Bitcoin/public point to address: Difference between revisions

=={{header|D}}==

Requires the D module from the SHA-256 task.

{{trans|C}}

{{trans|Go}}

<lang d>import std.stdio, std.algorithm, std.digest.ripemd, sha_256;

// A Bitcoin public point.

struct PPoint { ubyte[32] x, y; }

private enum bitcoinVersion = 0;

private enum RIPEMD160_digest_len = typeof("".ripemd160Of).length;

private alias sha = SHA256.digest;

alias Address = ubyte[1 + 4 + RIPEMD160_digest_len];

/** Returns a base 58 encoded bitcoin address corresponding

to the receiver. */

char[] toBase58(ref Address a) pure nothrow {

static immutable symbols = "123456789" ~

"ABCDEFGHJKLMNPQRSTUVWXYZ" ~

"abcdefghijkmnopqrstuvwxyz";

static assert(symbols.length == 58);

auto result = new typeof(return)(34);

foreach_reverse (ref ri; result) {

uint c = 0;

foreach (ref ai; a) {

c = c * 256 + ai;

ai = cast(ubyte)(c / symbols.length);

c %= symbols.length;

}

ri = symbols[c];

}

size_t i = 1;

for (; i < result.length && result[i] == '1'; i++) {}

return result[i - 1 .. $];

}

char[] bitcoinEncode(in ref PPoint p) pure nothrow {

ubyte[typeof(PPoint.x).length + typeof(PPoint.y).length + 1] s;

s[0] = 4;

s[1 .. 1 + p.x.length] = p.x[];

s[1 + p.x.length .. $] = p.y[];

Address rmd;

rmd[0] = bitcoinVersion;

rmd[1 .. RIPEMD160_digest_len + 1] = s.sha.ripemd160Of;

rmd[$-4 .. $] = rmd[0 .. RIPEMD160_digest_len + 1].sha.sha[0 .. 4];

return rmd.toBase58;

}

void main() {

PPoint p = {

cast(typeof(PPoint.x))

x"50863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B2352",

cast(typeof(PPoint.y))

x"2CD470243453A299FA9E77237716103ABC11A1DF38855ED6F2EE187E9C582BA6"};

p.bitcoinEncode.writeln;

}</lang>

{{out}}

<pre>16UwLL9Risc3QfPqBUvKofHmBQ7wMtjvM</pre>