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);
305 log_error(LOG_LEVEL_RECEIVED, "TLS: %N", ret, buf);
311 /*********************************************************************
313 * Function : ssl_flush_socket
315 * Description : Send any pending "buffered" content with given
316 * SSL connection. Alternative to function flush_socket.
319 * 1 : ssl = SSL context to send buffer to
320 * 2 : iob = The I/O buffer to flush, usually csp->iob.
322 * Returns : On success, the number of bytes send are returned (zero
323 * indicates nothing was sent). On error, -1 is returned.
325 *********************************************************************/
326 extern long ssl_flush_socket(mbedtls_ssl_context *ssl, struct iob *iob)
328 /* Computing length of buffer part to send */
329 long len = iob->eod - iob->cur;
336 /* Sending data to given SSl context */
337 if (ssl_send_data(ssl, (const unsigned char *)iob->cur, (size_t)len) < 0)
341 iob->eod = iob->cur = iob->buf;
346 /*********************************************************************
348 * Function : ssl_debug_callback
350 * Description : Debug callback function for mbedtls library.
351 * Prints info into log file.
354 * 1 : ctx = File to save log in
355 * 2 : level = Debug level
356 * 3 : file = File calling debug message
357 * 4 : line = Line calling debug message
358 * 5 : str = Debug message
362 *********************************************************************/
363 static void ssl_debug_callback(void *ctx, int level, const char *file, int line, const char *str)
367 fprintf((FILE *)ctx, "%s:%04d: %s", file, line, str);
369 log_error(LOG_LEVEL_INFO, "SSL debug message: %s:%04d: %s", file, line, str);
374 /*********************************************************************
376 * Function : create_client_ssl_connection
378 * Description : Creates TLS/SSL secured connection with client
381 * 1 : csp = Current client state (buffers, headers, etc...)
383 * Returns : 0 on success, negative value if connection wasn't created
386 *********************************************************************/
387 extern int create_client_ssl_connection(struct client_state *csp)
389 /* Paths to certificates file and key file */
390 char *key_file = NULL;
391 char *ca_file = NULL;
392 char *cert_file = NULL;
394 char err_buf[ERROR_BUF_SIZE];
397 * Initializing mbedtls structures for TLS/SSL connection
399 mbedtls_net_init(&(csp->mbedtls_client_attr.socket_fd));
400 mbedtls_ssl_init(&(csp->mbedtls_client_attr.ssl));
401 mbedtls_ssl_config_init(&(csp->mbedtls_client_attr.conf));
402 mbedtls_x509_crt_init(&(csp->mbedtls_client_attr.server_cert));
403 mbedtls_pk_init(&(csp->mbedtls_client_attr.prim_key));
404 #if defined(MBEDTLS_SSL_CACHE_C)
405 mbedtls_ssl_cache_init(&(csp->mbedtls_client_attr.cache));
409 * Preparing hash of host for creating certificates
411 ret = host_to_hash(csp);
414 log_error(LOG_LEVEL_ERROR, "Generating hash of host failed: %d", ret);
420 * Preparing paths to certificates files and key file
422 ca_file = csp->config->ca_cert_file;
423 cert_file = make_certs_path(csp->config->certificate_directory,
424 (const char *)csp->http->hash_of_host_hex, CERT_FILE_TYPE);
425 key_file = make_certs_path(csp->config->certificate_directory,
426 (const char *)csp->http->hash_of_host_hex, KEY_FILE_TYPE);
428 if (cert_file == NULL || key_file == NULL)
435 * Generating certificate for requested host. Mutex to prevent
436 * certificate and key inconsistence must be locked.
