diff --git a/app/src/main/java/com/m2049r/xmrwallet/util/BitcoinAddressValidator.java b/app/src/main/java/com/m2049r/xmrwallet/util/BitcoinAddressValidator.java
index 5d1dda91..76fa8979 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/util/BitcoinAddressValidator.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/util/BitcoinAddressValidator.java
@@ -16,12 +16,13 @@
package com.m2049r.xmrwallet.util;
-// based on https://rosettacode.org/wiki/Bitcoin/address_validation#Java
+// mostly based on https://rosettacode.org/wiki/Bitcoin/address_validation#Java
import com.m2049r.xmrwallet.model.NetworkType;
import com.m2049r.xmrwallet.model.WalletManager;
import java.math.BigInteger;
+import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
@@ -31,8 +32,9 @@ public class BitcoinAddressValidator {
private static final String ALPHABET = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
public static boolean validate(String addrress) {
- return validate(addrress,
- WalletManager.getInstance().getNetworkType() != NetworkType.NetworkType_Mainnet);
+ boolean testnet = WalletManager.getInstance().getNetworkType() != NetworkType.NetworkType_Mainnet;
+ if (validate(addrress, testnet)) return true;
+ return validateBech32Segwit(addrress, testnet);
}
public static boolean validate(String addrress, boolean testnet) {
@@ -85,4 +87,112 @@ public class BitcoinAddressValidator {
throw new IllegalStateException(e);
}
}
+
+ //
+ // validate Bech32 segwit
+ // see https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki for spec
+ //
+
+ private static final String DATA_CHARS = "qpzry9x8gf2tvdw0s3jn54khce6mua7l";
+
+ public static boolean validateBech32Segwit(String bech32, boolean testnet) {
+ if (!bech32.equals(bech32.toLowerCase()) && !bech32.equals(bech32.toUpperCase())) {
+ return false; // mixing upper and lower case not allowed
+ }
+ bech32 = bech32.toLowerCase();
+
+ if (testnet && !bech32.startsWith("tb1")) return false;
+ if (!testnet && !bech32.startsWith("bc1")) return false;
+
+ if ((bech32.length() < 14) || (bech32.length() > 74)) return false;
+ int mod = bech32.length() % 8;
+ if ((mod == 0) || (mod == 3) || (mod == 5)) return false;
+
+ int sep = -1;
+ final byte[] bytes = bech32.getBytes(StandardCharsets.US_ASCII);
+ for (int i = 0; i < bytes.length; i++) {
+ if ((bytes[i] < 33) || (bytes[i] > 126)) {
+ return false;
+ }
+ if (bytes[i] == 49) sep = i; // 49 := '1' in ASCII
+ }
+
+ if (sep != 2) return false; // bech32 always has len(hrp)==2
+ if (sep > bytes.length - 7) {
+ return false; // min 6 bytes data
+ }
+ if (bytes.length < 8) { // hrp{min}=1 + sep=1 + data{min}=6 := 8
+ return false; // too short
+ }
+ if (bytes.length > 90) {
+ return false; // too long
+ }
+
+ final byte[] hrp = Arrays.copyOfRange(bytes, 0, sep);
+
+ final byte[] data = Arrays.copyOfRange(bytes, sep + 1, bytes.length);
+ for (int i = 0; i < data.length; i++) {
+ int b = DATA_CHARS.indexOf(data[i]);
+ if (b < 0) return false; // invalid character
+ data[i] = (byte) b;
+ }
+
+ if (!validateBech32Data(data)) return false;
+
+ return verifyChecksum(hrp, data);
+ }
+
+ private static int polymod(byte[] values) {
+ final int[] GEN = {0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3};
+ int chk = 1;
+ for (byte v : values) {
+ byte b = (byte) (chk >> 25);
+ chk = ((chk & 0x1ffffff) << 5) ^ v;
+ for (int i = 0; i < 5; i++) {
+ chk ^= ((b >> i) & 1) == 1 ? GEN[i] : 0;
+ }
+ }
+ return chk;
+ }
+
+ private static byte[] hrpExpand(byte[] hrp) {
+ final byte[] expanded = new byte[(2 * hrp.length) + 1];
+ int i = 0;
+ for (int j = 0; j < hrp.length; j++) {
+ expanded[i++] = (byte) (hrp[j] >> 5);
+ }
+ expanded[i++] = 0;
+ for (int j = 0; j < hrp.length; j++) {
+ expanded[i++] = (byte) (hrp[j] & 0x1f);
+ }
+ return expanded;
+ }
+
+ private static boolean verifyChecksum(byte[] hrp, byte[] data) {
+ final byte[] hrpExpanded = hrpExpand(hrp);
+ final byte[] values = new byte[hrpExpanded.length + data.length];
+ System.arraycopy(hrpExpanded, 0, values, 0, hrpExpanded.length);
+ System.arraycopy(data, 0, values, hrpExpanded.length, data.length);
+ return (polymod(values) == 1);
+ }
+
+ private static boolean validateBech32Data(final byte[] data) {
+ if ((data[0] < 0) || (data[0] > 16)) return false; // witness version
+ final int programLength = data.length - 1 - 6; // 1-byte version at beginning & 6-byte checksum at end
