1 /*********************************************************************
3 * File : $Source: /cvsroot/ijbswa/current/ssl.c,v $
5 * Purpose : File with TLS/SSL extension. Contains methods for
6 * creating, using and closing TLS/SSL connections.
8 * Copyright : Written by and Copyright (c) 2017 Vaclav Svec. FIT CVUT.
9 * Copyright (C) 2018-2020 by Fabian Keil <fk@fabiankeil.de>
11 * This program is free software; you can redistribute it
12 * and/or modify it under the terms of the GNU General
13 * Public License as published by the Free Software
14 * Foundation; either version 2 of the License, or (at
15 * your option) any later version.
17 * This program is distributed in the hope that it will
18 * be useful, but WITHOUT ANY WARRANTY; without even the
19 * implied warranty of MERCHANTABILITY or FITNESS FOR A
20 * PARTICULAR PURPOSE. See the GNU General Public
21 * License for more details.
23 * The GNU General Public License should be included with
24 * this file. If not, you can view it at
25 * http://www.gnu.org/copyleft/gpl.html
26 * or write to the Free Software Foundation, Inc., 59
27 * Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 *********************************************************************/
34 #if !defined(MBEDTLS_CONFIG_FILE)
35 # include "mbedtls/config.h"
37 # include MBEDTLS_CONFIG_FILE
40 #include "mbedtls/md5.h"
41 #include "mbedtls/pem.h"
42 #include "mbedtls/base64.h"
43 #include "mbedtls/error.h"
54 * Macros for searching begin and end of certificates.
55 * Necessary to convert structure mbedtls_x509_crt to crt file.
57 #define PEM_BEGIN_CRT "-----BEGIN CERTIFICATE-----\n"
58 #define PEM_END_CRT "-----END CERTIFICATE-----\n"
63 #define ERROR_BUF_SIZE 1024 /* Size of buffer for error messages */
64 #define CERTIFICATE_BUF_SIZE 16384 /* Size of buffer to save certificate. Value 4096 is mbedtls library buffer size for certificate in DER form */
65 #define PRIVATE_KEY_BUF_SIZE 16000 /* Size of buffer to save private key. Value 16000 is taken from mbed TLS library examples. */
66 #define RSA_KEY_PUBLIC_EXPONENT 65537 /* Public exponent for RSA private key generating */
67 #define RSA_KEYSIZE 2048 /* Size of generated RSA keys */
68 #define GENERATED_CERT_VALID_FROM "20100101000000" /* Date and time, which will be set in generated certificates as parameter valid from */
69 #define GENERATED_CERT_VALID_TO "20401231235959" /* Date and time, which will be set in generated certificates as parameter valid to */
70 #define CERT_SIGNATURE_ALGORITHM MBEDTLS_MD_SHA256 /* The MD algorithm to use for the signature */
71 #define CERT_SERIAL_NUM_LENGTH 4 /* Bytes of hash to be used for creating serial number of certificate. Min=2 and max=16 */
72 #define INVALID_CERT_INFO_BUF_SIZE 2048 /* Size of buffer for message with information about reason of certificate invalidity. Data after the end of buffer will not be saved */
73 #define CERT_PARAM_COMMON_NAME "CN="
74 #define CERT_PARAM_ORGANIZATION ",O="
75 #define CERT_PARAM_ORG_UNIT ",OU="
76 #define CERT_PARAM_COUNTRY ",C=CZ"
77 #define KEY_FILE_TYPE ".pem"
78 #define CERT_FILE_TYPE ".crt"
79 #define CERT_SUBJECT_PASSWORD ""
80 #define CERT_INFO_PREFIX ""
83 * Properties of cert for generating
86 char *issuer_crt; /* filename of the issuer certificate */
87 char *subject_key; /* filename of the subject key file */
88 char *issuer_key; /* filename of the issuer key file */
89 const char *subject_pwd; /* password for the subject key file */
90 const char *issuer_pwd; /* password for the issuer key file */
91 char *output_file; /* where to store the constructed key file */
92 const char *subject_name; /* subject name for certificate */
93 char issuer_name[ISSUER_NAME_BUF_SIZE]; /* issuer name for certificate */
94 const char *not_before; /* validity period not before */
95 const char *not_after; /* validity period not after */
96 const char *serial; /* serial number string */
97 int is_ca; /* is a CA certificate */
98 int max_pathlen; /* maximum CA path length */
102 * Properties of key for generating
105 mbedtls_pk_type_t type; /* type of key to generate */
106 int rsa_keysize; /* length of key in bits */
107 char *key_file_path; /* filename of the key file */
110 static int generate_webpage_certificate(struct client_state *csp);
111 static char *make_certs_path(const char *conf_dir, const char *file_name, const char *suffix);
112 static int file_exists(const char *path);
113 static int host_to_hash(struct client_state *csp);
114 static int ssl_verify_callback(void *data, mbedtls_x509_crt *crt, int depth, uint32_t *flags);
115 static void free_certificate_chain(struct client_state *csp);
116 static unsigned int get_certificate_mutex_id(struct client_state *csp);
117 static unsigned long get_certificate_serial(struct client_state *csp);
118 static void free_client_ssl_structures(struct client_state *csp);
119 static void free_server_ssl_structures(struct client_state *csp);
120 static int seed_rng(struct client_state *csp);
122 /*********************************************************************
124 * Function : client_use_ssl
126 * Description : Tests if client in current client state structure
127 * should use SSL connection or standard connection.
130 * 1 : csp = Current client state (buffers, headers, etc...)
132 * Returns : If client should use TLS/SSL connection, 1 is returned.
133 * Otherwise 0 is returned.
135 *********************************************************************/
136 extern int client_use_ssl(const struct client_state *csp)
138 return csp->http->client_ssl;
142 /*********************************************************************
144 * Function : server_use_ssl
146 * Description : Tests if server in current client state structure
147 * should use SSL connection or standard connection.
150 * 1 : csp = Current client state (buffers, headers, etc...)
152 * Returns : If server should use TLS/SSL connection, 1 is returned.
153 * Otherwise 0 is returned.
155 *********************************************************************/
156 extern int server_use_ssl(const struct client_state *csp)
158 return csp->http->server_ssl;
162 /*********************************************************************
164 * Function : is_ssl_pending
166 * Description : Tests if there are some waiting data on ssl connection
169 * 1 : ssl = SSL context to test
171 * Returns : 0 => No data are pending
172 * >0 => Pending data length
174 *********************************************************************/
175 extern size_t is_ssl_pending(mbedtls_ssl_context *ssl)
182 return mbedtls_ssl_get_bytes_avail(ssl);
186 /*********************************************************************
188 * Function : ssl_send_data
190 * Description : Sends the content of buf (for n bytes) to given SSL
191 * connection context.
194 * 1 : ssl = SSL context to send data to
195 * 2 : buf = Pointer to data to be sent
196 * 3 : len = Length of data to be sent to the SSL context
198 * Returns : Length of sent data or negative value on error.
