1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
// Copyright (c) 2018-2021 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifndef BITCOIN_SCRIPT_DESCRIPTOR_H
#define BITCOIN_SCRIPT_DESCRIPTOR_H
#include <outputtype.h>
#include <script/script.h>
#include <script/sign.h>
#include <script/signingprovider.h>
#include <optional>
#include <vector>
using ExtPubKeyMap = std::unordered_map<uint32_t, CExtPubKey>;
/** Cache for single descriptor's derived extended pubkeys */
class DescriptorCache {
private:
/** Map key expression index -> map of (key derivation index -> xpub) */
std::unordered_map<uint32_t, ExtPubKeyMap> m_derived_xpubs;
/** Map key expression index -> parent xpub */
ExtPubKeyMap m_parent_xpubs;
/** Map key expression index -> last hardened xpub */
ExtPubKeyMap m_last_hardened_xpubs;
public:
/** Cache a parent xpub
*
* @param[in] key_exp_pos Position of the key expression within the descriptor
* @param[in] xpub The CExtPubKey to cache
*/
void CacheParentExtPubKey(uint32_t key_exp_pos, const CExtPubKey& xpub);
/** Retrieve a cached parent xpub
*
* @param[in] key_exp_pos Position of the key expression within the descriptor
* @param[out] xpub The CExtPubKey to get from cache
*/
bool GetCachedParentExtPubKey(uint32_t key_exp_pos, CExtPubKey& xpub) const;
/** Cache an xpub derived at an index
*
* @param[in] key_exp_pos Position of the key expression within the descriptor
* @param[in] der_index Derivation index of the xpub
* @param[in] xpub The CExtPubKey to cache
*/
void CacheDerivedExtPubKey(uint32_t key_exp_pos, uint32_t der_index, const CExtPubKey& xpub);
/** Retrieve a cached xpub derived at an index
*
* @param[in] key_exp_pos Position of the key expression within the descriptor
* @param[in] der_index Derivation index of the xpub
* @param[out] xpub The CExtPubKey to get from cache
*/
bool GetCachedDerivedExtPubKey(uint32_t key_exp_pos, uint32_t der_index, CExtPubKey& xpub) const;
/** Cache a last hardened xpub
*
* @param[in] key_exp_pos Position of the key expression within the descriptor
* @param[in] xpub The CExtPubKey to cache
*/
void CacheLastHardenedExtPubKey(uint32_t key_exp_pos, const CExtPubKey& xpub);
/** Retrieve a cached last hardened xpub
*
* @param[in] key_exp_pos Position of the key expression within the descriptor
* @param[out] xpub The CExtPubKey to get from cache
*/
bool GetCachedLastHardenedExtPubKey(uint32_t key_exp_pos, CExtPubKey& xpub) const;
/** Retrieve all cached parent xpubs */
ExtPubKeyMap GetCachedParentExtPubKeys() const;
/** Retrieve all cached derived xpubs */
std::unordered_map<uint32_t, ExtPubKeyMap> GetCachedDerivedExtPubKeys() const;
/** Retrieve all cached last hardened xpubs */
ExtPubKeyMap GetCachedLastHardenedExtPubKeys() const;
/** Combine another DescriptorCache into this one.
* Returns a cache containing the items from the other cache unknown to current cache
*/
DescriptorCache MergeAndDiff(const DescriptorCache& other);
};
/** \brief Interface for parsed descriptor objects.
*
* Descriptors are strings that describe a set of scriptPubKeys, together with
* all information necessary to solve them. By combining all information into
* one, they avoid the need to separately import keys and scripts.
*
* Descriptors may be ranged, which occurs when the public keys inside are
* specified in the form of HD chains (xpubs).
*
* Descriptors always represent public information - public keys and scripts -
* but in cases where private keys need to be conveyed along with a descriptor,
* they can be included inside by changing public keys to private keys (WIF
* format), and changing xpubs by xprvs.
*
* Reference documentation about the descriptor language can be found in
* doc/descriptors.md.
*/
struct Descriptor {
virtual ~Descriptor() = default;
/** Whether the expansion of this descriptor depends on the position. */
virtual bool IsRange() const = 0;
/** Whether this descriptor has all information about signing ignoring lack of private keys.
* This is true for all descriptors except ones that use `raw` or `addr` constructions. */
virtual bool IsSolvable() const = 0;
/** Convert the descriptor back to a string, undoing parsing. */
virtual std::string ToString(bool compat_format=false) const = 0;
/** Whether this descriptor will return one scriptPubKey or multiple (aka is or is not combo) */
virtual bool IsSingleType() const = 0;
/** Convert the descriptor to a private string. This fails if the provided provider does not have the relevant private keys. */
virtual bool ToPrivateString(const SigningProvider& provider, std::string& out) const = 0;
/** Convert the descriptor to a normalized string. Normalized descriptors have the xpub at the last hardened step. This fails if the provided provider does not have the private keys to derive that xpub. */
virtual bool ToNormalizedString(const SigningProvider& provider, std::string& out, const DescriptorCache* cache = nullptr) const = 0;
/** Expand a descriptor at a specified position.
