Bitcoin Core  27.99.0
P2P Digital Currency
key_io.cpp
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1 // Copyright (c) 2014-2021 The Bitcoin Core developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 
5 #include <key_io.h>
6 
7 #include <base58.h>
8 #include <bech32.h>
9 #include <script/interpreter.h>
10 #include <script/solver.h>
11 #include <tinyformat.h>
12 #include <util/strencodings.h>
13 
14 #include <algorithm>
15 #include <assert.h>
16 #include <string.h>
17 
19 static constexpr std::size_t BECH32_WITNESS_PROG_MAX_LEN = 40;
20 
21 namespace {
22 class DestinationEncoder
23 {
24 private:
25  const CChainParams& m_params;
26 
27 public:
28  explicit DestinationEncoder(const CChainParams& params) : m_params(params) {}
29 
30  std::string operator()(const PKHash& id) const
31  {
32  std::vector<unsigned char> data = m_params.Base58Prefix(CChainParams::PUBKEY_ADDRESS);
33  data.insert(data.end(), id.begin(), id.end());
34  return EncodeBase58Check(data);
35  }
36 
37  std::string operator()(const ScriptHash& id) const
38  {
39  std::vector<unsigned char> data = m_params.Base58Prefix(CChainParams::SCRIPT_ADDRESS);
40  data.insert(data.end(), id.begin(), id.end());
41  return EncodeBase58Check(data);
42  }
43 
44  std::string operator()(const WitnessV0KeyHash& id) const
45  {
46  std::vector<unsigned char> data = {0};
47  data.reserve(33);
48  ConvertBits<8, 5, true>([&](unsigned char c) { data.push_back(c); }, id.begin(), id.end());
49  return bech32::Encode(bech32::Encoding::BECH32, m_params.Bech32HRP(), data);
50  }
51 
52  std::string operator()(const WitnessV0ScriptHash& id) const
53  {
54  std::vector<unsigned char> data = {0};
55  data.reserve(53);
56  ConvertBits<8, 5, true>([&](unsigned char c) { data.push_back(c); }, id.begin(), id.end());
57  return bech32::Encode(bech32::Encoding::BECH32, m_params.Bech32HRP(), data);
58  }
59 
60  std::string operator()(const WitnessV1Taproot& tap) const
61  {
62  std::vector<unsigned char> data = {1};
63  data.reserve(53);
64  ConvertBits<8, 5, true>([&](unsigned char c) { data.push_back(c); }, tap.begin(), tap.end());
65  return bech32::Encode(bech32::Encoding::BECH32M, m_params.Bech32HRP(), data);
66  }
67 
68  std::string operator()(const WitnessUnknown& id) const
69  {
70  const std::vector<unsigned char>& program = id.GetWitnessProgram();
71  if (id.GetWitnessVersion() < 1 || id.GetWitnessVersion() > 16 || program.size() < 2 || program.size() > 40) {
72  return {};
73  }
74  std::vector<unsigned char> data = {(unsigned char)id.GetWitnessVersion()};
75  data.reserve(1 + (program.size() * 8 + 4) / 5);
76  ConvertBits<8, 5, true>([&](unsigned char c) { data.push_back(c); }, program.begin(), program.end());
77  return bech32::Encode(bech32::Encoding::BECH32M, m_params.Bech32HRP(), data);
78  }
79 
80  std::string operator()(const CNoDestination& no) const { return {}; }
81  std::string operator()(const PubKeyDestination& pk) const { return {}; }
82 };
83 
84 CTxDestination DecodeDestination(const std::string& str, const CChainParams& params, std::string& error_str, std::vector<int>* error_locations)
85 {
86  std::vector<unsigned char> data;
87  uint160 hash;
88  error_str = "";
89 
90  // Note this will be false if it is a valid Bech32 address for a different network
91  bool is_bech32 = (ToLower(str.substr(0, params.Bech32HRP().size())) == params.Bech32HRP());
92 
93  if (!is_bech32 && DecodeBase58Check(str, data, 21)) {
94  // base58-encoded Bitcoin addresses.
95  // Public-key-hash-addresses have version 0 (or 111 testnet).
96  // The data vector contains RIPEMD160(SHA256(pubkey)), where pubkey is the serialized public key.
97  const std::vector<unsigned char>& pubkey_prefix = params.Base58Prefix(CChainParams::PUBKEY_ADDRESS);
98  if (data.size() == hash.size() + pubkey_prefix.size() && std::equal(pubkey_prefix.begin(), pubkey_prefix.end(), data.begin())) {
99  std::copy(data.begin() + pubkey_prefix.size(), data.end(), hash.begin());
100  return PKHash(hash);
101  }
102  // Script-hash-addresses have version 5 (or 196 testnet).
