#
#
# Nimrod's Runtime Library
# (c) Copyright 2010 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
## Module for computing MD5 checksums.
type
MD5State = array[0..3, int32]
MD5Block = array[0..15, int32]
MD5CBits = array[0..7, int8]
MD5Digest* = array[0..15, int8]
MD5Buffer = array[0..63, int8]
MD5Context* {.final.} = object
State: MD5State
Count: array[0..1, int32]
Buffer: MD5Buffer
const
padding: cstring = "\x80\0\0\0" &
"\0\0\0\0\0\0\0\0" &
"\0\0\0\0\0\0\0\0" &
"\0\0\0\0\0\0\0\0" &
"\0\0\0\0\0\0\0\0" &
"\0\0\0\0\0\0\0\0" &
"\0\0\0\0\0\0\0\0" &
"\0\0\0\0\0\0\0\0" &
"\0\0\0\0"
proc F(x, y, z: int32): int32 {.inline.} =
Result = (x and y) or ((not x) and z)
proc G(x, y, z: int32): int32 {.inline.} =
Result = (x and z) or (y and (not z))
proc H(x, y, z: int32): int32 {.inline.} =
Result = x xor y xor z
proc I(x, y, z: int32): int32 {.inline.} =
Result = y xor (x or (not z))
proc rot(x: var int32, n: int8) {.inline.} =
x = toU32(x shl ze(n)) or (x shr toU32(32 -% ze(n)))
proc FF(a: var int32, b, c, d, x: int32, s: int8, ac: int32) =
a = a +% F(b, c, d) +% x +% ac
rot(a, s)
a = a +% b
proc GG(a: var int32, b, c, d, x: int32, s: int8, ac: int32) =
a = a +% G(b, c, d) +% x +% ac
rot(a, s)
a = a +% b
proc HH(a: var int32, b, c, d, x: int32, s: int8, ac: int32) =
a = a +% H(b, c, d) +% x +% ac
rot(a, s)
a = a +% b
proc II(a: var int32, b, c, d, x: int32, s: int8, ac: int32) =
a = a +% I(b, c, d) +% x +% ac
rot(a, s)
a = a +% b
proc encode(dest: var MD5Block, src: cstring) =
var j = 0
for i in 0..high(dest):
dest[i] = toU32(ord(src[j]) or
ord(src[j+1]) shl 8 or
ord(src[j+2]) shl 16 or
ord(src[j+3]) shl 24)
inc(j, 4)
proc decode(dest: var openarray[int8], src: openarray[int32]) =
var i = 0
for j in 0..high(src):
dest[i] = toU8(src[j] and 0xff'i32)
dest[i+1] = toU8(src[j] shr 8'i32 and 0xff'i32)
dest[i+2] = toU8(src[j] shr 16'i32 and 0xff'i32)
dest[i+3] = toU8(src[j] shr 24'i32 and 0xff'i32)
inc(i, 4)
proc transform(Buffer: pointer, State: var MD5State) =
var
myBlock: MD5Block
encode(myBlock, cast[cstring](buffer))
var a = State[0]
var b = State[1]
var c = State[2]
var d = State[3]
FF(a, b, c, d, myBlock[0], 7'i8, 0xD76AA478'i32)
FF(d, a, b, c, myBlock[1], 12'i8, 0xE8C7B756'i32)
FF(c, d, a, b, myBlock[2], 17'i8, 0x242070DB'i32)
FF(b, c, d, a, myBlock[3], 22'i8, 0xC1BDCEEE'i32)
FF(a, b, c, d, myBlock[4], 7'i8, 0xF57C0FAF'i32)
FF(d, a, b, c, myBlock[5], 12'i8, 0x4787C62A'i32)
FF(c, d, a, b, myBlock[6], 17'i8, 0xA8304613'i32)
FF(b, c, d, a, myBlock[7], 22'i8, 0xFD469501'i32)
FF(a, b, c, d, myBlock[8], 7'i8, 0x698098D8'i32)
FF(d, a, b, c, myBlock[9], 12'i8, 0x8B44F7AF'i32)