200 *********************************************************************/
201 extern int ssl_send_data(mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len)
204 size_t max_fragment_size = 0; /* Maximal length of data in one SSL fragment*/
205 int send_len = 0; /* length of one data part to send */
206 int pos = 0; /* Position of unsent part in buffer */
213 /* Getting maximal length of data sent in one fragment */
214 max_fragment_size = mbedtls_ssl_get_max_frag_len(ssl);
217 * Whole buffer must be sent in many fragments, because each fragment
218 * has its maximal length.
222 /* Compute length of data, that can be send in next fragment */
223 if ((pos + (int)max_fragment_size) > len)
225 send_len = (int)len - pos;
229 send_len = (int)max_fragment_size;
233 * Sending one part of the buffer
235 while ((ret = mbedtls_ssl_write(ssl,
236 (const unsigned char *)(buf + pos),
237 (size_t)send_len)) < 0)
239 if (ret != MBEDTLS_ERR_SSL_WANT_READ &&
240 ret != MBEDTLS_ERR_SSL_WANT_WRITE)
242 char err_buf[ERROR_BUF_SIZE];
244 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
245 log_error(LOG_LEVEL_ERROR,
246 "Sending data over TLS/SSL failed: %s", err_buf);
250 /* Adding count of sent bytes to position in buffer */
251 pos = pos + send_len;
258 /*********************************************************************
260 * Function : ssl_recv_data
262 * Description : Receives data from given SSL context and puts
266 * 1 : ssl = SSL context to receive data from
267 * 2 : buf = Pointer to buffer where data will be written
268 * 3 : max_length = Maximum number of bytes to read
270 * Returns : Number of bytes read, 0 for EOF, or -1
273 *********************************************************************/
274 extern int ssl_recv_data(mbedtls_ssl_context *ssl, unsigned char *buf, size_t max_length)
277 memset(buf, 0, max_length);
280 * Receiving data from SSL context into buffer
284 ret = mbedtls_ssl_read(ssl, buf, max_length);
285 } while (ret == MBEDTLS_ERR_SSL_WANT_READ
286 || ret == MBEDTLS_ERR_SSL_WANT_WRITE);
290 char err_buf[ERROR_BUF_SIZE];
292 if (ret == MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY)
294 log_error(LOG_LEVEL_CONNECT,
295 "The peer notified us that the connection is going to be closed");
298 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
299 log_error(LOG_LEVEL_ERROR,
300 "Receiving data over TLS/SSL failed: %s", err_buf);
309 /*********************************************************************
311 * Function : ssl_flush_socket
313 * Description : Send any pending "buffered" content with given
314 * SSL connection. Alternative to function flush_socket.
317 * 1 : ssl = SSL context to send buffer to
318 * 2 : iob = The I/O buffer to flush, usually csp->iob.
320 * Returns : On success, the number of bytes send are returned (zero
321 * indicates nothing was sent). On error, -1 is returned.
323 *********************************************************************/
324 extern long ssl_flush_socket(mbedtls_ssl_context *ssl, struct iob *iob)
326 /* Computing length of buffer part to send */
327 long len = iob->eod - iob->cur;
334 /* Sending data to given SSl context */
335 if (ssl_send_data(ssl, (const unsigned char *)iob->cur, (size_t)len) < 0)
339 iob->eod = iob->cur = iob->buf;
344 /*********************************************************************
346 * Function : ssl_debug_callback
348 * Description : Debug callback function for mbedtls library.
349 * Prints info into log file.
352 * 1 : ctx = File to save log in
353 * 2 : level = Debug level
354 * 3 : file = File calling debug message
355 * 4 : line = Line calling debug message
356 * 5 : str = Debug message
360 *********************************************************************/
361 static void ssl_debug_callback(void *ctx, int level, const char *file, int line, const char *str)
365 fprintf((FILE *)ctx, "%s:%04d: %s", file, line, str);
367 log_error(LOG_LEVEL_INFO, "SSL debug message: %s:%04d: %s", file, line, str);
372 /*********************************************************************
374 * Function : create_client_ssl_connection
376 * Description : Creates TLS/SSL secured connection with client
379 * 1 : csp = Current client state (buffers, headers, etc...)
381 * Returns : 0 on success, negative value if connection wasn't created
384 *********************************************************************/
385 extern int create_client_ssl_connection(struct client_state *csp)
387 /* Paths to certificates file and key file */
388 char *key_file = NULL;
389 char *ca_file = NULL;
390 char *cert_file = NULL;
392 char err_buf[ERROR_BUF_SIZE];
395 * Initializing mbedtls structures for TLS/SSL connection
397 mbedtls_net_init(&(csp->mbedtls_client_attr.socket_fd));
398 mbedtls_ssl_init(&(csp->mbedtls_client_attr.ssl));
399 mbedtls_ssl_config_init(&(csp->mbedtls_client_attr.conf));
400 mbedtls_x509_crt_init(&(csp->mbedtls_client_attr.server_cert));
401 mbedtls_pk_init(&(csp->mbedtls_client_attr.prim_key));
402 #if defined(MBEDTLS_SSL_CACHE_C)
403 mbedtls_ssl_cache_init(&(csp->mbedtls_client_attr.cache));
407 * Preparing hash of host for creating certificates
409 ret = host_to_hash(csp);
412 log_error(LOG_LEVEL_ERROR, "Generating hash of host failed: %d", ret);
418 * Preparing paths to certificates files and key file
420 ca_file = csp->config->ca_cert_file;
421 cert_file = make_certs_path(csp->config->certificate_directory,
422 (const char *)csp->http->hash_of_host_hex, CERT_FILE_TYPE);
423 key_file = make_certs_path(csp->config->certificate_directory,
424 (const char *)csp->http->hash_of_host_hex, KEY_FILE_TYPE);
426 if (cert_file == NULL || key_file == NULL)
433 * Generating certificate for requested host. Mutex to prevent
434 * certificate and key inconsistence must be locked.