103  // The data vector contains RIPEMD160(SHA256(cscript)), where cscript is the serialized redemption script.
104  const std::vector<unsigned char>& script_prefix = params.Base58Prefix(CChainParams::SCRIPT_ADDRESS);
105  if (data.size() == hash.size() + script_prefix.size() && std::equal(script_prefix.begin(), script_prefix.end(), data.begin())) {
106  std::copy(data.begin() + script_prefix.size(), data.end(), hash.begin());
107  return ScriptHash(hash);
108  }
109 
110  // If the prefix of data matches either the script or pubkey prefix, the length must have been wrong
111  if ((data.size() >= script_prefix.size() &&
112  std::equal(script_prefix.begin(), script_prefix.end(), data.begin())) ||
113  (data.size() >= pubkey_prefix.size() &&
114  std::equal(pubkey_prefix.begin(), pubkey_prefix.end(), data.begin()))) {
115  error_str = "Invalid length for Base58 address (P2PKH or P2SH)";
116  } else {
117  error_str = "Invalid or unsupported Base58-encoded address.";
118  }
119  return CNoDestination();
120  } else if (!is_bech32) {
121  // Try Base58 decoding without the checksum, using a much larger max length
122  if (!DecodeBase58(str, data, 100)) {
123  error_str = "Invalid or unsupported Segwit (Bech32) or Base58 encoding.";
124  } else {
125  error_str = "Invalid checksum or length of Base58 address (P2PKH or P2SH)";
126  }
127  return CNoDestination();
128  }
129 
130  data.clear();
131  const auto dec = bech32::Decode(str);
132  if (dec.encoding == bech32::Encoding::BECH32 || dec.encoding == bech32::Encoding::BECH32M) {
133  if (dec.data.empty()) {
134  error_str = "Empty Bech32 data section";
135  return CNoDestination();
136  }
137  // Bech32 decoding
138  if (dec.hrp != params.Bech32HRP()) {
139  error_str = strprintf("Invalid or unsupported prefix for Segwit (Bech32) address (expected %s, got %s).", params.Bech32HRP(), dec.hrp);
140  return CNoDestination();
141  }
142  int version = dec.data[0]; // The first 5 bit symbol is the witness version (0-16)
143  if (version == 0 && dec.encoding != bech32::Encoding::BECH32) {
144  error_str = "Version 0 witness address must use Bech32 checksum";
145  return CNoDestination();
146  }
147  if (version != 0 && dec.encoding != bech32::Encoding::BECH32M) {
148  error_str = "Version 1+ witness address must use Bech32m checksum";
149  return CNoDestination();
150  }
151  // The rest of the symbols are converted witness program bytes.
152  data.reserve(((dec.data.size() - 1) * 5) / 8);
153  if (ConvertBits<5, 8, false>([&](unsigned char c) { data.push_back(c); }, dec.data.begin() + 1, dec.data.end())) {
154 
155  std::string_view byte_str{data.size() == 1 ? "byte" : "bytes"};
156 
157  if (version == 0) {
158  {
159  WitnessV0KeyHash keyid;
160  if (data.size() == keyid.size()) {
161  std::copy(data.begin(), data.end(), keyid.begin());
162  return keyid;
163  }
164  }
165  {
166  WitnessV0ScriptHash scriptid;
167  if (data.size() == scriptid.size()) {
168  std::copy(data.begin(), data.end(), scriptid.begin());
169  return scriptid;
170  }
171  }
172 
173  error_str = strprintf("Invalid Bech32 v0 address program size (%d %s), per BIP141", data.size(), byte_str);
174  return CNoDestination();
175  }
176 
177  if (version == 1 && data.size() == WITNESS_V1_TAPROOT_SIZE) {
179  WitnessV1Taproot tap;
180  std::copy(data.begin(), data.end(), tap.begin());
181  return tap;
182  }
183 
184  if (version > 16) {
185  error_str = "Invalid Bech32 address witness version";
186  return CNoDestination();
187  }
188 
189  if (data.size() < 2 || data.size() > BECH32_WITNESS_PROG_MAX_LEN) {
190  error_str = strprintf("Invalid Bech32 address program size (%d %s)", data.size(), byte_str);
191  return CNoDestination();
192  }
193 
194  return WitnessUnknown{version, data};
195  } else {
196  error_str = strprintf("Invalid padding in Bech32 data section");
197  return CNoDestination();
198  }
199  }
200 
201  // Perform Bech32 error location
202  auto res = bech32::LocateErrors(str);
203  error_str = res.first;
204  if (error_locations) *error_locations = std::move(res.second);
