1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2014 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.
6 #ifndef BITCOIN_PUBKEY_H
7 #define BITCOIN_PUBKEY_H
10 #include "serialize.h"
18 * const unsigned int PRIVATE_KEY_SIZE = 279;
19 * const unsigned int PUBLIC_KEY_SIZE = 65;
20 * const unsigned int SIGNATURE_SIZE = 72;
22 * see www.keylength.com
23 * script supports up to 75 for single byte push
26 /** A reference to a CKey: the Hash160 of its serialized public key */
27 class CKeyID
: public uint160
30 CKeyID() : uint160() {}
31 CKeyID(const uint160
& in
) : uint160(in
) {}
34 typedef uint256 ChainCode
;
36 /** An encapsulated public key. */
42 * Just store the serialized data.
43 * Its length can very cheaply be computed from the first byte.
45 unsigned char vch
[65];
47 //! Compute the length of a pubkey with a given first byte.
48 unsigned int static GetLen(unsigned char chHeader
)
50 if (chHeader
== 2 || chHeader
== 3)
52 if (chHeader
== 4 || chHeader
== 6 || chHeader
== 7)
57 //! Set this key data to be invalid
64 //! Construct an invalid public key.
70 //! Initialize a public key using begin/end iterators to byte data.
72 void Set(const T pbegin
, const T pend
)
74 int len
= pend
== pbegin
? 0 : GetLen(pbegin
[0]);
75 if (len
&& len
== (pend
- pbegin
))
76 memcpy(vch
, (unsigned char*)&pbegin
[0], len
);
81 //! Construct a public key using begin/end iterators to byte data.
83 CPubKey(const T pbegin
, const T pend
)
88 //! Construct a public key from a byte vector.
89 CPubKey(const std::vector
<unsigned char>& vch
)
91 Set(vch
.begin(), vch
.end());
94 //! Simple read-only vector-like interface to the pubkey data.
95 unsigned int size() const { return GetLen(vch
[0]); }
96 const unsigned char* begin() const { return vch
; }
97 const unsigned char* end() const { return vch
+ size(); }
98 const unsigned char& operator[](unsigned int pos
) const { return vch
[pos
]; }
100 //! Comparator implementation.
101 friend bool operator==(const CPubKey
& a
, const CPubKey
& b
)
103 return a
.vch
[0] == b
.vch
[0] &&
104 memcmp(a
.vch
, b
.vch
, a
.size()) == 0;
106 friend bool operator!=(const CPubKey
& a
, const CPubKey
& b
)
110 friend bool operator<(const CPubKey
& a
, const CPubKey
& b
)
112 return a
.vch
[0] < b
.vch
[0] ||
113 (a
.vch
[0] == b
.vch
[0] && memcmp(a
.vch
, b
.vch
, a
.size()) < 0);
116 //! Implement serialization, as if this was a byte vector.
117 unsigned int GetSerializeSize(int nType
, int nVersion
) const
121 template <typename Stream
>
122 void Serialize(Stream
& s
, int nType
, int nVersion
) const
124 unsigned int len
= size();
125 ::WriteCompactSize(s
, len
);
126 s
.write((char*)vch
, len
);
128 template <typename Stream
>
129 void Unserialize(Stream
& s
, int nType
, int nVersion
)
131 unsigned int len
= ::ReadCompactSize(s
);
133 s
.read((char*)vch
, len
);
135 // invalid pubkey, skip available data
143 //! Get the KeyID of this public key (hash of its serialization)
146 return CKeyID(Hash160(vch
, vch
+ size()));
149 //! Get the 256-bit hash of this public key.
150 uint256
GetHash() const
152 return Hash(vch
, vch
+ size());
156 * Check syntactic correctness.
158 * Note that this is consensus critical as CheckSig() calls it!
165 //! fully validate whether this is a valid public key (more expensive than IsValid())
166 bool IsFullyValid() const;
168 //! Check whether this is a compressed public key.
169 bool IsCompressed() const
175 * Verify a DER signature (~72 bytes).
176 * If this public key is not fully valid, the return value will be false.
178 bool Verify(const uint256
& hash
, const std::vector
<unsigned char>& vchSig
) const;
181 * Check whether a signature is normalized (lower-S).
183 static bool CheckLowS(const std::vector
<unsigned char>& vchSig
);
185 //! Recover a public key from a compact signature.
186 bool RecoverCompact(const uint256
& hash
, const std::vector
<unsigned char>& vchSig
);
188 //! Turn this public key into an uncompressed public key.
191 //! Derive BIP32 child pubkey.
192 bool Derive(CPubKey
& pubkeyChild
, ChainCode
&ccChild
, unsigned int nChild
, const ChainCode
& cc
) const;
196 unsigned char nDepth
;
197 unsigned char vchFingerprint
[4];
202 friend bool operator==(const CExtPubKey
&a
, const CExtPubKey
&b
)
204 return a
.nDepth
== b
.nDepth
&& memcmp(&a
.vchFingerprint
[0], &b
.vchFingerprint
[0], 4) == 0 && a
.nChild
== b
.nChild
&&
205 a
.chaincode
== b
.chaincode
&& a
.pubkey
== b
.pubkey
;
208 void Encode(unsigned char code
[74]) const;
209 void Decode(const unsigned char code
[74]);
210 bool Derive(CExtPubKey
& out
, unsigned int nChild
) const;
213 /** Users of this module must hold an ECCVerifyHandle. The constructor and
214 * destructor of these are not allowed to run in parallel, though. */
215 class ECCVerifyHandle
224 #endif // BITCOIN_PUBKEY_H