436 unsigned int cert_mutex_id = get_certificate_mutex_id(csp);
437 privoxy_mutex_lock(&(certificates_mutexes[cert_mutex_id]));
439 ret = generate_webpage_certificate(csp);
442 log_error(LOG_LEVEL_ERROR,
443 "Generate_webpage_certificate failed: %d", ret);
444 privoxy_mutex_unlock(&(certificates_mutexes[cert_mutex_id]));
448 privoxy_mutex_unlock(&(certificates_mutexes[cert_mutex_id]));
461 * Loading CA file, webpage certificate and key files
463 ret = mbedtls_x509_crt_parse_file(&(csp->mbedtls_client_attr.server_cert),
467 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
468 log_error(LOG_LEVEL_ERROR,
469 "Loading webpage certificate %s failed: %s", cert_file, err_buf);
474 ret = mbedtls_x509_crt_parse_file(&(csp->mbedtls_client_attr.server_cert),
478 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
479 log_error(LOG_LEVEL_ERROR,
480 "Loading CA certificate %s failed: %s", ca_file, err_buf);
485 ret = mbedtls_pk_parse_keyfile(&(csp->mbedtls_client_attr.prim_key),
489 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
490 log_error(LOG_LEVEL_ERROR,
491 "Loading and parsing webpage certificate private key %s failed: %s",
498 * Setting SSL parameters
500 ret = mbedtls_ssl_config_defaults(&(csp->mbedtls_client_attr.conf),
501 MBEDTLS_SSL_IS_SERVER, MBEDTLS_SSL_TRANSPORT_STREAM,
502 MBEDTLS_SSL_PRESET_DEFAULT);
505 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
506 log_error(LOG_LEVEL_ERROR,
507 "mbedtls_ssl_config_defaults failed: %s", err_buf);
512 mbedtls_ssl_conf_rng(&(csp->mbedtls_client_attr.conf),
513 mbedtls_ctr_drbg_random, &ctr_drbg);
514 mbedtls_ssl_conf_dbg(&(csp->mbedtls_client_attr.conf),
515 ssl_debug_callback, stdout);
517 #if defined(MBEDTLS_SSL_CACHE_C)
518 mbedtls_ssl_conf_session_cache(&(csp->mbedtls_client_attr.conf),
519 &(csp->mbedtls_client_attr.cache), mbedtls_ssl_cache_get,
520 mbedtls_ssl_cache_set);
524 * Setting certificates
526 ret = mbedtls_ssl_conf_own_cert(&(csp->mbedtls_client_attr.conf),
527 &(csp->mbedtls_client_attr.server_cert),
528 &(csp->mbedtls_client_attr.prim_key));
531 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
532 log_error(LOG_LEVEL_ERROR,
533 "mbedtls_ssl_conf_own_cert failed: %s", err_buf);
538 ret = mbedtls_ssl_setup(&(csp->mbedtls_client_attr.ssl),
539 &(csp->mbedtls_client_attr.conf));
542 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
543 log_error(LOG_LEVEL_ERROR, "mbedtls_ssl_setup failed: %s", err_buf);
548 mbedtls_ssl_set_bio(&(csp->mbedtls_client_attr.ssl),
549 &(csp->mbedtls_client_attr.socket_fd), mbedtls_net_send,
550 mbedtls_net_recv, NULL);
551 mbedtls_ssl_session_reset(&(csp->mbedtls_client_attr.ssl));
554 * Setting socket fd in mbedtls_net_context structure. This structure
555 * can't be set by mbedtls functions, because we already have created
556 * a TCP connection when this function is called.
558 csp->mbedtls_client_attr.socket_fd.fd = csp->cfd;
561 * Handshake with client
563 log_error(LOG_LEVEL_CONNECT,
564 "Performing the TLS/SSL handshake with client. Hash of host: %s",
565 csp->http->hash_of_host_hex);
566 while ((ret = mbedtls_ssl_handshake(&(csp->mbedtls_client_attr.ssl))) != 0)
568 if (ret != MBEDTLS_ERR_SSL_WANT_READ &&
569 ret != MBEDTLS_ERR_SSL_WANT_WRITE)
571 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
572 log_error(LOG_LEVEL_ERROR,
573 "medtls_ssl_handshake with client failed: %s", err_buf);
579 log_error(LOG_LEVEL_CONNECT, "Client successfully connected over TLS/SSL");
580 csp->ssl_with_client_is_opened = 1;
584 * Freeing allocated paths to files
589 /* Freeing structures if connection wasn't created successfully */
592 free_client_ssl_structures(csp);
598 /*********************************************************************
600 * Function : close_client_ssl_connection
602 * Description : Closes TLS/SSL connection with client. This function
603 * checks if this connection is already created.
606 * 1 : csp = Current client state (buffers, headers, etc...)
610 *********************************************************************/
611 extern void close_client_ssl_connection(struct client_state *csp)
615 if (csp->ssl_with_client_is_opened == 0)
621 * Notifying the peer that the connection is being closed.
624 ret = mbedtls_ssl_close_notify(&(csp->mbedtls_client_attr.ssl));
625 } while (ret == MBEDTLS_ERR_SSL_WANT_WRITE);
627 free_client_ssl_structures(csp);
628 csp->ssl_with_client_is_opened = 0;
632 /*********************************************************************
634 * Function : free_client_ssl_structures
636 * Description : Frees structures used for SSL communication with
640 * 1 : csp = Current client state (buffers, headers, etc...)
644 *********************************************************************/
645 static void free_client_ssl_structures(struct client_state *csp)
648 * We can't use function mbedtls_net_free, because this function
649 * inter alia close TCP connection on setted fd. Instead of this
650 * function, we change fd to -1, which is the same what does
651 * rest of mbedtls_net_free function.
653 csp->mbedtls_client_attr.socket_fd.fd = -1;
655 /* Freeing mbedtls structures */
656 mbedtls_x509_crt_free(&(csp->mbedtls_client_attr.server_cert));
657 mbedtls_pk_free(&(csp->mbedtls_client_attr.prim_key));
658 mbedtls_ssl_free(&(csp->mbedtls_client_attr.ssl));
659 mbedtls_ssl_config_free(&(csp->mbedtls_client_attr.conf));
660 #if defined(MBEDTLS_SSL_CACHE_C)
661 mbedtls_ssl_cache_free(&(csp->mbedtls_client_attr.cache));
666 /*********************************************************************
668 * Function : create_server_ssl_connection
670 * Description : Creates TLS/SSL secured connection with server.
673 * 1 : csp = Current client state (buffers, headers, etc...)
675 * Returns : 0 on success, negative value if connection wasn't created
678 *********************************************************************/
679 extern int create_server_ssl_connection(struct client_state *csp)
682 char err_buf[ERROR_BUF_SIZE];
683 char *trusted_cas_file = NULL;
684 int auth_mode = MBEDTLS_SSL_VERIFY_REQUIRED;
686 csp->server_cert_verification_result = SSL_CERT_NOT_VERIFIED;
687 csp->server_certs_chain.next = NULL;
689 /* Setting path to file with trusted CAs */
690 trusted_cas_file = csp->config->trusted_cas_file;
693 * Initializing mbedtls structures for TLS/SSL connection
695 mbedtls_net_init(&(csp->mbedtls_server_attr.socket_fd));
696 mbedtls_ssl_init(&(csp->mbedtls_server_attr.ssl));
697 mbedtls_ssl_config_init(&(csp->mbedtls_server_attr.conf));
698 mbedtls_x509_crt_init(&(csp->mbedtls_server_attr.ca_cert));
701 * Setting socket fd in mbedtls_net_context structure. This structure
702 * can't be set by mbedtls functions, because we already have created
703 * TCP connection when calling this function.