205  return CNoDestination();
206 }
207 } // namespace
208 
209 CKey DecodeSecret(const std::string& str)
210 {
211  CKey key;
212  std::vector<unsigned char> data;
213  if (DecodeBase58Check(str, data, 34)) {
214  const std::vector<unsigned char>& privkey_prefix = Params().Base58Prefix(CChainParams::SECRET_KEY);
215  if ((data.size() == 32 + privkey_prefix.size() || (data.size() == 33 + privkey_prefix.size() && data.back() == 1)) &&
216  std::equal(privkey_prefix.begin(), privkey_prefix.end(), data.begin())) {
217  bool compressed = data.size() == 33 + privkey_prefix.size();
218  key.Set(data.begin() + privkey_prefix.size(), data.begin() + privkey_prefix.size() + 32, compressed);
219  }
220  }
221  if (!data.empty()) {
222  memory_cleanse(data.data(), data.size());
223  }
224  return key;
225 }
226 
227 std::string EncodeSecret(const CKey& key)
228 {
229  assert(key.IsValid());
230  std::vector<unsigned char> data = Params().Base58Prefix(CChainParams::SECRET_KEY);
231  data.insert(data.end(), UCharCast(key.begin()), UCharCast(key.end()));
232  if (key.IsCompressed()) {
233  data.push_back(1);
234  }
235  std::string ret = EncodeBase58Check(data);
236  memory_cleanse(data.data(), data.size());
237  return ret;
238 }
239 
240 CExtPubKey DecodeExtPubKey(const std::string& str)
241 {
242  CExtPubKey key;
243  std::vector<unsigned char> data;
244  if (DecodeBase58Check(str, data, 78)) {
245  const std::vector<unsigned char>& prefix = Params().Base58Prefix(CChainParams::EXT_PUBLIC_KEY);
246  if (data.size() == BIP32_EXTKEY_SIZE + prefix.size() && std::equal(prefix.begin(), prefix.end(), data.begin())) {
247  key.Decode(data.data() + prefix.size());
248  }
249  }
250  return key;
251 }
252 
253 std::string EncodeExtPubKey(const CExtPubKey& key)
254 {
255  std::vector<unsigned char> data = Params().Base58Prefix(CChainParams::EXT_PUBLIC_KEY);
256  size_t size = data.size();
257  data.resize(size + BIP32_EXTKEY_SIZE);
258  key.Encode(data.data() + size);
259  std::string ret = EncodeBase58Check(data);
260  return ret;
261 }
262 
263 CExtKey DecodeExtKey(const std::string& str)
264 {
265  CExtKey key;
266  std::vector<unsigned char> data;
267  if (DecodeBase58Check(str, data, 78)) {
268  const std::vector<unsigned char>& prefix = Params().Base58Prefix(CChainParams::EXT_SECRET_KEY);
269  if (data.size() == BIP32_EXTKEY_SIZE + prefix.size() && std::equal(prefix.begin(), prefix.end(), data.begin())) {
270  key.Decode(data.data() + prefix.size());
271  }
272  }
273  return key;
274 }
275 
276 std::string EncodeExtKey(const CExtKey& key)
277 {
278  std::vector<unsigned char> data = Params().Base58Prefix(CChainParams::EXT_SECRET_KEY);
279  size_t size = data.size();
280  data.resize(size + BIP32_EXTKEY_SIZE);
281  key.Encode(data.data() + size);
282  std::string ret = EncodeBase58Check(data);
283  memory_cleanse(data.data(), data.size());
284  return ret;
285 }
286 
287 std::string EncodeDestination(const CTxDestination& dest)
288 {
289  return std::visit(DestinationEncoder(Params()), dest);
290 }
291 
292 CTxDestination DecodeDestination(const std::string& str, std::string& error_msg, std::vector<int>* error_locations)
293 {
294  return DecodeDestination(str, Params(), error_msg, error_locations);
295 }
296 
297 CTxDestination DecodeDestination(const std::string& str)
298 {
299  std::string error_msg;
300  return DecodeDestination(str, error_msg);
301 }
302 
303 bool IsValidDestinationString(const std::string& str, const CChainParams& params)
304 {
305  std::string error_msg;
306  return IsValidDestination(DecodeDestination(str, params, error_msg, nullptr));
307 }
308 
309 bool IsValidDestinationString(const std::string& str)
310 {
311  return IsValidDestinationString(str, Params());
312 }
bool IsValidDestination(const CTxDestination &dest)
Check whether a CTxDestination corresponds to one with an address.
std::variant< CNoDestination, PubKeyDestination, PKHash, ScriptHash, WitnessV0ScriptHash, WitnessV0KeyHash, WitnessV1Taproot, WitnessUnknown > CTxDestination
A txout script categorized into standard templates.
