This commit converts the wallet to use the new secure hierarchical
deterministic wallet address manager package as well as the walletdb
package.
The following is an overview of modified functionality:
- The wallet must now be created before starting the executable
- A new flag --create has been added to create the new wallet using wizard
style question and answer prompts
- Starting the process without an existing wallet will instruct now
display a message to run it with --create
- Providing the --create flag with an existing wallet will simply show an
error and return
In addition the snacl package has been modified to return the memory after
performing scrypt operations to the OS.
Previously a runtime.GC was being invoked which forced it to release the
memory as far as the garbage collector is concerned, but the memory was
not released back to the OS immediatley. This modification allows the
memory to be released immedately since it won't be needed again until the
next wallet unlock.
This is performed by saving the SHA512(salt+passphrase) of the
waddrmgr.Manager private passphrase each time the manager is unlocked.
If another call to Unlock is performed before the next Lock, the hash
is applied to the new input. If it matches, we know the passphrase is
(likely) equal, so return early and continue using the crypto keys
already in memory. If it does not match, we know for certain the
passphrase is incorrect and the manager is locked.
The slice of keys which must have their private extended keys derived
on unlock was never being removed from and all of these keys were
being rederived unnecessarily on every unlock. Fix this by re-slicing
the deriveOnUnlock slice to remove the just derived key if the
derivation was successful.
This commit converts the waddrmgr package to use the new walletdb package
semantics.
Since waddrmgr no longer controls the database, it is unable to make a
copy of the database and return it as the old ExportWatchingOnly function
required. As a result, it has been renamed to ConvertToWatchingOnly and
it now modifies the namespace provided to it. The idea is that the caller
which does control the database can now make a copy of the database, get
the waddrmgr namespace in the database copy and invoke the new function
to modify it. This also works well with other packages that might also
need to make modifications for watching-only mode.
In addition, the following changes are made:
- All places that worked with database paths now work with the
walletdb.Namespace interface
- The managerTx code is replaced to use the walletdb.Tx interface
- The code which checks if the manager already exists is updated to work
with the walletdb.Namespace interface
- The LatestDbVersion constant is now LatestMgrVersion since it no longer
controls the database
This commit adds comments about the specific crypto key types, moves the
selectCryptoKey function before the Encrypt/Decrypt functions that call it
to be more consistent with the rest of the code base, and slightly
modifies the verbiage of the comment.
The crypto key type unsed in the manager is not needed outside of the
package. Also, rather than having the newCryptoKey func return the
specific cryptoKey type, make it return the EncryptorDecryptor interface.
This will allow it to be overridden with another type that implements the
interface from the tests.
Useful to test error conditions.
Also provide a new function that wraps snacl.GenerateCryptoKey(),
defined as a variable so that it can be replaced in tests.
This commit implements a new secure, scalable, hierarchical deterministic
wallet address manager package.
The following is an overview of features:
- BIP0032 hierarchical deterministic keys
- BIP0043/BIP0044 multi-account hierarchy
- Strong focus on security:
- Fully encrypted database including public information such as
addresses as well as private information such as private keys and
scripts needed to redeem pay-to-script-hash transactions
- Hardened against memory scraping through the use of actively clearing
private material from memory when locked
- Different crypto keys used for public, private, and script data
- Ability for different passphrases for public and private data
- Scrypt-based key derivation
- NaCl-based secretbox cryptography (XSalsa20 and Poly1305)
- Multi-tier scalable key design to allow instant password changes
regardless of the number of addresses stored
- Import WIF keys
- Import pay-to-script-hash scripts for things such as multi-signature
transactions
- Ability to export a watching-only version which does not contain any
private key material
- Programmatically detectable errors, including encapsulation of errors
from packages it relies on
- Address synchronization capabilities
This commit only provides the implementation package. It does not
include integration into to the existing wallet code base or conversion of
existing addresses. That functionality will be provided by future
commits.