705 csp->mbedtls_server_attr.socket_fd.fd = csp->server_connection.sfd;
718 * Loading file with trusted CAs
720 ret = mbedtls_x509_crt_parse_file(&(csp->mbedtls_server_attr.ca_cert),
724 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
725 log_error(LOG_LEVEL_ERROR, "Loading trusted CAs file %s failed: %s",
726 trusted_cas_file, err_buf);
732 * Set TLS/SSL options
734 ret = mbedtls_ssl_config_defaults(&(csp->mbedtls_server_attr.conf),
735 MBEDTLS_SSL_IS_CLIENT,
736 MBEDTLS_SSL_TRANSPORT_STREAM,
737 MBEDTLS_SSL_PRESET_DEFAULT);
740 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
741 log_error(LOG_LEVEL_ERROR, "mbedtls_ssl_config_defaults failed: %s",
748 * Setting how strict should certificate verification be and other
749 * parameters for certificate verification
751 if (csp->dont_verify_certificate)
753 auth_mode = MBEDTLS_SSL_VERIFY_NONE;
756 mbedtls_ssl_conf_authmode(&(csp->mbedtls_server_attr.conf), auth_mode);
757 mbedtls_ssl_conf_ca_chain(&(csp->mbedtls_server_attr.conf),
758 &(csp->mbedtls_server_attr.ca_cert), NULL);
760 /* Setting callback function for certificates verification */
761 mbedtls_ssl_conf_verify(&(csp->mbedtls_server_attr.conf),
762 ssl_verify_callback, (void *)csp);
764 mbedtls_ssl_conf_rng(&(csp->mbedtls_server_attr.conf),
765 mbedtls_ctr_drbg_random, &ctr_drbg);
766 mbedtls_ssl_conf_dbg(&(csp->mbedtls_server_attr.conf),
767 ssl_debug_callback, stdout);
769 ret = mbedtls_ssl_setup(&(csp->mbedtls_server_attr.ssl),
770 &(csp->mbedtls_server_attr.conf));
773 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
774 log_error(LOG_LEVEL_ERROR, "mbedtls_ssl_setup failed: %s", err_buf);
780 * Set the hostname to check against the received server certificate
782 ret = mbedtls_ssl_set_hostname(&(csp->mbedtls_server_attr.ssl),
786 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
787 log_error(LOG_LEVEL_ERROR, "mbedtls_ssl_set_hostname failed: %s",
793 mbedtls_ssl_set_bio(&(csp->mbedtls_server_attr.ssl),
794 &(csp->mbedtls_server_attr.socket_fd), mbedtls_net_send,
795 mbedtls_net_recv, NULL);
798 * Handshake with server
800 log_error(LOG_LEVEL_CONNECT,
801 "Performing the TLS/SSL handshake with server");
803 while ((ret = mbedtls_ssl_handshake(&(csp->mbedtls_server_attr.ssl))) != 0)
805 if (ret != MBEDTLS_ERR_SSL_WANT_READ
806 && ret != MBEDTLS_ERR_SSL_WANT_WRITE)
808 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
810 if (ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED)
812 log_error(LOG_LEVEL_ERROR,
813 "Server certificate verification failed: %s", err_buf);
814 csp->server_cert_verification_result =
815 mbedtls_ssl_get_verify_result(&(csp->mbedtls_server_attr.ssl));
821 log_error(LOG_LEVEL_ERROR,
822 "mbedtls_ssl_handshake with server failed: %s", err_buf);
829 log_error(LOG_LEVEL_CONNECT, "Server successfully connected over TLS/SSL");
832 * Server certificate chain is valid, so we can clean
833 * chain, because we will not send it to client.
835 free_certificate_chain(csp);
837 csp->ssl_with_server_is_opened = 1;
838 csp->server_cert_verification_result =
839 mbedtls_ssl_get_verify_result(&(csp->mbedtls_server_attr.ssl));
842 /* Freeing structures if connection wasn't created successfully */
845 free_server_ssl_structures(csp);
852 /*********************************************************************
854 * Function : close_server_ssl_connection
856 * Description : Closes TLS/SSL connection with server. This function
857 * checks if this connection is already opened.
860 * 1 : csp = Current client state (buffers, headers, etc...)
864 *********************************************************************/
865 static void close_server_ssl_connection(struct client_state *csp)
869 if (csp->ssl_with_server_is_opened == 0)
875 * Notifying the peer that the connection is being closed.
878 ret = mbedtls_ssl_close_notify(&(csp->mbedtls_server_attr.ssl));
879 } while (ret == MBEDTLS_ERR_SSL_WANT_WRITE);
881 free_server_ssl_structures(csp);
882 csp->ssl_with_server_is_opened = 0;
886 /*********************************************************************
888 * Function : free_server_ssl_structures
890 * Description : Frees structures used for SSL communication with server
893 * 1 : csp = Current client state (buffers, headers, etc...)
897 *********************************************************************/
898 static void free_server_ssl_structures(struct client_state *csp)
901 * We can't use function mbedtls_net_free, because this function
902 * inter alia close TCP connection on setted fd. Instead of this
903 * function, we change fd to -1, which is the same what does
904 * rest of mbedtls_net_free function.
906 csp->mbedtls_client_attr.socket_fd.fd = -1;
908 mbedtls_x509_crt_free(&(csp->mbedtls_server_attr.ca_cert));
909 mbedtls_ssl_free(&(csp->mbedtls_server_attr.ssl));
910 mbedtls_ssl_config_free(&(csp->mbedtls_server_attr.conf));
914 /*********************************************************************
916 * Function : close_client_and_server_ssl_connections
918 * Description : Checks if client or server should use secured
919 * connection over SSL and if so, closes all of them.
922 * 1 : csp = Current client state (buffers, headers, etc...)
926 *********************************************************************/
927 extern void close_client_and_server_ssl_connections(struct client_state *csp)
929 if (client_use_ssl(csp) == 1)
931 close_client_ssl_connection(csp);
933 if (server_use_ssl(csp) == 1)
935 close_server_ssl_connection(csp);
939 /*====================== Certificates ======================*/
941 /*********************************************************************
943 * Function : write_certificate
945 * Description : Writes certificate into file.
948 * 1 : crt = certificate to write into file
949 * 2 : output_file = path to save certificate file
950 * 3 : f_rng = mbedtls_ctr_drbg_random
951 * 4 : p_rng = mbedtls_ctr_drbg_context
953 * Returns : Length of written certificate on success or negative value
956 *********************************************************************/
957 static int write_certificate(mbedtls_x509write_cert *crt, const char *output_file,
958 int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
962 unsigned char cert_buf[CERTIFICATE_BUF_SIZE + 1]; /* Buffer for certificate in PEM format + terminating NULL */
964 char err_buf[ERROR_BUF_SIZE];
966 memset(cert_buf, 0, sizeof(cert_buf));
969 * Writing certificate into PEM string. If buffer is too small, function
970 * returns specific error and no buffer overflow can happen.
