text: /*
   * libwebsockets - small server side websockets and web server implementation
   *
   * Copyright (C) 2010 - 2020 Andy Green <andy@warmcat.com>
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to
   * deal in the Software without restriction, including without limitation the
   * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
   * sell copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
   * IN THE SOFTWARE.
   */
  
  #include "private-lib-core.h"
  
  static int
  OpenSSL_client_verify_callback(int preverify_ok, X509_STORE_CTX *x509_ctx)
  {
  	return 0;
  }
  
  int
  lws_ssl_client_bio_create(struct lws *wsi)
  {
  	char hostname[128], *p;
  	const char *alpn_comma = wsi->a.context->tls.alpn_default;
  	struct alpn_ctx protos;
  
  	if (wsi->stash)
  		lws_strncpy(hostname, wsi->stash->cis[CIS_HOST], sizeof(hostname));
  	else
  		if (lws_hdr_copy(wsi, hostname, sizeof(hostname),
  				_WSI_TOKEN_CLIENT_HOST) <= 0) {
  			lwsl_err("%s: Unable to get hostname\n", __func__);
  
  			return -1;
  		}
  
  	/*
  	 * remove any :port part on the hostname... necessary for network
  	 * connection but typical certificates do not contain it
  	 */
  	p = hostname;
  	while (*p) {
  		if (*p == ':') {
  			*p = '\0';
  			break;
  		}
  		p++;
  	}
  
  	wsi->tls.ssl = SSL_new(wsi->a.vhost->tls.ssl_client_ctx);
  	if (!wsi->tls.ssl) {
  		lwsl_info("%s: SSL_new() failed\n", __func__);
  		return -1;
  	}
  
  	if (wsi->a.vhost->tls.ssl_info_event_mask)
  		SSL_set_info_callback(wsi->tls.ssl, lws_ssl_info_callback);
  
  	if (!(wsi->tls.use_ssl & LCCSCF_SKIP_SERVER_CERT_HOSTNAME_CHECK)) {
  		X509_VERIFY_PARAM *param = SSL_get0_param(wsi->tls.ssl);
  		/* Enable automatic hostname checks */
  	//	X509_VERIFY_PARAM_set_hostflags(param,
  	//				X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS);
  		X509_VERIFY_PARAM_set1_host(param, hostname, 0);
  	}
  
  	if (wsi->a.vhost->tls.alpn)
  		alpn_comma = wsi->a.vhost->tls.alpn;
  
  	if (wsi->stash) {
  		lws_strncpy(hostname, wsi->stash->cis[CIS_HOST], sizeof(hostname));
  		alpn_comma = wsi->stash->cis[CIS_ALPN];
  	} else {
  		if (lws_hdr_copy(wsi, hostname, sizeof(hostname),
  				_WSI_TOKEN_CLIENT_ALPN) > 0)
  			alpn_comma = hostname;
  	}
  
  	lwsl_info("%s: %s: client conn sending ALPN list '%s'\n",
  		  __func__, lws_wsi_tag(wsi), alpn_comma);
  
  	protos.len = (uint8_t)lws_alpn_comma_to_openssl(alpn_comma, protos.data,
  					       sizeof(protos.data) - 1);
  
  	/* with mbedtls, protos is not pointed to after exit from this call */
  	SSL_set_alpn_select_cb(wsi->tls.ssl, &protos);
  
  	/*
  	 * use server name indication (SNI), if supported,
  	 * when establishing connection
  	 */
  	SSL_set_verify(wsi->tls.ssl, SSL_VERIFY_PEER,
  		       OpenSSL_client_verify_callback);
  
  	SSL_set_fd(wsi->tls.ssl, (int)wsi->desc.sockfd);
  
  	if (wsi->sys_tls_client_cert) {
  		lws_system_blob_t *b = lws_system_get_blob(wsi->a.context,
  					LWS_SYSBLOB_TYPE_CLIENT_CERT_DER,
  					wsi->sys_tls_client_cert - 1);
  		const uint8_t *pem_data = NULL;
  		uint8_t *data = NULL;
  		lws_filepos_t flen;
  		size_t size;
  		int err = 0;
  
  		if (!b)
  			goto no_client_cert;
  
