Fix SSL error handling by youknowone · Pull Request #6351 · RustPython/RustPython

⚠️ Potential issue | 🟠 Major

PEM error calls pass empty reason string; swap reason/message usage

In load_cert_chain, the non-password PEM error paths build the SSL error as:

super::compat::SslError::create_ssl_error_with_reason(
    vm,
    Some("SSL"),
    "",
    "PEM lib",
)

(and similarly in the _ and non-io::Error branches).

Per create_ssl_error_with_reason’s contract and other call sites, reason should hold a short reason like "PEM lib", while message is the main display string. Using an empty reason here means exc.reason is not informative and is inconsistent with comments like // [SSL] PEM lib and with usages such as the NO_START_LINE path.

Recommend at least giving reason a non-empty value and, ideally, including the [SSL] … prefix in the message, e.g.:

- super::compat::SslError::create_ssl_error_with_reason(
-     vm,
-     Some("SSL"),
-     "",
-     "PEM lib",
- )
+ super::compat::SslError::create_ssl_error_with_reason(
+     vm,
+     Some("SSL"),
+     "PEM lib",
+     "[SSL] PEM lib",
+ )

Apply the same pattern to the _ arm and the else branch so that all PEM-lib errors expose a consistent and non-empty reason attribute.

In crates/stdlib/src/ssl.rs around lines 1256 to 1280, the PEM error branches
call create_ssl_error_with_reason(vm, Some("SSL"), "", "PEM lib") leaving the
reason empty; change these calls so reason receives a short non-empty identifier
(e.g. "PEM lib") and message receives the full display string (e.g. "[SSL] PEM
lib" or include context), i.e. swap the empty-string reason and the current
message value so exc.reason is informative; apply the same change to the `_` arm
and the final `else` branch so all PEM parsing error paths consistently pass a
non-empty reason and an appropriate message.