Data commit

Task/Bitcoin-address-validation/PHP/bitcoin-address-validation.php

@@ -0,0 +1,56 @@
+function validate($address){
+        $decoded = decodeBase58($address);
+
+        $d1 = hash("sha256", substr($decoded,0,21), true);
+        $d2 = hash("sha256", $d1, true);
+
+        if(substr_compare($decoded, $d2, 21, 4)){
+                throw new \Exception("bad digest");
+        }
+        return true;
+}
+function decodeBase58($input) {
+        $alphabet = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
+
+        $out = array_fill(0, 25, 0);
+        for($i=0;$i<strlen($input);$i++){
+                if(($p=strpos($alphabet, $input[$i]))===false){
+                        throw new \Exception("invalid character found");
+                }
+                $c = $p;
+                for ($j = 25; $j--; ) {
+                        $c += (int)(58 * $out[$j]);
+                        $out[$j] = (int)($c % 256);
+                        $c /= 256;
+                        $c = (int)$c;
+                }
+                if($c != 0){
+                    throw new \Exception("address too long");
+                }
+        }
+
+        $result = "";
+        foreach($out as $val){
+                $result .= chr($val);
+        }
+
+        return $result;
+}
+
+function main () {
+  $s = array(
+                "1Q1pE5vPGEEMqRcVRMbtBK842Y6Pzo6nK9",
+                "1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62i",
+                "1Q1pE5vPGEEMqRcVRMbtBK842Y6Pzo6nJ9",
+                "1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62I",
+        );
+  foreach($s as $btc){
+    $message = "OK";
+    try{
+        validate($btc);
+    }catch(\Exception $e){ $message = $e->getMessage(); }
+    echo "$btc: $message\n";
+  }
+}
+
+main();