  		/*
  		 * Set up the per-connection client cert
  		 */
  
  		size = lws_system_blob_get_size(b);
  		if (!size)
  			goto no_client_cert;
  
  		if (lws_system_blob_get_single_ptr(b, &pem_data))
  			goto no_client_cert;
  
  		if (lws_tls_alloc_pem_to_der_file(wsi->a.context, NULL,
  						  (const char *)pem_data, size,
  						  &data, &flen))
  			goto no_client_cert;
  		size = (size_t) flen;
  
  		err = SSL_use_certificate_ASN1(wsi->tls.ssl, data, (int)size);
  		lws_free_set_NULL(data);
  		if (err != 1)
  			goto no_client_cert;
  
  		b = lws_system_get_blob(wsi->a.context,
  					LWS_SYSBLOB_TYPE_CLIENT_KEY_DER,
  					wsi->sys_tls_client_cert - 1);
  		if (!b)
  			goto no_client_cert;
  		size = lws_system_blob_get_size(b);
  		if (!size)
  			goto no_client_cert;
  
  		if (lws_system_blob_get_single_ptr(b, &pem_data))
  			goto no_client_cert;
  
  		if (lws_tls_alloc_pem_to_der_file(wsi->a.context, NULL,
  						  (const char *)pem_data, size,
  						  &data, &flen))
  			goto no_client_cert;
  		size = (size_t) flen;
  
  		err = SSL_use_PrivateKey_ASN1(0, wsi->tls.ssl, data, (int)size);
  		lws_free_set_NULL(data);
  		if (err != 1)
  			goto no_client_cert;
  
  		/* no wrapper api for check key */
  
  		lwsl_notice("%s: set system client cert %u\n", __func__,
  				wsi->sys_tls_client_cert - 1);
  	}
  
  	return 0;
  
  no_client_cert:
  	lwsl_err("%s: unable to set up system client cert %d\n", __func__,
  			wsi->sys_tls_client_cert - 1);
  
  	return 1;
  }
  
  int ERR_get_error(void)
  {
  	return 0;
  }
  
  enum lws_ssl_capable_status
  lws_tls_client_connect(struct lws *wsi, char *errbuf, size_t elen)
  {
  	int m, n = SSL_connect(wsi->tls.ssl), en;
  	const unsigned char *prot;
  	unsigned int len;
  
  	if (n == 1) {
  		SSL_get0_alpn_selected(wsi->tls.ssl, &prot, &len);
  		lws_role_call_alpn_negotiated(wsi, (const char *)prot);
  		lwsl_info("client connect OK\n");
  		return LWS_SSL_CAPABLE_DONE;
  	}
  
  	en = (int)LWS_ERRNO;
  	m = SSL_get_error(wsi->tls.ssl, n);
  
  	if (m == SSL_ERROR_WANT_READ || SSL_want_read(wsi->tls.ssl))
  		return LWS_SSL_CAPABLE_MORE_SERVICE_READ;
  
  	if (m == SSL_ERROR_WANT_WRITE || SSL_want_write(wsi->tls.ssl))
  		return LWS_SSL_CAPABLE_MORE_SERVICE_WRITE;
  
  	if (!n) /* we don't know what he wants, but he says to retry */
  		return LWS_SSL_CAPABLE_MORE_SERVICE;
  
  	if (m == SSL_ERROR_SYSCALL && !en)
  		return LWS_SSL_CAPABLE_MORE_SERVICE;
  
  	lws_snprintf(errbuf, elen, "mbedtls connect %d %d %d", n, m, en);
  
  	return LWS_SSL_CAPABLE_ERROR;
  }
  
  int
  lws_tls_client_confirm_peer_cert(struct lws *wsi, char *ebuf, size_t ebuf_len)
  {
  	int n;
  	unsigned int avoid = 0;
  	X509 *peer = SSL_get_peer_certificate(wsi->tls.ssl);
  	struct lws_context_per_thread *pt = &wsi->a.context->pt[(int)wsi->tsi];
  	const char *type = "";
  	char *sb = (char *)&pt->serv_buf[0];
  
