diff options
Diffstat (limited to 'lib/pure/md5.nim')
| -rw-r--r-- | lib/pure/md5.nim | 222 |
1 files changed, 157 insertions, 65 deletions
diff --git a/lib/pure/md5.nim b/lib/pure/md5.nim index 1ff3a9824..9c3f6d51b 100644 --- a/lib/pure/md5.nim +++ b/lib/pure/md5.nim @@ -7,13 +7,28 @@ # distribution, for details about the copyright. # -## Module for computing MD5 checksums. +## Module for computing [MD5 checksums](https://en.wikipedia.org/wiki/MD5). +## +## This module also works at compile time and in JavaScript. +## +## See also +## ======== +## * `base64 module<base64.html>`_ for a Base64 encoder and decoder +## * `sha1 module <sha1.html>`_ for the SHA-1 checksum algorithm +## * `hashes module<hashes.html>`_ for efficient computations of hash values +## for diverse Nim types + +{.deprecated: "use command `nimble install checksums` and import `checksums/md5` instead".} + +when defined(nimHasStyleChecks): + {.push styleChecks: off.} type MD5State = array[0..3, uint32] MD5Block = array[0..15, uint32] MD5CBits = array[0..7, uint8] MD5Digest* = array[0..15, uint8] + ## MD5 checksum of a string, obtained with the `toMD5 proc <#toMD5,string>`_. MD5Buffer = array[0..63, uint8] MD5Context* {.final.} = object state: MD5State @@ -21,15 +36,16 @@ type 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" + padding: array[0..63, uint8] = [ + 0x80'u8, 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: uint32): uint32 {.inline.} = result = (x and y) or ((not x) and z) @@ -66,7 +82,7 @@ proc II(a: var uint32, b, c, d, x: uint32, s: uint8, ac: uint32) = rot(a, s) a = a + b -proc encode(dest: var MD5Block, src: cstring) = +proc encode(dest: var MD5Block, src: openArray[uint8]) = var j = 0 for i in 0..high(dest): dest[i] = uint32(ord(src[j])) or @@ -84,10 +100,35 @@ proc decode(dest: var openArray[uint8], src: openArray[uint32]) = dest[i+3] = uint8(src[j] shr 24 and 0xff'u32) inc(i, 4) -proc transform(buffer: pointer, state: var MD5State) = +template slice(s: cstring, a, b): openArray[uint8] = + when nimvm: + # toOpenArray is not implemented in VM + toOpenArrayByte($s, a, b) + else: + when defined(js): + # toOpenArrayByte for cstring is not implemented in JS + toOpenArrayByte($s, a, b) + else: + s.toOpenArrayByte(a, b) + +template slice(s: openArray[uint8], a, b): openArray[uint8] = + s.toOpenArray(a, b) + +const useMem = declared(copyMem) + +template memOrNot(withMem, withoutMem): untyped = + when nimvm: + withoutMem + else: + when useMem: + withMem + else: + withoutMem + +proc transform(buffer: openArray[uint8], state: var MD5State) = var myBlock: MD5Block - encode(myBlock, cast[cstring](buffer)) + encode(myBlock, buffer) var a = state[0] var b = state[1] var c = state[2] @@ -161,58 +202,37 @@ proc transform(buffer: pointer, state: var MD5State) = state[2] = state[2] + c state[3] = state[3] + d -proc md5Init*(c: var MD5Context) = - ## initializes a MD5Context - c.state[0] = 0x67452301'u32 - c.state[1] = 0xEFCDAB89'u32 - c.state[2] = 0x98BADCFE'u32 - c.state[3] = 0x10325476'u32 - c.count[0] = 0'u32 - c.count[1] = 0'u32 - zeroMem(addr(c.buffer), sizeof(MD5buffer)) +proc md5Init*(c: var MD5Context) {.raises: [], tags: [], gcsafe.} +proc md5Update*(c: var MD5Context, input: openArray[uint8]) {.raises: [], + tags: [], gcsafe.} +proc md5Final*(c: var MD5Context, digest: var MD5Digest) {.raises: [], tags: [], gcsafe.} -proc md5Update*(c: var MD5Context, input: cstring, len: int) = - ## updates the MD5Context with the `input` data of length `len` - var input = input - var Index = int((c.count[0] shr 3) and 0x3F) - c.count[0] = c.count[0] + (uint32(len) shl 3) - if c.count[0] < (uint32(len) shl 3): c.count[1] = c.count[1] + 1'u32 - c.count[1] = c.count[1] + (uint32(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 md5Update*(c: var MD5Context, input: cstring, len: int) {.raises: [], + tags: [], gcsafe.