v/vlib/crypto/blowfish/block.v

149 lines
4.5 KiB
V

module blowfish
// expand_key performs a key expansion on the given Blowfish cipher.
pub fn expand_key(key []byte, mut bf Blowfish) {
mut j := 0
for i := 0; i < 18; i++ {
mut d := u32(0)
for k := 0; k < 4; k++ {
d = d << 8 | u32(key[j])
j++
if j >= key.len {
j = 0
}
}
bf.p[i] ^= d
}
mut l := u32(0)
mut r := u32(0)
for i := 0; i < 18; i += 2 {
arr := setup_tables(l, r, mut bf)
bf.p[i], bf.p[i + 1] = arr[0], arr[1]
}
for i := 0; i < 256; i += 2 {
arr := setup_tables(l, r, mut bf)
bf.s[0][i], bf.s[0][i + 1] = arr[0], arr[1]
}
for i := 0; i < 256; i += 2 {
arr := setup_tables(l, r, mut bf)
bf.s[1][i], bf.s[1][i + 1] = arr[0], arr[1]
}
for i := 0; i < 256; i += 2 {
arr := setup_tables(l, r, mut bf)
bf.s[2][i], bf.s[2][i + 1] = arr[0], arr[1]
}
for i := 0; i < 256; i += 2 {
arr := setup_tables(l, r, mut bf)
bf.s[3][i], bf.s[3][i + 1] = arr[0], arr[1]
}
}
// expand_key_with_salt using salt to expand the key.
pub fn expand_key_with_salt(key []byte, salt []byte, mut bf Blowfish) {
mut j := 0
for i := 0; i < 18; i++ {
bf.p[i] ^= get_next_word(key, &j)
}
j = 0
mut l := u32(0)
mut r := u32(0)
for i := 0; i < 18; i += 2 {
l ^= get_next_word(key, &j)
r ^= get_next_word(key, &j)
arr := setup_tables(l, r, mut bf)
bf.p[i], bf.p[i + 1] = arr[0], arr[1]
}
for i := 0; i < 256; i += 2 {
l ^= get_next_word(key, &j)
r ^= get_next_word(key, &j)
arr := setup_tables(l, r, mut bf)
bf.s[0][i], bf.s[0][i + 1] = arr[0], arr[1]
}
for i := 0; i < 256; i += 2 {
l ^= get_next_word(key, &j)
r ^= get_next_word(key, &j)
arr := setup_tables(l, r, mut bf)
bf.s[1][i], bf.s[1][i + 1] = arr[0], arr[1]
}
for i := 0; i < 256; i += 2 {
l ^= get_next_word(key, &j)
r ^= get_next_word(key, &j)
arr := setup_tables(l, r, mut bf)
bf.s[2][i], bf.s[2][i + 1] = arr[0], arr[1]
}
for i := 0; i < 256; i += 2 {
l ^= get_next_word(key, &j)
r ^= get_next_word(key, &j)
arr := setup_tables(l, r, mut bf)
bf.s[3][i], bf.s[3][i + 1] = arr[0], arr[1]
}
}
// setup_tables sets up the Blowfish cipher's pi and substitution tables.
fn setup_tables(l u32, r u32, mut bf Blowfish) []u32 {
mut xl := l
mut xr := r
xl ^= bf.p[0]
xr ^= ((bf.s[0][byte(xl >> 24)] + bf.s[1][byte(xl >> 16)]) ^ bf.s[2][byte(xl >> 8)]) +
(bf.s[3][byte(xl)] ^ bf.p[1])
xl ^= ((bf.s[0][byte(xr >> 24)] + bf.s[1][byte(xr >> 16)]) ^ bf.s[2][byte(xr >> 8)]) +
(bf.s[3][byte(xr)] ^ bf.p[2])
xr ^= ((bf.s[0][byte(xl >> 24)] + bf.s[1][byte(xl >> 16)]) ^ bf.s[2][byte(xl >> 8)]) +
(bf.s[3][byte(xl)] ^ bf.p[3])
xl ^= ((bf.s[0][byte(xr >> 24)] + bf.s[1][byte(xr >> 16)]) ^ bf.s[2][byte(xr >> 8)]) +
(bf.s[3][byte(xr)] ^ bf.p[4])
xr ^= ((bf.s[0][byte(xl >> 24)] + bf.s[1][byte(xl >> 16)]) ^ bf.s[2][byte(xl >> 8)]) +
(bf.s[3][byte(xl)] ^ bf.p[5])
xl ^= ((bf.s[0][byte(xr >> 24)] + bf.s[1][byte(xr >> 16)]) ^ bf.s[2][byte(xr >> 8)]) +
(bf.s[3][byte(xr)] ^ bf.p[6])
xr ^= ((bf.s[0][byte(xl >> 24)] + bf.s[1][byte(xl >> 16)]) ^ bf.s[2][byte(xl >> 8)]) +
(bf.s[3][byte(xl)] ^ bf.p[7])
xl ^= ((bf.s[0][byte(xr >> 24)] + bf.s[1][byte(xr >> 16)]) ^ bf.s[2][byte(xr >> 8)]) +
(bf.s[3][byte(xr)] ^ bf.p[8])
xr ^= ((bf.s[0][byte(xl >> 24)] + bf.s[1][byte(xl >> 16)]) ^ bf.s[2][byte(xl >> 8)]) +
(bf.s[3][byte(xl)] ^ bf.p[9])
xl ^= ((bf.s[0][byte(xr >> 24)] + bf.s[1][byte(xr >> 16)]) ^ bf.s[2][byte(xr >> 8)]) +
(bf.s[3][byte(xr)] ^ bf.p[10])
xr ^= ((bf.s[0][byte(xl >> 24)] + bf.s[1][byte(xl >> 16)]) ^ bf.s[2][byte(xl >> 8)]) +
(bf.s[3][byte(xl)] ^ bf.p[11])
xl ^= ((bf.s[0][byte(xr >> 24)] + bf.s[1][byte(xr >> 16)]) ^ bf.s[2][byte(xr >> 8)]) +
(bf.s[3][byte(xr)] ^ bf.p[12])
xr ^= ((bf.s[0][byte(xl >> 24)] + bf.s[1][byte(xl >> 16)]) ^ bf.s[2][byte(xl >> 8)]) +
(bf.s[3][byte(xl)] ^ bf.p[13])
xl ^= ((bf.s[0][byte(xr >> 24)] + bf.s[1][byte(xr >> 16)]) ^ bf.s[2][byte(xr >> 8)]) +
(bf.s[3][byte(xr)] ^ bf.p[14])
xr ^= ((bf.s[0][byte(xl >> 24)] + bf.s[1][byte(xl >> 16)]) ^ bf.s[2][byte(xl >> 8)]) +
(bf.s[3][byte(xl)] ^ bf.p[15])
xl ^= ((bf.s[0][byte(xr >> 24)] + bf.s[1][byte(xr >> 16)]) ^ bf.s[2][byte(xr >> 8)]) +
(bf.s[3][byte(xr)] ^ bf.p[16])
xr ^= bf.p[17]
res := [xl, xr]
return res
}
// get_next_word returns the next big-endian u32 value from the byte
// slice at the given position in a circular manner, updating the position.
fn get_next_word(b []byte, pos &int) u32 {
mut w := u32(0)
mut j := 0
unsafe {
j = *pos
}
for i := 0; i < 4; i++ {
w = w << 8 | u32(b[j])
j++
if j >= b.len {
j = 0
}
}
unsafe {
*pos = j
}
return w
}