  	if (!peer) {
  #if defined(LWS_WITH_SYS_METRICS)
  		lws_metrics_hist_bump_describe_wsi(wsi, lws_metrics_priv_to_pub(
  					wsi->a.context->mth_conn_failures),
  						   "tls=\"nocert\"");
  #endif
  		lwsl_info("peer did not provide cert\n");
  		lws_snprintf(ebuf, ebuf_len, "no peer cert");
  
  		return -1;
  	}
  
  	n = (int)SSL_get_verify_result(wsi->tls.ssl);
  	lwsl_debug("get_verify says %d\n", n);
  
  	switch (n) {
  	case X509_V_OK:
  		return 0;
  
  	case X509_V_ERR_HOSTNAME_MISMATCH:
  		type = "hostname";
  		avoid = LCCSCF_SKIP_SERVER_CERT_HOSTNAME_CHECK;
  		break;
  
  	case X509_V_ERR_INVALID_CA:
  		type = "invalidca";
  		avoid = LCCSCF_ALLOW_SELFSIGNED;
  		break;
  
  	case X509_V_ERR_CERT_NOT_YET_VALID:
  		type = "notyetvalid";
  		avoid = LCCSCF_ALLOW_EXPIRED;
  		break;
  
  	case X509_V_ERR_CERT_HAS_EXPIRED:
  		type = "expired";
  		avoid = LCCSCF_ALLOW_EXPIRED;
  		break;
  	}
  
  	lwsl_info("%s: cert problem: %s\n", __func__, type);
  #if defined(LWS_WITH_SYS_METRICS)
  	{
  		char buckname[64];
  		lws_snprintf(buckname, sizeof(buckname), "tls=\"%s\"", type);
  		lws_metrics_hist_bump_describe_wsi(wsi,
  		     lws_metrics_priv_to_pub(wsi->a.context->mth_conn_failures),
  			      buckname);
  	}
  #endif
  	if (wsi->tls.use_ssl & avoid) {
  		lwsl_info("%s: allowing anyway\n", __func__);
  
  		return 0;
  	}
  
  	lws_snprintf(ebuf, ebuf_len,
  		"server's cert didn't look good, %s (use_ssl 0x%x) X509_V_ERR = %d: %s\n",
  		type, (unsigned int)wsi->tls.use_ssl, n,
  		ERR_error_string((unsigned long)n, sb));
  
  	lwsl_info("%s\n", ebuf);
  
  	lws_tls_err_describe_clear();
  
  	return -1;
  }
  
  int
  lws_tls_client_create_vhost_context(struct lws_vhost *vh,
  				    const struct lws_context_creation_info *info,
  				    const char *cipher_list,
  				    const char *ca_filepath,
  				    const void *ca_mem,
  				    unsigned int ca_mem_len,
  				    const char *cert_filepath,
  				    const void *cert_mem,
  				    unsigned int cert_mem_len,
  				    const char *private_key_filepath,
  					const void *key_mem,
  					unsigned int key_mem_len
  					)
  {
  	X509 *d2i_X509(X509 **cert, const unsigned char *buffer, long len);
  	SSL_METHOD *method = (SSL_METHOD *)TLS_client_method();
  	unsigned long error;
  	int n;
  
  	if (!method) {
  		error = (unsigned long)ERR_get_error();
  		lwsl_err("problem creating ssl method %lu: %s\n",
  			error, ERR_error_string(error,
  				      (char *)vh->context->pt[0].serv_buf));
  		return 1;
  	}
  	/* create context */
  	vh->tls.ssl_client_ctx = SSL_CTX_new(method);
  	if (!vh->tls.ssl_client_ctx) {
  		error = (unsigned long)ERR_get_error();
  		lwsl_err("problem creating ssl context %lu: %s\n",
  			error, ERR_error_string(error,
  				      (char *)vh->context->pt[0].serv_buf));
  		return 1;
  	}
  
