feat(crypto): remove SignatureError, use secp256k1::Error instead

crypto/src/signature.rs

@@ -1,45 +1,33 @@
 //! Signature module
 
 use crate::key::CryptoEngine;
-use failure::Fail;
-use secp256k1::{Message, SecretKey};
+use secp256k1::{Error, Message, SecretKey};
 
 /// Signature
 pub type Signature = secp256k1::Signature;
 
 /// PublicKey
 pub type PublicKey = secp256k1::PublicKey;
 
-/// The error type for operations with signatures
-#[derive(Debug, PartialEq, Fail)]
-pub enum SignatureError {
-    #[fail(display = "Fail in verify process")]
-    /// Fail in verify process
-    VerifyError,
-}
-
-/// Sign data with provided secret key
-/// - Returns an Error if data is all zeros or is not a 32-byte array
-pub fn sign(
-    secp: &CryptoEngine,
-    secret_key: SecretKey,
-    data: &[u8],
-) -> Result<Signature, failure::Error> {
+/// Sign `data` with provided secret key. `data` must be the 32-byte output of a cryptographically
+/// secure hash function, otherwise this function is not secure.
+/// - Returns an Error if data is not a 32-byte array
+pub fn sign(secp: &CryptoEngine, secret_key: SecretKey, data: &[u8]) -> Result<Signature, Error> {
     let msg = Message::from_slice(data)?;
 
     Ok(secp.sign(&msg, &secret_key))
 }
-/// Verify signature with a provided public key
+/// Verify signature with a provided public key.
+/// - Returns an Error if data is not a 32-byte array
 pub fn verify(
     secp: &CryptoEngine,
     public_key: &PublicKey,
     data: &[u8],
     sig: &Signature,
-) -> Result<(), failure::Error> {
-    let msg = Message::from_slice(data).unwrap();
+) -> Result<(), Error> {
+    let msg = Message::from_slice(data)?;
 
     secp.verify(&msg, sig, public_key)
-        .map_err(|_| SignatureError::VerifyError.into())
 }
 
 #[cfg(test)]

validations/src/tests/mod.rs

@@ -482,7 +482,7 @@ where
         x.unwrap_err().downcast::<TransactionError>().unwrap(),
         TransactionError::VerifyTransactionSignatureFail {
             hash,
-            msg: "Fail in verify process".to_string(),
+            msg: "secp: signature failed verification".to_string(),
         },
     );
 
@@ -495,7 +495,7 @@ where
         x.unwrap_err().downcast::<TransactionError>().unwrap(),
         TransactionError::VerifyTransactionSignatureFail {
             hash,
-            // A "Fail in verify process" msg would also be correct here
+            // A "secp: signature failed verification" msg would also be correct here
             msg: TransactionError::PublicKeyHashMismatch {
                 expected_pkh: MY_PKH_1.parse().unwrap(),
                 signature_pkh,
@@ -2705,7 +2705,7 @@ fn commitment_signatures() {
         x.unwrap_err().downcast::<TransactionError>().unwrap(),
         TransactionError::VerifyTransactionSignatureFail {
             hash,
-            msg: "Fail in verify process".to_string(),
+            msg: "secp: signature failed verification".to_string(),
         },
     );
 

wallet/src/repository/error.rs

@@ -79,6 +79,8 @@ pub enum Error {
     UnknownFeeType,
     #[fail(display = "Wallet not found")]
     WalletNotFound,
+    #[fail(display = "Secp256k1 error: {}", _0)]
+    Secp256k1(#[cause] witnet_crypto::secp256k1::Error),
 }
 
 impl From<failure::Error> for Error {
@@ -147,3 +149,9 @@ impl From<TransactionError> for Error {
         }
     }
 }
+
+impl From<witnet_crypto::secp256k1::Error> for Error {
+    fn from(err: witnet_crypto::secp256k1::Error) -> Self {
+        Error::Secp256k1(err)
+    }
+}