972 if ((ret = mbedtls_x509write_crt_pem(crt, cert_buf,
973 sizeof(cert_buf) - 1, f_rng, p_rng)) != 0)
975 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
976 log_error(LOG_LEVEL_ERROR,
977 "Writing certificate into buffer failed: %s", err_buf);
981 len = strlen((char *)cert_buf);
984 * Saving certificate into file
986 if ((f = fopen(output_file, "w")) == NULL)
988 log_error(LOG_LEVEL_ERROR, "Opening file %s to save certificate failed",
993 if (fwrite(cert_buf, 1, len, f) != len)
995 log_error(LOG_LEVEL_ERROR,
996 "Writing certificate into file %s failed", output_file);
1007 /*********************************************************************
1009 * Function : write_private_key
1011 * Description : Writes private key into file and copies saved
1012 * content into given pointer to string. If function
1013 * returns 0 for success, this copy must be freed by
1017 * 1 : key = key to write into file
1018 * 2 : ret_buf = pointer to string with created key file content
1019 * 3 : key_file_path = path where to save key file
1021 * Returns : Length of written private key on success or negative value
1024 *********************************************************************/
1025 static int write_private_key(mbedtls_pk_context *key, unsigned char **ret_buf,
1026 const char *key_file_path)
1028 size_t len = 0; /* Length of created key */
1029 FILE *f = NULL; /* File to save certificate */
1031 char err_buf[ERROR_BUF_SIZE];
1033 /* Initializing buffer for key file content */
1034 *ret_buf = zalloc_or_die(PRIVATE_KEY_BUF_SIZE + 1);
1037 * Writing private key into PEM string
1039 if ((ret = mbedtls_pk_write_key_pem(key, *ret_buf, PRIVATE_KEY_BUF_SIZE)) != 0)
1041 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1042 log_error(LOG_LEVEL_ERROR,
1043 "Writing private key into PEM string failed: %s", err_buf);
1047 len = strlen((char *)*ret_buf);
1050 * Saving key into file
1052 if ((f = fopen(key_file_path, "wb")) == NULL)
1054 log_error(LOG_LEVEL_ERROR,
1055 "Opening file %s to save private key failed: %E",
1061 if (fwrite(*ret_buf, 1, len, f) != len)
1064 log_error(LOG_LEVEL_ERROR,
1065 "Writing private key into file %s failed",
1084 /*********************************************************************
1086 * Function : generate_key
1088 * Description : Tests if private key for host saved in csp already
1089 * exists. If this file doesn't exists, a new key is
1090 * generated and saved in a file. The generated key is also
1091 * copied into given parameter key_buf, which must be then
1092 * freed by caller. If file with key exists, key_buf
1093 * contain NULL and no private key is generated.
1096 * 1 : csp = Current client state (buffers, headers, etc...)
1097 * 2 : key_buf = buffer to save new generated key
1099 * Returns : -1 => Error while generating private key
1100 * 0 => Key already exists
1101 * >0 => Length of generated private key
1103 *********************************************************************/
1104 static int generate_key(struct client_state *csp, unsigned char **key_buf)
1106 mbedtls_pk_context key;
1107 key_options key_opt;
1109 char err_buf[ERROR_BUF_SIZE];
1111 key_opt.key_file_path = NULL;
1114 * Initializing structures for key generating
1116 mbedtls_pk_init(&key);
1119 * Preparing path for key file and other properties for generating key
1121 key_opt.type = MBEDTLS_PK_RSA;
1122 key_opt.rsa_keysize = RSA_KEYSIZE;
1124 key_opt.key_file_path = make_certs_path(csp->config->certificate_directory,
1125 (char *)csp->http->hash_of_host_hex, KEY_FILE_TYPE);
1126 if (key_opt.key_file_path == NULL)
1133 * Test if key already exists. If so, we don't have to create it again.
1135 if (file_exists(key_opt.key_file_path) == 1)
1144 ret = seed_rng(csp);
1152 * Setting attributes of private key and generating it
1154 if ((ret = mbedtls_pk_setup(&key,
1155 mbedtls_pk_info_from_type(key_opt.type))) != 0)
1157 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1158 log_error(LOG_LEVEL_ERROR, "mbedtls_pk_setup failed: %s", err_buf);
1163 ret = mbedtls_rsa_gen_key(mbedtls_pk_rsa(key), mbedtls_ctr_drbg_random,
1164 &ctr_drbg, (unsigned)key_opt.rsa_keysize, RSA_KEY_PUBLIC_EXPONENT);
1167 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1168 log_error(LOG_LEVEL_ERROR, "Key generating failed: %s", err_buf);
1174 * Exporting private key into file
1176 if ((ret = write_private_key(&key, key_buf, key_opt.key_file_path)) < 0)
1178 log_error(LOG_LEVEL_ERROR,
1179 "Writing private key into file %s failed", key_opt.key_file_path);
1186 * Freeing used variables
1188 freez(key_opt.key_file_path);
1190 mbedtls_pk_free(&key);
1196 /*********************************************************************
1198 * Function : generate_webpage_certificate
1200 * Description : Creates certificate file in presetted directory.
1201 * If certificate already exists, no other certificate
1202 * will be created. Subject of certificate is named
1203 * by csp->http->host from parameter. This function also
1204 * triggers generating of private key for new certificate.
1207 * 1 : csp = Current client state (buffers, headers, etc...)
1209 * Returns : -1 => Error while creating certificate.
1210 * 0 => Certificate already exists.
1211 * >0 => Length of created certificate.
1213 *********************************************************************/
1214 static int generate_webpage_certificate(struct client_state *csp)
1216 mbedtls_x509_crt issuer_cert;
1217 mbedtls_pk_context loaded_issuer_key, loaded_subject_key;
1218 mbedtls_pk_context *issuer_key = &loaded_issuer_key;
1219 mbedtls_pk_context *subject_key = &loaded_subject_key;
1220 mbedtls_x509write_cert cert;
1223 unsigned char *key_buf = NULL; /* Buffer for created key */
1226 char err_buf[ERROR_BUF_SIZE];
1227 cert_options cert_opt;
1229 /* Paths to keys and certificates needed to create certificate */
1230 cert_opt.issuer_key = NULL;
1231 cert_opt.subject_key = NULL;
1232 cert_opt.issuer_crt = NULL;
1233 cert_opt.output_file = NULL;
1236 * Create key for requested host
1238 int subject_key_len = generate_key(csp, &key_buf);
1239 if (subject_key_len < 0)
1241 log_error(LOG_LEVEL_ERROR, "Key generating failed");
1246 * Initializing structures for certificate generating
1248 mbedtls_x509write_crt_init(&cert);
1249 mbedtls_x509write_crt_set_md_alg(&cert, CERT_SIGNATURE_ALGORITHM);
1250 mbedtls_pk_init(&loaded_issuer_key);
1251 mbedtls_pk_init(&loaded_subject_key);
1252 mbedtls_mpi_init(&serial);
1253 mbedtls_x509_crt_init(&issuer_cert);
1256 * Presetting parameters for certificate. We must compute total length
1259 size_t cert_params_len = strlen(CERT_PARAM_COMMON_NAME) +
1260 strlen(CERT_PARAM_ORGANIZATION) + strlen(CERT_PARAM_COUNTRY) +
1261 strlen(CERT_PARAM_ORG_UNIT) +
1262 3 * strlen(csp->http->host) + 1;
1263 char cert_params[cert_params_len];
1264 memset(cert_params, 0, cert_params_len);
1267 * Converting unsigned long serial number to char * serial number.
1268 * We must compute length of serial number in string + terminating null.