*
* @param[in] pos The position at which to expand the descriptor. If IsRange() is false, this is ignored.
* @param[in] provider The provider to query for private keys in case of hardened derivation.
* @param[out] output_scripts The expanded scriptPubKeys.
* @param[out] out Scripts and public keys necessary for solving the expanded scriptPubKeys (may be equal to `provider`).
* @param[out] write_cache Cache data necessary to evaluate the descriptor at this point without access to private keys.
*/
virtual bool Expand(int pos, const SigningProvider& provider, std::vector<CScript>& output_scripts, FlatSigningProvider& out, DescriptorCache* write_cache = nullptr) const = 0;
/** Expand a descriptor at a specified position using cached expansion data.
*
* @param[in] pos The position at which to expand the descriptor. If IsRange() is false, this is ignored.
* @param[in] read_cache Cached expansion data.
* @param[out] output_scripts The expanded scriptPubKeys.
* @param[out] out Scripts and public keys necessary for solving the expanded scriptPubKeys (may be equal to `provider`).
*/
virtual bool ExpandFromCache(int pos, const DescriptorCache& read_cache, std::vector<CScript>& output_scripts, FlatSigningProvider& out) const = 0;
/** Expand the private key for a descriptor at a specified position, if possible.
*
* @param[in] pos The position at which to expand the descriptor. If IsRange() is false, this is ignored.
* @param[in] provider The provider to query for the private keys.
* @param[out] out Any private keys available for the specified `pos`.
*/
virtual void ExpandPrivate(int pos, const SigningProvider& provider, FlatSigningProvider& out) const = 0;
/** @return The OutputType of the scriptPubKey(s) produced by this descriptor. Or nullopt if indeterminate (multiple or none) */
virtual std::optional<OutputType> GetOutputType() const = 0;
/** Get the size of the scriptPubKey for this descriptor. */
virtual std::optional<int64_t> ScriptSize() const = 0;
/** Get the maximum size of a satisfaction for this descriptor, in weight units.
*
* @param use_max_sig Whether to assume ECDSA signatures will have a high-r.
*/
virtual std::optional<int64_t> MaxSatisfactionWeight(bool use_max_sig) const = 0;
/** Get the maximum size number of stack elements for satisfying this descriptor. */
virtual std::optional<int64_t> MaxSatisfactionElems() const = 0;
/** Return all (extended) public keys for this descriptor, including any from subdescriptors.
*
* @param[out] pubkeys Any public keys
* @param[out] ext_pubs Any extended public keys
*/
virtual void GetPubKeys(std::set<CPubKey>& pubkeys, std::set<CExtPubKey>& ext_pubs) const = 0;
};
/** Parse a `descriptor` string. Included private keys are put in `out`.
*
* If the descriptor has a checksum, it must be valid. If `require_checksum`
* is set, the checksum is mandatory - otherwise it is optional.
*
* If a parse error occurs, or the checksum is missing/invalid, or anything
* else is wrong, `nullptr` is returned.
*/
std::unique_ptr<Descriptor> Parse(const std::string& descriptor, FlatSigningProvider& out, std::string& error, bool require_checksum = false);
/** Get the checksum for a `descriptor`.
*
* - If it already has one, and it is correct, return the checksum in the input.
* - If it already has one that is wrong, return "".
* - If it does not already have one, return the checksum that would need to be added.
*/
std::string GetDescriptorChecksum(const std::string& descriptor);
/** Find a descriptor for the specified `script`, using information from `provider` where possible.
*
* A non-ranged descriptor which only generates the specified script will be returned in all
* circumstances.
*
* For public keys with key origin information, this information will be preserved in the returned
* descriptor.
*
* - If all information for solving `script` is present in `provider`, a descriptor will be returned
* which is IsSolvable() and encapsulates said information.
* - Failing that, if `script` corresponds to a known address type, an "addr()" descriptor will be
* returned (which is not IsSolvable()).
* - Failing that, a "raw()" descriptor is returned.
*/
std::unique_ptr<Descriptor> InferDescriptor(const CScript& script, const SigningProvider& provider);
/** Unique identifier that may not change over time, unless explicitly marked as not backwards compatible.
* This is not part of BIP 380, not guaranteed to be interoperable and should not be exposed to the user.
*/
uint256 DescriptorID(const Descriptor& desc);
#endif // BITCOIN_SCRIPT_DESCRIPTOR_H
|
