Detect/report server hang-up in SSL_connect().

This condition does not leave traces in the SSL error queue,
and must be checked explicitly.  Result from debugging Jerry Seibert's
issue with outlook.com/pop3.live.com.

2 files changed, 16 insertions, 2 deletions

diff --git a/NEWS b/NEWS
index 8911d990..905c2566 100644
--- a/NEWS
+++ b/NEWS
@@ -81,10 +81,13 @@ fetchmail-6.4.0 (not yet released):
   tls1.2+ (case insensitively).
 
 ## CHANGES
+* fetchmail 6.3.X is unsupported.
 * Fetchmail now supports --sslproto auto and --sslproto tls1+ (same as ssl23).
 * --sslproto tls1.1+ and tls1.2+ are now supported for auto-negotiation with a
   minimum specified TLS protocol version.
-* fetchmail 6.3.X is unsupported.
+* Fetchmail now detects if the server hangs up prematurely during SSL_connect()
+  and reports this condition as such, and not just as SSL connection failure.
+  (OpenSSL 1.0.2 reported incompatible with pop3.live.com by Jerry Seibert).
 
 ## FIXES
 * Fix a typo in the FAQ. Submitted by David Lawyer, Debian Bug#706776.
diff --git a/socket.c b/socket.c
index 5b25ac08..5ed62546 100644
--- a/socket.c
+++ b/socket.c
@@ -878,6 +878,7 @@ int SSLOpen(int sock, char *mycert, char *mykey, const char *myproto, int certck
         int i;
 	int avoid_ssl_versions = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
 	long sslopts = SSL_OP_ALL;
+	int ssle_connect = 0;
 
 	SSL_load_error_strings();
 	SSL_library_init();
@@ -1019,8 +1020,18 @@ int SSLOpen(int sock, char *mycert, char *mykey, const char *myproto, int certck
 	}
 
 	if (SSL_set_fd(_ssl_context[sock], sock) == 0 
-	    || SSL_connect(_ssl_context[sock]) < 1) {
+	    || (ssle_connect = SSL_connect(_ssl_context[sock])) < 1) {
+		int e = errno;
+		unsigned long ssle_err_from_queue = ERR_peek_error();
+		unsigned long ssle_err_from_get_error = SSL_get_error(_ssl_context[sock], ssle_connect);
 		ERR_print_errors_fp(stderr);
+		if (SSL_ERROR_SYSCALL == ssle_err_from_get_error && 0 == ssle_err_from_queue) {
+		    if (0 == ssle_connect) {
+			report(stderr, GT_("Server shut down connection prematurely during SSL_connect().\n"));
+		    } else if (ssle_connect < 0) {
+			report(stderr, GT_("System error during SSL_connect(): %s\n"), strerror(e));
+		    }
+		}
 		SSL_free( _ssl_context[sock] );
 		_ssl_context[sock] = NULL;
 		SSL_CTX_free(_ctx[sock]);