proper bech32 address validation

baked_in.go

@@ -109,6 +109,7 @@ var (
 		"isbn13":           isISBN13,
 		"eth_addr":         isEthereumAddress,
 		"btc_addr":         isBitcoinAddress,
+		"btc_addr_bech32":  isBitcoinBech32Address,
 		"uuid":             isUUID,
 		"uuid3":            isUUID3,
 		"uuid4":            isUUID4,
@@ -393,16 +394,28 @@ func isISBN10(fl FieldLevel) bool {
 
 // IsEthereumAddress is the validation function for validating if the field's value is a valid ethereum address based currently only on the format
 func isEthereumAddress(fl FieldLevel) bool {
-	field := fl.Field()
+	address := fl.Field().String()
+
+	if !ethAddressRegex.MatchString(address) {
+		return false
+	}
+
+	if ethaddressRegexUpper.MatchString(address) || ethAddressRegexLower.MatchString(address) {
+		return true
+	}
 
-	return ethAddressRegex.MatchString(field.String())
+	// checksum validation is blocked by https://github.com/golang/crypto/pull/28
+
+	return true
 }
 
-// IsBitcoinAddress is the validation function for validating if the field's value is a valid btc address, currently only based on the format
+// IsBitcoinAddress is the validation function for validating if the field's value is a valid btc address
 func isBitcoinAddress(fl FieldLevel) bool {
 	address := fl.Field().String()
 
-	if btcAddressRegex.MatchString(address) {
+	if !btcAddressRegex.MatchString(address) {
+		return false
+	}
 
 	alphabet := []byte("123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz")
 
@@ -411,10 +424,6 @@ func isBitcoinAddress(fl FieldLevel) bool {
 	for _, n := range []byte(address) {
 		d := bytes.IndexByte(alphabet, n)
 
-			if(d == -1){
-				return false
-			}
-
 		for i := 24; i >= 0; i-- {
 			d += 58 * int(decode[i])
 			decode[i] = byte(d % 256)
@@ -439,12 +448,96 @@ func isBitcoinAddress(fl FieldLevel) bool {
 	copy(computedchecksum[:], h.Sum(d[:0]))
 	copy(validchecksum[:], decode[21:])
 
-		println(address, "::", validchecksum[:], computedchecksum[:])
-
 	return validchecksum == computedchecksum
+}
+
+// IsBitcoinAddress is the validation function for validating if the field's value is a valid bech32 btc address
+func isBitcoinBech32Address(fl FieldLevel) bool {
+	address := fl.Field().String()
+
+	if !btcAddressRegexBech32.MatchString(address){
+		return false
+	}
+
+	am := len(address) % 8
+
+	if am == 0 || am == 3 || am == 5{
+		return false
+	}
+
+	address = strings.ToLower(address)
+
+	alphabet := "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
+
+	hr := []int{3, 3, 0, 2, 3} // the human readable part will always be bc
+	dp := []int{}
+
+	for _, c := range []rune(address[3:]) {
+		dp = append(dp, strings.IndexRune(alphabet, c))
+	}
+
+	ver := dp[0]
+
+	if ver < 0 || ver > 16{
+		return false
+	}
+
+	if ver == 0 {
+		if len(address) != 42 && len(address) != 62 {
+			return false
+		}
+	}
+
+	values := append(hr, dp...)
+
+	GEN := []int{ 0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3 }
+
+	p := 1
+
+	for _, v := range values {
+		b := p >> 25
+		p = (p & 0x1ffffff) << 5 ^ v
+
+		for i := 0; i < 5; i++ {
+			if (b >> uint(i)) & 1 == 1 {
+				p ^= GEN[i]
+			}
+		}
+	}
+
+	if p != 1 {
+		return false
+	}
+
+	b := uint(0)
+	acc := 0
+	mv := (1 << 5) - 1
+
+	sw := []int{}
+
+	dp = dp[:len(dp) - 6]
+
+	for _, v := range dp[1:]{
+		if v < 0 || (v >> 5) != 0{
+			return false
+		}
+		acc = (acc << 5) | v
+		b += 5
+		for b >= 8{
+			b -= 8
+			sw = append(sw, (acc>>b)&mv)
+		}
+	}
+
+	if len(sw) < 2 || len(sw) > 40{
+		return false
 	}
 
-	return btcAddressRegexBech32.MatchString(address)
+	if ver == 0 && len(sw) != 20 && len(sw) != 32 {
+		return false
+	}
+
+	return true
 }
 
 // ExcludesRune is the validation function for validating that the field's value does not contain the rune specified within the param.

doc.go

@@ -613,14 +613,23 @@ Bitcoin Address
 
 This validates that a string value contains a valid bitcoin address.
 The format of the string is checked to ensure it matches one of the three formats
-P2PKH, P2SH, or Bech32. Currently no further validation is performed.
+P2PKH, P2SH and performs checksum validation.
 
