libcurl: update to 7.57

1 files changed, 937 insertions, 0 deletions

diff --git a/libs/libcurl/src/vtls/polarssl.c b/libs/libcurl/src/vtls/polarssl.c
new file mode 100644
index 0000000000..df29fa945e
--- /dev/null
+++ b/libs/libcurl/src/vtls/polarssl.c
@@ -0,0 +1,937 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2012 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 2010 - 2011, Hoi-Ho Chan, <hoiho.chan@gmail.com>
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+/*
+ * Source file for all PolarSSL-specific code for the TLS/SSL layer. No code
+ * but vtls.c should ever call or use these functions.
+ *
+ */
+
+#include "curl_setup.h"
+
+#ifdef USE_POLARSSL
+#include <polarssl/net.h>
+#include <polarssl/ssl.h>
+#include <polarssl/certs.h>
+#include <polarssl/x509.h>
+#include <polarssl/version.h>
+#include <polarssl/sha256.h>
+
+#if POLARSSL_VERSION_NUMBER < 0x01030000
+#error too old PolarSSL
+#endif
+
+#include <polarssl/error.h>
+#include <polarssl/entropy.h>
+#include <polarssl/ctr_drbg.h>
+
+#include "urldata.h"
+#include "sendf.h"
+#include "inet_pton.h"
+#include "polarssl.h"
+#include "vtls.h"
+#include "parsedate.h"
+#include "connect.h" /* for the connect timeout */
+#include "select.h"
+#include "strcase.h"
+#include "polarssl_threadlock.h"
+#include "curl_printf.h"
+#include "curl_memory.h"
+/* The last #include file should be: */
+#include "memdebug.h"
+
+/* See https://tls.mbed.org/discussions/generic/
+   howto-determine-exact-buffer-len-for-mbedtls_pk_write_pubkey_der
+*/
+#define RSA_PUB_DER_MAX_BYTES   (38 + 2 * POLARSSL_MPI_MAX_SIZE)
+#define ECP_PUB_DER_MAX_BYTES   (30 + 2 * POLARSSL_ECP_MAX_BYTES)
+
+#define PUB_DER_MAX_BYTES   (RSA_PUB_DER_MAX_BYTES > ECP_PUB_DER_MAX_BYTES ? \
+                             RSA_PUB_DER_MAX_BYTES : ECP_PUB_DER_MAX_BYTES)
+
+struct ssl_backend_data {
+  ctr_drbg_context ctr_drbg;
+  entropy_context entropy;
+  ssl_context ssl;
+  int server_fd;
+  x509_crt cacert;
+  x509_crt clicert;
+  x509_crl crl;
+  rsa_context rsa;
+};
+
+#define BACKEND connssl->backend
+
+/* apply threading? */
+#if defined(USE_THREADS_POSIX) || defined(USE_THREADS_WIN32)
+#define THREADING_SUPPORT
+#endif
+
+#ifndef POLARSSL_ERROR_C
+#define error_strerror(x,y,z)
+#endif /* POLARSSL_ERROR_C */
+
+
+#if defined(THREADING_SUPPORT)
+static entropy_context entropy;
+
+static int  entropy_init_initialized  = 0;
+
+/* start of entropy_init_mutex() */
+static void entropy_init_mutex(entropy_context *ctx)
+{
+  /* lock 0 = entropy_init_mutex() */
+  Curl_polarsslthreadlock_lock_function(0);
+  if(entropy_init_initialized == 0) {
+    entropy_init(ctx);
+    entropy_init_initialized = 1;
+  }
+  Curl_polarsslthreadlock_unlock_function(0);
+}
+/* end of entropy_init_mutex() */
+
+/* start of entropy_func_mutex() */
+static int entropy_func_mutex(void *data, unsigned char *output, size_t len)
+{
+  int ret;
+  /* lock 1 = entropy_func_mutex() */
+  Curl_polarsslthreadlock_lock_function(1);
+  ret = entropy_func(data, output, len);
+  Curl_polarsslthreadlock_unlock_function(1);
+
+  return ret;
+}
+/* end of entropy_func_mutex() */
+
+#endif /* THREADING_SUPPORT */
+
+/* Define this to enable lots of debugging for PolarSSL */
+#undef POLARSSL_DEBUG
+
+#ifdef POLARSSL_DEBUG
