Bitcoin Core  27.99.0
P2P Digital Currency
message.cpp
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1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2022 The Bitcoin Core developers
3 // Distributed under the MIT software license, see the accompanying
4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
5 
6 #include <hash.h>
7 #include <key.h>
8 #include <key_io.h>
9 #include <pubkey.h>
10 #include <uint256.h>
11 #include <util/message.h>
12 #include <util/strencodings.h>
13 
14 #include <cassert>
15 #include <optional>
16 #include <string>
17 #include <variant>
18 #include <vector>
19 
24 const std::string MESSAGE_MAGIC = "Bitcoin Signed Message:\n";
25 
27  const std::string& address,
28  const std::string& signature,
29  const std::string& message)
30 {
31  CTxDestination destination = DecodeDestination(address);
32  if (!IsValidDestination(destination)) {
34  }
35 
36  if (std::get_if<PKHash>(&destination) == nullptr) {
38  }
39 
40  auto signature_bytes = DecodeBase64(signature);
41  if (!signature_bytes) {
43  }
44 
45  CPubKey pubkey;
46  if (!pubkey.RecoverCompact(MessageHash(message), *signature_bytes)) {
48  }
49 
50  if (!(PKHash(pubkey) == *std::get_if<PKHash>(&destination))) {
52  }
53 
55 }
56 
58  const CKey& privkey,
59  const std::string& message,
60  std::string& signature)
61 {
62  std::vector<unsigned char> signature_bytes;
63 
64  if (!privkey.SignCompact(MessageHash(message), signature_bytes)) {
65  return false;
66  }
67 
68  signature = EncodeBase64(signature_bytes);
69 
70  return true;
71 }
72 
73 uint256 MessageHash(const std::string& message)
74 {
75  HashWriter hasher{};
76  hasher << MESSAGE_MAGIC << message;
77 
78  return hasher.GetHash();
79 }
80 
81 std::string SigningResultString(const SigningResult res)
82 {
83  switch (res) {
84  case SigningResult::OK:
85  return "No error";
87  return "Private key not available";
89  return "Sign failed";
90  // no default case, so the compiler can warn about missing cases
91  }
92  assert(false);
93 }
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
An encapsulated private key.
Definition: key.h:33
bool SignCompact(const uint256 &hash, std::vector< unsigned char > &vchSig) const
Create a compact signature (65 bytes), which allows reconstructing the used public key.
Definition: key.cpp:249
An encapsulated public key.
Definition: pubkey.h:34
bool RecoverCompact(const uint256 &hash, const std::vector< unsigned char > &vchSig)
Recover a public key from a compact signature.
Definition: pubkey.cpp:296
A writer stream (for serialization) that computes a 256-bit hash.
Definition: hash.h:101
256-bit opaque blob.
Definition: uint256.h:106
CTxDestination DecodeDestination(const std::string &str, std::string &error_msg, std::vector< int > *error_locations)
Definition: key_io.cpp:292
SigningResult
Definition: message.h:43
@ PRIVATE_KEY_NOT_AVAILABLE
@ OK
No error.
MessageVerificationResult
The result of a signed message verification.
Definition: message.h:23
@ ERR_MALFORMED_SIGNATURE
The provided signature couldn't be parsed (maybe invalid base64).
@ ERR_INVALID_ADDRESS
The provided address is invalid.
@ ERR_ADDRESS_NO_KEY
The provided address is valid but does not refer to a public key.
@ ERR_NOT_SIGNED
The message was not signed with the private key of the provided address.
@ OK
The message verification was successful.
@ ERR_PUBKEY_NOT_RECOVERED
A public key could not be recovered from the provided signature and message.
uint256 MessageHash(const std::string &message)
Hashes a message for signing and verification in a manner that prevents inadvertently signing a trans...
Definition: message.cpp:73
bool MessageSign(const CKey &privkey, const std::string &message, std::string &signature)
Sign a message.
Definition: message.cpp:57
const std::string MESSAGE_MAGIC
Text used to signify that a signed message follows and to prevent inadvertently signing a transaction...
Definition: message.cpp:24
std::string SigningResultString(const SigningResult res)
Definition: message.cpp:81
MessageVerificationResult MessageVerify(const std::string &address, const std::string &signature, const std::string &message)
Verify a signed message.
Definition: message.cpp:26
std::string EncodeBase64(Span< const unsigned char > input)
std::optional< std::vector< unsigned char > > DecodeBase64(std::string_view str)
assert(!tx.IsCoinBase())