diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/blowfish/block.go')
| -rw-r--r-- | vendor/golang.org/x/crypto/blowfish/block.go | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/blowfish/block.go b/vendor/golang.org/x/crypto/blowfish/block.go new file mode 100644 index 0000000..9d80f19 --- /dev/null +++ b/vendor/golang.org/x/crypto/blowfish/block.go @@ -0,0 +1,159 @@ +// Copyright 2010 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. + +package blowfish + +// getNextWord returns the next big-endian uint32 value from the byte slice +// at the given position in a circular manner, updating the position. +func getNextWord(b []byte, pos *int) uint32 { + var w uint32 + j := *pos + for i := 0; i < 4; i++ { + w = w<<8 | uint32(b[j]) + j++ + if j >= len(b) { + j = 0 + } + } + *pos = j + return w +} + +// ExpandKey performs a key expansion on the given *Cipher. Specifically, it +// performs the Blowfish algorithm's key schedule which sets up the *Cipher's +// pi and substitution tables for calls to Encrypt. This is used, primarily, +// by the bcrypt package to reuse the Blowfish key schedule during its +// set up. It's unlikely that you need to use this directly. +func ExpandKey(key []byte, c *Cipher) { + j := 0 + for i := 0; i < 18; i++ { + // Using inlined getNextWord for performance. + var d uint32 + for k := 0; k < 4; k++ { + d = d<<8 | uint32(key[j]) + j++ + if j >= len(key) { + j = 0 + } + } + c.p[i] ^= d + } + + var l, r uint32 + for i := 0; i < 18; i += 2 { + l, r = encryptBlock(l, r, c) + c.p[i], c.p[i+1] = l, r + } + + for i := 0; i < 256; i += 2 { + l, r = encryptBlock(l, r, c) + c.s0[i], c.s0[i+1] = l, r + } + for i := 0; i < 256; i += 2 { + l, r = encryptBlock(l, r, c) + c.s1[i], c.s1[i+1] = l, r + } + for i := 0; i < 256; i += 2 { + l, r = encryptBlock(l, r, c) + c.s2[i], c.s2[i+1] = l, r + } + for i := 0; i < 256; i += 2 { + l, r = encryptBlock(l, r, c) + c.s3[i], c.s3[i+1] = l, r + } +} + +// This is similar to ExpandKey, but folds the salt during the key +// schedule. While ExpandKey is essentially expandKeyWithSalt with an all-zero +// salt passed in, reusing ExpandKey turns out to be a place of inefficiency +// and specializing it here is useful. +func expandKeyWithSalt(key []byte, salt []byte, c *Cipher) { + j := 0 + for i := 0; i < 18; i++ { + c.p[i] ^= getNextWord(key, &j) + } + + j = 0 + var l, r uint32 + for i := 0; i < 18; i += 2 { + l ^= getNextWord(salt, &j) + r ^= getNextWord(salt, &j) + l, r = encryptBlock(l, r, c) + c.p[i], c.p[i+1] = l, r + } + + for i := 0; i < 256; i += 2 { + l ^= getNextWord(salt, &j) + r ^= getNextWord(salt, &j) + l, r = encryptBlock(l, r, c) + c.s0[i], c.s0[i+1] = l, r + } + + for i := 0; i < 256; i += 2 { + l ^= getNextWord(salt, &j) + r ^= getNextWord(salt, &j) + l, r = encryptBlock(l, r, c) + c.s1[i], c.s1[i+1] = l, r + } + + for i := 0; i < 256; i += 2 { + l ^= getNextWord(salt, &j) + r ^= getNextWord(salt, &j) + l, r = encryptBlock(l, r, c) + c.s2[i], c.s2[i+1] = l, r + } + + for i := 0; i < 256; i += 2 { + l ^= getNextWord(salt, &j) + r ^= getNextWord(salt, &j) + l, r = encryptBlock(l, r, c) + c.s3[i], c.s3[i+1] = l, r + } +} + +func encryptBlock(l, r uint32, c *Cipher) (uint32, uint32) { + xl, xr := l, r + xl ^= c.p[0] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[1] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[2] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[3] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[4] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[5] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[6] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[7] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[8] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[9] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[10] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[11] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[12] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[13] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[14] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[15] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[16] + xr ^= c.p[17] + return xr, xl +} + +func decryptBlock(l, r uint32, c *Cipher) (uint32, uint32) { + xl, xr := l, r + xl ^= c.p[17] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[16] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[15] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[14] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[13] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[12] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[11] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[10] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[9] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[8] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[7] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[6] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[5] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[4] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[3] + xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[2] + xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[1] + xr ^= c.p[0] + return xr, xl +} |