FF(c, d, a, b, myBlock[10], 17'i8, 0xFFFF5BB1'i32)
FF(b, c, d, a, myBlock[11], 22'i8, 0x895CD7BE'i32)
FF(a, b, c, d, myBlock[12], 7'i8, 0x6B901122'i32)
FF(d, a, b, c, myBlock[13], 12'i8, 0xFD987193'i32)
FF(c, d, a, b, myBlock[14], 17'i8, 0xA679438E'i32)
FF(b, c, d, a, myBlock[15], 22'i8, 0x49B40821'i32)
GG(a, b, c, d, myBlock[1], 5'i8, 0xF61E2562'i32)
GG(d, a, b, c, myBlock[6], 9'i8, 0xC040B340'i32)
GG(c, d, a, b, myBlock[11], 14'i8, 0x265E5A51'i32)
GG(b, c, d, a, myBlock[0], 20'i8, 0xE9B6C7AA'i32)
GG(a, b, c, d, myBlock[5], 5'i8, 0xD62F105D'i32)
GG(d, a, b, c, myBlock[10], 9'i8, 0x02441453'i32)
GG(c, d, a, b, myBlock[15], 14'i8, 0xD8A1E681'i32)
GG(b, c, d, a, myBlock[4], 20'i8, 0xE7D3FBC8'i32)
GG(a, b, c, d, myBlock[9], 5'i8, 0x21E1CDE6'i32)
GG(d, a, b, c, myBlock[14], 9'i8, 0xC33707D6'i32)
GG(c, d, a, b, myBlock[3], 14'i8, 0xF4D50D87'i32)
GG(b, c, d, a, myBlock[8], 20'i8, 0x455A14ED'i32)
GG(a, b, c, d, myBlock[13], 5'i8, 0xA9E3E905'i32)
GG(d, a, b, c, myBlock[2], 9'i8, 0xFCEFA3F8'i32)
GG(c, d, a, b, myBlock[7], 14'i8, 0x676F02D9'i32)
GG(b, c, d, a, myBlock[12], 20'i8, 0x8D2A4C8A'i32)
HH(a, b, c, d, myBlock[5], 4'i8, 0xFFFA3942'i32)
HH(d, a, b, c, myBlock[8], 11'i8, 0x8771F681'i32)
HH(c, d, a, b, myBlock[11], 16'i8, 0x6D9D6122'i32)
HH(b, c, d, a, myBlock[14], 23'i8, 0xFDE5380C'i32)
HH(a, b, c, d, myBlock[1], 4'i8, 0xA4BEEA44'i32)
HH(d, a, b, c, myBlock[4], 11'i8, 0x4BDECFA9'i32)
HH(c, d, a, b, myBlock[7], 16'i8, 0xF6BB4B60'i32)
HH(b, c, d, a, myBlock[10], 23'i8, 0xBEBFBC70'i32)
HH(a, b, c, d, myBlock[13], 4'i8, 0x289B7EC6'i32)
HH(d, a, b, c, myBlock[0], 11'i8, 0xEAA127FA'i32)
HH(c, d, a, b, myBlock[3], 16'i8, 0xD4EF3085'i32)
HH(b, c, d, a, myBlock[6], 23'i8, 0x04881D05'i32)
HH(a, b, c, d, myBlock[9], 4'i8, 0xD9D4D039'i32)
HH(d, a, b, c, myBlock[12], 11'i8, 0xE6DB99E5'i32)
HH(c, d, a, b, myBlock[15], 16'i8, 0x1FA27CF8'i32)
HH(b, c, d, a, myBlock[2], 23'i8, 0xC4AC5665'i32)
II(a, b, c, d, myBlock[0], 6'i8, 0xF4292244'i32)
II(d, a, b, c, myBlock[7], 10'i8, 0x432AFF97'i32)
II(c, d, a, b, myBlock[14], 15'i8, 0xAB9423A7'i32)
II(b, c, d, a, myBlock[5], 21'i8, 0xFC93A039'i32)
II(a, b, c, d, myBlock[12], 6'i8, 0x655B59C3'i32)
II(d, a, b, c, myBlock[3], 10'i8, 0x8F0CCC92'i32)
II(c, d, a, b, myBlock[10], 15'i8, 0xFFEFF47D'i32)
II(b, c, d, a, myBlock[1], 21'i8, 0x85845DD1'i32)
II(a, b, c, d, myBlock[8], 6'i8, 0x6FA87E4F'i32)
II(d, a, b, c, myBlock[15], 10'i8, 0xFE2CE6E0'i32)
II(c, d, a, b, myBlock[6], 15'i8, 0xA3014314'i32)
II(b, c, d, a, myBlock[13], 21'i8, 0x4E0811A1'i32)
II(a, b, c, d, myBlock[4], 6'i8, 0xF7537E82'i32)
II(d, a, b, c, myBlock[11], 10'i8, 0xBD3AF235'i32)
