Propagate ParseError when retrieving ohttp parameter

payjoin/src/ohttp.rs

@@ -237,6 +237,7 @@ impl serde::Serialize for OhttpKeys {
 
 #[derive(Debug)]
 pub enum ParseOhttpKeysError {
+    MissingOhttpKeys,
     InvalidFormat,
     InvalidPublicKey,
     DecodeBech32(bech32::primitives::decode::CheckedHrpstringError),
@@ -246,6 +247,7 @@ pub enum ParseOhttpKeysError {
 impl std::fmt::Display for ParseOhttpKeysError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
+            ParseOhttpKeysError::MissingOhttpKeys => write!(f, "Missing ohttp keys"),
             ParseOhttpKeysError::InvalidFormat => write!(f, "Invalid format"),
             ParseOhttpKeysError::InvalidPublicKey => write!(f, "Invalid public key"),
             ParseOhttpKeysError::DecodeBech32(e) => write!(f, "Failed to decode base64: {}", e),
@@ -260,7 +262,7 @@ impl std::error::Error for ParseOhttpKeysError {
         match self {
             ParseOhttpKeysError::DecodeBech32(e) => Some(e),
             ParseOhttpKeysError::DecodeKeyConfig(e) => Some(e),
-            ParseOhttpKeysError::InvalidFormat | ParseOhttpKeysError::InvalidPublicKey => None,
+            ParseOhttpKeysError::MissingOhttpKeys | ParseOhttpKeysError::InvalidFormat | ParseOhttpKeysError::InvalidPublicKey => None,
         }
     }
 }

payjoin/src/uri/url_ext.rs

@@ -7,13 +7,13 @@ use url::Url;
 
 use super::error::ParseReceiverPubkeyError;
 use crate::hpke::HpkePublicKey;
-use crate::OhttpKeys;
+use crate::ohttp::{OhttpKeys, ParseOhttpKeysError};
 
 /// Parse and set fragment parameters from `&pj=` URI parameter URLs
 pub(crate) trait UrlExt {
     fn receiver_pubkey(&self) -> Result<HpkePublicKey, ParseReceiverPubkeyError>;
     fn set_receiver_pubkey(&mut self, exp: HpkePublicKey);
-    fn ohttp(&self) -> Option<OhttpKeys>;
+    fn ohttp(&self) -> Result<OhttpKeys, ParseOhttpKeysError>;
     fn set_ohttp(&mut self, ohttp: OhttpKeys);
     fn exp(&self) -> Option<std::time::SystemTime>;
     fn set_exp(&mut self, exp: std::time::SystemTime);
@@ -50,8 +50,10 @@ impl UrlExt for Url {
     }
 
     /// Retrieve the ohttp parameter from the URL fragment
-    fn ohttp(&self) -> Option<OhttpKeys> {
-        get_param(self, "OH1", |value| OhttpKeys::from_str(value).ok())
+    fn ohttp(&self) -> Result<OhttpKeys, ParseOhttpKeysError> {
+        let value = get_param(self, "OH1", |v| Some(v.to_owned()))
+            .ok_or(ParseOhttpKeysError::MissingOhttpKeys)?;
+        OhttpKeys::from_str(&value)
     }
 
     /// Set the ohttp parameter in the URL fragment
@@ -142,7 +144,16 @@ mod tests {
         url.set_ohttp(ohttp_keys.clone());
 
         assert_eq!(url.fragment(), Some(serialized));
-        assert_eq!(url.ohttp(), Some(ohttp_keys));
+        assert_eq!(url.ohttp(), Ok(ohttp_keys));
+    }
+
+    #[test]
+    fn test_errors_when_parsing_ohttp() {
+        let missing_ohttp_url = Url::parse("https://example.com").unwrap();
+        assert!(matches!(missing_ohttp_url.ohttp(), Err(ParseOhttpKeysError::MissingOhttpKeys)));
+
+        let invalid_ohttp_url = Url::parse("https://example.com?ohttp=@@@@@@@").unwrap();
+        assert!(matches!(invalid_ohttp_url.ohttp(), Err(ParseOhttpKeysError::InvalidFormat)));
     }
 
     #[test]