+
+ // since we are coming from our own decoder, we don't need to verify data is 5-bit bytes
+
+ final int convertedSize = programLength * 5 / 8;
+ final int remainderSize = programLength * 5 % 8;
+
+ if ((convertedSize < 2) || (convertedSize > 40)) return false;
+
+ if ((data[0] == 0) && (convertedSize != 20) && (convertedSize != 32)) return false;
+
+ if (remainderSize >= 5) return false;
+ // ignore checksum at end and get last byte of program
+ if ((data[data.length - 1 - 6] & ((1 << remainderSize) - 1)) != 0) return false;
+
+ return true;
+ }
}
\ No newline at end of file
diff --git a/app/src/test/java/com/m2049r/xmrwallet/util/BitcoinAddressValidatorTest.java b/app/src/test/java/com/m2049r/xmrwallet/util/BitcoinAddressValidatorTest.java
index 5882723f..c2502fb4 100644
--- a/app/src/test/java/com/m2049r/xmrwallet/util/BitcoinAddressValidatorTest.java
+++ b/app/src/test/java/com/m2049r/xmrwallet/util/BitcoinAddressValidatorTest.java
@@ -18,6 +18,7 @@ package com.m2049r.xmrwallet.util;
import org.junit.Test;
+import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
@@ -54,4 +55,38 @@ public class BitcoinAddressValidatorTest {
assertTrue(!BitcoinAddressValidator.validate("3NagLCvw8fLwtoUrK7s2mJPy9k6hoyWvTU ", false));
assertTrue(!BitcoinAddressValidator.validate(" 3NagLCvw8fLwtoUrK7s2mJPy9k6hoyWvTU ", false));
}
+
+ @Test
+ public void validSegwit() {
+ // see https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki
+ assertTrue(BitcoinAddressValidator.validateBech32Segwit("bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4", false));
+ assertTrue(BitcoinAddressValidator.validateBech32Segwit("tb1qw508d6qejxtdg4y5r3zarvary0c5xw7kxpjzsx", true));
+ assertTrue(BitcoinAddressValidator.validateBech32Segwit("bc1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3qccfmv3", false));
+ assertTrue(BitcoinAddressValidator.validateBech32Segwit("tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sl5k7", true));
+
+ assertTrue(BitcoinAddressValidator.validateBech32Segwit("BC1QW508D6QEJXTDG4Y5R3ZARVARY0C5XW7KV8F3T4", false));
+ assertTrue(BitcoinAddressValidator.validateBech32Segwit("tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sl5k7", true));
+ assertTrue(BitcoinAddressValidator.validateBech32Segwit("bc1pw508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7k7grplx", false));
+ assertTrue(BitcoinAddressValidator.validateBech32Segwit("BC1SW50QA3JX3S", false));
+ assertTrue(BitcoinAddressValidator.validateBech32Segwit("bc1zw508d6qejxtdg4y5r3zarvaryvg6kdaj", false));
+ assertTrue(BitcoinAddressValidator.validateBech32Segwit("tb1qqqqqp399et2xygdj5xreqhjjvcmzhxw4aywxecjdzew6hylgvsesrxh6hy", true));
+
+ assertTrue(BitcoinAddressValidator.validateBech32Segwit("bc1q76awjp3nmklgnf0yyu0qncsekktf4e3qj248t4", false)); // electrum blog
+
+ }
+
+ @Test
+ public void invalidSegwit() {
+ // see https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki
+ assertFalse(BitcoinAddressValidator.validateBech32Segwit("tc1qw508d6qejxtdg4y5r3zarvary0c5xw7kg3g4ty", true)); // Invalid human-readable part
+ assertFalse(BitcoinAddressValidator.validateBech32Segwit("bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t5", true)); // Invalid checksum
+ assertFalse(BitcoinAddressValidator.validateBech32Segwit("BC13W508D6QEJXTDG4Y5R3ZARVARY0C5XW7KN40WF2", true)); // Invalid witness version
+ assertFalse(BitcoinAddressValidator.validateBech32Segwit("bc1rw5uspcuh", true)); // Invalid program length
+ assertFalse(BitcoinAddressValidator.validateBech32Segwit("bc10w508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7kw5rljs90", true)); // Invalid program length
+ assertFalse(BitcoinAddressValidator.validateBech32Segwit("BC1QR508D6QEJXTDG4Y5R3ZARVARYV98GJ9P", true)); // Invalid program length for witness version 0 (per BIP141)
+ assertFalse(BitcoinAddressValidator.validateBech32Segwit("tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sL5k7", true)); // Mixed case
+ assertFalse(BitcoinAddressValidator.validateBech32Segwit("bc1zw508d6qejxtdg4y5r3zarvaryvqyzf3du", true)); // zero padding of more than 4 bits
+ assertFalse(BitcoinAddressValidator.validateBech32Segwit("tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3pjxtptv", true)); // Non-zero padding in 8-to-5 conversion
+ assertFalse(BitcoinAddressValidator.validateBech32Segwit("bc1gmk9yu", true)); // Empty data section
+ }
}