+static void polarssl_debug(void *context, int level, const char *line)
+{
+  struct Curl_easy *data = NULL;
+
+  if(!context)
+    return;
+
+  data = (struct Curl_easy *)context;
+
+  infof(data, "%s", line);
+  (void) level;
+}
+#else
+#endif
+
+/* ALPN for http2? */
+#ifdef POLARSSL_SSL_ALPN
+#  define HAS_ALPN
+#endif
+
+static Curl_recv polarssl_recv;
+static Curl_send polarssl_send;
+
+static CURLcode polarssl_version_from_curl(int *polarver, long ssl_version)
+{
+  switch(ssl_version) {
+    case CURL_SSLVERSION_TLSv1_0:
+      *polarver = SSL_MINOR_VERSION_1;
+      return CURLE_OK;
+    case CURL_SSLVERSION_TLSv1_1:
+      *polarver = SSL_MINOR_VERSION_2;
+      return CURLE_OK;
+    case CURL_SSLVERSION_TLSv1_2:
+      *polarver = SSL_MINOR_VERSION_3;
+      return CURLE_OK;
+    case CURL_SSLVERSION_TLSv1_3:
+      break;
+  }
+  return CURLE_SSL_CONNECT_ERROR;
+}
+
+static CURLcode
+set_ssl_version_min_max(struct connectdata *conn, int sockindex)
+{
+  struct Curl_easy *data = conn->data;
+  struct ssl_connect_data* connssl = &conn->ssl[sockindex];
+  long ssl_version = SSL_CONN_CONFIG(version);
+  long ssl_version_max = SSL_CONN_CONFIG(version_max);
+  int ssl_min_ver = SSL_MINOR_VERSION_1;
+  int ssl_max_ver = SSL_MINOR_VERSION_1;
+  CURLcode result = CURLE_OK;
+
+  switch(ssl_version) {
+    case CURL_SSLVERSION_DEFAULT:
+    case CURL_SSLVERSION_TLSv1:
+      ssl_version = CURL_SSLVERSION_TLSv1_0;
+      ssl_version_max = CURL_SSLVERSION_MAX_TLSv1_2;
+      break;
+  }
+
+  switch(ssl_version_max) {
+    case CURL_SSLVERSION_MAX_NONE:
+      ssl_version_max = ssl_version << 16;
+      break;
+    case CURL_SSLVERSION_MAX_DEFAULT:
+      ssl_version_max = CURL_SSLVERSION_MAX_TLSv1_2;
+      break;
+  }
+
+  result = polarssl_version_from_curl(&ssl_min_ver, ssl_version);
+  if(result) {
+    failf(data, "unsupported min version passed via CURLOPT_SSLVERSION");
+    return result;
+  }
+  result = polarssl_version_from_curl(&ssl_max_ver, ssl_version_max >> 16);
+  if(result) {
+    failf(data, "unsupported max version passed via CURLOPT_SSLVERSION");
+    return result;
+  }
+
+  ssl_set_min_version(&BACKEND->ssl, SSL_MAJOR_VERSION_3, ssl_min_ver);
+  ssl_set_max_version(&BACKEND->ssl, SSL_MAJOR_VERSION_3, ssl_max_ver);
+
+  return result;
+}
+
+static CURLcode
+polarssl_connect_step1(struct connectdata *conn,
+                       int sockindex)
+{
+  struct Curl_easy *data = conn->data;
+  struct ssl_connect_data* connssl = &conn->ssl[sockindex];
+  const char *capath = SSL_CONN_CONFIG(CApath);
+  const char * const hostname = SSL_IS_PROXY() ? conn->http_proxy.host.name :
+    conn->host.name;
+  const long int port = SSL_IS_PROXY() ? conn->port : conn->remote_port;
+  int ret = -1;
+  char errorbuf[128];
+  errorbuf[0] = 0;
+
+  /* PolarSSL only supports SSLv3 and TLSv1 */
+  if(SSL_CONN_CONFIG(version) == CURL_SSLVERSION_SSLv2) {
+    failf(data, "PolarSSL does not support SSLv2");
+    return CURLE_SSL_CONNECT_ERROR;
+  }
+
+#ifdef THREADING_SUPPORT
+  entropy_init_mutex(&entropy);
+
+  if((ret = ctr_drbg_init(&BACKEND->ctr_drbg, entropy_func_mutex, &entropy,
+                          NULL, 0)) != 0) {
+    error_strerror(ret, errorbuf, sizeof(errorbuf));
+    failf(data, "Failed - PolarSSL: ctr_drbg_init returned (-0x%04X) %s\n",
+          -ret, errorbuf);
