Support user implemented signer. #495
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utACK.
This doesn't touch BtcSwapTx::partial_sign, which we use in the context of refund_tx_wrapper.partial_sign(), which take as arg the swap's refund keypair and internally calls MusigSession::partial_sign.
However this doesn't depend on user keys, so indeed the user-supplied signer shouldn't play a role for partial_sign.
lib/core/src/signer.rs
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| .to_keypair(&secp); | ||
| let s = msg.as_slice(); | ||
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| let double_hashed_msg: Message = Message::from_digest_slice(s) |
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nit: variable name is misleading as we don't know it's double hashed
lib/core/src/wallet.rs
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| // Prefix and double hash message | ||
| let mut engine = sha256::HashEngine::default(); | ||
| engine.write_all(LN_MESSAGE_PREFIX)?; | ||
| engine.write_all(message.as_bytes())?; | ||
| let hashed_msg = sha256::Hash::from_engine(engine); | ||
| let double_hashed_msg = Message::from(sha256::Hash::hash(&hashed_msg)); | ||
| let double_hashed_msg = Message::from_digest(hashed_msg.into_inner()); |
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This doesn't seem to be double hashing any more?
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Indeed calling sign-message / check-message with the CLI finds the signature as invalid.
Changing the line to
let double_hashed_msg = Message::from_digest(sha256::Hash::hash(&hashed_msg).into_inner());fixes the problem.
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Good catch guys. I fixed that and added a test for this case.
lib/core/src/model.rs
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| // The master xpub encoded as 78 bytes length as defined in bip32 specification. | ||
| // For reference: https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#user-content-Serialization_format | ||
| fn xpub(&self) -> Result<Vec<u8>, SignerError>; | ||
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| // The derived xpub encoded as 78 bytes length as defined in bip32 specification. | ||
| // The derivation path is a string represents the shorter notation of the key tree to derive. For example: | ||
| // m/49'/1'/0'/0/0 | ||
| // m/48'/1'/0'/0/0 | ||
| // For reference: https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#user-content-The_key_tree | ||
| fn derive_xpub(&self, derivation_path: String) -> Result<Vec<u8>, SignerError>; | ||
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| // Sign an ECDSA message using the private key derived from the given derivation path | ||
| fn sign_ecdsa(&self, msg: Vec<u8>, derivation_path: String) -> Result<Vec<u8>, SignerError>; | ||
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| // Sign an ECDSA message using the private key derived from the master key | ||
| fn sign_ecdsa_recoverable(&self, msg: Vec<u8>) -> Result<Vec<u8>, SignerError>; | ||
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| // Return the master blinding key for SLIP77: https://github.com/satoshilabs/slips/blob/master/slip-0077.md | ||
| fn slip77_master_blinding_key(&self) -> Result<Vec<u8>, SignerError>; | ||
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| // HMAC-SHA256 using the private key derived from the given derivation path | ||
| // This is used to calculate the linking key of lnurl-auth specification: https://github.com/lnurl/luds/blob/luds/05.md | ||
| fn hmac_sha256(&self, msg: Vec<u8>, derivation_path: String) -> Result<Vec<u8>, SignerError>; |
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Can you /// them for rustdocs?
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All commits to packages/flutter/example can be removed, the example app removed in PR #510
This PR allows users o initialize the sdk via their own signer implementation instead of passing the mnemonic phrase to the sdk.
A new function was added connect_with_signer and the Signer trait should be implemented and passed to the function.
For now we excluded flutter and react native because of binding issues.