Data commit

Task/Bitcoin-address-validation/Perl/bitcoin-address-validation.pl

@@ -0,0 +1,32 @@
+my @b58 = qw{
+      1 2 3 4 5 6 7 8 9
+    A B C D E F G H   J K L M N   P Q R S T U V W X Y Z
+    a b c d e f g h i j k   m n o p q r s t u v w x y z
+};
+my %b58 = map { $b58[$_] => $_ } 0 .. 57;
+
+sub unbase58 {
+    use integer;
+    my @out;
+    my $azeroes = length($1) if $_[0] =~ /^(1*)/;
+    for my $c ( map { $b58{$_} } $_[0] =~ /./g ) {
+        for (my $j = 25; $j--; ) {
+            $c += 58 * ($out[$j] // 0);
+            $out[$j] = $c % 256;
+            $c /= 256;
+        }
+    }
+    my $bzeroes = length($1) if join('', @out) =~ /^(0*)/;
+    die "not a 25 byte address\n" if $bzeroes != $azeroes;
+    return @out;
+}
+
+sub check_bitcoin_address {
+    # Does nothing if address is valid
+    # dies otherwise
+    use Digest::SHA qw(sha256);
+    my @byte = unbase58 shift;
+    die "wrong checksum\n" unless
+    (pack 'C*', @byte[21..24]) eq
+    substr sha256(sha256 pack 'C*', @byte[0..20]), 0, 4;
+}