crypto/sha256: new package

R=rsc
CC=golang-dev
https://golang.org/cl/176062

src/pkg/Makefile

@@ -33,6 +33,7 @@ DIRS=\
 	crypto/rc4\
 	crypto/rsa\
 	crypto/sha1\
+	crypto/sha256\
 	crypto/subtle\
 	crypto/tls\
 	crypto/x509\

src/pkg/crypto/sha256/Makefile

@@ -0,0 +1,12 @@
+# Copyright 2009 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+include ../../../Make.$(GOARCH)
+
+TARG=crypto/sha256
+GOFILES=\
+	sha256.go\
+	sha256block.go\
+
+include ../../../Make.pkg

src/pkg/crypto/sha256/sha256.go

@@ -0,0 +1,123 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This package implements the SHA256 hash algorithm as defined in FIPS 180-2.
+package sha256
+
+import (
+	"hash";
+	"os";
+)
+
+// The size of a SHA256 checksum in bytes.
+const Size = 32
+
+const (
+	_Chunk	= 64;
+	_Init0	= 0x6A09E667;
+	_Init1	= 0xBB67AE85;
+	_Init2	= 0x3C6EF372;
+	_Init3	= 0xA54FF53A;
+	_Init4	= 0x510E527F;
+	_Init5	= 0x9B05688C;
+	_Init6	= 0x1F83D9AB;
+	_Init7	= 0x5BE0CD19;
+)
+
+// digest represents the partial evaluation of a checksum.
+type digest struct {
+	h	[8]uint32;
+	x	[_Chunk]byte;
+	nx	int;
+	len	uint64;
+}
+
+func (d *digest) Reset() {
+	d.h[0] = _Init0;
+	d.h[1] = _Init1;
+	d.h[2] = _Init2;
+	d.h[3] = _Init3;
+	d.h[4] = _Init4;
+	d.h[5] = _Init5;
+	d.h[6] = _Init6;
+	d.h[7] = _Init7;
+	d.nx = 0;
+	d.len = 0;
+}
+
+// New returns a new hash.Hash computing the SHA256 checksum.
+func New() hash.Hash {
+	d := new(digest);
+	d.Reset();
+	return d;
+}
+
+func (d *digest) Size() int	{ return Size }
+
+func (d *digest) Write(p []byte) (nn int, err os.Error) {
+	nn = len(p);
+	d.len += uint64(nn);
+	if d.nx > 0 {
+		n := len(p);
+		if n > _Chunk-d.nx {
+			n = _Chunk - d.nx
+		}
+		for i := 0; i < n; i++ {
+			d.x[d.nx+i] = p[i]
+		}
+		d.nx += n;
+		if d.nx == _Chunk {
+			_Block(d, &d.x);
+			d.nx = 0;
+		}
+		p = p[n:];
+	}
+	n := _Block(d, p);
+	p = p[n:];
+	if len(p) > 0 {
+		for i := 0; i < len(p); i++ {
+			d.x[i] = p[i]
+		}
+		d.nx = len(p);
+	}
+	return;
+}
+
+func (d *digest) Sum() []byte {
+	// Padding.  Add a 1 bit and 0 bits until 56 bytes mod 64.
+	len := d.len;
+	var tmp [64]byte;
+	tmp[0] = 0x80;
+	if len%64 < 56 {
+		d.Write(tmp[0 : 56-len%64])
+	} else {
+		d.Write(tmp[0 : 64+56-len%64])
+	}
+
+	// Length in bits.
+	len <<= 3;
+	for i := uint(0); i < 8; i++ {
+		tmp[i] = byte(len >> (56 - 8*i))
+	}
+	d.Write(tmp[0:8]);
+
+	if d.nx != 0 {
+		panicln("oops")
+	}
+
+	p := make([]byte, 32);
+	j := 0;
+	for i := 0; i < 8; i++ {
+		s := d.h[i];
+		p[j] = byte(s >> 24);
+		j++;
+		p[j] = byte(s >> 16);
+		j++;
+		p[j] = byte(s >> 8);
+		j++;
+		p[j] = byte(s);
+		j++;
+	}
+	return p;
+}

