RIPEMD-160 is another hash function; it computes a 160-bit message digest.

There is a RIPEMD-160 home page, with test vectors and pseudocode for RIPEMD-160.
For padding the message, RIPEMD-160 acts like MD4 (RFC 1320).

Find the RIPEMD-160 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Code”.
You may either call an RIPEMD-160 library, or implement RIPEMD-160 in your language.

=for CREDITS
Crypto-JS v2.0.0
http:#code.google.com/p/crypto-js/
Copyright (c) 2009, Jeff Mott. All rights reserved.
 
sub rotl($n, $b) { $n +< $b +| $n +> (32 - $b) }
sub prefix:<m^> { +^$^x % 2**32 }
sub infix:<m+> { ($^x + $^y) % 2**32 }
 
constant r1 = <
    0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
    7 4 13 1 10 6 15 3 12 0 9 5 2 14 11 8
    3 10 14 4 9 15 8 1 2 7 0 6 13 11 5 12
    1 9 11 10 0 8 12 4 13 3 7 15 14 5 6 2
    4 0 5 9 7 12 2 10 14 1 3 8 11 6 15 13
>;
constant r2 = <
    5 14 7 0 9 2 11 4 13 6 15 8 1 10 3 12
    6 11 3 7 0 13 5 10 14 15 8 12 4 9 1 2
    15 5 1 3 7 14 6 9 11 8 12 2 10 0 4 13
    8 6 4 1 3 11 15 0 5 12 2 13 9 7 10 14
    12 15 10 4 1 5 8 7 6 2 13 14 0 3 9 11
>;
constant s1 = <
    11 14 15 12 5 8 7 9 11 13 14 15 6 7 9 8
    7 6 8 13 11 9 7 15 7 12 15 9 11 7 13 12
    11 13 6 7 14 9 13 15 14 8 13 6 5 12 7 5
    11 12 14 15 14 15 9 8 9 14 5 6 8 6 5 12
    9 15 5 11 6 8 13 12 5 12 13 14 11 8 5 6
>;
constant s2 = <
    8 9 9 11 13 15 15 5 7 7 8 11 14 14 12 6
    9 13 15 7 12 8 9 11 7 7 12 7 6 15 13 11
    9 7 15 11 8 6 6 14 12 13 5 14 13 13 7 5
    15 5 8 11 14 14 6 14 6 9 12 9 12 5 15 8
    8 5 12 9 12 5 14 6 8 13 6 5 15 13 11 11
>;
constant F = 
    * +^ * +^ *,
    { ($^x +& $^y) +| (m^$^x +& $^z) },
    (* +| m^*) +^ *,
    { ($^x +& $^z) +| ($^y +& m^$^z) },
    * +^ (* +| m^*),
;
constant K1 = flat | <0x00000000 0x5a827999 0x6ed9eba1 0x8f1bbcdc 0xa953fd4e> »xx» 16;
constant K2 = flat | <0x50a28be6 0x5c4dd124 0x6d703ef3 0x7a6d76e9 0x00000000> »xx» 16;
 
our proto rmd160($) returns Blob {*}
multi rmd160(Str $s) { rmd160 $s.encode: 'ascii' }
multi rmd160(Blob $data) {
    my @b = | $data, 0x80;
    push @b, 0 until (8*@b-448) %% 512;
    my $len = 8 * $data.elems;
    push @b, | gather for ^8 { take $len % 256; $len div= 256 }
 
    my @word = gather for @b -> $a, $b, $c, $d {
        take reduce * *256 + *, $d, $c, $b, $a;
    }
 
    my @h = 0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0xc3d2e1f0;
    loop (my $i = 0; $i < @word; $i += 16) {
        my @X = my @Y = @h;
        for ^80 -> $j {
            my $T = rotl(
                @X[0] m+ F[$j div 16](|@X[1..3]) m+ (@word[$i+r1[$j]] // 0) m+ K1[$j], s1[$j]              
            ) m+ @X[4];
            @X = @X[4], $T, @X[1], rotl(@X[2], 10) % 2**32, @X[3];
            $T = rotl(
                @Y[0] m+ F[(79-$j) div 16](|@Y[1..3]) m+ (@word[$i+r2[$j]] // 0) m+ K2[$j], s2[$j]
            ) m+ @Y[4];
            @Y = @Y[4], $T, @Y[1], rotl(@Y[2], 10) % 2**32, @Y[3];
        }
        @h = (flat @h[1..4,^1]) Z[m+] (flat @X[2..4,^2]) Z[m+] flat @Y[3..4,^3];
    }
    return Blob.new: gather for @h -> $word is rw {
        for ^4 { take $word % 256; $word div= 256 }
    }
}
 
say rmd160 "Rosetta Code";