+  }
+#else
+  entropy_init(&BACKEND->entropy);
+
+  if((ret = ctr_drbg_init(&BACKEND->ctr_drbg, entropy_func, &BACKEND->entropy,
+                          NULL, 0)) != 0) {
+    error_strerror(ret, errorbuf, sizeof(errorbuf));
+    failf(data, "Failed - PolarSSL: ctr_drbg_init returned (-0x%04X) %s\n",
+          -ret, errorbuf);
+  }
+#endif /* THREADING_SUPPORT */
+
+  /* Load the trusted CA */
+  memset(&BACKEND->cacert, 0, sizeof(x509_crt));
+
+  if(SSL_CONN_CONFIG(CAfile)) {
+    ret = x509_crt_parse_file(&BACKEND->cacert,
+                              SSL_CONN_CONFIG(CAfile));
+
+    if(ret<0) {
+      error_strerror(ret, errorbuf, sizeof(errorbuf));
+      failf(data, "Error reading ca cert file %s - PolarSSL: (-0x%04X) %s",
+            SSL_CONN_CONFIG(CAfile), -ret, errorbuf);
+
+      if(SSL_CONN_CONFIG(verifypeer))
+        return CURLE_SSL_CACERT_BADFILE;
+    }
+  }
+
+  if(capath) {
+    ret = x509_crt_parse_path(&BACKEND->cacert, capath);
+
+    if(ret<0) {
+      error_strerror(ret, errorbuf, sizeof(errorbuf));
+      failf(data, "Error reading ca cert path %s - PolarSSL: (-0x%04X) %s",
+            capath, -ret, errorbuf);
+
+      if(SSL_CONN_CONFIG(verifypeer))
+        return CURLE_SSL_CACERT_BADFILE;
+    }
+  }
+
+  /* Load the client certificate */
+  memset(&BACKEND->clicert, 0, sizeof(x509_crt));
+
+  if(SSL_SET_OPTION(cert)) {
+    ret = x509_crt_parse_file(&BACKEND->clicert,
+                              SSL_SET_OPTION(cert));
+
+    if(ret) {
+      error_strerror(ret, errorbuf, sizeof(errorbuf));
+      failf(data, "Error reading client cert file %s - PolarSSL: (-0x%04X) %s",
+            SSL_SET_OPTION(cert), -ret, errorbuf);
+
+      return CURLE_SSL_CERTPROBLEM;
+    }
+  }
+
+  /* Load the client private key */
+  if(SSL_SET_OPTION(key)) {
+    pk_context pk;
+    pk_init(&pk);
+    ret = pk_parse_keyfile(&pk, SSL_SET_OPTION(key),
+                           SSL_SET_OPTION(key_passwd));
+    if(ret == 0 && !pk_can_do(&pk, POLARSSL_PK_RSA))
+      ret = POLARSSL_ERR_PK_TYPE_MISMATCH;
+    if(ret == 0)
+      rsa_copy(&BACKEND->rsa, pk_rsa(pk));
+    else
+      rsa_free(&BACKEND->rsa);
+    pk_free(&pk);
+
+    if(ret) {
+      error_strerror(ret, errorbuf, sizeof(errorbuf));
+      failf(data, "Error reading private key %s - PolarSSL: (-0x%04X) %s",
+            SSL_SET_OPTION(key), -ret, errorbuf);
+
+      return CURLE_SSL_CERTPROBLEM;
+    }
+  }
+
+  /* Load the CRL */
+  memset(&BACKEND->crl, 0, sizeof(x509_crl));
+
+  if(SSL_SET_OPTION(CRLfile)) {
+    ret = x509_crl_parse_file(&BACKEND->crl,
+                              SSL_SET_OPTION(CRLfile));
+
+    if(ret) {
+      error_strerror(ret, errorbuf, sizeof(errorbuf));
+      failf(data, "Error reading CRL file %s - PolarSSL: (-0x%04X) %s",
+            SSL_SET_OPTION(CRLfile), -ret, errorbuf);
+
+      return CURLE_SSL_CRL_BADFILE;
+    }
+  }
+
+  infof(data, "PolarSSL: Connecting to %s:%d\n", hostname, port);
+
+  if(ssl_init(&BACKEND->ssl)) {
+    failf(data, "PolarSSL: ssl_init failed");
+    return CURLE_SSL_CONNECT_ERROR;
+  }
+
+  switch(SSL_CONN_CONFIG(version)) {
+  case CURL_SSLVERSION_DEFAULT:
+  case CURL_SSLVERSION_TLSv1:
+    ssl_set_min_version(&BACKEND->ssl, SSL_MAJOR_VERSION_3,
+                        SSL_MINOR_VERSION_1);
