openpgp: Fix a crash in the Cleartext Signature Framework.

  - See #977.

2 files changed, 21 insertions, 2 deletions

diff --git a/openpgp/src/parse/hashed_reader.rs b/openpgp/src/parse/hashed_reader.rs
index 1ec70d62..28ebe2a2 100644
--- a/openpgp/src/parse/hashed_reader.rs
+++ b/openpgp/src/parse/hashed_reader.rs
@@ -341,7 +341,8 @@ impl Cookie {
                 t!("{:?}: {:?} hashing {} stashed bytes.",
                    hashes_for, h.map(|ctx| ctx.algo()),
                    stashed_data.len());
-                assert!(matches!(h, HashingMode::Text(_)),
+                assert!(matches!(h, HashingMode::Text(_)
+                                 | HashingMode::TextLastWasCr(_)),
                         "CSF transformation uses text signatures");
                 h.update(&stashed_data[..]);
             }
@@ -366,7 +367,8 @@ impl Cookie {
         for h in self.sig_groups[0].hashes.iter_mut() {
             t!("{:?}: {:?} hashing {} bytes.",
                hashes_for, h.map(|ctx| ctx.algo()), l);
-            assert!(matches!(h, HashingMode::Text(_)),
+            assert!(matches!(h, HashingMode::Text(_)
+                             | HashingMode::TextLastWasCr(_)),
                     "CSF transformation uses text signatures");
             h.update(&data[..l]);
         }
diff --git a/openpgp/src/parse/stream.rs b/openpgp/src/parse/stream.rs
index 730f515b..79022e8c 100644
--- a/openpgp/src/parse/stream.rs
+++ b/openpgp/src/parse/stream.rs
@@ -3924,4 +3924,21 @@ wgoEAAAAAAB6CkAAxADLBq8AAKurq8IKBCC/CAAAAAD0sA==
             .unwrap();
         Ok(())
     }
+
+    /// Checks for a crash related to HashedReader's HashingMode.
+    #[test]
+    fn csf_hashing_mode_assertion_failure() -> Result<()> {
+        let p = P::new();
+        let m = b"-----BEGIN PGP SIGNED MESSAGE-----
+---BEGIN PGP SIGNATURE
+0iHUEARYIAB0QCyUHMcArrZbte9msAndEO9clJG5wpCAEA2/";
+
+        let mut h = VHelper::new(0, 0, 0, 0, vec![
+            Cert::from_bytes(crate::tests::key("testy.pgp"))?,
+        ]);
+        h.error_out = false;
+        let _ = VerifierBuilder::from_bytes(m)?
+            .with_policy(&p, None, h);
+        Ok(())
+    }
 }