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author | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
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committer | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
commit | 554fd8c5195424bdbcabf5de30fdc183aba391bd (patch) | |
tree | 976dc5ab7fddf506dadce60ae936f43f58787092 /libgo/go/crypto/sha256/sha256.go | |
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Diffstat (limited to 'libgo/go/crypto/sha256/sha256.go')
-rw-r--r-- | libgo/go/crypto/sha256/sha256.go | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/libgo/go/crypto/sha256/sha256.go b/libgo/go/crypto/sha256/sha256.go new file mode 100644 index 000000000..57a8ffa0d --- /dev/null +++ b/libgo/go/crypto/sha256/sha256.go @@ -0,0 +1,159 @@ +// 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 SHA224 and SHA256 hash algorithms as defined in FIPS 180-2. +package sha256 + +import ( + "hash" + "os" +) + +// The size of a SHA256 checksum in bytes. +const Size = 32 + +// The size of a SHA224 checksum in bytes. +const Size224 = 28 + +const ( + _Chunk = 64 + _Init0 = 0x6A09E667 + _Init1 = 0xBB67AE85 + _Init2 = 0x3C6EF372 + _Init3 = 0xA54FF53A + _Init4 = 0x510E527F + _Init5 = 0x9B05688C + _Init6 = 0x1F83D9AB + _Init7 = 0x5BE0CD19 + _Init0_224 = 0xC1059ED8 + _Init1_224 = 0x367CD507 + _Init2_224 = 0x3070DD17 + _Init3_224 = 0xF70E5939 + _Init4_224 = 0xFFC00B31 + _Init5_224 = 0x68581511 + _Init6_224 = 0x64F98FA7 + _Init7_224 = 0xBEFA4FA4 +) + +// digest represents the partial evaluation of a checksum. +type digest struct { + h [8]uint32 + x [_Chunk]byte + nx int + len uint64 + is224 bool // mark if this digest is SHA-224 +} + +func (d *digest) Reset() { + if !d.is224 { + 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 + } else { + d.h[0] = _Init0_224 + d.h[1] = _Init1_224 + d.h[2] = _Init2_224 + d.h[3] = _Init3_224 + d.h[4] = _Init4_224 + d.h[5] = _Init5_224 + d.h[6] = _Init6_224 + d.h[7] = _Init7_224 + } + 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 +} + +// New224 returns a new hash.Hash computing the SHA224 checksum. +func New224() hash.Hash { + d := new(digest) + d.is224 = true + d.Reset() + return d +} + +func (d *digest) Size() int { + if !d.is224 { + return Size + } + return Size224 +} + +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[0:]) + d.nx = 0 + } + p = p[n:] + } + n := _Block(d, p) + p = p[n:] + if len(p) > 0 { + d.nx = copy(d.x[:], p) + } + return +} + +func (d0 *digest) Sum() []byte { + // Make a copy of d0 so that caller can keep writing and summing. + d := new(digest) + *d = *d0 + + // 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 { + panic("d.nx != 0") + } + + p := make([]byte, 32) + j := 0 + for _, s := range d.h { + p[j+0] = byte(s >> 24) + p[j+1] = byte(s >> 16) + p[j+2] = byte(s >> 8) + p[j+3] = byte(s >> 0) + j += 4 + } + if d.is224 { + return p[0:28] + } + return p +} |