+    break;
+  case CURL_SSLVERSION_SSLv3:
+    ssl_set_min_version(&BACKEND->ssl, SSL_MAJOR_VERSION_3,
+                        SSL_MINOR_VERSION_0);
+    ssl_set_max_version(&BACKEND->ssl, SSL_MAJOR_VERSION_3,
+                        SSL_MINOR_VERSION_0);
+    infof(data, "PolarSSL: Forced min. SSL Version to be SSLv3\n");
+    break;
+  case CURL_SSLVERSION_TLSv1_0:
+  case CURL_SSLVERSION_TLSv1_1:
+  case CURL_SSLVERSION_TLSv1_2:
+  case CURL_SSLVERSION_TLSv1_3:
+    {
+      CURLcode result = set_ssl_version_min_max(conn, sockindex);
+      if(result != CURLE_OK)
+        return result;
+      break;
+    }
+  default:
+    failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
+    return CURLE_SSL_CONNECT_ERROR;
+  }
+
+  ssl_set_endpoint(&BACKEND->ssl, SSL_IS_CLIENT);
+  ssl_set_authmode(&BACKEND->ssl, SSL_VERIFY_OPTIONAL);
+
+  ssl_set_rng(&BACKEND->ssl, ctr_drbg_random,
+              &BACKEND->ctr_drbg);
+  ssl_set_bio(&BACKEND->ssl,
+              net_recv, &conn->sock[sockindex],
+              net_send, &conn->sock[sockindex]);
+
+  ssl_set_ciphersuites(&BACKEND->ssl, ssl_list_ciphersuites());
+
+  /* Check if there's a cached ID we can/should use here! */
+  if(SSL_SET_OPTION(primary.sessionid)) {
+    void *old_session = NULL;
+
+    Curl_ssl_sessionid_lock(conn);
+    if(!Curl_ssl_getsessionid(conn, &old_session, NULL, sockindex)) {
+      ret = ssl_set_session(&BACKEND->ssl, old_session);
+      if(ret) {
+        Curl_ssl_sessionid_unlock(conn);
+        failf(data, "ssl_set_session returned -0x%x", -ret);
+        return CURLE_SSL_CONNECT_ERROR;
+      }
+      infof(data, "PolarSSL re-using session\n");
+    }
+    Curl_ssl_sessionid_unlock(conn);
+  }
+
+  ssl_set_ca_chain(&BACKEND->ssl,
+                   &BACKEND->cacert,
+                   &BACKEND->crl,
+                   hostname);
+
+  ssl_set_own_cert_rsa(&BACKEND->ssl,
+                       &BACKEND->clicert, &BACKEND->rsa);
+
+  if(ssl_set_hostname(&BACKEND->ssl, hostname)) {
+    /* ssl_set_hostname() sets the name to use in CN/SAN checks *and* the name
+       to set in the SNI extension. So even if curl connects to a host
+       specified as an IP address, this function must be used. */
+    failf(data, "couldn't set hostname in PolarSSL");
+    return CURLE_SSL_CONNECT_ERROR;
+  }
+
+#ifdef HAS_ALPN
+  if(conn->bits.tls_enable_alpn) {
+    static const char *protocols[3];
+    int cur = 0;
+
+#ifdef USE_NGHTTP2
+    if(data->set.httpversion >= CURL_HTTP_VERSION_2) {
+      protocols[cur++] = NGHTTP2_PROTO_VERSION_ID;
+      infof(data, "ALPN, offering %s\n", NGHTTP2_PROTO_VERSION_ID);
+    }
+#endif
+
+    protocols[cur++] = ALPN_HTTP_1_1;
+    infof(data, "ALPN, offering %s\n", ALPN_HTTP_1_1);
+
+    protocols[cur] = NULL;
+
+    ssl_set_alpn_protocols(&BACKEND->ssl, protocols);
+  }
+#endif
+
+#ifdef POLARSSL_DEBUG
+  ssl_set_dbg(&BACKEND->ssl, polarssl_debug, data);
+#endif
+
+  connssl->connecting_state = ssl_connect_2;
+
+  return CURLE_OK;
+}
+
+static CURLcode
+polarssl_connect_step2(struct connectdata *conn,
+                       int sockindex)
+{
+  int ret;
+  struct Curl_easy *data = conn->data;
+  struct ssl_connect_data* connssl = &conn->ssl[sockindex];
+  char buffer[1024];
+  const char * const pinnedpubkey = SSL_IS_PROXY() ?
