Electrum

This commit fixes a bug in the Electrum Bitcoin wallet that could crash or fail when trying to move funds from a watch-only wallet that only has imported addresses (no private keys). The fix makes the wallet more careful when it doesn't know the exact script type for an address, returning 'unknown' instead of crashing, and only setting a script descriptor when one actually exists. There is no direct evidence this was a security vulnerability exploitable by an attacker; it appears to be a reliability/functional bug fix.

This is a purely cosmetic change to a test file. It wraps two existing test blocks inside Python 'subTest' contexts so that if one part fails, the other still runs and the failure message is clearer. No production code was changed, and no security behavior is affected.

This commit refactors how Electrum's submarine-swap server pays Lightning invoices from clients. The main visible change is that the swap server no longer maintains its own retry queue for pending invoices; instead it delegates directly to the wallet's existing invoice-payment logic, which now rejects duplicate in-flight payment attempts. A new regression test confirms that a second payment attempt with the same payment hash is blocked while the first is still running. The commit also fixes a small bug where an HTTP endpoint called a coroutine without awaiting it. Overall the change looks like a hardening/cleanup rather than an obvious vulnerability fix, but it removes a custom retry mechanism and tightens duplicate-payment protection, which can have security relevance in Lightning.

This commit adds safety checks to Electrum's encryption helper functions and includes a self-test that runs when the program starts. The new checks make sure AES keys and initialization vectors (IVs) are the correct length before encrypting or decrypting, which helps catch programming mistakes early. The self-tests verify that hash and encryption functions produce known correct outputs, so Electrum will fail immediately if a cryptographic library is broken or misconfigured rather than silently producing bad results.

This commit adds self-tests to Electrum's cryptography code. When the program starts, it now runs a few known test vectors through hash and encryption functions and crashes immediately if the results are wrong. This is a defensive hardening change, not a fix for an active security flaw.

This commit adds a 5-second timeout and a small cache to a helper that runs the 'git describe' command when Electrum's crash reporter builds a diagnostic report. The change mainly prevents the crash reporter from hanging on slow filesystems. A code comment also flags that the helper searches the system path for a program named 'git', which could theoretically be abused if an attacker controls the program search path, but the commit does not claim this is an exploitable vulnerability.

This change tightens validation of BIP32 master keys (the root keys used to derive all wallet addresses). Previously, Electrum would accept an extended public or private key that claimed to be a master key (depth 0) but had a non-zero child number or parent fingerprint. Such keys violate the BIP32 specification and could cause confusion or interoperability problems, but the patch is a defensive validation fix rather than a clear remote-exploitable vulnerability.

This update makes Electrum stricter when reading a BIP32 extended private key (the long encoded string that can generate all your wallet's addresses). BIP32 requires that the 33-byte private-key field start with a zero byte before the actual 32-byte secret. Electrum now rejects keys that violate this rule, which closes a gap where a malformed key could be accepted and later produce unexpected public keys or wallet behavior.

This commit tightens validation of Bitcoin wallet master keys. Under the BIP32 standard, a master key must have zero values for its 'child number' and 'parent fingerprint' fields. The change makes Electrum reject extended keys that violate this rule, preventing malformed or intentionally crafted master keys from being accepted. This is a defensive correctness fix rather than an active exploit patch.

Electrum added a check to reject malformed BIP32 extended private keys ('xprv...') where the private key data does not start with a required zero byte. Previously, such invalid keys may have been accepted. This is a defensive validation fix that prevents non-standard or corrupted keys from being processed, reducing the risk of key-handling bugs or unexpected behavior.