438 unsigned int cert_mutex_id = get_certificate_mutex_id(csp);
439 privoxy_mutex_lock(&(certificates_mutexes[cert_mutex_id]));
441 ret = generate_webpage_certificate(csp);
444 log_error(LOG_LEVEL_ERROR,
445 "Generate_webpage_certificate failed: %d", ret);
446 privoxy_mutex_unlock(&(certificates_mutexes[cert_mutex_id]));
450 privoxy_mutex_unlock(&(certificates_mutexes[cert_mutex_id]));
463 * Loading CA file, webpage certificate and key files
465 ret = mbedtls_x509_crt_parse_file(&(csp->mbedtls_client_attr.server_cert),
469 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
470 log_error(LOG_LEVEL_ERROR,
471 "Loading webpage certificate %s failed: %s", cert_file, err_buf);
476 ret = mbedtls_x509_crt_parse_file(&(csp->mbedtls_client_attr.server_cert),
480 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
481 log_error(LOG_LEVEL_ERROR,
482 "Loading CA certificate %s failed: %s", ca_file, err_buf);
487 ret = mbedtls_pk_parse_keyfile(&(csp->mbedtls_client_attr.prim_key),
491 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
492 log_error(LOG_LEVEL_ERROR,
493 "Loading and parsing webpage certificate private key %s failed: %s",
500 * Setting SSL parameters
502 ret = mbedtls_ssl_config_defaults(&(csp->mbedtls_client_attr.conf),
503 MBEDTLS_SSL_IS_SERVER, MBEDTLS_SSL_TRANSPORT_STREAM,
504 MBEDTLS_SSL_PRESET_DEFAULT);
507 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
508 log_error(LOG_LEVEL_ERROR,
509 "mbedtls_ssl_config_defaults failed: %s", err_buf);
514 mbedtls_ssl_conf_rng(&(csp->mbedtls_client_attr.conf),
515 mbedtls_ctr_drbg_random, &ctr_drbg);
516 mbedtls_ssl_conf_dbg(&(csp->mbedtls_client_attr.conf),
517 ssl_debug_callback, stdout);
519 #if defined(MBEDTLS_SSL_CACHE_C)
520 mbedtls_ssl_conf_session_cache(&(csp->mbedtls_client_attr.conf),
521 &(csp->mbedtls_client_attr.cache), mbedtls_ssl_cache_get,
522 mbedtls_ssl_cache_set);
526 * Setting certificates
528 ret = mbedtls_ssl_conf_own_cert(&(csp->mbedtls_client_attr.conf),
529 &(csp->mbedtls_client_attr.server_cert),
530 &(csp->mbedtls_client_attr.prim_key));
533 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
534 log_error(LOG_LEVEL_ERROR,
535 "mbedtls_ssl_conf_own_cert failed: %s", err_buf);
540 ret = mbedtls_ssl_setup(&(csp->mbedtls_client_attr.ssl),
541 &(csp->mbedtls_client_attr.conf));
544 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
545 log_error(LOG_LEVEL_ERROR, "mbedtls_ssl_setup failed: %s", err_buf);
550 mbedtls_ssl_set_bio(&(csp->mbedtls_client_attr.ssl),
551 &(csp->mbedtls_client_attr.socket_fd), mbedtls_net_send,
552 mbedtls_net_recv, NULL);
553 mbedtls_ssl_session_reset(&(csp->mbedtls_client_attr.ssl));
556 * Setting socket fd in mbedtls_net_context structure. This structure
557 * can't be set by mbedtls functions, because we already have created
558 * a TCP connection when this function is called.
560 csp->mbedtls_client_attr.socket_fd.fd = csp->cfd;
563 * Handshake with client
565 log_error(LOG_LEVEL_CONNECT,
566 "Performing the TLS/SSL handshake with client. Hash of host: %s",
567 csp->http->hash_of_host_hex);
568 while ((ret = mbedtls_ssl_handshake(&(csp->mbedtls_client_attr.ssl))) != 0)
570 if (ret != MBEDTLS_ERR_SSL_WANT_READ &&
571 ret != MBEDTLS_ERR_SSL_WANT_WRITE)
573 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
574 log_error(LOG_LEVEL_ERROR,
575 "medtls_ssl_handshake with client failed: %s", err_buf);
581 log_error(LOG_LEVEL_CONNECT, "Client successfully connected over TLS/SSL");
582 csp->ssl_with_client_is_opened = 1;
586 * Freeing allocated paths to files
591 /* Freeing structures if connection wasn't created successfully */
594 free_client_ssl_structures(csp);
600 /*********************************************************************
602 * Function : close_client_ssl_connection
604 * Description : Closes TLS/SSL connection with client. This function
605 * checks if this connection is already created.
608 * 1 : csp = Current client state (buffers, headers, etc...)