+            data->set.str[STRING_SSL_PINNEDPUBLICKEY_PROXY] :
+            data->set.str[STRING_SSL_PINNEDPUBLICKEY_ORIG];
+
+
+  char errorbuf[128];
+  errorbuf[0] = 0;
+
+  conn->recv[sockindex] = polarssl_recv;
+  conn->send[sockindex] = polarssl_send;
+
+  ret = ssl_handshake(&BACKEND->ssl);
+
+  switch(ret) {
+  case 0:
+    break;
+
+  case POLARSSL_ERR_NET_WANT_READ:
+    connssl->connecting_state = ssl_connect_2_reading;
+    return CURLE_OK;
+
+  case POLARSSL_ERR_NET_WANT_WRITE:
+    connssl->connecting_state = ssl_connect_2_writing;
+    return CURLE_OK;
+
+  default:
+    error_strerror(ret, errorbuf, sizeof(errorbuf));
+    failf(data, "ssl_handshake returned - PolarSSL: (-0x%04X) %s",
+          -ret, errorbuf);
+    return CURLE_SSL_CONNECT_ERROR;
+  }
+
+  infof(data, "PolarSSL: Handshake complete, cipher is %s\n",
+        ssl_get_ciphersuite(&BACKEND->ssl) );
+
+  ret = ssl_get_verify_result(&BACKEND->ssl);
+
+  if(ret && SSL_CONN_CONFIG(verifypeer)) {
+    if(ret & BADCERT_EXPIRED)
+      failf(data, "Cert verify failed: BADCERT_EXPIRED");
+
+    if(ret & BADCERT_REVOKED) {
+      failf(data, "Cert verify failed: BADCERT_REVOKED");
+      return CURLE_SSL_CACERT;
+    }
+
+    if(ret & BADCERT_CN_MISMATCH)
+      failf(data, "Cert verify failed: BADCERT_CN_MISMATCH");
+
+    if(ret & BADCERT_NOT_TRUSTED)
+      failf(data, "Cert verify failed: BADCERT_NOT_TRUSTED");
+
+    return CURLE_PEER_FAILED_VERIFICATION;
+  }
+
+  if(ssl_get_peer_cert(&(BACKEND->ssl))) {
+    /* If the session was resumed, there will be no peer certs */
+    memset(buffer, 0, sizeof(buffer));
+
+    if(x509_crt_info(buffer, sizeof(buffer), (char *)"* ",
+                     ssl_get_peer_cert(&(BACKEND->ssl))) != -1)
+      infof(data, "Dumping cert info:\n%s\n", buffer);
+  }
+
+  /* adapted from mbedtls.c */
+  if(pinnedpubkey) {
+    int size;
+    CURLcode result;
+    x509_crt *p;
+    unsigned char pubkey[PUB_DER_MAX_BYTES];
+    const x509_crt *peercert;
+
+    peercert = ssl_get_peer_cert(&BACKEND->ssl);
+
+    if(!peercert || !peercert->raw.p || !peercert->raw.len) {
+      failf(data, "Failed due to missing peer certificate");
+      return CURLE_SSL_PINNEDPUBKEYNOTMATCH;
+    }
+
+    p = calloc(1, sizeof(*p));
+
+    if(!p)
+      return CURLE_OUT_OF_MEMORY;
+
+    x509_crt_init(p);
+
+    /* Make a copy of our const peercert because pk_write_pubkey_der
+       needs a non-const key, for now.