1270 unsigned long certificate_serial = get_certificate_serial(csp);
1271 int serial_num_size = snprintf(NULL, 0, "%lu", certificate_serial) + 1;
1272 if (serial_num_size <= 0)
1274 serial_num_size = 1;
1277 char serial_num_text[serial_num_size]; /* Buffer for serial number */
1278 ret = snprintf(serial_num_text, (size_t)serial_num_size, "%lu", certificate_serial);
1279 if (ret < 0 || ret >= serial_num_size)
1281 log_error(LOG_LEVEL_ERROR,
1282 "Converting certificate serial number into string failed");
1288 * Preparing parameters for certificate
1290 strlcpy(cert_params, CERT_PARAM_COMMON_NAME, cert_params_len);
1291 strlcat(cert_params, csp->http->host, cert_params_len);
1292 strlcat(cert_params, CERT_PARAM_ORGANIZATION, cert_params_len);
1293 strlcat(cert_params, csp->http->host, cert_params_len);
1294 strlcat(cert_params, CERT_PARAM_ORG_UNIT, cert_params_len);
1295 strlcat(cert_params, csp->http->host, cert_params_len);
1296 strlcat(cert_params, CERT_PARAM_COUNTRY, cert_params_len);
1298 cert_opt.issuer_crt = csp->config->ca_cert_file;
1299 cert_opt.issuer_key = csp->config->ca_key_file;
1300 cert_opt.subject_key = make_certs_path(csp->config->certificate_directory,
1301 (const char *)csp->http->hash_of_host_hex, KEY_FILE_TYPE);
1302 cert_opt.output_file = make_certs_path(csp->config->certificate_directory,
1303 (const char *)csp->http->hash_of_host_hex, CERT_FILE_TYPE);
1305 if (cert_opt.subject_key == NULL || cert_opt.output_file == NULL)
1311 cert_opt.subject_pwd = CERT_SUBJECT_PASSWORD;
1312 cert_opt.issuer_pwd = csp->config->ca_password;
1313 cert_opt.subject_name = cert_params;
1314 cert_opt.not_before = GENERATED_CERT_VALID_FROM;
1315 cert_opt.not_after = GENERATED_CERT_VALID_TO;
1316 cert_opt.serial = serial_num_text;
1318 cert_opt.max_pathlen = -1;
1321 * Test if certificate exists and private key was already created
1323 if (file_exists(cert_opt.output_file) == 1 && subject_key_len == 0)
1332 ret = seed_rng(csp);
1340 * Parse serial to MPI
1342 ret = mbedtls_mpi_read_string(&serial, 10, cert_opt.serial);
1345 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1346 log_error(LOG_LEVEL_ERROR,
1347 "mbedtls_mpi_read_string failed: %s", err_buf);
1353 * Loading certificates
1355 ret = mbedtls_x509_crt_parse_file(&issuer_cert, cert_opt.issuer_crt);
1358 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1359 log_error(LOG_LEVEL_ERROR, "Loading issuer certificate %s failed: %s",
1360 cert_opt.issuer_crt, err_buf);
1365 ret = mbedtls_x509_dn_gets(cert_opt.issuer_name,
1366 sizeof(cert_opt.issuer_name), &issuer_cert.subject);
1369 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1370 log_error(LOG_LEVEL_ERROR, "mbedtls_x509_dn_gets failed: %s", err_buf);
1376 * Loading keys from file or from buffer
1378 if (key_buf != NULL && subject_key_len > 0)
1380 /* Key was created in this function and is stored in buffer */
1381 ret = mbedtls_pk_parse_key(&loaded_subject_key, key_buf,
1382 (size_t)(subject_key_len + 1), (unsigned const char *)
1383 cert_opt.subject_pwd, strlen(cert_opt.subject_pwd));
1387 /* Key wasn't created in this function, because it already existed */
1388 ret = mbedtls_pk_parse_keyfile(&loaded_subject_key,
1389 cert_opt.subject_key, cert_opt.subject_pwd);
1394 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1395 log_error(LOG_LEVEL_ERROR, "Parsing subject key %s failed: %s",
1396 cert_opt.subject_key, err_buf);
1401 ret = mbedtls_pk_parse_keyfile(&loaded_issuer_key, cert_opt.issuer_key,
1402 cert_opt.issuer_pwd);
1405 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1406 log_error(LOG_LEVEL_ERROR,
1407 "Parsing issuer key %s failed: %s", cert_opt.issuer_key, err_buf);
1413 * Check if key and issuer certificate match
1415 if (!mbedtls_pk_can_do(&issuer_cert.pk, MBEDTLS_PK_RSA) ||
1416 mbedtls_mpi_cmp_mpi(&mbedtls_pk_rsa(issuer_cert.pk)->N,
1417 &mbedtls_pk_rsa(*issuer_key)->N) != 0 ||
1418 mbedtls_mpi_cmp_mpi(&mbedtls_pk_rsa(issuer_cert.pk)->E,
1419 &mbedtls_pk_rsa(*issuer_key)->E) != 0)
1421 log_error(LOG_LEVEL_ERROR,
1422 "Issuer key doesn't match issuer certificate");
1427 mbedtls_x509write_crt_set_subject_key(&cert, subject_key);
1428 mbedtls_x509write_crt_set_issuer_key(&cert, issuer_key);
1431 * Setting parameters of signed certificate
1433 ret = mbedtls_x509write_crt_set_subject_name(&cert, cert_opt.subject_name);
1436 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1437 log_error(LOG_LEVEL_ERROR,
1438 "Setting subject name in signed certificate failed: %s", err_buf);
1443 ret = mbedtls_x509write_crt_set_issuer_name(&cert, cert_opt.issuer_name);
1446 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1447 log_error(LOG_LEVEL_ERROR,
1448 "Setting issuer name in signed certificate failed: %s", err_buf);
1453 ret = mbedtls_x509write_crt_set_serial(&cert, &serial);
1456 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1457 log_error(LOG_LEVEL_ERROR,
1458 "Setting serial number in signed certificate failed: %s", err_buf);
1463 ret = mbedtls_x509write_crt_set_validity(&cert, cert_opt.not_before,
1464 cert_opt.not_after);
1467 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1468 log_error(LOG_LEVEL_ERROR,
1469 "Setting validity in signed certificate failed: %s", err_buf);
1475 * Setting the basicConstraints extension for certificate
1477 ret = mbedtls_x509write_crt_set_basic_constraints(&cert, cert_opt.is_ca,
1478 cert_opt.max_pathlen);
1481 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1482 log_error(LOG_LEVEL_ERROR, "Setting the basicConstraints extension "
1483 "in signed certificate failed: %s", err_buf);
1488 #if defined(MBEDTLS_SHA1_C)
1489 /* Setting the subjectKeyIdentifier extension for certificate */
1490 ret = mbedtls_x509write_crt_set_subject_key_identifier(&cert);
1493 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1494 log_error(LOG_LEVEL_ERROR, "mbedtls_x509write_crt_set_subject_key_"
1495 "identifier failed: %s", err_buf);
1500 /* Setting the authorityKeyIdentifier extension for certificate */
1501 ret = mbedtls_x509write_crt_set_authority_key_identifier(&cert);
1504 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1505 log_error(LOG_LEVEL_ERROR, "mbedtls_x509write_crt_set_authority_key_"
1506 "identifier failed: %s", err_buf);
1510 #endif /* MBEDTLS_SHA1_C */
1513 * Writing certificate into file
1515 ret = write_certificate(&cert, cert_opt.output_file,
1516 mbedtls_ctr_drbg_random, &ctr_drbg);
1519 log_error(LOG_LEVEL_ERROR, "Writing certificate into file failed");
1525 * Freeing used structures
1527 mbedtls_x509write_crt_free(&cert);
1528 mbedtls_pk_free(&loaded_subject_key);
1529 mbedtls_pk_free(&loaded_issuer_key);
1530 mbedtls_mpi_free(&serial);
1531 mbedtls_x509_crt_free(&issuer_cert);
1533 freez(cert_opt.subject_key);
1534 freez(cert_opt.output_file);
1541 /*********************************************************************
1543 * Function : make_certs_path
1545 * Description : Creates path to file from three pieces. This fuction
1546 * takes parameters and puts them in one new mallocated
1547 * char * in correct order. Returned variable must be freed
1548 * by caller. This function is mainly used for creating
1549 * paths of certificates and keys files.