612 *********************************************************************/
613 extern void close_client_ssl_connection(struct client_state *csp)
617 if (csp->ssl_with_client_is_opened == 0)
623 * Notifying the peer that the connection is being closed.
626 ret = mbedtls_ssl_close_notify(&(csp->mbedtls_client_attr.ssl));
627 } while (ret == MBEDTLS_ERR_SSL_WANT_WRITE);
629 free_client_ssl_structures(csp);
630 csp->ssl_with_client_is_opened = 0;
634 /*********************************************************************
636 * Function : free_client_ssl_structures
638 * Description : Frees structures used for SSL communication with
642 * 1 : csp = Current client state (buffers, headers, etc...)
646 *********************************************************************/
647 static void free_client_ssl_structures(struct client_state *csp)
650 * We can't use function mbedtls_net_free, because this function
651 * inter alia close TCP connection on setted fd. Instead of this
652 * function, we change fd to -1, which is the same what does
653 * rest of mbedtls_net_free function.
655 csp->mbedtls_client_attr.socket_fd.fd = -1;
657 /* Freeing mbedtls structures */
658 mbedtls_x509_crt_free(&(csp->mbedtls_client_attr.server_cert));
659 mbedtls_pk_free(&(csp->mbedtls_client_attr.prim_key));
660 mbedtls_ssl_free(&(csp->mbedtls_client_attr.ssl));
661 mbedtls_ssl_config_free(&(csp->mbedtls_client_attr.conf));
662 #if defined(MBEDTLS_SSL_CACHE_C)
663 mbedtls_ssl_cache_free(&(csp->mbedtls_client_attr.cache));
668 /*********************************************************************
670 * Function : create_server_ssl_connection
672 * Description : Creates TLS/SSL secured connection with server.
675 * 1 : csp = Current client state (buffers, headers, etc...)
677 * Returns : 0 on success, negative value if connection wasn't created
680 *********************************************************************/
681 extern int create_server_ssl_connection(struct client_state *csp)
684 char err_buf[ERROR_BUF_SIZE];
685 char *trusted_cas_file = NULL;
686 int auth_mode = MBEDTLS_SSL_VERIFY_REQUIRED;
688 csp->server_cert_verification_result = SSL_CERT_NOT_VERIFIED;
689 csp->server_certs_chain.next = NULL;
691 /* Setting path to file with trusted CAs */
692 trusted_cas_file = csp->config->trusted_cas_file;
695 * Initializing mbedtls structures for TLS/SSL connection
697 mbedtls_net_init(&(csp->mbedtls_server_attr.socket_fd));
698 mbedtls_ssl_init(&(csp->mbedtls_server_attr.ssl));
699 mbedtls_ssl_config_init(&(csp->mbedtls_server_attr.conf));
700 mbedtls_x509_crt_init(&(csp->mbedtls_server_attr.ca_cert));
703 * Setting socket fd in mbedtls_net_context structure. This structure
704 * can't be set by mbedtls functions, because we already have created
705 * TCP connection when calling this function.