+       https://github.com/ARMmbed/mbedtls/issues/396 */
+    if(x509_crt_parse_der(p, peercert->raw.p, peercert->raw.len)) {
+      failf(data, "Failed copying peer certificate");
+      x509_crt_free(p);
+      free(p);
+      return CURLE_SSL_PINNEDPUBKEYNOTMATCH;
+    }
+
+    size = pk_write_pubkey_der(&p->pk, pubkey, PUB_DER_MAX_BYTES);
+
+    if(size <= 0) {
+      failf(data, "Failed copying public key from peer certificate");
+      x509_crt_free(p);
+      free(p);
+      return CURLE_SSL_PINNEDPUBKEYNOTMATCH;
+    }
+
+    /* pk_write_pubkey_der writes data at the end of the buffer. */
+    result = Curl_pin_peer_pubkey(data,
+                                  pinnedpubkey,
+                                  &pubkey[PUB_DER_MAX_BYTES - size], size);
+    if(result) {
+      x509_crt_free(p);
+      free(p);
+      return result;
+    }
+
+    x509_crt_free(p);
+    free(p);
+  }
+
+#ifdef HAS_ALPN
+  if(conn->bits.tls_enable_alpn) {
+    const char *next_protocol = ssl_get_alpn_protocol(&BACKEND->ssl);
+
+    if(next_protocol != NULL) {
+      infof(data, "ALPN, server accepted to use %s\n", next_protocol);
+
+#ifdef USE_NGHTTP2
+      if(!strncmp(next_protocol, NGHTTP2_PROTO_VERSION_ID,
+                  NGHTTP2_PROTO_VERSION_ID_LEN)) {
+        conn->negnpn = CURL_HTTP_VERSION_2;
+      }
+      else
+#endif
+        if(!strncmp(next_protocol, ALPN_HTTP_1_1, ALPN_HTTP_1_1_LENGTH)) {
+          conn->negnpn = CURL_HTTP_VERSION_1_1;
+        }
+    }
+    else
+      infof(data, "ALPN, server did not agree to a protocol\n");
+  }
+#endif
+
+  connssl->connecting_state = ssl_connect_3;
+  infof(data, "SSL connected\n");
+
+  return CURLE_OK;
+}
+
+static CURLcode
+polarssl_connect_step3(struct connectdata *conn,
+                       int sockindex)
+{
+  CURLcode retcode = CURLE_OK;
+  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+  struct Curl_easy *data = conn->data;
+
+  DEBUGASSERT(ssl_connect_3 == connssl->connecting_state);
+
+  if(SSL_SET_OPTION(primary.sessionid)) {
+    int ret;
+    ssl_session *our_ssl_sessionid;
+    void *old_ssl_sessionid = NULL;
+
+    our_ssl_sessionid = malloc(sizeof(ssl_session));
+    if(!our_ssl_sessionid)
+      return CURLE_OUT_OF_MEMORY;
+
+    memset(our_ssl_sessionid, 0, sizeof(ssl_session));
+
+    ret = ssl_get_session(&BACKEND->ssl, our_ssl_sessionid);
+    if(ret) {
+      failf(data, "ssl_get_session returned -0x%x", -ret);
+      return CURLE_SSL_CONNECT_ERROR;
+    }
+
+    /* If there's already a matching session in the cache, delete it */
+    Curl_ssl_sessionid_lock(conn);
+    if(!Curl_ssl_getsessionid(conn, &old_ssl_sessionid, NULL, sockindex))
+      Curl_ssl_delsessionid(conn, old_ssl_sessionid);
+
+    retcode = Curl_ssl_addsessionid(conn, our_ssl_sessionid, 0, sockindex);
+    Curl_ssl_sessionid_unlock(conn);
+    if(retcode) {
+      free(our_ssl_sessionid);
+      failf(data, "failed to store ssl session");
+      return retcode;
+    }
+  }
+
+  connssl->connecting_state = ssl_connect_done;
+
+  return CURLE_OK;
+}
+
+static ssize_t polarssl_send(struct connectdata *conn,
+                             int sockindex,
+                             const void *mem,
+                             size_t len,
+                             CURLcode *curlcode)
+{
+  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+  int ret = -1;
+
+  ret = ssl_write(&BACKEND->ssl,
+                  (unsigned char *)mem, len);
+
+  if(ret < 0) {
+    *curlcode = (ret == POLARSSL_ERR_NET_WANT_WRITE) ?
+      CURLE_AGAIN : CURLE_SEND_ERROR;
+    ret = -1;
+  }
+
+  return ret;
+}
+
+static void Curl_polarssl_close(struct connectdata *conn, int sockindex)
+{
+  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+  rsa_free(&BACKEND->rsa);
+  x509_crt_free(&BACKEND->clicert);
+  x509_crt_free(&BACKEND->cacert);
+  x509_crl_free(&BACKEND->crl);
+  ssl_free(&BACKEND->ssl);
+}
+
+static ssize_t polarssl_recv(struct connectdata *conn,
+                             int num,
+                             char *buf,
+                             size_t buffersize,
+                             CURLcode *curlcode)
+{
+  struct ssl_connect_data *connssl = &conn->ssl[num];
+  int ret = -1;
+  ssize_t len = -1;
+
+  memset(buf, 0, buffersize);
+  ret = ssl_read(&BACKEND->ssl, (unsigned char *)buf, buffersize);
+
+  if(ret <= 0) {
+    if(ret == POLARSSL_ERR_SSL_PEER_CLOSE_NOTIFY)
+      return 0;
+
+    *curlcode = (ret == POLARSSL_ERR_NET_WANT_READ) ?
