Introduce NetworkError::from_hyper_error and from_ssl_error

components/net_traits/lib.rs

@@ -22,6 +22,7 @@ extern crate lazy_static;
 extern crate log;
 extern crate msg;
 extern crate num_traits;
+extern crate openssl;
 extern crate parse_hosts;
 extern crate serde;
 #[macro_use]
@@ -35,16 +36,19 @@ extern crate webrender_traits;
 use cookie_rs::Cookie;
 use filemanager_thread::FileManagerThreadMsg;
 use heapsize::HeapSizeOf;
+use hyper::Error as HyperError;
 use hyper::header::{ContentType, Headers, ReferrerPolicy as ReferrerPolicyHeader};
 use hyper::http::RawStatus;
 use hyper::mime::{Attr, Mime};
 use hyper_serde::Serde;
-use ipc_channel::Error;
+use ipc_channel::Error as IpcError;
 use ipc_channel::ipc::{self, IpcReceiver, IpcSender};
 use ipc_channel::router::ROUTER;
+use openssl::ssl::error::{OpensslError, SslError};
 use request::{Request, RequestInit};
 use response::{HttpsState, Response};
 use servo_url::ServoUrl;
+use std::error::Error;
 use storage_thread::StorageThreadMsg;
 
 pub mod blob_url_store;
@@ -265,7 +269,7 @@ impl<T: FetchResponseListener> Action<T> for FetchResponseMsg {
 /// Handle to a resource thread
 pub type CoreResourceThread = IpcSender<CoreResourceMsg>;
 
-pub type IpcSendResult = Result<(), Error>;
+pub type IpcSendResult = Result<(), IpcError>;
 
 /// Abstraction of the ability to send a particular type of message,
 /// used by net_traits::ResourceThreads to ease the use its IpcSender sub-fields
@@ -526,6 +530,69 @@ pub enum NetworkError {
     SslValidation(ServoUrl, String),
 }
 
+impl NetworkError {
+    pub fn from_hyper_error(url: &ServoUrl, error: HyperError) -> Self {
+        if let HyperError::Ssl(ref ssl_error) = error {
+            if let Some(ssl_error) = ssl_error.downcast_ref::<SslError>() {
+                return NetworkError::from_ssl_error(url, ssl_error);
+            }
+        }
+        NetworkError::Internal(error.description().to_owned())
+    }
+
+    fn from_ssl_error(url: &ServoUrl, error: &SslError) -> Self {
+        if let SslError::OpenSslErrors(ref errors) = *error {
+            if errors.iter().any(is_cert_verify_error) {
+                let mut error_report = vec![format!("ssl error ({}):", openssl::version::version())];
+                let mut suggestion = None;
+                for err in errors {
+                    if is_unknown_message_digest_err(err) {
+                        suggestion = Some("<b>Servo recommends upgrading to a newer OpenSSL version.</b>");
+                    }
+                    error_report.push(format_ssl_error(err));
+                }
+
+                if let Some(suggestion) = suggestion {
+                    error_report.push(suggestion.to_owned());
+                }
+
+                let error_report = error_report.join("<br>\n");
+                return NetworkError::SslValidation(url.clone(), error_report);
+            }
+        }
+        NetworkError::Internal(error.description().to_owned())
+    }
+}
+
+fn format_ssl_error(error: &OpensslError) -> String {
+    match error {
+        &OpensslError::UnknownError { ref library, ref function, ref reason } => {
+            format!("{}: {} - {}", library, function, reason)
+        }
+    }
+}
+
+// FIXME: This incredibly hacky. Make it more robust, and at least test it.
+fn is_cert_verify_error(error: &OpensslError) -> bool {
+    match error {
+        &OpensslError::UnknownError { ref library, ref function, ref reason } => {
+            library == "SSL routines" &&
+            function.to_uppercase() == "SSL3_GET_SERVER_CERTIFICATE" &&
+            reason == "certificate verify failed"
+        }
+    }
+}
+
+fn is_unknown_message_digest_err(error: &OpensslError) -> bool {
+    match error {
+        &OpensslError::UnknownError { ref library, ref function, ref reason } => {
+            library == "asn1 encoding routines" &&
+            function == "ASN1_item_verify" &&
+            reason == "unknown message digest algorithm"
+        }
+    }
+}
+
 /// Normalize `slice`, as defined by
 /// [the Fetch Spec](https://fetch.spec.whatwg.org/#concept-header-value-normalize).
 pub fn trim_http_whitespace(mut slice: &[u8]) -> &[u8] {