wallet: Add exportaddresskey RPC for descriptor wallets #36697

Adds exportaddresskey "address" ( "key_type" ) to export locally available private keys for an address in a descriptor wallet. Callers can obtain private keys without identifying the descriptor index and reproducing key derivation outside Core.

The RPC has two modes:

• wallet (default) returns the original wallet keys, with their public keys and roles.
• taproot_output returns effective Taproot key-path keys using the known output commitment. Direct output keys are returned without another tweak. MuSig2 participant secrets are never combined into an aggregate private key.

Supported constructions include single-key addresses, recognized P2SH/P2WSH scripts, multisig, Miniscript, and Taproot, including MuSig2 participants. A locally available key can be exported even when the wallet cannot satisfy all spending conditions.

Lookup is limited to existing wallet metadata and known derivation indices. Encrypted wallets must be unlocked. Missing spending data, unavailable keys, and inconsistent wallet data have distinct errors.

The result contains hexadecimal private scalars, not WIF. Exported keys are not a wallet backup; scripts, cosigners, or other spending data may still be needed. Reused keys and MuSig2 participants may control other outputs.

Includes key, descriptor, wallet manager, wallet RPC, and console-history tests. Functional coverage reconstructs scripts independently and verifies spending with exported keys, partial ownership, authorization, inconsistent metadata, and absence of wallet or nonce mutation.

The initial single-key implementation was ported from Bitcoin Roots and now extended to cover more use-cases. Initial motivation was the lack of dumppriv since v30 and the need for it in the making of the Quietproof client.

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The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

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External sites

• Code coverage & benchmarks: https://corecheck.dev/bitcoin/bitcoin/pulls/36697
• Ralph review <img src=https://review.fish.foo/assets/bitcoin/bitcoin/36697.png alt="Ralph review status"> https://git.fish.foo/bitcoin/bitcoin/pulls/36697#author-ralph

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Reviews

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Conflicts

Reviewers, this pull request conflicts with the following ones:

• #36641 _{<img src="https://drahtbot.space/ack_count/bitcoin/bitcoin/36641.svg">} (wallet: bound pending MuSig2 sessions by fametrano)
• #36188 _{<img src="https://drahtbot.space/ack_count/bitcoin/bitcoin/36188.svg">} (crypto: plug hardware optimized SHA256 into libsecp256k1's context by furszy)
• #36167 _{<img src="https://drahtbot.space/ack_count/bitcoin/bitcoin/36167.svg">} ([RFC] Enable -Wunused by fanquake)
• #35918 _{<img src="https://drahtbot.space/ack_count/bitcoin/bitcoin/35918.svg">} (descriptor: Expose key expression parsing by pseudoramdom)
• #35713 _{<img src="https://drahtbot.space/ack_count/bitcoin/bitcoin/35713.svg">} (Remove boost as a unit test runner by rustaceanrob)
• #35444 _{<img src="https://drahtbot.space/ack_count/bitcoin/bitcoin/35444.svg">} (wallet: make descriptor SPKM mutex non-recursive by w0xlt)
• #34520 _{<img src="https://drahtbot.space/ack_count/bitcoin/bitcoin/34520.svg">} (refactor: Add [[nodiscard]] to functions returning bool+mutable ref by maflcko)

If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

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LLM Linter (✨ experimental)

Possible places where named args for integral literals may be used (e.g. func(x, /*named_arg=*/0) in C++, and func(x, named_arg=0) in Python):

• src/test/key_tests.cpp: internal.Set(secret.begin(), secret.end(), true)
• src/wallet/test/scriptpubkeyman_tests.cpp: even.Set(one.begin(), one.end(), true)
• src/wallet/test/scriptpubkeyman_tests.cpp: odd.Set(minus_one.begin(), minus_one.end(), true)
• src/wallet/test/scriptpubkeyman_tests.cpp: uncompressed.Set(one.begin(), one.end(), false)
• src/wallet/test/scriptpubkeyman_tests.cpp: uncompressed.Set(complete->begin(), complete->end(), false)
• src/wallet/test/scriptpubkeyman_tests.cpp: positive.Set(bytes.begin(), bytes.end(), true)
• src/wallet/test/scriptpubkeyman_tests.cpp: opposite.Set(opposite_bytes.begin(), opposite_bytes.end(), false)
• src/wallet/test/scriptpubkeyman_tests.cpp: participant.Set(one.begin(), one.end(), true)
• src/wallet/test/scriptpubkeyman_tests.cpp: uncompressed.Set(one.begin(), one.end(), false)
• src/wallet/test/scriptpubkeyman_tests.cpp: opposite.Set(minus_one.begin(), minus_one.end(), true)
• src/wallet/test/scriptpubkeyman_tests.cpp: opposite_uncompressed.Set(minus_one.begin(), minus_one.end(), false)
• test/functional/wallet_exportaddresskey.py: wallet.lockunspent(False, [{'txid': coins[0]['txid'], 'vout': coins[0]['vout']}], True)

Possible places where comparison-specific test macros should replace generic comparisons:

• test/functional/wallet_exportaddresskey.py: assert tweak < ORDER in derive_leaf → Prefer assert_greater_than(ORDER, tweak).
• test/functional/wallet_exportaddresskey.py: assert tweak < ORDER in musig_public_key → Prefer assert_greater_than(ORDER, tweak).
• test/functional/wallet_exportaddresskey.py: assert tweak < ORDER in taproot_output_secret → Prefer assert_greater_than(ORDER, tweak).

^{2026-10-30 06:20:30}

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🚧 At least one of the CI tasks failed. _{Task test ancestor commits: https://github.com/bitcoin/bitcoin/actions/runs/40948337977/job/123709495885} _{LLM reason (✨ experimental): CI failed during compilation: Clang’s thread-safety analysis rejected AssertLockHeld(wallet.cs_wallet) in scriptpubkeyman_tests.cpp because the wallet lock wasn’t held.}

<details><summary>Hints</summary>

Try to run the tests locally, according to the documentation. However, a CI failure may still happen due to a number of reasons, for example:

• Possibly due to a silent merge conflict (the changes in this pull request being incompatible with the current code in the target branch). If so, make sure to rebase on the latest commit of the target branch.

• A sanitizer issue, which can only be found by compiling with the sanitizer and running the affected test.

• An intermittent issue.

Leave a comment here, if you need help tracking down a confusing failure.

</details>