feat/multisig support

README.md

@@ -7,6 +7,7 @@ generic message signing and verification.
 ## Types of Signatures 
 
 At the moment this crate supports `P2TR`, `P2WPKH` and `P2SH-P2WPKH` single-sig
+addresses, as well as `P2WSH`, `P2SH-P2WSH` and `P2SH` CHECKMULTISIG multisig
 addresses. Feedback through issues or PRs on the interface design and security
 is welcome and encouraged. 
 

examples/simple_sign_verify_encoded.rs

@@ -5,7 +5,7 @@ fn main() {
   let message = "Hello World";
   let wif_private_key = "L3VFeEujGtevx9w18HD1fhRbCH67Az2dpCymeRE1SoPK6XQtaN2k";
 
-  let base64_signature = sign_simple_encoded(address, message, wif_private_key).unwrap();
+  let base64_signature = sign_simple_encoded(address, message, &[wif_private_key], None).unwrap();
 
   assert!(verify_simple_encoded(address, message, &base64_signature).is_ok());
 }

src/error.rs

@@ -10,7 +10,7 @@ pub enum Error {
   },
   #[snafu(display("Failed to parse private key"))]
   PrivateKeyParse { source: bitcoin::key::FromWifError },
-  #[snafu(display("Unsuported address `{address}`, only P2TR, P2WPKH and P2SH-P2WPKH allowed"))]
+  #[snafu(display("Unsupported address `{address}`, only P2TR, P2WPKH, P2SH-P2WPKH, and P2WSH/P2SH multisig allowed"))]
   UnsupportedAddress { address: String },
   #[snafu(display("Decode error for signature `{signature}`"))]
   SignatureDecode {
@@ -66,4 +66,24 @@ pub enum Error {
   InvalidWitness,
   #[snafu(display("Public key does not match"))]
   PublicKeyMismatch,
+  #[snafu(display("At least one private key is required"))]
+  NoPrivateKeys,
+  #[snafu(display("Non-standard sighash type: {source}"))]
+  SigHashTypeNonStandard {
+    source: bitcoin::sighash::NonStandardSighashTypeError,
+  },
+  #[snafu(display("Signer's public key not present in multisig script"))]
+  UnknownSigner,
+  #[snafu(display("Duplicate private key provided"))]
+  DuplicateSigner,
+  #[snafu(display("Expected exactly {required} private keys, got {provided}"))]
+  SignatureCount { required: usize, provided: usize },
+  #[snafu(display("P2WPKH requires a compressed public key"))]
+  UncompressedPublicKey {
+    source: bitcoin::key::UncompressedPublicKeyError,
+  },
+  #[snafu(display("Failed to parse witness script"))]
+  WitnessScriptParse {
+    source: bitcoin::hex::HexToBytesError,
+  },
 }