1 files changed, 91 insertions, 0 deletions
diff --git a/packages/taler-util/src/segwit_addr.ts b/packages/taler-util/src/segwit_addr.ts
new file mode 100644
index 000000000..becc5d197
--- /dev/null
+++ b/packages/taler-util/src/segwit_addr.ts
@@ -0,0 +1,91 @@
+// Copyright (c) 2017, 2021 Pieter Wuille
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+import bech32 from "./bech32.js"
+
+export default {
+  encode: encode,
+  decode: decode
+};
+
+function convertbits(data: any, frombits: number, tobits: number, pad: boolean): any[] {
+  var acc = 0;
+  var bits = 0;
+  var ret = [];
+  var maxv = (1 << tobits) - 1;
+  for (var p = 0; p < data.length; ++p) {
+    var value = data[p];
+    if (value < 0 || (value >> frombits) !== 0) {
+      return []; //check this, was returning null
+    }
+    acc = (acc << frombits) | value;
+    bits += frombits;
+    while (bits >= tobits) {
+      bits -= tobits;
+      ret.push((acc >> bits) & maxv);
+    }
+  }
+  if (pad) {
+    if (bits > 0) {
+      ret.push((acc << (tobits - bits)) & maxv);
+    }
+  } else if (bits >= frombits || ((acc << (tobits - bits)) & maxv)) {
+    return []; //check this, was returning null
+  }
+  return ret;
+}
+
+function decode(hrp: any, addr: string) {
+  var bech32m = false;
+  var dec = bech32.decode(addr, bech32.encodings.BECH32);
+  if (dec === null) {
+    dec = bech32.decode(addr, bech32.encodings.BECH32M);
+    bech32m = true;
+  }
+  if (dec === null || dec.hrp !== hrp || dec.data.length < 1 || dec.data[0] > 16) {
+    return null;
+  }
+  var res = convertbits(dec.data.slice(1), 5, 8, false);
+  if (res === null || res.length < 2 || res.length > 40) {
+    return null;
+  }
+  if (dec.data[0] === 0 && res.length !== 20 && res.length !== 32) {
+    return null;
+  }
+  if (dec.data[0] === 0 && bech32m) {
+    return null;
+  }
+  if (dec.data[0] !== 0 && !bech32m) {
+    return null;
+  }
+  return { version: dec.data[0], program: res };
+}
+
+function encode(hrp: any, version: number, program: any): string {
+  var enc = bech32.encodings.BECH32;
+  if (version > 0) {
+    enc = bech32.encodings.BECH32M;
+  }
+  var ret = bech32.encode(hrp, [version].concat(convertbits(program, 8, 5, true)), enc);
+  if (decode(hrp, ret/*, enc*/) === null) {
+    return ""; //check this was returning null
+  }
+  return ret;
+}
+\ No newline at end of file