Initialize return values to an error

Initializing the return values to an error is best practice and makes
the library more robust against programmer errors.
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 57e5d8a..b632998 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -35,6 +35,7 @@
 #define mbedtls_free      free
 #endif
 
+#include "mbedtls/error.h"
 #include "mbedtls/debug.h"
 #include "mbedtls/ssl.h"
 #include "mbedtls/ssl_internal.h"
@@ -402,7 +403,7 @@
                                         unsigned char *buf,
                                         size_t *olen )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char *p = buf;
     const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
     size_t kkpp_len;
@@ -766,7 +767,7 @@
  */
 static int ssl_generate_random( mbedtls_ssl_context *ssl )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char *p = ssl->handshake->randbytes;
 #if defined(MBEDTLS_HAVE_TIME)
     mbedtls_time_t t;
@@ -858,7 +859,7 @@
 
 static int ssl_write_client_hello( mbedtls_ssl_context *ssl )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t i, n, olen, ext_len = 0;
     unsigned char *buf;
     unsigned char *p, *q;
@@ -1470,7 +1471,7 @@
                                    const unsigned char *buf,
                                    size_t len )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
     if( ssl->handshake->ciphersuite_info->key_exchange !=
         MBEDTLS_KEY_EXCHANGE_ECJPAKE )
@@ -2384,7 +2385,7 @@
                                     size_t offset, size_t *olen,
                                     size_t pms_offset )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t len_bytes = ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ? 0 : 2;
     unsigned char *p = ssl->handshake->premaster + pms_offset;
     mbedtls_pk_context * peer_pk;
@@ -2531,7 +2532,7 @@
     defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
 static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     const mbedtls_ecp_keypair *peer_key;
     mbedtls_pk_context * peer_pk;
 
@@ -2582,7 +2583,7 @@
 
 static int ssl_parse_server_key_exchange( mbedtls_ssl_context *ssl )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
         ssl->handshake->ciphersuite_info;
     unsigned char *p = NULL, *end = NULL;
@@ -2971,7 +2972,7 @@
 #else /* MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
 static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char *buf;
     size_t n = 0;
     size_t cert_type_len = 0, dn_len = 0;
@@ -3135,7 +3136,7 @@
 
 static int ssl_parse_server_hello_done( mbedtls_ssl_context *ssl )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server hello done" ) );
 
@@ -3174,7 +3175,7 @@
 
 static int ssl_write_client_key_exchange( mbedtls_ssl_context *ssl )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
     size_t header_len;
     size_t content_len;
@@ -3595,7 +3596,7 @@
 {
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
         ssl->handshake->ciphersuite_info;
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) );
 
@@ -3790,7 +3791,7 @@
 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
 static int ssl_parse_new_session_ticket( mbedtls_ssl_context *ssl )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     uint32_t lifetime;
     size_t ticket_len;
     unsigned char *ticket;