1552 * 1 : conf_dir = Name/path of directory where is the file.
1553 * '.' can be used for current directory.
1554 * 2 : file_name = Name of file in conf_dir without suffix.
1555 * 3 : suffix = Suffix of given file_name.
1557 * Returns : path => Path was built up successfully
1558 * NULL => Path can't be built up
1560 *********************************************************************/
1561 static char *make_certs_path(const char *conf_dir, const char *file_name,
1564 /* Test if all given parameters are valid */
1565 if (conf_dir == NULL || *conf_dir == '\0' || file_name == NULL ||
1566 *file_name == '\0' || suffix == NULL || *suffix == '\0')
1568 log_error(LOG_LEVEL_ERROR,
1569 "make_certs_path failed: bad input parameters");
1574 size_t path_size = strlen(conf_dir)
1575 + strlen(file_name) + strlen(suffix) + 2;
1577 /* Setting delimiter and editing path length */
1578 #if defined(_WIN32) || defined(__OS2__)
1579 char delim[] = "\\";
1581 #else /* ifndef _WIN32 || __OS2__ */
1583 #endif /* ifndef _WIN32 || __OS2__ */
1586 * Building up path from many parts
1589 if (*conf_dir != '/' && basedir && *basedir)
1592 * Replacing conf_dir with basedir. This new variable contains
1593 * absolute path to cwd.
1595 path_size += strlen(basedir) + 2;
1596 path = zalloc_or_die(path_size);
1598 strlcpy(path, basedir, path_size);
1599 strlcat(path, delim, path_size);
1600 strlcat(path, conf_dir, path_size);
1601 strlcat(path, delim, path_size);
1602 strlcat(path, file_name, path_size);
1603 strlcat(path, suffix, path_size);
1606 #endif /* defined unix */
1608 path = zalloc_or_die(path_size);
1610 strlcpy(path, conf_dir, path_size);
1611 strlcat(path, delim, path_size);
1612 strlcat(path, file_name, path_size);
1613 strlcat(path, suffix, path_size);
1620 /*********************************************************************
1622 * Function : get_certificate_mutex_id
1624 * Description : Computes mutex id from host name hash. This hash must
1625 * be already saved in csp structure
1628 * 1 : csp = Current client state (buffers, headers, etc...)
1630 * Returns : Mutex id for given host name
1632 *********************************************************************/
1633 static unsigned int get_certificate_mutex_id(struct client_state *csp) {
1634 #ifdef LIMIT_MUTEX_NUMBER
1635 return (unsigned int)(csp->http->hash_of_host[0] % 32);
1637 return (unsigned int)(csp->http->hash_of_host[1]
1638 + 256 * (int)csp->http->hash_of_host[0]);
1639 #endif /* LIMIT_MUTEX_NUMBER */
1643 /*********************************************************************
1645 * Function : get_certificate_serial
1647 * Description : Computes serial number for new certificate from host
1648 * name hash. This hash must be already saved in csp
1652 * 1 : csp = Current client state (buffers, headers, etc...)
1654 * Returns : Serial number for new certificate
1656 *********************************************************************/
1657 static unsigned long get_certificate_serial(struct client_state *csp) {
1658 unsigned long exp = 1;
1659 unsigned long serial = 0;
1661 int i = CERT_SERIAL_NUM_LENGTH;
1662 /* Length of hash is 16 bytes, we must avoid to read next chars */
1674 serial += exp * (unsigned)csp->http->hash_of_host[i];
1681 /*********************************************************************
1683 * Function : ssl_send_certificate_error
1685 * Description : Sends info about invalid server certificate to client.
1686 * Sent message is including all trusted chain certificates,
1687 * that can be downloaded in web browser.
1690 * 1 : csp = Current client state (buffers, headers, etc...)
1694 *********************************************************************/
1695 extern void ssl_send_certificate_error(struct client_state *csp)
1697 size_t message_len = 0;
1699 struct certs_chain *cert = NULL;
1701 /* Header of message with certificate informations */
1702 const char message_begin[] =
1703 "HTTP/1.1 200 OK\r\n"
1704 "Content-Type: text/html\r\n"
1705 "Connection: close\r\n\r\n"
1706 "<html><body><h1>Invalid server certificate</h1><p>Reason: ";
1707 const char message_end[] = "</body></html>\r\n\r\n";
1708 char reason[INVALID_CERT_INFO_BUF_SIZE];
1709 memset(reason, 0, sizeof(reason));
1711 /* Get verification message from verification return code */
1712 mbedtls_x509_crt_verify_info(reason, sizeof(reason), " ",
1713 csp->server_cert_verification_result);
1716 * Computing total length of message with all certificates inside
1718 message_len = strlen(message_begin) + strlen(message_end)
1719 + strlen(reason) + strlen("</p>") + 1;
1721 cert = &(csp->server_certs_chain);
1722 while (cert->next != NULL)
1724 size_t base64_len = 4 * ((strlen(cert->file_buf) + 2) / 3) + 1;
1726 message_len += strlen(cert->text_buf) + strlen("<pre></pre>\n")
1727 + base64_len + strlen("<a href=\"data:application"
1728 "/x-x509-ca-cert;base64,\">Download certificate</a>");
1733 * Joining all blocks in one long message
1735 char message[message_len];
1736 memset(message, 0, message_len);
1738 strlcpy(message, message_begin, message_len);
1739 strlcat(message, reason , message_len);
1740 strlcat(message, "</p>" , message_len);
1742 cert = &(csp->server_certs_chain);
1743 while (cert->next != NULL)
1746 size_t base64_len = 4 * ((strlen(cert->file_buf) + 2) / 3) + 1; /* +1 for terminating null*/
1747 char base64_buf[base64_len];
1748 memset(base64_buf, 0, base64_len);
1750 /* Encoding certificate into base64 code */
1751 ret = mbedtls_base64_encode((unsigned char*)base64_buf,
1752 base64_len, &olen, (const unsigned char*)cert->file_buf,
1753 strlen(cert->file_buf));
1756 log_error(LOG_LEVEL_ERROR,
1757 "Encoding to base64 failed, buffer is to small");
1760 strlcat(message, "<pre>", message_len);
1761 strlcat(message, cert->text_buf, message_len);
1762 strlcat(message, "</pre>\n", message_len);
1766 strlcat(message, "<a href=\"data:application/x-x509-ca-cert;base64,",
1768 strlcat(message, base64_buf, message_len);
1769 strlcat(message, "\">Download certificate</a>", message_len);
1774 strlcat(message, message_end, message_len);
1777 * Sending final message to client
1779 ssl_send_data(&(csp->mbedtls_client_attr.ssl),
1780 (const unsigned char *)message, strlen(message));
1782 * Waiting before closing connection. Some browsers don't show received
1783 * message if there isn't this delay.
