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v/vlib/crypto/sha1/sha1.v
2022-01-04 12:21:12 +03:00

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// Copyright (c) 2019-2022 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
// Package sha1 implements the SHA-1 hash algorithm as defined in RFC 3174.
// SHA-1 is cryptographically broken and should not be used for secure
// applications.
// Based off: https://github.com/golang/go/blob/master/src/crypto/sha1
// Last commit: https://github.com/golang/go/commit/3ce865d7a0b88714cc433454ae2370a105210c01
module sha1
import encoding.binary
pub const (
// The size of a SHA-1 checksum in bytes.
size = 20
// The blocksize of SHA-1 in bytes.
block_size = 64
)
const (
chunk = 64
init0 = 0x67452301
init1 = 0xEFCDAB89
init2 = 0x98BADCFE
init3 = 0x10325476
init4 = 0xC3D2E1F0
)
// digest represents the partial evaluation of a checksum.
struct Digest {
mut:
h []u32
x []byte
nx int
len u64
}
fn (mut d Digest) reset() {
d.x = []byte{len: sha1.chunk}
d.h = []u32{len: (5)}
d.h[0] = u32(sha1.init0)
d.h[1] = u32(sha1.init1)
d.h[2] = u32(sha1.init2)
d.h[3] = u32(sha1.init3)
d.h[4] = u32(sha1.init4)
d.nx = 0
d.len = 0
}
// new returns a new Digest (implementing hash.Hash) computing the SHA1 checksum.
pub fn new() &Digest {
mut d := &Digest{}
d.reset()
return d
}
// write writes the contents of `p_` to the internal hash representation.
[manualfree]
pub fn (mut d Digest) write(p_ []byte) ?int {
nn := p_.len
unsafe {
mut p := p_
d.len += u64(nn)
if d.nx > 0 {
n := copy(d.x[d.nx..], p)
d.nx += n
if d.nx == sha1.chunk {
block(mut d, d.x)
d.nx = 0
}
if n >= p.len {
p = []
} else {
p = p[n..]
}
}
if p.len >= sha1.chunk {
n := p.len & ~(sha1.chunk - 1)
block(mut d, p[..n])
if n >= p.len {
p = []
} else {
p = p[n..]
}
}
if p.len > 0 {
d.nx = copy(d.x, p)
}
}
return nn
}
// sum returns a copy of the generated sum of the bytes in `b_in`.
pub fn (d &Digest) sum(b_in []byte) []byte {
// Make a copy of d so that caller can keep writing and summing.
mut d0 := *d
hash := d0.checksum()
mut b_out := b_in.clone()
for b in hash {
b_out << b
}
return b_out
}
// checksum returns the byte checksum of the `Digest`.
fn (mut d Digest) checksum() []byte {
mut len := d.len
// Padding. Add a 1 bit and 0 bits until 56 bytes mod 64.
mut tmp := []byte{len: (64)}
tmp[0] = 0x80
if int(len) % 64 < 56 {
d.write(tmp[..56 - int(len) % 64]) or { panic(err) }
} else {
d.write(tmp[..64 + 56 - int(len) % 64]) or { panic(err) }
}
// Length in bits.
len <<= 3
binary.big_endian_put_u64(mut tmp, len)
d.write(tmp[..8]) or { panic(err) }
mut digest := []byte{len: sha1.size}
binary.big_endian_put_u32(mut digest, d.h[0])
binary.big_endian_put_u32(mut digest[4..], d.h[1])
binary.big_endian_put_u32(mut digest[8..], d.h[2])
binary.big_endian_put_u32(mut digest[12..], d.h[3])
binary.big_endian_put_u32(mut digest[16..], d.h[4])
return digest
}
// sum returns the SHA-1 checksum of the bytes passed in `data`.
pub fn sum(data []byte) []byte {
mut d := new()
d.write(data) or { panic(err) }
return d.checksum()
}
fn block(mut dig Digest, p []byte) {
// For now just use block_generic until we have specific
// architecture optimized versions
block_generic(mut dig, p)
}
// size returns the size of the checksum in bytes.
pub fn (d &Digest) size() int {
return sha1.size
}
// block_size returns the block size of the checksum in bytes.
pub fn (d &Digest) block_size() int {
return sha1.block_size
}
// hexhash returns a hexadecimal SHA1 hash sum `string` of `s`.
pub fn hexhash(s string) string {
return sum(s.bytes()).hex()
}