Updated README and CHANGELOG

CHANGELOG.md

@@ -5,7 +5,20 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [1.1.1] - 2023-06-29
+## [2.0.0] - 2024-05-16
+
+### Added
+
+- Added regtest support for signing and verifying BIP-137 and BIP-322 signatures.
+- Added `useStrictVerification` argument in `Verifier.verifySignature`. See README for its usage.
+
+### Changed
+
+- Removed `network` argument in `Signer.sign`; the network is now automatically inferred from the given address.
+- Moved `Address.compressPublicKey` and `Address.uncompressPublicKey` to `Key.compressPublicKey` and `Key.uncompressPublicKey` respectively.
+- Updated dependencies.
+
+## [1.1.1] - 2024-04-05
 
 ### Fixed
 

README.md

@@ -5,19 +5,69 @@
 
 A Javascript library that provides utility functions related to the BIP-322 signature scheme.
 
-## Limitations
-
-Only P2PKH, P2SH-P2WPKH, P2WPKH, and single-key-spend P2TR are supported in this library.
-
 ## Documentation
 
 Available at https://acken2.github.io/bip322-js/
 
 ## Supported Features
 
-1. Generate raw toSpend and toSign BIP-322 transactions
-2. Sign a BIP-322 signature using a private key
-3. Verify a simple BIP-322 signature
+The following features are supported on mainnet, testnet, and regtest 
+for P2PKH, P2SH-P2WPKH, P2WPKH, and single-key-spend P2TR addresses:
+
+1. Generate raw toSpend and toSign BIP-322 transactions.
+2. Sign a BIP-322 signature using a private key.
+3. Verify a legacy BIP-137 signature loosely (see below).
+4. Verify a simple BIP-322 signature.
+
+## Usage
+
+Use the **Signer** class to sign a BIP-322 signature:
+```js
+Signer.sign(privateKey, address, message)
+```
+
+Use the **Verifier** class to verify a BIP-322 signature (which also validates a BIP-137 signature):
+```js
+Verifier.verifySignature(address, message, signature)
+```
+
+## Loose BIP-137 Verification
+
+A BIP-322 signature is backward compatible with the legacy signature scheme (i.e., BIP-137 signature). 
+As a result, this library also recognizes valid BIP-137 signatures.
+
+In a BIP-137 signature, a header flag indicates the type of Bitcoin address for which the signature is signed:
+- 27-30: P2PKH uncompressed
+- 31-34: P2PKH compressed
+- 35-38: Segwit P2SH
+- 39-42: Segwit Bech32
+
+However, some wallets' implementations of the BIP-137 signature did not strictly follow this header flag specification, 
+and some may have signed signatures with the wrong header (e.g., using header 27 for a native segwit address).
+
+It is trivial, however, to convert a BIP-137 signature with an incorrect header flag to one with the correct header 
+flag since the "address type" component in the header flag is not part of the actual signature.
+
+As such, some BIP-137 signature verifiers online, such as [this one](https://www.verifybitcoinmessage.com/), 
+actively help to swap out any erroneous header flags.
+
+This library defines this behavior as **"Loose BIP-137 Verification"**.
+
+This behavior assumes that a signature proving ownership of the private key associated with public key $X$ 
+is valid for all addresses $y_1$, $y_2$, ..., $y_n$ derivable from the same public key $X$.
+
+This behavior is enabled by default in this library, but can be disabled by passing the 
+optional useStrictVerification flag in Verifier.verifySignature:
+
+```js
+Verifier.verifySignature(signerAddress, message, signatureBase64, true)
+```
+
+Consequently, this also allows BIP-137 signatures to be used for taproot addresses, which is technically out-of-spec 
+according to both BIP-137 and BIP-322 specifications, as implemented by some wallet implementations. 
+Please refer to [issue #1](https://github.com/ACken2/bip322-js/issues/1) for relevant discussions.
+
+Note that this behavior does not exist in actual BIP-322 signature due to how BIP-322 signature is constructed.
 
 ## Example
 
@@ -27,14 +77,26 @@ const { BIP322, Signer, Verifier } = require('bip322-js');
 
 // Signing a BIP-322 signature with a private key
 const privateKey = 'L3VFeEujGtevx9w18HD1fhRbCH67Az2dpCymeRE1SoPK6XQtaN2k';
-const address = 'bc1q9vza2e8x573nczrlzms0wvx3gsqjx7vavgkx0l';
+const address = 'bc1q9vza2e8x573nczrlzms0wvx3gsqjx7vavgkx0l'; // P2WPKH address
+const addressTestnet = 'tb1q9vza2e8x573nczrlzms0wvx3gsqjx7vaxwd45v'; // Equivalent testnet address
+const addressRegtest = 'bcrt1q9vza2e8x573nczrlzms0wvx3gsqjx7vay85cr9'; // Equivalent regtest address
+const taprootAddress = 'bc1ppv609nr0vr25u07u95waq5lucwfm6tde4nydujnu8npg4q75mr5sxq8lt3'; // P2TR address
+const nestedSegwitAddress = '37qyp7jQAzqb2rCBpMvVtLDuuzKAUCVnJb'; // P2SH-P2WPKH address
 const message = 'Hello World';
 const signature = Signer.sign(privateKey, address, message);
-console.log(signature);
+const signatureTestnet = Signer.sign(privateKey, addressTestnet, message); // Wworks with testnet address
+const signatureRegtest = Signer.sign(privateKey, addressRegtest, message); // And regtest address
+const signatureP2TR = Signer.sign(privateKey, taprootAddress, message); // Also works with P2TR address
+const signatureP2SH = Signer.sign(privateKey, nestedSegwitAddress, message); // And P2SH-P2WPKH address
+console.log({ signature, signatureTestnet, signatureRegtest, signatureP2TR, signatureP2SH });
 
 // Verifying a simple BIP-322 signature
 const validity = Verifier.verifySignature(address, message, signature);
-console.log(validity); // True
+const validityTestnet = Verifier.verifySignature(addressTestnet, message, signatureTestnet); // Works with testnet address
+const validityRegtest = Verifier.verifySignature(addressRegtest, message, signatureRegtest); // And regtest address
+const validityP2TR = Verifier.verifySignature(taprootAddress, message, signatureP2TR); // Also works with P2TR address
+const validityP2SH = Verifier.verifySignature(nestedSegwitAddress, message, signatureP2SH); // And P2SH-P2WPKH address
+console.log({ validity, validityTestnet, validityRegtest, validityP2TR, validityP2SH }); // True
 
 // You can also get the raw unsigned BIP-322 toSpend and toSign transaction directly
 const scriptPubKey = Buffer.from('00142b05d564e6a7a33c087f16e0f730d1440123799d', 'hex');
@@ -44,4 +106,14 @@ const toSign = BIP322.buildToSignTx(toSpendTxId, scriptPubKey); // bitcoin.Psbt
 // Do whatever you want to do with the PSBT
 ```
 
-More working examples can be found within the unit test for BIP322, Signer, and Verifier.
+More working examples can be found within the unit test for BIP322, Signer, and Verifier.
+
+## Migration Guide from v1.X
+
+There are only two non-backward-compatible changes in the API:
+
+1. If you previously used `Address.compressPublicKey` or `Address.uncompressPublicKey`, 
+replace them with `Key.compressPublicKey` and `Key.uncompressPublicKey` respectively.
+
+2. In v1.X, there was an option to pass the `network` parameter into `Signer.sign`: `Signer.sign(privateKey, address, message, network)`. 
+This option has been removed, as the network is now automatically inferred from the given address.