1787 free_certificate_chain(csp);
1791 /*********************************************************************
1793 * Function : ssl_verify_callback
1795 * Description : This is a callback function for certificate verification.
1796 * It's called for all certificates in server certificate
1797 * trusted chain and it's preparing information about this
1798 * certificates. Prepared informations can be used to inform
1799 * user about invalid certificates.
1802 * 1 : csp_void = Current client state (buffers, headers, etc...)
1803 * 2 : crt = certificate from trusted chain
1804 * 3 : depth = depth in trusted chain
1805 * 4 : flags = certificate flags
1807 * Returns : 0 on success and negative value on error
1809 *********************************************************************/
1810 static int ssl_verify_callback(void *csp_void, mbedtls_x509_crt *crt,
1811 int depth, uint32_t *flags)
1813 struct client_state *csp = (struct client_state *)csp_void;
1814 struct certs_chain *last = &(csp->server_certs_chain);
1819 * Searching for last item in certificates linked list
1821 while (last->next != NULL)
1827 * Preparing next item in linked list for next certificate
1829 last->next = malloc_or_die(sizeof(struct certs_chain));
1830 last->next->next = NULL;
1831 memset(last->next->text_buf, 0, sizeof(last->next->text_buf));
1832 memset(last->next->file_buf, 0, sizeof(last->next->file_buf));
1835 * Saving certificate file into buffer
1837 if ((ret = mbedtls_pem_write_buffer(PEM_BEGIN_CRT, PEM_END_CRT,
1838 crt->raw.p, crt->raw.len, (unsigned char *)last->file_buf,
1839 sizeof(last->file_buf)-1, &olen)) != 0)
1845 * Saving certificate information into buffer
1847 mbedtls_x509_crt_info(last->text_buf, sizeof(last->text_buf) - 1,
1848 CERT_INFO_PREFIX, crt);
1854 /*********************************************************************
1856 * Function : free_certificate_chain
1858 * Description : Frees certificates linked list. This linked list is
1859 * used to save informations about certificates in
1863 * 1 : csp = Current client state (buffers, headers, etc...)
1867 *********************************************************************/
1868 static void free_certificate_chain(struct client_state *csp)
1870 struct certs_chain *cert = csp->server_certs_chain.next;
1872 /* Cleaning buffers */
1873 memset(csp->server_certs_chain.text_buf, 0,
1874 sizeof(csp->server_certs_chain.text_buf));
1875 memset(csp->server_certs_chain.file_buf, 0,
1876 sizeof(csp->server_certs_chain.file_buf));
1877 csp->server_certs_chain.next = NULL;
1879 /* Freeing memory in whole linked list */
1884 struct certs_chain *cert_for_free = cert;
1886 freez(cert_for_free);
1887 } while (cert != NULL);
1892 /*********************************************************************
1894 * Function : file_exists
1896 * Description : Tests if file exists and is readable.
1899 * 1 : path = Path to tested file.
1901 * Returns : 1 => File exists and is readable.
1902 * 0 => File doesn't exist or is not readable.
1904 *********************************************************************/
1905 static int file_exists(const char *path)
1908 if ((f = fopen(path, "r")) != NULL)
1918 /*********************************************************************
1920 * Function : host_to_hash
1922 * Description : Creates MD5 hash from host name. Host name is loaded
1923 * from structure csp and saved again into it.
1926 * 1 : csp = Current client state (buffers, headers, etc...)
1928 * Returns : 1 => Error while creating hash
1929 * 0 => Hash created successfully
1931 *********************************************************************/
1932 static int host_to_hash(struct client_state *csp)
1936 #if !defined(MBEDTLS_MD5_C)
1937 log_error(LOG_LEVEL_ERROR, "MBEDTLS_MD5_C is not defined. Can't create"
1938 "MD5 hash for certificate and key name.");
1941 memset(csp->http->hash_of_host, 0, sizeof(csp->http->hash_of_host));
1942 mbedtls_md5((unsigned char *)csp->http->host, strlen(csp->http->host),
1943 csp->http->hash_of_host);
1945 /* Converting hash into string with hex */
1949 if ((ret = sprintf((char *)csp->http->hash_of_host_hex + 2 * i, "%02x",
1950 csp->http->hash_of_host[i])) < 0)
1952 log_error(LOG_LEVEL_ERROR, "Sprintf return value: %d", ret);
1958 #endif /* MBEDTLS_MD5_C */
1962 /*********************************************************************
1964 * Function : tunnel_established_successfully
1966 * Description : Check if parent proxy server response contains
1967 * informations about successfully created connection with
1968 * destination server. (HTTP/... 2xx ...)
1971 * 1 : server_response = Buffer with parent proxy server response
1972 * 2 : response_len = Length of server_response
1974 * Returns : 1 => Connection created successfully
1975 * 0 => Connection wasn't created successfully
1977 *********************************************************************/
1978 extern int tunnel_established_successfully(const char *server_response,
1979 unsigned int response_len)
1981 unsigned int pos = 0;
1983 if (server_response == NULL)
1988 /* Tests if "HTTP/" string is at the begin of received response */
1989 if (strncmp(server_response, "HTTP/", 5) != 0)
1994 for (pos = 0; pos < response_len; pos++)
1996 if (server_response[pos] == ' ')
2003 * response_len -3 because of buffer end, response structure and 200 code.
2004 * There must be at least 3 chars after space.
2005 * End of buffer: ... 2xx'\0'
2008 if (pos >= (response_len - 3))
2013 /* Test HTTP status code */
2014 if (server_response[pos + 1] != '2')
2023 /*********************************************************************
2025 * Function : seed_rng
2027 * Description : Seeding the RNG for all SSL uses
2030 * 1 : csp = Current client state (buffers, headers, etc...)
2032 * Returns : -1 => RNG wasn't seed successfully
2033 * 0 => RNG is seeded successfully
2035 *********************************************************************/
2036 static int seed_rng(struct client_state *csp)
2039 char err_buf[ERROR_BUF_SIZE];
2041 if (rng_seeded == 0)
2043 privoxy_mutex_lock(&rng_mutex);
2044 if (rng_seeded == 0)
2046 mbedtls_ctr_drbg_init(&ctr_drbg);
2047 mbedtls_entropy_init(&entropy);
2048 ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func,
2052 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
2053 log_error(LOG_LEVEL_ERROR,
2054 "mbedtls_ctr_drbg_seed failed: %s", err_buf);
2055 privoxy_mutex_unlock(&rng_mutex);
2060 privoxy_mutex_unlock(&rng_mutex);