From e4925b4abe0b7bc18820a60da24e510f042c027a Mon Sep 17 00:00:00 2001 From: Josh Rickmar Date: Wed, 11 Sep 2013 20:52:35 -0400 Subject: [PATCH] Add functions to encode and decode payment addresses. --- addrconvs.go | 78 ++++++++++++++++++++++++++++++++++++++++++++ addrconvs_test.go | 83 +++++++++++++++++++++++++++++++++++++++++++++++ test_coverage.txt | 33 ++++++++++--------- 3 files changed, 178 insertions(+), 16 deletions(-) create mode 100644 addrconvs.go create mode 100644 addrconvs_test.go diff --git a/addrconvs.go b/addrconvs.go new file mode 100644 index 0000000..205b220 --- /dev/null +++ b/addrconvs.go @@ -0,0 +1,78 @@ +package btcutil + +import ( + "bytes" + "code.google.com/p/go.crypto/ripemd160" + "errors" + "github.com/conformal/btcwire" +) + +// ErrAddrUnknownNet describes an error where the address identifier +// byte is not recognized as belonging to neither the Bitcoin MainNet nor +// TestNet. +var ErrAddrUnknownNet = errors.New("unrecognized network identifier byte") + +// ErrMalformedAddress describes an error where an address is improperly +// formatted, either due to an incorrect length of the hashed pubkey or +// a non-matching checksum. +var ErrMalformedAddress = errors.New("malformed address") + +// Constants used to specify which network a payment address belongs +// to. Mainnet address cannot be used on the Testnet, and vice versa. +const ( + // MainNetAddr is the address identifier for MainNet + MainNetAddr = 0x00 + + // TestNetAddr is the address identifier for TestNet + TestNetAddr = 0x6f +) + +// EncodeAddress takes a 20-byte raw payment address (hash160 of the +// uncompressed pubkey) and a network identifying byte and encodes the +// payment address in a human readable string. +func EncodeAddress(addrHash []byte, netID byte) (encoded string, err error) { + if len(addrHash) != ripemd160.Size { + return "", ErrMalformedAddress + } + if netID != MainNetAddr && netID != TestNetAddr { + return "", ErrAddrUnknownNet + } + + tosum := append([]byte{netID}, addrHash...) + cksum := btcwire.DoubleSha256(tosum) + + a := append([]byte{netID}, addrHash...) + a = append(a, cksum[:4]...) + + return Base58Encode(a), nil +} + +// DecodeAddress decodes a human readable payment address string +// returning the 20-byte decoded address, along with the network +// identifying byte. +func DecodeAddress(addr string) (addrHash []byte, netID byte, err error) { + decoded := Base58Decode(addr) + + // Length of decoded address must be 20 bytes + 1 byte for a network + // identifier byte + 4 bytes of checksum. + if len(decoded) != ripemd160.Size+5 { + return nil, 0x00, ErrMalformedAddress + } + + netID = decoded[0] + if netID != MainNetAddr && netID != TestNetAddr { + return nil, 0x00, ErrAddrUnknownNet + } + addrHash = decoded[1:21] + + // Checksum is first four bytes of double SHA256 of the network byte + // and addrHash. Verify this matches the final 4 bytes of the decoded + // address. + tosum := append([]byte{netID}, addrHash...) + cksum := btcwire.DoubleSha256(tosum)[:4] + if !bytes.Equal(cksum, decoded[len(decoded)-4:]) { + return nil, 0x00, ErrMalformedAddress + } + + return addrHash, netID, nil +} diff --git a/addrconvs_test.go b/addrconvs_test.go new file mode 100644 index 0000000..68fde5f --- /dev/null +++ b/addrconvs_test.go @@ -0,0 +1,83 @@ +// Copyright (c) 2013 Conformal Systems LLC. +// Use of this source code is governed by an ISC +// license that can be found in the LICENSE file. + +package btcutil_test + +import ( + "bytes" + "github.com/conformal/btcutil" + "testing" +) + +var encodeTests = []struct { + raw []byte + net byte + res string + err error +}{ + {[]byte{0xe3, 0x4c, 0xce, 0x70, 0xc8, 0x63, 0x73, 0x27, 0x3e, 0xfc, 0xc5, 0x4c, 0xe7, 0xd2, 0xa4, 0x91, 0xbb, 0x4a, 0x0e, 0x84}, + btcutil.MainNetAddr, "1MirQ9bwyQcGVJPwKUgapu5ouK2E2Ey4gX", nil}, + {[]byte{0x0e, 0xf0, 0x30, 0x10, 0x7f, 0xd2, 0x6e, 0x0b, 0x6b, 0xf4, 0x05, 0x12, 0xbc, 0xa2, 0xce, 0xb1, 0xdd, 0x80, 0xad, 0xaa}, + btcutil.MainNetAddr, "12MzCDwodF9G1e7jfwLXfR164RNtx4BRVG", nil}, + {[]byte{0x78, 0xb3, 0x16, 0xa0, 0x86, 0x47, 0xd5, 0xb7, 0x72, 0x83, 0xe5, 0x12, 0xd3, 0x60, 0x3f, 0x1f, 0x1c, 0x8d, 0xe6, 0x8f}, + btcutil.TestNetAddr, "mrX9vMRYLfVy1BnZbc5gZjuyaqH3ZW2ZHz", nil}, + + // Raw address not 20 bytes (padded with leading 