1// Copyright (c) 2009-2010 Satoshi Nakamoto
2// Copyright (c) 2009-present 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#ifndef BITCOIN_COMMON_SIGNMESSAGE_H
7#define BITCOIN_COMMON_SIGNMESSAGE_H
8
9#include <uint256.h>
10
11#include <string>
12
13class CKey;
14
15extern const std::string MESSAGE_MAGIC;
16
17/** The result of a signed message verification.
18 * Message verification takes as an input:
19 * - address (with whose private key the message is supposed to have been signed)
20 * - signature
21 * - message
22 */
23enum class MessageVerificationResult {
24    //! The provided address is invalid.
25    ERR_INVALID_ADDRESS,
26
27    //! The provided address is valid but does not refer to a public key.
28    ERR_ADDRESS_NO_KEY,
29
30    //! The provided signature couldn't be parsed (maybe invalid base64).
31    ERR_MALFORMED_SIGNATURE,
32
33    //! A public key could not be recovered from the provided signature and message.
34    ERR_PUBKEY_NOT_RECOVERED,
35
36    //! The message was not signed with the private key of the provided address.
37    ERR_NOT_SIGNED,
38
39    //! The message verification was successful.
40    OK
41};
42
43enum class SigningResult {
44    OK, //!< No error
45    PRIVATE_KEY_NOT_AVAILABLE,
46    SIGNING_FAILED,
47};
48
49/** Verify a signed message.
50 * @param[in] address Signer's bitcoin address, it must refer to a public key.
51 * @param[in] signature The signature in base64 format.
52 * @param[in] message The message that was signed.
53 * @return result code */
54MessageVerificationResult MessageVerify(
55    const std::string& address,
56    const std::string& signature,
57    const std::string& message);
58
59/** Sign a message.
60 * @param[in] privkey Private key to sign with.
61 * @param[in] message The message to sign.
62 * @param[out] signature Signature, base64 encoded, only set if true is returned.
63 * @return true if signing was successful. */
64bool MessageSign(
65    const CKey& privkey,
66    const std::string& message,
67    std::string& signature);
68
69/**
70 * Hashes a message for signing and verification in a manner that prevents
71 * inadvertently signing a transaction.
72 */
73uint256 MessageHash(const std::string& message);
74
75std::string SigningResultString(SigningResult res);
76
77#endif // BITCOIN_COMMON_SIGNMESSAGE_H
78