707 csp->mbedtls_server_attr.socket_fd.fd = csp->server_connection.sfd;
720 * Loading file with trusted CAs
722 ret = mbedtls_x509_crt_parse_file(&(csp->mbedtls_server_attr.ca_cert),
726 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
727 log_error(LOG_LEVEL_ERROR, "Loading trusted CAs file %s failed: %s",
728 trusted_cas_file, err_buf);
734 * Set TLS/SSL options
736 ret = mbedtls_ssl_config_defaults(&(csp->mbedtls_server_attr.conf),
737 MBEDTLS_SSL_IS_CLIENT,
738 MBEDTLS_SSL_TRANSPORT_STREAM,
739 MBEDTLS_SSL_PRESET_DEFAULT);
742 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
743 log_error(LOG_LEVEL_ERROR, "mbedtls_ssl_config_defaults failed: %s",
750 * Setting how strict should certificate verification be and other
751 * parameters for certificate verification
753 if (csp->dont_verify_certificate)
755 auth_mode = MBEDTLS_SSL_VERIFY_NONE;
758 mbedtls_ssl_conf_authmode(&(csp->mbedtls_server_attr.conf), auth_mode);
759 mbedtls_ssl_conf_ca_chain(&(csp->mbedtls_server_attr.conf),
760 &(csp->mbedtls_server_attr.ca_cert), NULL);
762 /* Setting callback function for certificates verification */
763 mbedtls_ssl_conf_verify(&(csp->mbedtls_server_attr.conf),
764 ssl_verify_callback, (void *)csp);
766 mbedtls_ssl_conf_rng(&(csp->mbedtls_server_attr.conf),
767 mbedtls_ctr_drbg_random, &ctr_drbg);
768 mbedtls_ssl_conf_dbg(&(csp->mbedtls_server_attr.conf),
769 ssl_debug_callback, stdout);
771 ret = mbedtls_ssl_setup(&(csp->mbedtls_server_attr.ssl),
772 &(csp->mbedtls_server_attr.conf));
775 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
776 log_error(LOG_LEVEL_ERROR, "mbedtls_ssl_setup failed: %s", err_buf);
782 * Set the hostname to check against the received server certificate
784 ret = mbedtls_ssl_set_hostname(&(csp->mbedtls_server_attr.ssl),
788 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
789 log_error(LOG_LEVEL_ERROR, "mbedtls_ssl_set_hostname failed: %s",
795 mbedtls_ssl_set_bio(&(csp->mbedtls_server_attr.ssl),
796 &(csp->mbedtls_server_attr.socket_fd), mbedtls_net_send,
797 mbedtls_net_recv, NULL);
800 * Handshake with server
802 log_error(LOG_LEVEL_CONNECT,
803 "Performing the TLS/SSL handshake with server");
805 while ((ret = mbedtls_ssl_handshake(&(csp->mbedtls_server_attr.ssl))) != 0)
807 if (ret != MBEDTLS_ERR_SSL_WANT_READ
808 && ret != MBEDTLS_ERR_SSL_WANT_WRITE)
810 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
812 if (ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED)
814 log_error(LOG_LEVEL_ERROR,
815 "Server certificate verification failed: %s", err_buf);
816 csp->server_cert_verification_result =
817 mbedtls_ssl_get_verify_result(&(csp->mbedtls_server_attr.ssl));
823 log_error(LOG_LEVEL_ERROR,
824 "mbedtls_ssl_handshake with server failed: %s", err_buf);
831 log_error(LOG_LEVEL_CONNECT, "Server successfully connected over TLS/SSL");
834 * Server certificate chain is valid, so we can clean
835 * chain, because we will not send it to client.
837 free_certificate_chain(csp);
839 csp->ssl_with_server_is_opened = 1;
840 csp->server_cert_verification_result =
841 mbedtls_ssl_get_verify_result(&(csp->mbedtls_server_attr.ssl));
844 /* Freeing structures if connection wasn't created successfully */
847 free_server_ssl_structures(csp);
854 /*********************************************************************
856 * Function : close_server_ssl_connection
858 * Description : Closes TLS/SSL connection with server. This function
859 * checks if this connection is already opened.
862 * 1 : csp = Current client state (buffers, headers, etc...)
866 *********************************************************************/
867 static void close_server_ssl_connection(struct client_state *csp)
871 if (csp->ssl_with_server_is_opened == 0)
877 * Notifying the peer that the connection is being closed.
880 ret = mbedtls_ssl_close_notify(&(csp->mbedtls_server_attr.ssl));
881 } while (ret == MBEDTLS_ERR_SSL_WANT_WRITE);
883 free_server_ssl_structures(csp);
884 csp->ssl_with_server_is_opened = 0;
888 /*********************************************************************
890 * Function : free_server_ssl_structures
892 * Description : Frees structures used for SSL communication with server
895 * 1 : csp = Current client state (buffers, headers, etc...)
899 *********************************************************************/
900 static void free_server_ssl_structures(struct client_state *csp)
903 * We can't use function mbedtls_net_free, because this function
904 * inter alia close TCP connection on setted fd. Instead of this
905 * function, we change fd to -1, which is the same what does
906 * rest of mbedtls_net_free function.
908 csp->mbedtls_client_attr.socket_fd.fd = -1;
910 mbedtls_x509_crt_free(&(csp->mbedtls_server_attr.ca_cert));
911 mbedtls_ssl_free(&(csp->mbedtls_server_attr.ssl));
912 mbedtls_ssl_config_free(&(csp->mbedtls_server_attr.conf));
916 /*********************************************************************
918 * Function : close_client_and_server_ssl_connections
920 * Description : Checks if client or server should use secured
921 * connection over SSL and if so, closes all of them.
