bitcoin_key/
keypool.rs

1/**
2  | अनित्य अनात्मन्  मोक्ष 
3  |
4  */
5
6crate::ix!();
7
8//-------------------------------------------[.cpp/bitcoin/src/wallet/scriptpubkeyman.h]
9
10/**
11  | Default for -keypool
12  |
13  */
14pub const DEFAULT_KEYPOOL_SIZE: u32 = 1000;
15
16/** 
17 | A key from a CWallet's keypool
18 |
19 | The wallet holds one (for pre HD-split wallets)
20 | or several keypools. These are sets of keys
21 | that have not yet been used to provide
22 | addresses or receive change.
23 |
24 | The Bitcoin Core wallet was originally
25 | a collection of unrelated private keys with
26 | their associated addresses. If a non-HD wallet
27 | generated a key/address, gave that address out
28 | and then restored a backup from before that
29 | key's generation, then any funds sent to that
30 | address would be lost definitively.
31 |
32 | The keypool was implemented to avoid this
33 | scenario (commit: 10384941). The wallet would
34 | generate a set of keys (100 by default). When
35 | a new public key was required, either to give
36 | out as an address or to use in a change output,
37 | it would be drawn from the keypool. The keypool
38 | would then be topped up to maintain 100
39 | keys. This ensured that as long as the wallet
40 | hadn't used more than 100 keys since the
41 | previous backup, all funds would be safe, since
42 | a restored wallet would be able to scan for all
43 | owned addresses.
44 |
45 | A keypool also allowed encrypted wallets to
46 | give out addresses without having to be
47 | decrypted to generate a new private key.
48 |
49 | With the introduction of HD wallets (commit:
50 | f1902510), the keypool essentially became an
51 | address look-ahead pool. Restoring old backups
52 | can no longer definitively lose funds as long
53 | as the addresses used were from the wallet's HD
54 | seed (since all private keys can be rederived
55 | from the seed).  However, if many addresses
56 | were used since the backup, then the wallet may
57 | not know how far ahead in the HD chain to look
58 | for its addresses. The keypool is used to
59 | implement a 'gap limit'. The keypool maintains
60 | a set of keys (by default 1000) ahead of the
61 | last used key and scans for the addresses of
62 | those keys.  This avoids the risk of not seeing
63 | transactions involving the wallet's addresses,
64 | or of re-using the same address.  In the
65 | unlikely case where none of the addresses in
66 | the `gap limit` are used on-chain, the
67 | look-ahead will not be incremented to keep
68 | a constant size and addresses beyond this range
69 | will not be detected by an old backup. For this
70 | reason, it is not recommended to decrease
71 | keypool size lower than default value.
72 |
73 | The HD-split wallet feature added a second
74 | keypool (commit: 02592f4c). There is an
75 | external keypool (for addresses to hand out)
76 | and an internal keypool (for change addresses).
77 |
78 | Keypool keys are stored in the
79 | wallet/keystore's keymap. The keypool data is
80 | stored as sets of indexes in the wallet
81 | (setInternalKeyPool, setExternalKeyPool and
82 | set_pre_split_keypool), and a map from the key
83 | to the index (m_pool_key_to_index). The
84 | CKeyPool object is used to
85 | serialize/deserialize the pool data to/from the
86 | database.
87 */
88pub struct KeyPool {
89
90    /**
91      | The time at which the key was generated.
92      | Set in AddKeypoolPubKeyWithDB
93      |
94      */
95    n_time:      i64,
96
97    /**
98      | The public key
99      |
100      */
101    vch_pub_key: PubKey,
102
103    /**
104      | Whether this keypool entry is in the
105      | internal keypool (for change outputs)
106      |
107      */
108    internal:    bool,
109
110    /**
111      | Whether this key was generated for a
112      | keypool before the wallet was upgraded
113      | to HD-split
114      |
115      */
116    pre_split:   bool,
117}
118
119impl KeyPool {
120    
121    pub fn new(
122        vch_pub_key_in: &PubKey,
123        internal_in:    bool) -> Self {
124    
125        todo!();
126        /*
127
128        
129        */
130    }
131    
132    pub fn serialize<Stream>(&self, s: &mut Stream)  {
133    
134        todo!();
135        /*
136            int nVersion = s.GetVersion();
137            if (!(s.GetType() & SER_GETHASH)) {
138                s << nVersion;
139            }
140            s << nTime << vchPubKey << fInternal << m_pre_split;
141        */
142    }
143    
144    pub fn unserialize<Stream>(&mut self, s: &mut Stream)  {
145    
146        todo!();
147        /*
148            int nVersion = s.GetVersion();
149            if (!(s.GetType() & SER_GETHASH)) {
150                s >> nVersion;
151            }
152            s >> nTime >> vchPubKey;
153            try {
154                s >> fInternal;
155            } catch (std::ios_base::failure&) {
156                /* flag as external address if we can't read the internal boolean
157                   (this will be the case for any wallet before the HD chain split version) */
158                fInternal = false;
159            }
160            try {
161                s >> m_pre_split;
162            } catch (std::ios_base::failure&) {
163                /* flag as postsplit address if we can't read the m_pre_split boolean
164                   (this will be the case for any wallet that upgrades to HD chain split) */
165                m_pre_split = false;
166            }
167        */
168    }
169}
bitcoin_key/keypool.rs

bitcoin_key/
keypool.rs