 	Usage: btc_addr
 
+Bitcoin Bech32 Address (segwit)
+
+This validates that a string value contains a valid bitcoin Bech32 address as defined
+by bip-0173 (https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki)
+Special thanks to Pieter Wuille for providng reference implementations.
+
+	Usage: btc_addr_bech32
+
 Ethereum Address
 
 This validates that a string value contains a valid ethereum address.
 The format of the string is checked to ensure it matches the standard Ethereum address format
+Full validation is blocked by https://github.com/golang/crypto/pull/28
 
 	Usage: eth_addr
 

regexes.go

@@ -33,8 +33,10 @@ const (
 	hostnameRegexStringRFC952      = `^[a-zA-Z][a-zA-Z0-9\-\.]+[a-z-Az0-9]$`    // https://tools.ietf.org/html/rfc952
 	hostnameRegexStringRFC1123     = `^[a-zA-Z0-9][a-zA-Z0-9\-\.]+[a-z-Az0-9]$` // accepts hostname starting with a digit https://tools.ietf.org/html/rfc1123
 	btcAddressRegexString          = `^[13][a-km-zA-HJ-NP-Z1-9]{25,34}$`    // bitcoin address
-	btcAddressRegexStringBech32    = `^(bc1|[13])[a-zA-HJ-NP-Z0-9]{25,39}$`   // bitcoin bech32 address https://en.bitcoin.it/wiki/Bech32
+	btcAddressRegexStringBech32    = `^([bB][cC]1)[02-9ac-hj-np-zAC-HJ-NP-Z]{7,76}$`   // bitcoin bech32 address https://en.bitcoin.it/wiki/Bech32
 	ethAddressRegexString          = `^0x[0-9a-fA-F]{40}$`
+	ethAddressUpperRegexString     = `^0x[0-9A-F]{40}$`
+	ethAddressLowerRegexString     = `^0x[0-9a-f]{40}$`
 )
 
 var (
@@ -70,4 +72,6 @@ var (
 	btcAddressRegex          = regexp.MustCompile(btcAddressRegexString)
 	btcAddressRegexBech32    = regexp.MustCompile(btcAddressRegexStringBech32)
 	ethAddressRegex          = regexp.MustCompile(ethAddressRegexString)
+	ethaddressRegexUpper     = regexp.MustCompile(ethAddressUpperRegexString)
+	ethAddressRegexLower     = regexp.MustCompile(ethAddressLowerRegexString)
 )

validator_test.go

@@ -4452,12 +4452,8 @@ func TestBitcoinAddressValidation(t *testing.T){
 		{"3P141597f3E4gFr7JterCCQh9QjiTjiZrG", false}, // invalid p2sh address with valid characters
 		{"1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2", true}, // valid p2pkh address
 		{"3P14159f73E4gFr7JterCCQh9QjiTjiZrG", true}, // valid p2sh address
-		{"bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq", true}, // valid bech32 address
-
 	}
 
-
-
 	for i, test := range tests {
 
 		errs := validate.Var(test.param, "btc_addr")
@@ -4479,6 +4475,49 @@ func TestBitcoinAddressValidation(t *testing.T){
 	}
 }
 
+func TestBitcoinBech32AddressValidation(t *testing.T){
+
+	validate := New()
+
+	tests := []struct {
+		param    string
+		expected bool
+	}{
+		{"", false},
+		{"bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t5", false}, // invalid bech32 address with invalid startingcharacters
+		{"BC13W508D6QEJXTDG4Y5R3ZARVARY0C5XW7KN40WF2", false},
+		{"bc1rw5uspcuh", false},
+		{"bc10w508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7kw5rljs90", false},
+		{"BC1QR508D6QEJXTDG4Y5R3ZARVARYV98GJ9P", false},
+		{"bc10w508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7kw5rljs90", false},
+		{"bc1zw508d6qejxtdg4y5r3zarvaryvqyzf3du", false},
+		{"bc1gmk9yu", false},
+		{"BC1QW508D6QEJXTDG4Y5R3ZARVARY0C5XW7KV8F3T4", true},
+		{"bc1pw508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7k7grplx", true},
+		{"BC1SW50QA3JX3S", true},
+		{"bc1zw508d6qejxtdg4y5r3zarvaryvg6kdaj", true},
+	}
+
+	for i, test := range tests {
+
+		errs := validate.Var(test.param, "btc_addr_bech32")
+
+		if test.expected {
+			if !IsEqual(errs, nil) {
+				t.Fatalf("Index: %d btc_addr_bech32 failed with Error: %s", i, errs)
+			}
+		} else {
+			if IsEqual(errs, nil) {
+				t.Fatalf("Index: %d btc_addr_bech32 failed with Error: %s", i, errs)
+			} else {
+				val := getError(errs, "", "")
+				if val.Tag() != "btc_addr_bech32" {
+					t.Fatalf("Index: %d Latitude failed with Error: %s", i, errs)
+				}
+			}
+		}
+	}
+}
 
 
 func TestNoStructLevelValidation(t *testing.T) {