924 * 1 : csp = Current client state (buffers, headers, etc...)
928 *********************************************************************/
929 extern void close_client_and_server_ssl_connections(struct client_state *csp)
931 if (client_use_ssl(csp) == 1)
933 close_client_ssl_connection(csp);
935 if (server_use_ssl(csp) == 1)
937 close_server_ssl_connection(csp);
941 /*====================== Certificates ======================*/
943 /*********************************************************************
945 * Function : write_certificate
947 * Description : Writes certificate into file.
950 * 1 : crt = certificate to write into file
951 * 2 : output_file = path to save certificate file
952 * 3 : f_rng = mbedtls_ctr_drbg_random
953 * 4 : p_rng = mbedtls_ctr_drbg_context
955 * Returns : Length of written certificate on success or negative value
958 *********************************************************************/
959 static int write_certificate(mbedtls_x509write_cert *crt, const char *output_file,
960 int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
964 unsigned char cert_buf[CERTIFICATE_BUF_SIZE + 1]; /* Buffer for certificate in PEM format + terminating NULL */
966 char err_buf[ERROR_BUF_SIZE];
968 memset(cert_buf, 0, sizeof(cert_buf));
971 * Writing certificate into PEM string. If buffer is too small, function
972 * returns specific error and no buffer overflow can happen.
974 if ((ret = mbedtls_x509write_crt_pem(crt, cert_buf,
975 sizeof(cert_buf) - 1, f_rng, p_rng)) != 0)
977 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
978 log_error(LOG_LEVEL_ERROR,
979 "Writing certificate into buffer failed: %s", err_buf);
983 len = strlen((char *)cert_buf);
986 * Saving certificate into file
988 if ((f = fopen(output_file, "w")) == NULL)
990 log_error(LOG_LEVEL_ERROR, "Opening file %s to save certificate failed",
995 if (fwrite(cert_buf, 1, len, f) != len)
997 log_error(LOG_LEVEL_ERROR,
998 "Writing certificate into file %s failed", output_file);
1009 /*********************************************************************
1011 * Function : write_private_key
1013 * Description : Writes private key into file and copies saved
1014 * content into given pointer to string. If function
1015 * returns 0 for success, this copy must be freed by
1019 * 1 : key = key to write into file
1020 * 2 : ret_buf = pointer to string with created key file content
1021 * 3 : key_file_path = path where to save key file
1023 * Returns : Length of written private key on success or negative value
1026 *********************************************************************/
1027 static int write_private_key(mbedtls_pk_context *key, unsigned char **ret_buf,
1028 const char *key_file_path)
1030 size_t len = 0; /* Length of created key */
1031 FILE *f = NULL; /* File to save certificate */
1033 char err_buf[ERROR_BUF_SIZE];
1035 /* Initializing buffer for key file content */
1036 *ret_buf = zalloc_or_die(PRIVATE_KEY_BUF_SIZE + 1);
1039 * Writing private key into PEM string
1041 if ((ret = mbedtls_pk_write_key_pem(key, *ret_buf, PRIVATE_KEY_BUF_SIZE)) != 0)
1043 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1044 log_error(LOG_LEVEL_ERROR,
1045 "Writing private key into PEM string failed: %s", err_buf);
1049 len = strlen((char *)*ret_buf);
1052 * Saving key into file
1054 if ((f = fopen(key_file_path, "wb")) == NULL)
1056 log_error(LOG_LEVEL_ERROR,
1057 "Opening file %s to save private key failed: %E",
1063 if (fwrite(*ret_buf, 1, len, f) != len)
1066 log_error(LOG_LEVEL_ERROR,
1067 "Writing private key into file %s failed",
1086 /*********************************************************************
1088 * Function : generate_key
1090 * Description : Tests if private key for host saved in csp already
1091 * exists. If this file doesn't exists, a new key is
1092 * generated and saved in a file. The generated key is also
1093 * copied into given parameter key_buf, which must be then
1094 * freed by caller. If file with key exists, key_buf
1095 * contain NULL and no private key is generated.
