Do not automatically change the wallet format unless the user takes an
explicit action that implies an upgrade (encrypting, for now), or uses
-walletupgrade.
-walletupgrade optionally takes an integer argument: the client version
up to which upgrading is allowed. Without an argument, it is upgraded
to latest supported version. If an argument to -walletupgrade is
provided at the time the wallet is created, the new wallet will initially
not use features beyond that version.
Third, the current wallet version number is reported in getinfo.
so it takes a flag for how to interpret OP_EVAL.
Also increased IsStandard size of scriptSigs to 500 bytes, so
a 3-of-3 multisig transaction IsStandard.
OP_EVAL is a new opcode that evaluates an item on the stack as a script.
It enables a new type of bitcoin address that needs an arbitrarily
complex script to redeem.
Introduces two new RPC calls:
* dumpprivkey: retrieve the private key corresponding to an address
* importprivkey: add a private key to your wallet
The private key format is analoguous to the address format. It is
a 51-character base58-encoded string, that includes a version number
and a checksum.
Includes patch by mhanne:
* add optional account parameter for importprivkey, if omitted use default
SecureString is identical to std::string except with secure_allocator
substituting for std::allocator. This makes casting between them
impossible, so converting between the two at API boundaries requires
calling ::c_str() for now.
Also changed semantics of CWalletTx::GetTxTime(); now always returns the time the transaction was received by this node, not the average block time.
And added information about -DDEBUG_LOCKORDER to coding.txt.
Collapsed multiple wallet mutexes to a single cs_wallet, to avoid deadlocks with wallet methods that acquired locks in different order.
Also change master RPC call handler to acquire cs_main and cs_wallet locks before executing RPC calls; requiring each RPC call to acquire the right set of locks in the right order was too error-prone.
With the separation of CENT and MIN_TX_FEE, it is now reasonable
to create change outputs between 0.01 and 0.0005, as these are
spendable according to the policy, even though they require a fee
to be paid.
Also, when enough fee was already present, everything can go into
a change output, without further increasing the fee.
Instead of conversion functions between pubkey/uint160/address in
base58.h, have a fully fledged class CBitcoinAddress (CAddress was
already taken) to represent addresses.
This commit adds support for ckeys, or enCrypted private keys, to the wallet.
All keys are stored in memory in their encrypted form and thus the passphrase
is required from the user to spend coins, or to create new addresses.
Keys are encrypted with AES-256-CBC using OpenSSL's EVP library. The key is
calculated via EVP_BytesToKey using SHA512 with (by default) 25000 rounds and
a random salt.
By default, the user's wallet remains unencrypted until they call the RPC
command encryptwallet <passphrase> or, from the GUI menu, Options->
Encrypt Wallet.
When the user is attempting to call RPC functions which require the password
to unlock the wallet, an error will be returned unless they call
walletpassphrase <passphrase> <time to keep key in memory> first.
A keypoolrefill command has been added which tops up the users keypool
(requiring the passphrase via walletpassphrase first).
keypoolsize has been added to the output of getinfo to show the user the
number of keys left before they need to specify their passphrase (and call
keypoolrefill).
Note that walletpassphrase will automatically fill keypool in a separate
thread which it spawns when the passphrase is set. This could cause some
delays in other threads waiting for locks on the wallet passphrase, including
one which could cause the passphrase to be stored longer than expected,
however it will not allow the passphrase to be used longer than expected as
ThreadCleanWalletPassphrase will attempt to get a lock on the key as soon
as the specified lock time has arrived.
When the keypool runs out (and wallet is locked) GetOrReuseKeyFromPool
returns vchDefaultKey, meaning miners may start to generate many blocks to
vchDefaultKey instead of a new key each time.
A walletpassphrasechange <oldpassphrase> <newpassphrase> has been added to
allow the user to change their password via RPC.
Whenever keying material (unencrypted private keys, the user's passphrase,
the wallet's AES key) is stored unencrypted in memory, any reasonable attempt
is made to mlock/VirtualLock that memory before storing the keying material.
This is not true in several (commented) cases where mlock/VirtualLocking the
memory is not possible.
Although encryption of private keys in memory can be very useful on desktop
systems (as some small amount of protection against stupid viruses), on an
RPC server, the password is entered fairly insecurely. Thus, the only main
advantage encryption has for RPC servers is for RPC servers that do not spend
coins, except in rare cases, eg. a webserver of a merchant which only receives
payment except for cases of manual intervention.
Thanks to jgarzik for the original patch and sipa, gmaxwell and many others
for all their input.
Conflicts:
src/wallet.cpp
Pieter Wuille