mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2025-11-04 06:02:26 -06:00
160 lines
6 KiB
Go
160 lines
6 KiB
Go
|
// 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
|
||
|
|
}
|