FAQ MD5 Hash

REXX- MD5-Procedure
/* REXX */
RETURN MD5(ARG(1))
/* --- */
MD5 : procedure /* for MD5 details see RfC 1321 */
numeric digits 11 /* 32 bit addition + carry digit */
parse arg MSG /* if MSG < 12,500,000,000 bytes */
LEN = 8 * length( MSG ) /* MD5 operates on bit messages: */
PAD = LEN // 512 /* pad to length 448 modulo 512 */
if PAD < 448 then PAD = 448 - PAD
else PAD = 960 - PAD
PAD = left( '80'x, PAD / 8, '00'x )
MSG = MSG !! PAD !! reverse( x2c( d2x( LEN, 16 )))
A = '67452301'x ;
C = '98BADCFE'x ;
S11 = 7 ; S12 = 12 ;
S21 = 5 ; S22 = 9 ;
S31 = 4 ; S32 = 11 ;
S41 = 6 ; S42 = 10 ;
B = 'EFCDAB89'x
D = '10325476'x
S13 = 17 ; S14 = 22
S23 = 14 ; S24 = 20
S33 = 16 ; S34 = 23
S43 = 15 ; S44 = 21
do N = 1 to ( length( MSG ) / 4 ) / 16
K = N * 64 - 63
do J = 0 to 15
M.J = c2d( reverse( substr( MSG, K + J * 4, 4 )))
end J
AA = A ; BB = B ; CC = C ; DD = D
A = MD5.1( A, B, C, D, S11, M.0 + 3614090360 ) /* 1 */
D = MD5.1( D, A, B, C, S12, M.1 + 3905402710 ) /* 2 */
C = MD5.1( C, D, A, B, S13, M.2 + 606105819 ) /* 3 */
B = MD5.1( B, C, D, A, S14, M.3 + 3250441966 ) /* 4 */
A = MD5.1( A, B, C, D, S11, M.4 + 4118548399 ) /* 5 */
D = MD5.1( D, A, B, C, S12, M.5 + 1200080426 ) /* 6 */
C = MD5.1( C, D, A, B, S13, M.6 + 2821735955 ) /* 7 */
B = MD5.1( B, C, D, A, S14, M.7 + 4249261313 ) /* 8 */
A = MD5.1( A, B, C, D, S11, M.8 + 1770035416 ) /* 9 */
D = MD5.1( D, A, B, C, S12, M.9 + 2336552879 ) /* 10 */
C = MD5.1( C, D, A, B, S13, M.10+ 4294925233 ) /* 11 */
B = MD5.1( B, C, D, A, S14, M.11+ 2304563134 ) /* 12 */
A = MD5.1( A, B, C, D, S11, M.12+ 1804603682 ) /* 13 */
D = MD5.1( D, A, B, C, S12, M.13+ 4254626195 ) /* 14 */
C = MD5.1( C, D, A, B, S13, M.14+ 2792965006 ) /* 15 */
B = MD5.1( B, C, D, A, S14, M.15+ 1236535329 ) /* 16 */
A = MD5.2( A, B, C, D, S21, M.1 + 4129170786 ) /* 17 */
D = MD5.2( D, A, B, C, S22, M.6 + 3225465664 ) /* 18 */
C = MD5.2( C, D, A, B, S23, M.11+ 643717713 ) /* 19 */
B = MD5.2( B, C, D, A, S24, M.0 + 3921069994 ) /* 20 */
A = MD5.2( A, B, C, D, S21, M.5 + 3593408605 ) /* 21 */
D = MD5.2( D, A, B, C, S22, M.10+ 38016083 ) /* 22 */
C = MD5.2( C, D, A, B, S23, M.15+ 3634488961 ) /* 23 */
B = MD5.2( B, C, D, A, S24, M.4 + 3889429448 ) /* 24 */
A = MD5.2( A, B, C, D, S21, M.9 + 568446438 ) /* 25 */
D = MD5.2( D, A, B, C, S22, M.14+ 3275163606 ) /* 26 */
C = MD5.2( C, D, A, B, S23, M.3 + 4107603335 ) /* 27 */
B = MD5.2( B, C, D, A, S24, M.8 + 1163531501 ) /* 28 */
A = MD5.2( A, B, C, D, S21, M.13+ 2850285829 ) /* 29 */
D = MD5.2( D, A, B, C, S22, M.2 + 4243563512 ) /* 30 */
C = MD5.2( C, D, A, B, S23, M.7 + 1735328473 ) /* 31 */
B = MD5.2( B, C, D, A, S24, M.12+ 2368359562 ) /* 32 */
A = MD5.3( A, B, C, D, S31, M.5 + 4294588738 ) /* 33 */
D = MD5.3( D, A, B, C, S32, M.8 + 2272392833 ) /* 34 */
C = MD5.3( C, D, A, B, S33, M.11+ 1839030562 ) /* 35 */
B = MD5.3( B, C, D, A, S34, M.14+ 4259657740 ) /* 36 */
A = MD5.3( A, B, C, D, S31, M.1 + 2763975236 ) /* 37 */
D = MD5.3( D, A, B, C, S32, M.4 + 1272893353 ) /* 38 */
C = MD5.3( C, D, A, B, S33, M.7 + 4139469664 ) /* 39 */
B = MD5.3( B, C, D, A, S34, M.10+ 3200236656 ) /* 40 */
A = MD5.3( A, B, C, D, S31, M.13+ 681279174 ) /* 41 */