1098 * 1 : csp = Current client state (buffers, headers, etc...)
1099 * 2 : key_buf = buffer to save new generated key
1101 * Returns : -1 => Error while generating private key
1102 * 0 => Key already exists
1103 * >0 => Length of generated private key
1105 *********************************************************************/
1106 static int generate_key(struct client_state *csp, unsigned char **key_buf)
1108 mbedtls_pk_context key;
1109 key_options key_opt;
1111 char err_buf[ERROR_BUF_SIZE];
1113 key_opt.key_file_path = NULL;
1116 * Initializing structures for key generating
1118 mbedtls_pk_init(&key);
1121 * Preparing path for key file and other properties for generating key
1123 key_opt.type = MBEDTLS_PK_RSA;
1124 key_opt.rsa_keysize = RSA_KEYSIZE;
1126 key_opt.key_file_path = make_certs_path(csp->config->certificate_directory,
1127 (char *)csp->http->hash_of_host_hex, KEY_FILE_TYPE);
1128 if (key_opt.key_file_path == NULL)
1135 * Test if key already exists. If so, we don't have to create it again.
1137 if (file_exists(key_opt.key_file_path) == 1)
1146 ret = seed_rng(csp);
1154 * Setting attributes of private key and generating it
1156 if ((ret = mbedtls_pk_setup(&key,
1157 mbedtls_pk_info_from_type(key_opt.type))) != 0)
1159 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1160 log_error(LOG_LEVEL_ERROR, "mbedtls_pk_setup failed: %s", err_buf);
1165 ret = mbedtls_rsa_gen_key(mbedtls_pk_rsa(key), mbedtls_ctr_drbg_random,
1166 &ctr_drbg, (unsigned)key_opt.rsa_keysize, RSA_KEY_PUBLIC_EXPONENT);
1169 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1170 log_error(LOG_LEVEL_ERROR, "Key generating failed: %s", err_buf);
1176 * Exporting private key into file
1178 if ((ret = write_private_key(&key, key_buf, key_opt.key_file_path)) < 0)
1180 log_error(LOG_LEVEL_ERROR,
1181 "Writing private key into file %s failed", key_opt.key_file_path);
1188 * Freeing used variables
1190 freez(key_opt.key_file_path);
1192 mbedtls_pk_free(&key);
1198 /*********************************************************************
1200 * Function : generate_webpage_certificate
1202 * Description : Creates certificate file in presetted directory.
1203 * If certificate already exists, no other certificate
1204 * will be created. Subject of certificate is named
1205 * by csp->http->host from parameter. This function also
1206 * triggers generating of private key for new certificate.
1209 * 1 : csp = Current client state (buffers, headers, etc...)
1211 * Returns : -1 => Error while creating certificate.
1212 * 0 => Certificate already exists.
1213 * >0 => Length of created certificate.
1215 *********************************************************************/
1216 static int generate_webpage_certificate(struct client_state *csp)
1218 mbedtls_x509_crt issuer_cert;
1219 mbedtls_pk_context loaded_issuer_key, loaded_subject_key;
1220 mbedtls_pk_context *issuer_key = &loaded_issuer_key;
1221 mbedtls_pk_context *subject_key = &loaded_subject_key;
1222 mbedtls_x509write_cert cert;
1225 unsigned char *key_buf = NULL; /* Buffer for created key */
1228 char err_buf[ERROR_BUF_SIZE];
1229 cert_options cert_opt;
1231 /* Paths to keys and certificates needed to create certificate */
1232 cert_opt.issuer_key = NULL;
1233 cert_opt.subject_key = NULL;
1234 cert_opt.issuer_crt = NULL;
1235 cert_opt.output_file = NULL;
1238 * Create key for requested host
1240 int subject_key_len = generate_key(csp, &key_buf);
1241 if (subject_key_len < 0)
1243 log_error(LOG_LEVEL_ERROR, "Key generating failed");
1248 * Initializing structures for certificate generating
1250 mbedtls_x509write_crt_init(&cert);
1251 mbedtls_x509write_crt_set_md_alg(&cert, CERT_SIGNATURE_ALGORITHM);
1252 mbedtls_pk_init(&loaded_issuer_key);
1253 mbedtls_pk_init(&loaded_subject_key);
1254 mbedtls_mpi_init(&serial);
1255 mbedtls_x509_crt_init(&issuer_cert);
1258 * Presetting parameters for certificate. We must compute total length
1261 size_t cert_params_len = strlen(CERT_PARAM_COMMON_NAME) +
1262 strlen(CERT_PARAM_ORGANIZATION) + strlen(CERT_PARAM_COUNTRY) +
1263 strlen(CERT_PARAM_ORG_UNIT) +
1264 3 * strlen(csp->http->host) + 1;
1265 char cert_params[cert_params_len];
1266 memset(cert_params, 0, cert_params_len);
1269 * Converting unsigned long serial number to char * serial number.