0s) + {[]byte{0x00, 0x0e, 0xf0, 0x30, 0x10, 0x7f, 0xd2, 0x6e, 0x0b, 0x6b, 0xf4, 0x05, 0x12, 0xbc, 0xa2, 0xce, 0xb1, 0xdd, 0x80, 0xad, 0xaa}, + btcutil.MainNetAddr, "12MzCDwodF9G1e7jfwLXfR164RNtx4BRVG", btcutil.ErrMalformedAddress}, + + // Bad network byte + {make([]byte, 20), btcutil.MainNetAddr + 1, "", btcutil.ErrAddrUnknownNet}, +} + +func TestEncodeAddresses(t *testing.T) { + for i := range encodeTests { + res, err := btcutil.EncodeAddress(encodeTests[i].raw, + encodeTests[i].net) + if err != encodeTests[i].err { + t.Error(err) + continue + } + if err == nil && res != encodeTests[i].res { + t.Errorf("Results differ: Expected '%s', returned '%s'", + encodeTests[i].res, res) + } + } +} + +var decodeTests = []struct { + addr string + res []byte + net byte + err error +}{ + {"1MirQ9bwyQcGVJPwKUgapu5ouK2E2Ey4gX", + []byte{0xe3, 0x4c, 0xce, 0x70, 0xc8, 0x63, 0x73, 0x27, 0x3e, 0xfc, 0xc5, 0x4c, 0xe7, 0xd2, 0xa4, 0x91, 0xbb, 0x4a, 0x0e, 0x84}, + btcutil.MainNetAddr, nil}, + {"mrX9vMRYLfVy1BnZbc5gZjuyaqH3ZW2ZHz", + []byte{0x78, 0xb3, 0x16, 0xa0, 0x86, 0x47, 0xd5, 0xb7, 0x72, 0x83, 0xe5, 0x12, 0xd3, 0x60, 0x3f, 0x1f, 0x1c, 0x8d, 0xe6, 0x8f}, + btcutil.TestNetAddr, nil}, + + // Wrong length + {"01MirQ9bwyQcGVJPwKUgapu5ouK2E2Ey4gX", nil, btcutil.MainNetAddr, btcutil.ErrMalformedAddress}, + + // Bad magic + {"2MirQ9bwyQcGVJPwKUgapu5ouK2E2Ey4gX", nil, btcutil.MainNetAddr, btcutil.ErrAddrUnknownNet}, + + // Bad checksum + {"1MirQ9bwyQcGVJPwKUgapu5ouK2E2dpuqz", nil, btcutil.MainNetAddr, btcutil.ErrMalformedAddress}, +} + +func TestDecodeAddresses(t *testing.T) { + for i := range decodeTests { + res, _, err := btcutil.DecodeAddress(decodeTests[i].addr) + if err != decodeTests[i].err { + t.Error(err) + } + if err == nil && !bytes.Equal(res, decodeTests[i].res) { + t.Errorf("Results differ: Expected '%v', returned '%v'", + decodeTests[i].res, res) + } + } +} diff --git a/test_coverage.txt b/test_coverage.txt index 8145603..56a8bae 100644 --- a/test_coverage.txt +++ b/test_coverage.txt @@ -1,18 +1,19 @@ -github.com/conformal/btcutil/base58.go Base58Decode 100.00% (20/20) -github.com/conformal/btcutil/block.go Block.TxSha 100.00% (11/11) -github.com/conformal/btcutil/block.go Block.TxShas 100.00% (10/10) -github.com/conformal/btcutil/block.go NewBlockFromBytes 100.00% (7/7) -github.com/conformal/btcutil/block.go Block.Sha 100.00% (5/5) -github.com/conformal/btcutil/block.go NewBlockFromBlockAndBytes 100.00% (1/1) -github.com/conformal/btcutil/block.go OutOfRangeError.Error 100.00% (1/1) -github.com/conformal/btcutil/block.go Block.Height 100.00% (1/1) -github.com/conformal/btcutil/block.go Block.SetHeight 100.00% (1/1) -github.com/conformal/btcutil/block.go NewBlock 100.00% (1/1) -github.com/conformal/btcutil/block.go Block.ProtocolVersion 100.00% (1/1) -github.com/conformal/btcutil/block.go Block.MsgBlock 100.00% (1/1) -github.com/conformal/btcutil/base58.go Base58Encode 93.33% (14/15) -github.com/conformal/btcutil/block.go Block.TxLoc 88.89% (8/9) -github.com/conformal/btcutil/block.go Block.Bytes 88.89% (8/9) -github.com/conformal/btcutil ------------------------- 96.77% (90/93) +github.com/conformal/btcutil/base58.go Base58Decode 100.00% (20/20) +github.com/conformal/btcutil/base58.go Base58Encode 100.00% (15/15) +github.com/conformal/btcutil/addrconvs.go DecodeAddress 100.00% (12/12) +github.com/conformal/btcutil/block.go Block.TxSha 100.00% (11/11) +github.com/conformal/btcutil/block.go Block.TxShas 100.00% (10/10) +github.com/conformal/btcutil/addrconvs.go EncodeAddress 100.00% (9/9) +github.com/conformal/btcutil/block.go NewBlockFromBytes 100.00% (7/7) +github.com/conformal/btcutil/block.go Block.Sha 100.00% (5/5) +github.com/conformal/btcutil/block.go OutOfRangeError.Error 100.00% (1/1) +github.com/conformal/btcutil/block.go Block.Height 100.00% (1/1) +github.com/conformal/btcutil/block.go Block.SetHeight 100.00% (1/1) +github.com/conformal/btcutil/block.go NewBlock 100.00% (1/1) +github.com/conformal/btcutil/block.go NewBlockFromBlockAndBytes 100.00% (1/1) +github.com/conformal/btcutil/block.go Block.MsgBlock 100.00% (1/1) +github.com/conformal/btcutil/block.go Block.TxLoc 88.89% (8/9) +github.com/conformal/btcutil/block.go Block.Bytes 88.89% (8/9) +github.com/conformal/btcutil ------------------------- 98.23% (111/113)