v/vlib/crypto/sha1/sha1block.v

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2019-07-15 17:49:01 +02:00
module sha1
import math.bits
const (
_K0 = 0x5A827999
_K1 = 0x6ED9EBA1
_K2 = 0x8F1BBCDC
_K3 = 0xCA62C1D6
)
fn block(dig &Digest, p []byte) {
mut w := [u32(0); 16]
mut h0 := dig.h[0]
mut h1 := dig.h[1]
mut h2 := dig.h[2]
mut h3 := dig.h[3]
mut h4 := dig.h[4]
for p.len >= 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] = u32(u32(p[j])<<u32(24)) | u32(u32(p[j+1])<<u32(16)) | u32(u32(p[j+2])<<u32(8)) | u32(u32(p[j+3]))
}
mut a := h0
mut b := h1
mut c := h2
mut d := h3
mut e := h4
// Each of the four 20-iteration rounds
// differs only in the computation of f and
// the choice of K (_K0, _K1, etc).
mut i := 0
for i < 16 {
f := u32(b&c | (~b)&d)
t := bits.rotate_left_32(a, 5) + f + e + w[i&0xf] + u32(_K0)
e = d
d = c
c = bits.rotate_left_32(b, 30)
b = a
a = t
i++
}
for i < 20 {
tmp := w[(i-3)&0xf] ^ w[(i-8)&0xf] ^ w[(i-14)&0xf] ^ w[(i)&0xf]
w[i&0xf] = u32(tmp<<u32(1)) | u32(tmp>>u32(32-1))
f := b&c | (~b)&d
t := bits.rotate_left_32(a, 5) + f + e + w[i&0xf] + u32(_K0)
e = d
d = c
c = bits.rotate_left_32(b, 30)
b = a
a = t
i++
}
for i < 40 {
tmp := w[(i-3)&0xf] ^ w[(i-8)&0xf] ^ w[(i-14)&0xf] ^ w[(i)&0xf]
w[i&0xf] = u32(tmp<<u32(1)) | u32(tmp>>u32(32-1))
f := b ^ c ^ d
t := bits.rotate_left_32(a, 5) + f + e + w[i&0xf] + u32(_K1)
e = d
d = c
c = bits.rotate_left_32(b, 30)
b = a
a = t
i++
}
for i < 60 {
tmp := w[(i-3)&0xf] ^ w[(i-8)&0xf] ^ w[(i-14)&0xf] ^ w[(i)&0xf]
w[i&0xf] = u32(tmp<<u32(1)) | u32(tmp>>u32(32-1))
f := ((b | c) & d) | (b & c)
t := bits.rotate_left_32(a, 5) + f + e + w[i&0xf] + u32(_K2)
e = d
d = c
c = bits.rotate_left_32(b, 30)
b = a
a = t
i++
}
for i < 80 {
tmp := w[(i-3)&0xf] ^ w[(i-8)&0xf] ^ w[(i-14)&0xf] ^ w[(i)&0xf]
w[i&0xf] = u32(tmp<<u32(1)) | u32(tmp>>u32(32-1))
f := b ^ c ^ d
t := bits.rotate_left_32(a, 5) + f + e + w[i&0xf] + u32(_K3)
e = d
d = c
c = bits.rotate_left_32(b, 30)
b = a
a = t
i++
}
h0 += a
h1 += b
h2 += c
h3 += d
h4 += e
if Chunk >= p.len {
p = []byte
} else {
p = p.right(Chunk)
}
}
dig.h[0] = h0
dig.h[1] = h1
dig.h[2] = h2
dig.h[3] = h3
dig.h[4] = h4
}