II(c, d, a, b, myBlock[2], 15'i8, 0x2AD7D2BB'i32)
II(b, c, d, a, myBlock[9], 21'i8, 0xEB86D391'i32)
State[0] = State[0] +% a
State[1] = State[1] +% b
State[2] = State[2] +% c
State[3] = State[3] +% d
proc MD5Init*(c: var MD5Context) =
## initializes a MD5Context
c.State[0] = 0x67452301'i32
c.State[1] = 0xEFCDAB89'i32
c.State[2] = 0x98BADCFE'i32
c.State[3] = 0x10325476'i32
c.Count[0] = 0'i32
c.Count[1] = 0'i32
ZeroMem(addr(c.Buffer), SizeOf(MD5Buffer))
proc MD5Update*(c: var MD5Context, input: cstring, len: int) =
## updates the MD5Context with the `input` data of length `len`
var input = input
var Index = (c.Count[0] shr 3) and 0x3F
c.Count[0] = c.count[0] +% toU32(len shl 3)
if c.Count[0] < (len shl 3): c.Count[1] = c.count[1] +% 1'i32
c.Count[1] = c.count[1] +% toU32(len shr 29)
var PartLen = 64 - Index
if len >= PartLen:
CopyMem(addr(c.Buffer[Index]), Input, PartLen)
transform(addr(c.Buffer), c.State)
var i = PartLen
while i + 63 < len:
Transform(addr(Input[I]), c.State)
inc(i, 64)
CopyMem(addr(c.Buffer[0]), addr(Input[i]), len-i)
else:
CopyMem(addr(c.Buffer[Index]), addr(Input[0]), len)
proc MD5Final*(c: var MD5Context, digest: var MD5Digest) =
## finishes the MD5Context and stores the result in `digest`
var
Bits: MD5CBits
PadLen: int
decode(bits, c.Count)
var Index = (c.Count[0] shr 3) and 0x3F
if Index < 56: PadLen = 56 - Index
else: PadLen = 120 - Index
MD5Update(c, padding, PadLen)
MD5Update(c, cast[cstring](addr(Bits)), 8)
decode(digest, c.State)
ZeroMem(addr(c), SizeOf(MD5Context))
proc toMD5*(s: string): MD5Digest =
## computes the MD5Digest value for a string `s`
var c: MD5Context
MD5Init(c)
MD5Update(c, cstring(s), len(s))
MD5Final(c, result)
proc `$`*(D: MD5Digest): string =
## converts a MD5Digest value into its string representation
const digits = "0123456789abcdef"
result = ""
for i in 0..15:
add(result, Digits[(D[I] shr 4) and 0xF])
add(result, Digits[D[I] and 0xF])
proc getMD5*(s: string): string =
## computes an MD5 value of `s` and returns its string representation
var
c: MD5Context
d: MD5Digest
MD5Init(c)
MD5Update(c, cstring(s), len(s))
MD5Final(c, d)
result = $d
proc `==`*(D1, D2: MD5Digest): bool =
## checks if two MD5Digest values are identical
for i in 0..15:
if D1[i] != D2[i]: return false
return true
when isMainModule:
assert(getMD5("Franz jagt im komplett verwahrlosten Taxi quer durch Bayern") ==
"a3cca2b2aa1e3b5b3b5aad99a8529074")
assert(getMD5("Frank jagt im komplett verwahrlosten Taxi quer durch Bayern") ==
"7e716d0e702df0505fc72e2b89467910")
assert($toMD5("") == "d41d8cd98f00b204e9800998ecf8427e")