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Diffstat (limited to 'lib/pure/md5.nim')
| -rw-r--r-- | lib/pure/md5.nim | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/lib/pure/md5.nim b/lib/pure/md5.nim new file mode 100644 index 000000000..d9bb92949 --- /dev/null +++ b/lib/pure/md5.nim @@ -0,0 +1,245 @@ +# +# +# Nimrod's Runtime Library +# (c) Copyright 2009 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") + + |