Definition: addresstype.h:131
std::string EncodeBase58Check(Span< const unsigned char > input)
Encode a byte span into a base58-encoded string, including checksum.
Definition: base58.cpp:135
static bool DecodeBase58Check(const char *psz, std::vector< unsigned char > &vchRet, int max_ret_len)
Definition: base58.cpp:144
static bool DecodeBase58(const char *psz, std::vector< unsigned char > &vch, int max_ret_len)
Definition: base58.cpp:38
int ret
const CChainParams & Params()
Return the currently selected parameters.
size_t size() const
Definition: hash_type.h:63
unsigned char * begin()
Definition: hash_type.h:18
CChainParams defines various tweakable parameters of a given instance of the Bitcoin system.
Definition: chainparams.h:81
const std::vector< unsigned char > & Base58Prefix(Base58Type type) const
Definition: chainparams.h:117
const std::string & Bech32HRP() const
Definition: chainparams.h:118
An encapsulated private key.
Definition: key.h:33
const std::byte * end() const
Definition: key.h:116
bool IsValid() const
Check whether this private key is valid.
Definition: key.h:119
bool IsCompressed() const
Check whether the public key corresponding to this private key is (to be) compressed.
Definition: key.h:122
void Set(const T pbegin, const T pend, bool fCompressedIn)
Initialize using begin and end iterators to byte data.
Definition: key.h:99
const std::byte * begin() const
Definition: key.h:115
const unsigned char * begin() const
Definition: pubkey.h:295
static constexpr size_t size()
Definition: pubkey.h:293
const unsigned char * end() const
Definition: pubkey.h:296
static constexpr unsigned int size()
Definition: uint256.h:74
constexpr unsigned char * begin()
Definition: uint256.h:68
160-bit opaque blob.
Definition: uint256.h:95
void memory_cleanse(void *ptr, size_t len)
Secure overwrite a buffer (possibly containing secret data) with zero-bytes.
Definition: cleanse.cpp:14
static constexpr size_t WITNESS_V1_TAPROOT_SIZE
Definition: interpreter.h:229
static constexpr std::size_t BECH32_WITNESS_PROG_MAX_LEN
Maximum witness length for Bech32 addresses.
Definition: key_io.cpp:19
bool IsValidDestinationString(const std::string &str, const CChainParams &params)
Definition: key_io.cpp:303
std::string EncodeExtKey(const CExtKey &key)
Definition: key_io.cpp:276
CExtPubKey DecodeExtPubKey(const std::string &str)
Definition: key_io.cpp:240
CTxDestination DecodeDestination(const std::string &str, std::string &error_msg, std::vector< int > *error_locations)
Definition: key_io.cpp:292
std::string EncodeSecret(const CKey &key)
Definition: key_io.cpp:227
std::string EncodeDestination(const CTxDestination &dest)
Definition: key_io.cpp:287
CKey DecodeSecret(const std::string &str)
Definition: key_io.cpp:209
std::string EncodeExtPubKey(const CExtPubKey &key)
Definition: key_io.cpp:253
CExtKey DecodeExtKey(const std::string &str)
Definition: key_io.cpp:263
@ BECH32
Bech32 encoding as defined in BIP173.
@ BECH32M
Bech32m encoding as defined in BIP350.
std::string Encode(Encoding encoding, const std::string &hrp, const data &values)
Encode a Bech32 or Bech32m string.
Definition: bech32.cpp:357
DecodeResult Decode(const std::string &str)
Decode a Bech32 or Bech32m string.
Definition: bech32.cpp:373
std::pair< std::string, std::vector< int > > LocateErrors(const std::string &str)
Find index of an incorrect character in a Bech32 string.
Definition: bech32.cpp:400
const unsigned int BIP32_EXTKEY_SIZE
Definition: pubkey.h:19
const char * prefix
Definition: rest.cpp:1005
unsigned char * UCharCast(char *c)
Definition: span.h:288
Definition: key.h:210
void Decode(const unsigned char code[BIP32_EXTKEY_SIZE])
Definition: key.cpp:420
void Encode(unsigned char code[BIP32_EXTKEY_SIZE]) const
Definition: key.cpp:410
void Encode(unsigned char code[BIP32_EXTKEY_SIZE]) const
Definition: pubkey.cpp:378
void Decode(const unsigned char code[BIP32_EXTKEY_SIZE])
Definition: pubkey.cpp:387
CTxDestination subtype to encode any future Witness version.
Definition: addresstype.h:95
#define strprintf
Format arguments and return the string or write to given std::ostream (see tinyformat::format doc for...
Definition: tinyformat.h:1162
std::string ToLower(std::string_view str)
Returns the lowercase equivalent of the given string.
assert(!tx.IsCoinBase())