1270 * We must compute length of serial number in string + terminating null.
1272 unsigned long certificate_serial = get_certificate_serial(csp);
1273 int serial_num_size = snprintf(NULL, 0, "%lu", certificate_serial) + 1;
1274 if (serial_num_size <= 0)
1276 serial_num_size = 1;
1279 char serial_num_text[serial_num_size]; /* Buffer for serial number */
1280 ret = snprintf(serial_num_text, (size_t)serial_num_size, "%lu", certificate_serial);
1281 if (ret < 0 || ret >= serial_num_size)
1283 log_error(LOG_LEVEL_ERROR,
1284 "Converting certificate serial number into string failed");
1290 * Preparing parameters for certificate
1292 strlcpy(cert_params, CERT_PARAM_COMMON_NAME, cert_params_len);
1293 strlcat(cert_params, csp->http->host, cert_params_len);
1294 strlcat(cert_params, CERT_PARAM_ORGANIZATION, cert_params_len);
1295 strlcat(cert_params, csp->http->host, cert_params_len);
1296 strlcat(cert_params, CERT_PARAM_ORG_UNIT, cert_params_len);
1297 strlcat(cert_params, csp->http->host, cert_params_len);
1298 strlcat(cert_params, CERT_PARAM_COUNTRY, cert_params_len);
1300 cert_opt.issuer_crt = csp->config->ca_cert_file;
1301 cert_opt.issuer_key = csp->config->ca_key_file;
1302 cert_opt.subject_key = make_certs_path(csp->config->certificate_directory,
1303 (const char *)csp->http->hash_of_host_hex, KEY_FILE_TYPE);
1304 cert_opt.output_file = make_certs_path(csp->config->certificate_directory,
1305 (const char *)csp->http->hash_of_host_hex, CERT_FILE_TYPE);
1307 if (cert_opt.subject_key == NULL || cert_opt.output_file == NULL)
1313 cert_opt.subject_pwd = CERT_SUBJECT_PASSWORD;
1314 cert_opt.issuer_pwd = csp->config->ca_password;
1315 cert_opt.subject_name = cert_params;
1316 cert_opt.not_before = GENERATED_CERT_VALID_FROM;
1317 cert_opt.not_after = GENERATED_CERT_VALID_TO;
1318 cert_opt.serial = serial_num_text;
1320 cert_opt.max_pathlen = -1;
1323 * Test if certificate exists and private key was already created
1325 if (file_exists(cert_opt.output_file) == 1 && subject_key_len == 0)
1334 ret = seed_rng(csp);
1342 * Parse serial to MPI
1344 ret = mbedtls_mpi_read_string(&serial, 10, cert_opt.serial);
1347 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1348 log_error(LOG_LEVEL_ERROR,
1349 "mbedtls_mpi_read_string failed: %s", err_buf);
1355 * Loading certificates
1357 ret = mbedtls_x509_crt_parse_file(&issuer_cert, cert_opt.issuer_crt);
1360 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1361 log_error(LOG_LEVEL_ERROR, "Loading issuer certificate %s failed: %s",
1362 cert_opt.issuer_crt, err_buf);
1367 ret = mbedtls_x509_dn_gets(cert_opt.issuer_name,
1368 sizeof(cert_opt.issuer_name), &issuer_cert.subject);
1371 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1372 log_error(LOG_LEVEL_ERROR, "mbedtls_x509_dn_gets failed: %s", err_buf);
1378 * Loading keys from file or from buffer
1380 if (key_buf != NULL && subject_key_len > 0)
1382 /* Key was created in this function and is stored in buffer */
1383 ret = mbedtls_pk_parse_key(&loaded_subject_key, key_buf,
1384 (size_t)(subject_key_len + 1), (unsigned const char *)
1385 cert_opt.subject_pwd, strlen(cert_opt.subject_pwd));
1389 /* Key wasn't created in this function, because it already existed */
