feat: Make SignatureConfig::hash_signature_data more flexible

wiktor-k · wiktor-k · commit c6d6b2c0fae3 · 2024-08-19T12:13:07.000+02:00
Hashers from RustCrypto implement `std::io::Write` and making use of that
trait in the `hash_signature_data` makes it possible to use other hashers
which do not implement RustCrypto Hasher trait.

Additionally it allows using hashers which may fail during the digest
update (such as OpenSSL hashers).
diff --git a/src/packet/signature/config.rs b/src/packet/signature/config.rs
@@ -182,7 +182,7 @@ impl SignatureConfig {
         }
 
         self.hash_data_to_sign(&mut *hasher, data)?;
-        let len = self.hash_signature_data(&mut *hasher)?;
+        let len = self.hash_signature_data(&mut hasher)?;
         hasher.update(&self.trailer(len)?);
 
         let hash = &hasher.finish()[..];
@@ -272,7 +272,7 @@ impl SignatureConfig {
         // the packet content
         hasher.update(&packet_buf);
 
-        let len = self.hash_signature_data(&mut *hasher)?;
+        let len = self.hash_signature_data(&mut hasher)?;
         hasher.update(&self.trailer(len)?);
 
         let hash = &hasher.finish()[..];
@@ -318,7 +318,7 @@ impl SignatureConfig {
         // Key being bound
         key.serialize_for_hashing(&mut hasher)?;
 
-        let len = self.hash_signature_data(&mut *hasher)?;
+        let len = self.hash_signature_data(&mut hasher)?;
         hasher.update(&self.trailer(len)?);
 
         let hash = &hasher.finish()[..];
@@ -356,7 +356,7 @@ impl SignatureConfig {
 
         key.serialize_for_hashing(&mut hasher)?;
 
-        let len = self.hash_signature_data(&mut *hasher)?;
+        let len = self.hash_signature_data(&mut hasher)?;
         hasher.update(&self.trailer(len)?);
 
         let hash = &hasher.finish()[..];
@@ -372,7 +372,7 @@ impl SignatureConfig {
     }
 
     /// Calculate the serialized version of this packet, but only the part relevant for hashing.
-    pub fn hash_signature_data(&self, hasher: &mut dyn Hasher) -> Result<usize> {
+    pub fn hash_signature_data(&self, hasher: &mut dyn std::io::Write) -> Result<usize> {
         match self.version() {
             SignatureVersion::V2 | SignatureVersion::V3 => {
                 let created = {
@@ -389,7 +389,7 @@ impl SignatureConfig {
                 buf[0] = self.typ.into();
                 BigEndian::write_u32(&mut buf[1..], created.timestamp().try_into()?);
 
-                hasher.update(&buf);
+                hasher.write_all(&buf)?;
 
                 // no trailer
                 Ok(0)
@@ -424,7 +424,7 @@ impl SignatureConfig {
 
                 res.extend(hashed_subpackets);
 
-                hasher.update(&res);
+                hasher.write_all(&res)?;
 
                 Ok(res.len())
             }
diff --git a/src/packet/signature/types.rs b/src/packet/signature/types.rs
@@ -220,7 +220,7 @@ impl Signature {
         } else {
             self.config.hash_data_to_sign(&mut *hasher, data)?;
         }
-        let len = self.config.hash_signature_data(&mut *hasher)?;
+        let len = self.config.hash_signature_data(&mut hasher)?;
         hasher.update(&self.config.trailer(len)?);
 
         let hash = &hasher.finish()[..];
@@ -307,7 +307,7 @@ impl Signature {
             hasher.update(&packet_buf);
         }
 
-        let len = self.config.hash_signature_data(&mut *hasher)?;
+        let len = self.config.hash_signature_data(&mut hasher)?;
         hasher.update(&self.config.trailer(len)?);
 
         let hash = &hasher.finish()[..];
@@ -390,7 +390,7 @@ impl Signature {
             hasher.update(&key_buf);
         }
 
-        let len = self.config.hash_signature_data(&mut *hasher)?;
+        let len = self.config.hash_signature_data(&mut hasher)?;
         hasher.update(&self.config.trailer(len)?);
 
         let hash = &hasher.finish()[..];
@@ -426,7 +426,7 @@ impl Signature {
             hasher.update(&key_buf);
         }
 
-        let len = self.config.hash_signature_data(&mut *hasher)?;
+        let len = self.config.hash_signature_data(&mut hasher)?;
         hasher.update(&self.config.trailer(len)?);
 
         let hash = &hasher.finish()[..];
