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#
#
# The Nim Compiler
# (c) Copyright 2015 Nim Contributors
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
import strutils
const Sha1DigestSize = 20
type
Sha1Digest = array[0 .. Sha1DigestSize-1, uint8]
SecureHash* = distinct Sha1Digest
# Copyright (c) 2011, Micael Hildenborg
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# * Neither the name of Micael Hildenborg nor the
# names of its contributors may be used to endorse or promote products
# derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY Micael Hildenborg ''AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL Micael Hildenborg BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# Ported to Nim by Erik O'Leary
type
Sha1State* = array[0 .. 5-1, uint32]
Sha1Buffer = array[0 .. 80-1, uint32]
template clearBuffer(w: Sha1Buffer, len = 16) =
zeroMem(addr(w), len * sizeof(uint32))
proc init*(result: var Sha1State) =
result[0] = 0x67452301'u32
result[1] = 0xefcdab89'u32
result[2] = 0x98badcfe'u32
result[3] = 0x10325476'u32
result[4] = 0xc3d2e1f0'u32
proc innerHash(state: var Sha1State, w: var Sha1Buffer) =
var
a = state[0]
b = state[1]
c = state[2]
d = state[3]
e = state[4]
var round = 0
template rot(value, bits: uint32): uint32 =
(value shl bits) or (value shr (32u32 - bits))
template sha1(fun, val: uint32) =
let t = rot(a, 5) + fun + e + val + w[round]
e = d
d = c
c = rot(b, 30)
b = a
a = t
template process(body: untyped) =
w[round] = rot(w[round - 3] xor w[round - 8] xor w[round - 14] xor w[round - 16], 1)
body
inc(round)
template wrap(dest, value: untyped) =
let v = dest + value
dest = v
while round < 16:
sha1((b and c) or (not b and d), 0x5a827999'u32)
inc(round)
while round < 20:
process:
sha1((b and c) or (not b and d), 0x5a827999'u32)
while round < 40:
process:
sha1(b xor c xor d, 0x6ed9eba1'u32)
while round < 60:
process:
sha1((b and c) or (b and d) or (c and d), 0x8f1bbcdc'u32)
while round < 80:
process:
sha1(b xor c xor d, 0xca62c1d6'u32)
wrap state[0], a
wrap state[1], b
wrap state[2], c
wrap state[3], d
wrap state[4], e
proc sha1(src: cstring; len: int): Sha1Digest =
#Initialize state
var state: Sha1State
init(state)
#Create w buffer
var w: Sha1Buffer
#Loop through all complete 64byte blocks.
let byteLen = len
let endOfFullBlocks = byteLen - 64
var endCurrentBlock = 0
var currentBlock = 0
while currentBlock <= endOfFullBlocks:
endCurrentBlock = currentBlock + 64
var i = 0
while currentBlock < endCurrentBlock:
w[i] = uint32(src[currentBlock+3]) or
uint32(src[currentBlock+2]) shl 8'u32 or
uint32(src[currentBlock+1]) shl 16'u32 or
uint32(src[currentBlock]) shl 24'u32
currentBlock += 4
inc(i)
innerHash(state, w)
#Handle last and not full 64 byte block if existing
endCurrentBlock = byteLen - currentBlock
clearBuffer(w)
var lastBlockBytes = 0
while lastBlockBytes < endCurrentBlock:
var value = uint32(src[lastBlockBytes + currentBlock]) shl
((3'u32 - uint32(lastBlockBytes and 3)) shl 3)
w[lastBlockBytes shr 2] = w[lastBlockBytes shr 2] or value
inc(lastBlockBytes)
w[lastBlockBytes shr 2] = w[lastBlockBytes shr 2] or (
0x80'u32 shl ((3'u32 - uint32(lastBlockBytes and 3)) shl 3)
)
if endCurrentBlock >= 56:
innerHash(state, w)
clearBuffer(w)
w[15] = uint32(byteLen) shl 3
innerHash(state, w)
# Store hash in result pointer, and make sure we get in in the correct order
# on both endian models.
for i in 0 .. Sha1DigestSize-1:
result[i] = uint8((int(state[i shr 2]) shr ((3-(i and 3)) * 8)) and 255)
proc sha1(src: string): Sha1Digest =
## Calculate SHA1 from input string
sha1(src, src.len)
proc secureHash*(str: string): SecureHash = SecureHash(sha1(str))
proc secureHashFile*(filename: string): SecureHash = secureHash(readFile(filename))
proc `$`*(self: SecureHash): string =
result = ""
for v in Sha1Digest(self):
result.add(toHex(int(v), 2))
proc parseSecureHash*(hash: string): SecureHash =
for i in 0 ..< Sha1DigestSize:
Sha1Digest(result)[i] = uint8(parseHexInt(hash[i*2] & hash[i*2 + 1]))
proc `==`*(a, b: SecureHash): bool =
# Not a constant-time comparison, but that's acceptable in this context
Sha1Digest(a) == Sha1Digest(b)
when isMainModule:
let hash1 = secureHash("a93tgj0p34jagp9[agjp98ajrhp9aej]")
doAssert hash1 == hash1
doAssert parseSecureHash($hash1) == hash1
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