Address validation

1 files changed, 66 insertions, 0 deletions

diff --git a/public/js/check_address.js b/public/js/check_address.js
new file mode 100644
index 00000000..0ec3de3c
--- /dev/null
+++ b/public/js/check_address.js
@@ -0,0 +1,66 @@
+BigInteger.valueOf = nbv;
+BigInteger.prototype.toByteArrayUnsigned = function () {
+    var ba = this.toByteArray();
+    if (ba.length) {
+        if (ba[0] == 0)
+            ba = ba.slice(1);
+        return ba.map(function (v) {
+            return (v < 0) ? v + 256 : v;
+        });
+    } else
+        return ba;
+};        
+var Bitcoin = {};
+(function () {
+    var B58 = Bitcoin.Base58 = {
+        alphabet: "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz",
+        base: BigInteger.valueOf(58),
+        decode: function (input) {
+            bi = BigInteger.valueOf(0);
+            var leadingZerosNum = 0;
+            for (var i = input.length - 1; i >= 0; i--) {
+                var alphaIndex = B58.alphabet.indexOf(input[i]);
+                if (alphaIndex < 0) {
+                    throw "Invalid character";
+                }
+                bi = bi.add(BigInteger.valueOf(alphaIndex)
+                .multiply(B58.base.pow(input.length - 1 - i)));
+                if (input[i] == "1") leadingZerosNum++;
+                else leadingZerosNum = 0;
+            }
+            var bytes = bi.toByteArrayUnsigned();
+            while (leadingZerosNum-- > 0) bytes.unshift(0);
+            return bytes;
+        }
+    };
+})();
+Bitcoin.Address = function (bytes) {
+    if ("string" == typeof bytes)
+        bytes = Bitcoin.Address.decodeString(bytes);
+    this.hash = bytes;
+    this.version = Bitcoin.Address.networkVersion;
+};
+Bitcoin.Address.networkVersion = 0x00; // mainnet
+Bitcoin.Address.decodeString = function (string) {
+    var bytes = Bitcoin.Base58.decode(string);
+    var hash = bytes.slice(0, 21);
+    var checksum = Crypto.SHA256(Crypto.SHA256(hash, { asBytes: true }), { asBytes: true });
+    if (checksum[0] != bytes[21] ||
+        checksum[1] != bytes[22] ||
+        checksum[2] != bytes[23] ||
+        checksum[3] != bytes[24])
+        throw "Checksum validation failed!";
+    var version = hash.shift();
+    if (version != 0)
+        throw "Version " + version + " not supported!";
+    return hash;
+};
+
+function check_address(address) {
+    try {
+        Bitcoin.Address(address);
+        return true;
+    } catch (err) {
+        return false;
+    }
+}