-5
Your challenge is to output the MD5 hash of your input. The specification of MD5 can be found here. Crypto builtins are NOT allowed. Shortest code wins. Psuedocode:
//Note: All variables are unsigned 32 bit and wrap modulo 2^32 when calculating
var int[64] s, K
//s specifies the per-round shift amounts
s[ 0..15] := { 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22 }
s[16..31] := { 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20 }
s[32..47] := { 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23 }
s[48..63] := { 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21 }
//Use binary integer part of the sines of integers (Radians) as constants:
for i from 0 to 63
K[i] := floor(232 × abs(sin(i + 1)))
end for
//(Or just use the following precomputed table):
K[ 0.. 3] := { 0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee }
K[ 4.. 7] := { 0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501 }
K[ 8..11] := { 0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be }
K[12..15] := { 0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821 }
K[16..19] := { 0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa }
K[20..23] := { 0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8 }
K[24..27] := { 0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed }
K[28..31] := { 0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a }
K[32..35] := { 0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c }
K[36..39] := { 0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70 }
K[40..43] := { 0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05 }
K[44..47] := { 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665 }
K[48..51] := { 0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039 }
K[52..55] := { 0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1 }
K[56..59] := { 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1 }
K[60..63] := { 0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391 }
//Initialize variables:
var int a0 := 0x67452301 //A
var int b0 := 0xefcdab89 //B
var int c0 := 0x98badcfe //C
var int d0 := 0x10325476 //D
//Pre-processing: adding a single 1 bit
append "1" bit to message
// Notice: the input bytes are considered as bits strings,
// where the first bit is the most significant bit of the byte.[49]
//Pre-processing: padding with zeros
append "0" bit until message length in bits ≡ 448 (mod 512)
append original length in bits mod (2 pow 64) to message
//Process the message in successive 512-bit chunks:
for each 512-bit chunk of message
break chunk into sixteen 32-bit words M[j], 0 ≤ j ≤ 15
//Initialize hash value for this chunk:
var int A := a0
var int B := b0
var int C := c0
var int D := d0
//Main loop:
for i from 0 to 63
if 0 ≤ i ≤ 15 then
F := (B and C) or ((not B) and D)
g := i
else if 16 ≤ i ≤ 31
F := (D and B) or ((not D) and C)
g := (5×i + 1) mod 16
else if 32 ≤ i ≤ 47
F := B xor C xor D
g := (3×i + 5) mod 16
else if 48 ≤ i ≤ 63
F := C xor (B or (not D))
g := (7×i) mod 16
//Be wary of the below definitions of a,b,c,d
dTemp := D
D := C
C := B
B := B + leftrotate((A + F + K[i] + M[g]), s[i])
A := dTemp
end for
//Add this chunk's hash to result so far:
a0 := a0 + A
b0 := b0 + B
c0 := c0 + C
d0 := d0 + D
end for
var char digest[16] := a0 append b0 append c0 append d0 //(Output is in little-endian)
//leftrotate function definition
leftrotate (x, c)
return (x << c) binary or (x >> (32-c));
programmer5000
Posted 2017-06-11T20:20:00.990
Reputation: 7 828
4
Linking to an RFC isn't really sufficient, see the relevant sha256 question.
– FryAmTheEggman – 2017-06-11T20:30:31.6203I don't particularly like this challenge, simply because it decays to "Which language has the shortest built-in for MD5 hashing?" Although the general consensus in the past has been not to bar built-ins, I think in this case a better question would prohibit crypto builtins. – musicman523 – 2017-06-11T20:40:26.723
7Ok, that's cool, just change the restrictions, invalidating 4 answers. – Conor O'Brien – 2017-06-11T20:42:02.507
7This is the type of feedback that should be caught in the Sandbox – musicman523 – 2017-06-11T20:44:24.413
4It is unadvisable to make a trivial challenge and then change the specifications. Having a challenge that is literally "give me the shortest MD5 builtin" is bound to get many answers very quickly, and then changing the specifications and invalidating all of them is not a good idea. Additionally, this sort of stuff would have been caught in the Sandbox; even if the Sandbox seems very obselete now, linking it into chat and having a few people see it would have been enough to get this feedback. – HyperNeutrino – 2017-06-11T20:55:18.653
I'm voting to close; "md5 builtin" does not have an exact definition – MilkyWay90 – 2019-03-22T22:40:02.017
I now have a reasonably well-golfed answer to this in Jelly. If this is reopened, it's 327 bytes and is at BitLy link because TIO one too long for a comment.
– Nick Kennedy – 2019-03-24T23:42:25.880