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v/vlib/crypto/sha256/sha256.v
2022-04-15 15:35:35 +03:00

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V

// 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 sha256 implements the SHA224 and SHA256 hash algorithms as defined
// in FIPS 180-4.
// Based off: https://github.com/golang/go/tree/master/src/crypto/sha256
// Last commit: https://github.com/golang/go/commit/3ce865d7a0b88714cc433454ae2370a105210c01
module sha256
import encoding.binary
pub const (
// The size of a SHA256 checksum in bytes.
size = 32
// The size of a SHA224 checksum in bytes.
size224 = 28
// The blocksize of SHA256 and SHA224 in bytes.
block_size = 64
)
const (
chunk = 64
init0 = 0x6A09E667
init1 = 0xBB67AE85
init2 = 0x3C6EF372
init3 = 0xA54FF53A
init4 = 0x510E527F
init5 = 0x9B05688C
init6 = 0x1F83D9AB
init7 = 0x5BE0CD19
init0_224 = 0xC1059ED8
init1_224 = 0x367CD507
init2_224 = 0x3070DD17
init3_224 = 0xF70E5939
init4_224 = 0xFFC00B31
init5_224 = 0x68581511
init6_224 = 0x64F98FA7
init7_224 = 0xBEFA4FA4
)
// digest represents the partial evaluation of a checksum.
struct Digest {
mut:
h []u32
x []u8
nx int
len u64
is224 bool // mark if this digest is SHA-224
}
fn (mut d Digest) reset() {
d.h = []u32{len: (8)}
d.x = []u8{len: sha256.chunk}
if !d.is224 {
d.h[0] = u32(sha256.init0)
d.h[1] = u32(sha256.init1)
d.h[2] = u32(sha256.init2)
d.h[3] = u32(sha256.init3)
d.h[4] = u32(sha256.init4)
d.h[5] = u32(sha256.init5)
d.h[6] = u32(sha256.init6)
d.h[7] = u32(sha256.init7)
} else {
d.h[0] = u32(sha256.init0_224)
d.h[1] = u32(sha256.init1_224)
d.h[2] = u32(sha256.init2_224)
d.h[3] = u32(sha256.init3_224)
d.h[4] = u32(sha256.init4_224)
d.h[5] = u32(sha256.init5_224)
d.h[6] = u32(sha256.init6_224)
d.h[7] = u32(sha256.init7_224)
}
d.nx = 0
d.len = 0
}
// new returns a new Digest (implementing hash.Hash) computing the SHA256 checksum.
pub fn new() &Digest {
mut d := &Digest{}
d.reset()
return d
}
// new224 returns a new Digest (implementing hash.Hash) computing the SHA224 checksum.
pub fn new224() &Digest {
mut d := &Digest{}
d.is224 = true
d.reset()
return d
}
// write writes the contents of `p_` to the internal hash representation.
pub fn (mut d Digest) write(p_ []u8) ?int {
unsafe {
mut p := p_
nn := p.len
d.len += u64(nn)
if d.nx > 0 {
n := copy(mut d.x[d.nx..], p)
d.nx += n
if d.nx == sha256.chunk {
block(mut d, d.x)
d.nx = 0
}
if n >= p.len {
p = []
} else {
p = p[n..]
}
}
if p.len >= sha256.chunk {
n := p.len & ~(sha256.chunk - 1)
block(mut d, p[..n])
if n >= p.len {
p = []
} else {
p = p[n..]
}
}
if p.len > 0 {
d.nx = copy(mut d.x, p)
}
return nn
}
}
// sum returns the SHA256 or SHA224 checksum of digest with the data.
pub fn (d &Digest) sum(b_in []u8) []u8 {
// 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()
if d0.is224 {
for b in hash[..sha256.size224] {
b_out << b
}
} else {
for b in hash {
b_out << b
}
}
return b_out
}
// checksum returns the current byte checksum of the Digest.
pub fn (mut d Digest) checksum() []u8 {
mut len := d.len
// Padding. Add a 1 bit and 0 bits until 56 bytes mod 64.
mut tmp := []u8{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 <<= u64(3)
binary.big_endian_put_u64(mut tmp, len)
d.write(tmp[..8]) or { panic(err) }
if d.nx != 0 {
panic('d.nx != 0')
}
mut digest := []u8{len: sha256.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])
binary.big_endian_put_u32(mut digest[20..], d.h[5])
binary.big_endian_put_u32(mut digest[24..], d.h[6])
if !d.is224 {
binary.big_endian_put_u32(mut digest[28..], d.h[7])
}
return digest
}
// sum returns the SHA256 checksum of the bytes in `data`.
// Example: assert sha256.sum('V'.bytes()).len > 0 == true
pub fn sum(data []u8) []u8 {
return sum256(data)
}
// sum256 returns the SHA256 checksum of the data.
pub fn sum256(data []u8) []u8 {
mut d := new()
d.write(data) or { panic(err) }
return d.checksum()
}
// sum224 returns the SHA224 checksum of the data.
pub fn sum224(data []u8) []u8 {
mut d := new224()
d.write(data) or { panic(err) }
sum := d.checksum()
mut sum224 := []u8{len: sha256.size224}
copy(mut sum224, sum[..sha256.size224])
return sum224
}
fn block(mut dig Digest, p []u8) {
// 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 {
if !d.is224 {
return sha256.size
}
return sha256.size224
}
// block_size returns the block size of the checksum in bytes.
pub fn (d &Digest) block_size() int {
return sha256.block_size
}
// hexhash returns a hexadecimal SHA256 hash sum `string` of `s`.
// Example: assert sha256.hexhash('V') == 'de5a6f78116eca62d7fc5ce159d23ae6b889b365a1739ad2cf36f925a140d0cc'
pub fn hexhash(s string) string {
return sum256(s.bytes()).hex()
}
// hexhash_224 returns a hexadecimal SHA224 hash sum `string` of `s`.
pub fn hexhash_224(s string) string {
return sum224(s.bytes()).hex()
}