} = + ## Updates the `MD5Context` with the `input` data of length `len`. + ## + ## If you use the `toMD5 proc <#toMD5,string>`_, there's no need to call this + ## function explicitly. + md5Update(c, input.slice(0, len - 1)) -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 = int((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` + ## Computes the `MD5Digest` value for a string `s`. + ## + ## **See also:** + ## * `getMD5 proc <#getMD5,string>`_ which returns a string representation + ## of the `MD5Digest` + ## * `$ proc <#$,MD5Digest>`_ for converting MD5Digest to string + runnableExamples: + assert $toMD5("abc") == "900150983cd24fb0d6963f7d28e17f72" + var c: MD5Context md5Init(c) - md5Update(c, cstring(s), len(s)) + md5Update(c, s.slice(0, s.len - 1)) md5Final(c, result) proc `$`*(d: MD5Digest): string = - ## converts a MD5Digest value into its string representation + ## Converts a `MD5Digest` value into its string representation. const digits = "0123456789abcdef" result = "" for i in 0..15: @@ -220,24 +240,96 @@ proc `$`*(d: MD5Digest): string = add(result, digits[d[i].int and 0xF]) proc getMD5*(s: string): string = - ## computes an MD5 value of `s` and returns its string representation + ## Computes an MD5 value of `s` and returns its string representation. + ## + ## **See also:** + ## * `toMD5 proc <#toMD5,string>`_ which returns the `MD5Digest` of a string + runnableExamples: + assert getMD5("abc") == "900150983cd24fb0d6963f7d28e17f72" + var c: MD5Context d: MD5Digest md5Init(c) - md5Update(c, cstring(s), len(s)) + md5Update(c, s.slice(0, s.len - 1)) md5Final(c, d) result = $d proc `==`*(D1, D2: MD5Digest): bool = - ## checks if two MD5Digest values are identical + ## Checks if two `MD5Digest` values are identical. for i in 0..15: if D1[i] != D2[i]: return false return true -when isMainModule: - assert(getMD5("Franz jagt im komplett verwahrlosten Taxi quer durch Bayern") == - "a3cca2b2aa1e3b5b3b5aad99a8529074") - assert(getMD5("Frank jagt im komplett verwahrlosten Taxi quer durch Bayern") == - "7e716d0e702df0505fc72e2b89467910") - assert($toMD5("") == "d41d8cd98f00b204e9800998ecf8427e") + +proc clearBuffer(c: var MD5Context) {.inline.} = + memOrNot: + zeroMem(addr(c.buffer), sizeof(MD5Buffer)) + do: + reset(c.buffer) + +proc md5Init*(c: var MD5Context) = + ## Initializes an `MD5Context`. + ## + ## If you use the `toMD5 proc <#toMD5,string>`_, there's no need to call this + ## function explicitly. + c.state[0] = 0x67452301'u32 + c.state[1] = 0xEFCDAB89'u32 + c.state[2] = 0x98BADCFE'u32 + c.state[3] = 0x10325476'u32 + c.count[0] = 0'u32 + c.count[1] = 0'u32 + clearBuffer(c) + +proc writeBuffer(c: var MD5Context, index: int, + input: openArray[uint8], inputIndex, len: int) {.inline.} = + memOrNot: + copyMem(addr(c.buffer[index]), unsafeAddr(input[inputIndex]), len) + do: + # cannot use system.`[]=` for arrays and openarrays as + # it can raise RangeDefect which gets tracked + for i in 0..<len: + c.buffer[index + i] = input[inputIndex + i] + +proc md5Update*(c: var MD5Context, input: openArray[uint8]) = + ## Updates the `MD5Context` with the `input` data. + ## + ## If you use the `toMD5 proc <#toMD5,string>`_, there's no need to call this + ## function explicitly. + var Index = int((c.count[0] shr 3) and 0x3F) + c.count[0] = c.count[0] + (uint32(input.len) shl 3) + if c.count[0] < (uint32(input.len) shl 3): c.count[1] = c.count[1] + 1'u32 + c.count[1] = c.count[1] + (uint32(input.len) shr 29) + var PartLen = 64 - Index + if input.len >= PartLen: + writeBuffer(c, Index, input, 0, PartLen) + transform(c.buffer, c.state) + var i = PartLen + while i + 63 < input.len: + transform(input.slice(i, i + 63), c.state) + inc(i, 64) + if i < input.len: + writeBuffer(c, 0, input, i, input.len - i) + elif input.len > 0: + writeBuffer(c, Index, input, 0, input.len) + +proc md5Final*(c: var MD5Context, digest: var MD5Digest) = + ## Finishes the `MD5Context` and stores the result in `digest`. + ## + ## If you use the `toMD5 proc <#toMD5,string>`_, there's no need to call this + ## function explicitly. + var + Bits: MD5CBits + PadLen: int + decode(Bits, c.count) + var Index = int((c.count[0] shr 3) and 0x3F) + if Index < 56: PadLen = 56 - Index + else: PadLen = 120 - Index + md5Update(c, padding.slice(0, PadLen - 1)) + md5Update(c, Bits) + decode(digest, c.state) + clearBuffer(c) + + +when defined(nimHasStyleChecks): + {.pop.} #{.push styleChecks: off.} \ No newline at end of file |