src/pkg/crypto/sha256/sha256_test.go

@@ -0,0 +1,68 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// SHA256 hash algorithm.  See FIPS 180-2.
+
+package sha256
+
+import (
+	"fmt";
+	"io";
+	"testing";
+)
+
+type sha256Test struct {
+	out	string;
+	in	string;
+}
+
+var golden = []sha256Test{
+	sha256Test{"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855", ""},
+	sha256Test{"ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb", "a"},
+	sha256Test{"fb8e20fc2e4c3f248c60c39bd652f3c1347298bb977b8b4d5903b85055620603", "ab"},
+	sha256Test{"ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad", "abc"},
+	sha256Test{"88d4266fd4e6338d13b845fcf289579d209c897823b9217da3e161936f031589", "abcd"},
+	sha256Test{"36bbe50ed96841d10443bcb670d6554f0a34b761be67ec9c4a8ad2c0c44ca42c", "abcde"},
+	sha256Test{"bef57ec7f53a6d40beb640a780a639c83bc29ac8a9816f1fc6c5c6dcd93c4721", "abcdef"},
+	sha256Test{"7d1a54127b222502f5b79b5fb0803061152a44f92b37e23c6527baf665d4da9a", "abcdefg"},
+	sha256Test{"9c56cc51b374c3ba189210d5b6d4bf57790d351c96c47c02190ecf1e430635ab", "abcdefgh"},
+	sha256Test{"19cc02f26df43cc571bc9ed7b0c4d29224a3ec229529221725ef76d021c8326f", "abcdefghi"},
+	sha256Test{"72399361da6a7754fec986dca5b7cbaf1c810a28ded4abaf56b2106d06cb78b0", "abcdefghij"},
+	sha256Test{"a144061c271f152da4d151034508fed1c138b8c976339de229c3bb6d4bbb4fce", "Discard medicine more than two years old."},
+	sha256Test{"6dae5caa713a10ad04b46028bf6dad68837c581616a1589a265a11288d4bb5c4", "He who has a shady past knows that nice guys finish last."},
+	sha256Test{"ae7a702a9509039ddbf29f0765e70d0001177914b86459284dab8b348c2dce3f", "I wouldn't marry him with a ten foot pole."},
+	sha256Test{"6748450b01c568586715291dfa3ee018da07d36bb7ea6f180c1af6270215c64f", "Free! Free!/A trip/to Mars/for 900/empty jars/Burma Shave"},
+	sha256Test{"14b82014ad2b11f661b5ae6a99b75105c2ffac278cd071cd6c05832793635774", "The days of the digital watch are numbered.  -Tom Stoppard"},
+	sha256Test{"7102cfd76e2e324889eece5d6c41921b1e142a4ac5a2692be78803097f6a48d8", "Nepal premier won't resign."},
+	sha256Test{"23b1018cd81db1d67983c5f7417c44da9deb582459e378d7a068552ea649dc9f", "For every action there is an equal and opposite government program."},
+	sha256Test{"8001f190dfb527261c4cfcab70c98e8097a7a1922129bc4096950e57c7999a5a", "His money is twice tainted: 'taint yours and 'taint mine."},
+	sha256Test{"8c87deb65505c3993eb24b7a150c4155e82eee6960cf0c3a8114ff736d69cad5", "There is no reason for any individual to have a computer in their home. -Ken Olsen, 1977"},
+	sha256Test{"bfb0a67a19cdec3646498b2e0f751bddc41bba4b7f30081b0b932aad214d16d7", "It's a tiny change to the code and not completely disgusting. - Bob Manchek"},
+	sha256Test{"7f9a0b9bf56332e19f5a0ec1ad9c1425a153da1c624868fda44561d6b74daf36", "size:  a.out:  bad magic"},
+	sha256Test{"b13f81b8aad9e3666879af19886140904f7f429ef083286195982a7588858cfc", "The major problem is with sendmail.  -Mark Horton"},
+	sha256Test{"b26c38d61519e894480c70c8374ea35aa0ad05b2ae3d6674eec5f52a69305ed4", "Give me a rock, paper and scissors and I will move the world.  CCFestoon"},
+	sha256Test{"049d5e26d4f10222cd841a119e38bd8d2e0d1129728688449575d4ff42b842c1", "If the enemy is within range, then so are you."},
+	sha256Test{"0e116838e3cc1c1a14cd045397e29b4d087aa11b0853fc69ec82e90330d60949", "It's well we cannot hear the screams/That we create in others' dreams."},
+	sha256Test{"4f7d8eb5bcf11de2a56b971021a444aa4eafd6ecd0f307b5109e4e776cd0fe46", "You remind me of a TV show, but that's all right: I watch it anyway."},
+	sha256Test{"61c0cc4c4bd8406d5120b3fb4ebc31ce87667c162f29468b3c779675a85aebce", "C is as portable as Stonehedge!!"},
+	sha256Test{"1fb2eb3688093c4a3f80cd87a5547e2ce940a4f923243a79a2a1e242220693ac", "Even if I could be Shakespeare, I think I should still choose to be Faraday. - A. Huxley"},
+	sha256Test{"395585ce30617b62c80b93e8208ce866d4edc811a177fdb4b82d3911d8696423", "The fugacity of a constituent in a mixture of gases at a given temperature is proportional to its mole fraction.  Lewis-Randall Rule"},
+	sha256Test{"4f9b189a13d030838269dce846b16a1ce9ce81fe63e65de2f636863336a98fe6", "How can you write a big system without C++?  -Paul Glick"},
+}
+
+func TestGolden(t *testing.T) {
+	for i := 0; i < len(golden); i++ {
+		g := golden[i];
+		c := New();
+		for j := 0; j < 2; j++ {
+			io.WriteString(c, g.in);
+			s := fmt.Sprintf("%x", c.Sum());
+			if s != g.out {
+				t.Errorf("sha256[%d](%s) = %s want %s", j, g.in, s, g.out);
+				t.FailNow();
+			}
+			c.Reset();
+		}
+	}
+}