+      CURLE_AGAIN : CURLE_RECV_ERROR;
+    return -1;
+  }
+
+  len = ret;
+
+  return len;
+}
+
+static void Curl_polarssl_session_free(void *ptr)
+{
+  ssl_session_free(ptr);
+  free(ptr);
+}
+
+/* 1.3.10 was the first rebranded version. All new releases (in 1.3 branch and
+   higher) will be mbed TLS branded.. */
+
+static size_t Curl_polarssl_version(char *buffer, size_t size)
+{
+  unsigned int version = version_get_number();
+  return snprintf(buffer, size, "%s/%d.%d.%d",
+                  version >= 0x01030A00?"mbedTLS":"PolarSSL",
+                  version>>24, (version>>16)&0xff, (version>>8)&0xff);
+}
+
+static CURLcode
+polarssl_connect_common(struct connectdata *conn,
+                        int sockindex,
+                        bool nonblocking,
+                        bool *done)
+{
+  CURLcode result;
+  struct Curl_easy *data = conn->data;
+  struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+  curl_socket_t sockfd = conn->sock[sockindex];
+  long timeout_ms;
+  int what;
+
+  /* check if the connection has already been established */
+  if(ssl_connection_complete == connssl->state) {
+    *done = TRUE;
+    return CURLE_OK;
+  }
+
+  if(ssl_connect_1 == connssl->connecting_state) {
+    /* Find out how much more time we're allowed */
+    timeout_ms = Curl_timeleft(data, NULL, TRUE);
+
+    if(timeout_ms < 0) {
+      /* no need to continue if time already is up */
+      failf(data, "SSL connection timeout");
+      return CURLE_OPERATION_TIMEDOUT;
+    }
+
+    result = polarssl_connect_step1(conn, sockindex);
+    if(result)
+      return result;
+  }
+
+  while(ssl_connect_2 == connssl->connecting_state ||
+        ssl_connect_2_reading == connssl->connecting_state ||
+        ssl_connect_2_writing == connssl->connecting_state) {
+
+    /* check allowed time left */
+    timeout_ms = Curl_timeleft(data, NULL, TRUE);
+
+    if(timeout_ms < 0) {
+      /* no need to continue if time already is up */
+      failf(data, "SSL connection timeout");
+      return CURLE_OPERATION_TIMEDOUT;
+    }
+
+    /* if ssl is expecting something, check if it's available. */
+    if(connssl->connecting_state == ssl_connect_2_reading ||
+       connssl->connecting_state == ssl_connect_2_writing) {
+
+      curl_socket_t writefd = ssl_connect_2_writing ==
+        connssl->connecting_state?sockfd:CURL_SOCKET_BAD;
+      curl_socket_t readfd = ssl_connect_2_reading ==
+        connssl->connecting_state?sockfd:CURL_SOCKET_BAD;
+
+      what = Curl_socket_check(readfd, CURL_SOCKET_BAD, writefd,
+                               nonblocking?0:timeout_ms);
+      if(what < 0) {
+        /* fatal error */
+        failf(data, "select/poll on SSL socket, errno: %d", SOCKERRNO);
+        return CURLE_SSL_CONNECT_ERROR;
+      }
+      else if(0 == what) {
+        if(nonblocking) {
+          *done = FALSE;
+          return CURLE_OK;
+        }
+        else {
+          /* timeout */
+          failf(data, "SSL connection timeout");
+          return CURLE_OPERATION_TIMEDOUT;
+        }
+      }
+      /* socket is readable or writable */
+    }
+
+    /* Run transaction, and return to the caller if it failed or if
+     * this connection is part of a multi handle and this loop would
+     * execute again. This permits the owner of a multi handle to
+     * abort a connection attempt before step2 has completed while
+     * ensuring that a client using select() or epoll() will always
+     * have a valid fdset to wait on.
