COLDCARD firmware

This commit simply increments an automatically-generated Bitcoin block height constant by one. It is a routine data update with no code changes and no security implications.

This commit simply updates a stored Bitcoin blockchain height number from 963,074 to 963,190, along with its timestamp. It is a routine data refresh with no code logic changes and no apparent security relevance.

This commit only updates a linked external code submodule (ckcc-protocol) to a newer version. The actual code changes are not shown in this diff, only the submodule pointer was moved. There is no information in the commit itself about what changed in the submodule or whether it has any security relevance.

This commit adds a new, more secure USB encryption mode (ncry v3) to the COLDCARD hardware wallet firmware. It does not remove the older v1/v2 mode. The new mode adds message authentication tags and separate keys for each direction, which protects against tampering, replay, and reflection attacks on the USB cable. The commit also fixes a timing side-channel in user authentication by replacing direct HMAC comparisons with a constant-time comparison. The change is defensive and improves security, but the old unauthenticated modes remain available for compatibility, so users must actively choose v3 to get the stronger protection.

This commit changes how COLDCARD handles multisig wallet names. Previously, re-importing a wallet file or descriptor with a different name would silently rename the existing wallet. Now, renaming must be done through an explicit 'Rename' menu action, and re-importing a duplicate with a different name is rejected. This is a security-hardening UX change that prevents accidental or malicious wallet renaming during import, which could confuse users about which wallet they are signing for.

This commit only edits the project's 'Next-ChangeLog.md' file. It rewrites upcoming release notes, adds details, fixes wording, and updates release dates. No actual firmware code, build scripts, or security behavior changed in this commit. The changelog text does describe many security fixes, but those fixes are already present in other commits; this commit merely documents them.

This commit simply updates a stored Bitcoin blockchain height number from 960,398 to 963,074, along with its timestamp. It is a routine data refresh with no code logic changes and no apparent security relevance.

This commit only changes test code for the COLDCARD firmware. It makes the test suite more stable by letting developers specify a custom Bitcoin daemon path, adding a PSBT2 test flag, fixing a test that checks upload-during-approval behavior, and importing an extra constant for user-interface tests. None of these changes affect the actual firmware that runs on the device, so there is no security risk to users.

This commit only edits the wording of an upcoming release changelog. It does not change any firmware code, cryptographic algorithms, or security behavior. The edits clarify and reorganize descriptions of previously planned entropy-generation improvements, but they do not themselves introduce or fix any vulnerability.

This commit fixes a bug in the COLDCARD firmware update process. Previously, the maximum file size allowed for a firmware update file (.dfu) was set too small because it was based on the firmware's own size limit, not accounting for extra data that comes with 'factory' update images (which include a bootloader and a DFU wrapper). As a result, legitimate factory firmware files could not be selected from the MicroSD card picker. The fix separates the two limits: one for the actual firmware size, and a larger one for the .dfu container shown in the file picker. There is no direct evidence in the commit that this was a security vulnerability, but overly restrictive size checks can sometimes hide or complicate downgrade or supply-chain issues.

This change makes the COLDCARD wallet require the user to scroll down before showing a BIP-39 passphrase on screen. The goal is to reduce the chance that someone nearby (a shoulder-surfer) or a camera can read the secret passphrase when it appears automatically. It is a small user-interface hardening improvement, not a fix for a remote hack.

This commit changes how the COLDCARD hardware wallet generates random numbers used to protect backups, encrypted files, and two-factor authentication secrets. Previously these sensitive values were produced using only the STM32 chip's built-in random number generator (TRNG). Now they are produced through a stronger combined method: a Hash-DRBG (a NIST-style deterministic random-bit generator) that is seeded from both secure elements and the TRNG. The change is defensive hardening rather than a fix for a known exploitable bug, but it reduces the risk that a weakness in the STM32 TRNG alone could weaken user secrets.

This commit tightens security for temporary Bitcoin wallet seeds created by rolling dice on a COLDCARD hardware wallet. Previously, temporary dice-generated seeds skipped the same mandatory entropy checks and warnings used for permanent dice-generated seeds. The change makes temporary dice seeds follow the same rules, so users cannot accidentally create a weak wallet from too few dice rolls. This is a defensive hardening fix, not an active bug that steals funds, but weak entropy could let an attacker guess a wallet's private keys.