src/pkg/crypto/sha256/sha256block.go

@@ -0,0 +1,129 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// SHA256 block step.
+// In its own file so that a faster assembly or C version
+// can be substituted easily.
+
+package sha256
+
+var _K = []uint32{
+	0x428a2f98,
+	0x71374491,
+	0xb5c0fbcf,
+	0xe9b5dba5,
+	0x3956c25b,
+	0x59f111f1,
+	0x923f82a4,
+	0xab1c5ed5,
+	0xd807aa98,
+	0x12835b01,
+	0x243185be,
+	0x550c7dc3,
+	0x72be5d74,
+	0x80deb1fe,
+	0x9bdc06a7,
+	0xc19bf174,
+	0xe49b69c1,
+	0xefbe4786,
+	0x0fc19dc6,
+	0x240ca1cc,
+	0x2de92c6f,
+	0x4a7484aa,
+	0x5cb0a9dc,
+	0x76f988da,
+	0x983e5152,
+	0xa831c66d,
+	0xb00327c8,
+	0xbf597fc7,
+	0xc6e00bf3,
+	0xd5a79147,
+	0x06ca6351,
+	0x14292967,
+	0x27b70a85,
+	0x2e1b2138,
+	0x4d2c6dfc,
+	0x53380d13,
+	0x650a7354,
+	0x766a0abb,
+	0x81c2c92e,
+	0x92722c85,
+	0xa2bfe8a1,
+	0xa81a664b,
+	0xc24b8b70,
+	0xc76c51a3,
+	0xd192e819,
+	0xd6990624,
+	0xf40e3585,
+	0x106aa070,
+	0x19a4c116,
+	0x1e376c08,
+	0x2748774c,
+	0x34b0bcb5,
+	0x391c0cb3,
+	0x4ed8aa4a,
+	0x5b9cca4f,
+	0x682e6ff3,
+	0x748f82ee,
+	0x78a5636f,
+	0x84c87814,
+	0x8cc70208,
+	0x90befffa,
+	0xa4506ceb,
+	0xbef9a3f7,
+	0xc67178f2,
+}
+
+func _Block(dig *digest, p []byte) int {
+	var w [64]uint32;
+	n := 0;
+	h0, h1, h2, h3, h4, h5, h6, h7 := dig.h[0], dig.h[1], dig.h[2], dig.h[3], dig.h[4], dig.h[5], dig.h[6], dig.h[7];
+	for len(p) >= _Chunk {
+		// Can interlace the computation of w with the
+		// rounds below if needed for speed.
+		for i := 0; i < 16; i++ {
+			j := i * 4;
+			w[i] = uint32(p[j])<<24 | uint32(p[j+1])<<16 | uint32(p[j+2])<<8 | uint32(p[j+3]);
+		}
+		for i := 16; i < 64; i++ {
+			t1 := (w[i-2]>>17 | w[i-2]<<(32-17)) ^ (w[i-2]>>19 | w[i-2]<<(32-19)) ^ (w[i-2] >> 10);
+
+			t2 := (w[i-15]>>7 | w[i-15]<<(32-7)) ^ (w[i-15]>>18 | w[i-15]<<(32-18)) ^ (w[i-15] >> 3);
+
+			w[i] = t1 + w[i-7] + t2 + w[i-16];
+		}
+
+		a, b, c, d, e, f, g, h := h0, h1, h2, h3, h4, h5, h6, h7;
+
+		for i := 0; i < 64; i++ {
+			t1 := h + ((e>>6 | e<<(32-6)) ^ (e>>11 | e<<(32-11)) ^ (e>>25 | e<<(32-25))) + ((e & f) ^ (^e & g)) + _K[i] + w[i];
+
+			t2 := ((a>>2 | a<<(32-2)) ^ (a>>13 | a<<(32-13)) ^ (a>>22 | a<<(32-22))) + ((a & b) ^ (a & c) ^ (b & c));
+
+			h = g;
+			g = f;
+			f = e;
+			e = d + t1;
+			d = c;
+			c = b;
+			b = a;
+			a = t1 + t2;
+		}
+
+		h0 += a;
+		h1 += b;
+		h2 += c;
+		h3 += d;
+		h4 += e;
+		h5 += f;
+		h6 += g;
+		h7 += h;
+
+		p = p[_Chunk:];
+		n += _Chunk;
+	}
+
+	dig.h[0], dig.h[1], dig.h[2], dig.h[3], dig.h[4], dig.h[5], dig.h[6], dig.h[7] = h0, h1, h2, h3, h4, h5, h6, h7;
+	return n;
+}