  	if (!ca_filepath && (!ca_mem || !ca_mem_len))
  		return 0;
  
  	if (ca_filepath) {
  #if !defined(LWS_PLAT_OPTEE)
  		uint8_t *buf;
  		lws_filepos_t len;
  
  		if (alloc_file(vh->context, ca_filepath, &buf, &len)) {
  			lwsl_err("Load CA cert file %s failed\n", ca_filepath);
  			return 1;
  		}
  		vh->tls.x509_client_CA = d2i_X509(NULL, buf, (long)len);
  		free(buf);
  		lwsl_info("Loading client CA for verification %s\n", ca_filepath);
  #endif
  	} else {
  		vh->tls.x509_client_CA = d2i_X509(NULL, (uint8_t*)ca_mem, (long)ca_mem_len);
  		lwsl_info("%s: using mem client CA cert %d\n",
  			    __func__, ca_mem_len);
  	}
  
  	if (!vh->tls.x509_client_CA) {
  		lwsl_err("client CA: x509 parse failed\n");
  		return 1;
  	}
  
  	if (!vh->tls.ssl_ctx)
  		SSL_CTX_add_client_CA(vh->tls.ssl_client_ctx, vh->tls.x509_client_CA);
  	else
  		SSL_CTX_add_client_CA(vh->tls.ssl_ctx, vh->tls.x509_client_CA);
  
  	/* support for client-side certificate authentication */
  	if (cert_filepath) {
  #if !defined(LWS_PLAT_OPTEE)
  		uint8_t *buf;
  		lws_filepos_t amount;
  
  		if (lws_tls_use_any_upgrade_check_extant(cert_filepath) !=
  				LWS_TLS_EXTANT_YES &&
  		    (info->options & LWS_SERVER_OPTION_IGNORE_MISSING_CERT))
  			return 0;
  
  		lwsl_notice("%s: doing cert filepath %s\n", __func__,
  				cert_filepath);
  
  		if (alloc_file(vh->context, cert_filepath, &buf, &amount))
  			return 1;
  
  		buf[amount++] = '\0';
  
  		SSL_CTX_use_PrivateKey_ASN1(0, vh->tls.ssl_client_ctx,
  				buf, (long)amount);
  
  		n = SSL_CTX_use_certificate_ASN1(vh->tls.ssl_client_ctx,
  				(int)amount, buf);
  		lws_free(buf);
  		if (n < 1) {
  			lwsl_err("problem %d getting cert '%s'\n", n,
  				 cert_filepath);
  			lws_tls_err_describe_clear();
  			return 1;
  		}
  
  		lwsl_info("Loaded client cert %s\n", cert_filepath);
  #endif
  	} else if (cert_mem && cert_mem_len) {
  		/* lwsl_hexdump_notice(cert_mem, cert_mem_len - 1); */
  		SSL_CTX_use_PrivateKey_ASN1(0, vh->tls.ssl_client_ctx,
  				cert_mem, (long)cert_mem_len - 1);
  		n = SSL_CTX_use_certificate_ASN1(vh->tls.ssl_client_ctx,
  						 (int)cert_mem_len, cert_mem);
  		if (n < 1) {
  			lwsl_err("%s: (mbedtls) problem interpreting client cert\n",
  				 __func__);
  			lws_tls_err_describe_clear();
  			return 1;
  		}
  		lwsl_info("%s: using mem client cert %d\n",
  			    __func__, cert_mem_len);
  	}
  
  	return 0;
  }
  
  int
  lws_tls_client_vhost_extra_cert_mem(struct lws_vhost *vh,
                  const uint8_t *der, size_t der_len)
  {
  	if (SSL_CTX_add_client_CA_ASN1(vh->tls.ssl_client_ctx, (int)der_len, der) != 1) {
  		lwsl_err("%s: failed\n", __func__);
  			return 1;
  	}
  
  	return 0;
  }
  
  