Add a helper function for resetting SSL_get_error state. We repeat this in a bunch of places. Change-Id: Iee2c95a13e1645453f101d8be4be9ac78d520387 Reviewed-on: https://boringssl-review.googlesource.com/13051 Reviewed-by: David Benjamin <davidben@google.com>

diff --git a/ssl/d1_lib.c b/ssl/d1_lib.c
index ba3c844..258e9ab 100644
--- a/ssl/d1_lib.c
+++ b/ssl/d1_lib.c

@@ -236,9 +236,7 @@
 }
 
 int DTLSv1_handle_timeout(SSL *ssl) {
-  ssl->rwstate = SSL_NOTHING;
-  /* Functions which use SSL_get_error must clear the error queue on entry. */
-  ERR_clear_error();
+  ssl_reset_error_state(ssl);
 
   if (!SSL_is_dtls(ssl)) {
     return -1;

diff --git a/ssl/internal.h b/ssl/internal.h
index 97ae6a0..e26fa13 100644
--- a/ssl/internal.h
+++ b/ssl/internal.h

@@ -1946,6 +1946,9 @@
 
 void ssl_get_current_time(const SSL *ssl, struct timeval *out_clock);
 
+/* ssl_reset_error_state resets state for |SSL_get_error|. */
+void ssl_reset_error_state(SSL *ssl);
+
 
 #if defined(__cplusplus)
 } /* extern C */

diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index 806bdba..2e9f4a6 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c

@@ -612,11 +612,16 @@
   return ssl->wbio;
 }
 
-int SSL_do_handshake(SSL *ssl) {
+void ssl_reset_error_state(SSL *ssl) {
+  /* Functions which use |SSL_get_error| must reset I/O and error state on
+   * entry. */
   ssl->rwstate = SSL_NOTHING;
-  /* Functions which use SSL_get_error must clear the error queue on entry. */
   ERR_clear_error();
   ERR_clear_system_error();
+}
+
+int SSL_do_handshake(SSL *ssl) {
+  ssl_reset_error_state(ssl);
 
   if (ssl->handshake_func == NULL) {
     OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_TYPE_NOT_SET);
@@ -735,10 +740,7 @@
 }
 
 static int ssl_read_impl(SSL *ssl, void *buf, int num, int peek) {
-  ssl->rwstate = SSL_NOTHING;
-  /* Functions which use SSL_get_error must clear the error queue on entry. */
-  ERR_clear_error();
-  ERR_clear_system_error();
+  ssl_reset_error_state(ssl);
 
   if (ssl->handshake_func == NULL) {
     OPENSSL_PUT_ERROR(SSL, SSL_R_UNINITIALIZED);
@@ -784,10 +786,7 @@
 }
 
 int SSL_write(SSL *ssl, const void *buf, int num) {
-  ssl->rwstate = SSL_NOTHING;
-  /* Functions which use SSL_get_error must clear the error queue on entry. */
-  ERR_clear_error();
-  ERR_clear_system_error();
+  ssl_reset_error_state(ssl);
 
   if (ssl->handshake_func == NULL) {
     OPENSSL_PUT_ERROR(SSL, SSL_R_UNINITIALIZED);
@@ -815,10 +814,7 @@
 }
 
 int SSL_shutdown(SSL *ssl) {
-  ssl->rwstate = SSL_NOTHING;
-  /* Functions which use SSL_get_error must clear the error queue on entry. */
-  ERR_clear_error();
-  ERR_clear_system_error();
+  ssl_reset_error_state(ssl);
 
   if (ssl->handshake_func == NULL) {
     OPENSSL_PUT_ERROR(SSL, SSL_R_UNINITIALIZED);