at http://www.movable-type.co.uk/scripts/sha1.html +Sha1.Compute = function(subject) +{ + var i, j, tmp, redIndex, a, b, c, d, e; + + // 1) pretreatment + + // note: no check on message length, since the 2^64 boundary is + // a lot longer than what would be allowed by HTML/PHP + + // add trailing '1' bit (+ 0's padding) to string + subject += String.fromCharCode(0x80); + + // add 8 for two last reserved words to store message length + // 8 = 2 x 4, one 32-bits word is 4 characters (bytes) length. + var L = subject.length + 8; + + // initialize 512-bits blocks representing the message, each containing 16 32-bits words. + // NOTE: one char is 8 bits, so one block in the initial string is 64 chars. + var countBlocks = Math.ceil(L / 64); + var blocks = new Array(countBlocks); + for (i=0; i= 2^32. + // therefore we don't need to fill before-last block. + blocks[countBlocks-1][15] = (subject.length-1) * 8; + + // initialize parts of the final hash + var h0 = 0x67452301; + var h1 = 0xefcdab89; + var h2 = 0x98badcfe; + var h3 = 0x10325476; + var h4 = 0xc3d2e1f0; + + // initialize constants array + var k = [0x5a827999,0x6ed9eba1,0x8f1bbcdc,0xca62c1d6]; + + // 2) computations + + for (i=0; i>> (32 - n)); +} + +// [copy-pasted from Chris Veness implementation] +// Hexadecimal representation of a number +// (note toString(16) is implementation-dependant, and +// in IE returns signed numbers when used on full words) +Sha1.ToHexStr = function(x) +{ + var s=""; + for (var i=7; i>=0; i--) + { + var v = (x >>> (i*4)) & 0xf; + s += v.toString(16); + } + return s; +} + +try { module.exports = Sha1; } catch (err) { } -- 2.44.0