Commit 716302c2 authored by Daniel Stenberg's avatar Daniel Stenberg
Browse files

mbedtls: fix ALPN usage segfault 

Since we didn't keep the input argument around after having called
mbedtls, it could end up accessing the wrong memory when figuring out
the ALPN protocols.

Closes #642
parent 50cd9c8a

lib/urldata.h

+2 −1
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ 
 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.

 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.

 *

 * This software is licensed as described in the file COPYING, which

 * you should have received as part of this distribution. The terms
@@ -297,6 +297,7 @@ struct ssl_connect_data { 
  mbedtls_x509_crl crl;

  mbedtls_pk_context pk;

  mbedtls_ssl_config config;

  const char *protocols[3];

#elif defined(USE_POLARSSL)

  ctr_drbg_context ctr_drbg;

  entropy_context entropy;

lib/vtls/mbedtls.c

+6 −4
Original line number Diff line number Diff line
@@ -384,19 +384,21 @@ mbedtls_connect_step1(struct connectdata *conn, 


#ifdef HAS_ALPN

  if(data->set.ssl_enable_alpn) {

    const char *protocols[3];

    const char **p = protocols;

    const char **p = &connssl->protocols[0];

#ifdef USE_NGHTTP2

    if(data->set.httpversion >= CURL_HTTP_VERSION_2)

      *p++ = NGHTTP2_PROTO_VERSION_ID;

#endif

    *p++ = ALPN_HTTP_1_1;

    *p = NULL;

    if(mbedtls_ssl_conf_alpn_protocols(&connssl->config, protocols)) {

    /* this function doesn't clone the protocols array, which is why we need

       to keep it around */

    if(mbedtls_ssl_conf_alpn_protocols(&connssl->config,

                                       &connssl->protocols[0])) {

      failf(data, "Failed setting ALPN protocols");

      return CURLE_SSL_CONNECT_ERROR;

    }

    for(p = protocols; *p; ++p)

    for(p = &connssl->protocols[0]; *p; ++p)

      infof(data, "ALPN, offering %s\n", *p);

  }

#endif