+     */
+    result = polarssl_connect_step2(conn, sockindex);
+    if(result || (nonblocking &&
+                  (ssl_connect_2 == connssl->connecting_state ||
+                   ssl_connect_2_reading == connssl->connecting_state ||
+                   ssl_connect_2_writing == connssl->connecting_state)))
+      return result;
+
+  } /* repeat step2 until all transactions are done. */
+
+  if(ssl_connect_3 == connssl->connecting_state) {
+    result = polarssl_connect_step3(conn, sockindex);
+    if(result)
+      return result;
+  }
+
+  if(ssl_connect_done == connssl->connecting_state) {
+    connssl->state = ssl_connection_complete;
+    conn->recv[sockindex] = polarssl_recv;
+    conn->send[sockindex] = polarssl_send;
+    *done = TRUE;
+  }
+  else
+    *done = FALSE;
+
+  /* Reset our connect state machine */
+  connssl->connecting_state = ssl_connect_1;
+
+  return CURLE_OK;
+}
+
+static CURLcode Curl_polarssl_connect_nonblocking(struct connectdata *conn,
+                                                  int sockindex, bool *done)
+{
+  return polarssl_connect_common(conn, sockindex, TRUE, done);
+}
+
+
+static CURLcode Curl_polarssl_connect(struct connectdata *conn, int sockindex)
+{
+  CURLcode result;
+  bool done = FALSE;
+
+  result = polarssl_connect_common(conn, sockindex, FALSE, &done);
+  if(result)
+    return result;
+
+  DEBUGASSERT(done);
+
+  return CURLE_OK;
+}
+
+/*
+ * return 0 error initializing SSL
+ * return 1 SSL initialized successfully
+ */
+static int Curl_polarssl_init(void)
+{
+  return Curl_polarsslthreadlock_thread_setup();
+}
+
+static void Curl_polarssl_cleanup(void)
+{
+  (void)Curl_polarsslthreadlock_thread_cleanup();
+}
+
+static bool Curl_polarssl_data_pending(const struct connectdata *conn,
+                                       int sockindex)
+{
+  const struct ssl_connect_data *connssl = &conn->ssl[sockindex];
+  return ssl_get_bytes_avail(&BACKEND->ssl) != 0;
+}
+
+static void Curl_polarssl_sha256sum(const unsigned char *input,
+                                    size_t inputlen,
+                                    unsigned char *sha256sum,
+                                    size_t sha256len UNUSED_PARAM)
+{
+  (void)sha256len;
+  sha256(input, inputlen, sha256sum, 0);
+}
+
+static void *Curl_polarssl_get_internals(struct ssl_connect_data *connssl,
+                                         CURLINFO info UNUSED_PARAM)
+{
+  (void)info;
+  return &BACKEND->ssl;
+}
+
+const struct Curl_ssl Curl_ssl_polarssl = {
+  { CURLSSLBACKEND_POLARSSL, "polarssl" }, /* info */
+
+  1, /* have_ca_path */
+  0, /* have_certinfo */
+  1, /* have_pinnedpubkey */
+  0, /* have_ssl_ctx */
+  0, /* support_https_proxy */
+
+  sizeof(struct ssl_backend_data),
+
+  Curl_polarssl_init,                /* init */
+  Curl_polarssl_cleanup,             /* cleanup */
+  Curl_polarssl_version,             /* version */
+  Curl_none_check_cxn,               /* check_cxn */
+  Curl_none_shutdown,                /* shutdown */
+  Curl_polarssl_data_pending,        /* data_pending */
+  /* This might cause libcurl to use a weeker random!
+   * TODO: use Polarssl's CTR-DRBG or HMAC-DRBG
+  */
+  Curl_none_random,                  /* random */
+  Curl_none_cert_status_request,     /* cert_status_request */
+  Curl_polarssl_connect,             /* connect */
+  Curl_polarssl_connect_nonblocking, /* connect_nonblocking */
+  Curl_polarssl_get_internals,       /* get_internals */
+  Curl_polarssl_close,               /* close_one */
+  Curl_none_close_all,               /* close_all */
+  Curl_polarssl_session_free,        /* session_free */
+  Curl_none_set_engine,              /* set_engine */
+  Curl_none_set_engine_default,      /* set_engine_default */
+  Curl_none_engines_list,            /* engines_list */
+  Curl_none_false_start,             /* false_start */
+  Curl_none_md5sum,                  /* md5sum */
+  Curl_polarssl_sha256sum            /* sha256sum */
+};
+
+#endif /* USE_POLARSSL */