1390 ret = mbedtls_pk_parse_keyfile(&loaded_subject_key,
1391 cert_opt.subject_key, cert_opt.subject_pwd);
1396 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1397 log_error(LOG_LEVEL_ERROR, "Parsing subject key %s failed: %s",
1398 cert_opt.subject_key, err_buf);
1403 ret = mbedtls_pk_parse_keyfile(&loaded_issuer_key, cert_opt.issuer_key,
1404 cert_opt.issuer_pwd);
1407 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1408 log_error(LOG_LEVEL_ERROR,
1409 "Parsing issuer key %s failed: %s", cert_opt.issuer_key, err_buf);
1415 * Check if key and issuer certificate match
1417 if (!mbedtls_pk_can_do(&issuer_cert.pk, MBEDTLS_PK_RSA) ||
1418 mbedtls_mpi_cmp_mpi(&mbedtls_pk_rsa(issuer_cert.pk)->N,
1419 &mbedtls_pk_rsa(*issuer_key)->N) != 0 ||
1420 mbedtls_mpi_cmp_mpi(&mbedtls_pk_rsa(issuer_cert.pk)->E,
1421 &mbedtls_pk_rsa(*issuer_key)->E) != 0)
1423 log_error(LOG_LEVEL_ERROR,
1424 "Issuer key doesn't match issuer certificate");
1429 mbedtls_x509write_crt_set_subject_key(&cert, subject_key);
1430 mbedtls_x509write_crt_set_issuer_key(&cert, issuer_key);
1433 * Setting parameters of signed certificate
1435 ret = mbedtls_x509write_crt_set_subject_name(&cert, cert_opt.subject_name);
1438 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1439 log_error(LOG_LEVEL_ERROR,
1440 "Setting subject name in signed certificate failed: %s", err_buf);
1445 ret = mbedtls_x509write_crt_set_issuer_name(&cert, cert_opt.issuer_name);
1448 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1449 log_error(LOG_LEVEL_ERROR,
1450 "Setting issuer name in signed certificate failed: %s", err_buf);
1455 ret = mbedtls_x509write_crt_set_serial(&cert, &serial);
1458 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1459 log_error(LOG_LEVEL_ERROR,
1460 "Setting serial number in signed certificate failed: %s", err_buf);
1465 ret = mbedtls_x509write_crt_set_validity(&cert, cert_opt.not_before,
1466 cert_opt.not_after);
1469 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1470 log_error(LOG_LEVEL_ERROR,
1471 "Setting validity in signed certificate failed: %s", err_buf);
1477 * Setting the basicConstraints extension for certificate
1479 ret = mbedtls_x509write_crt_set_basic_constraints(&cert, cert_opt.is_ca,
1480 cert_opt.max_pathlen);
1483 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1484 log_error(LOG_LEVEL_ERROR, "Setting the basicConstraints extension "
1485 "in signed certificate failed: %s", err_buf);
1490 #if defined(MBEDTLS_SHA1_C)
1491 /* Setting the subjectKeyIdentifier extension for certificate */
1492 ret = mbedtls_x509write_crt_set_subject_key_identifier(&cert);
1495 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1496 log_error(LOG_LEVEL_ERROR, "mbedtls_x509write_crt_set_subject_key_"
1497 "identifier failed: %s", err_buf);
1502 /* Setting the authorityKeyIdentifier extension for certificate */
1503 ret = mbedtls_x509write_crt_set_authority_key_identifier(&cert);
1506 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
1507 log_error(LOG_LEVEL_ERROR, "mbedtls_x509write_crt_set_authority_key_"
1508 "identifier failed: %s", err_buf);
1512 #endif /* MBEDTLS_SHA1_C */
1515 * Writing certificate into file
1517 ret = write_certificate(&cert, cert_opt.output_file,
1518 mbedtls_ctr_drbg_random, &ctr_drbg);
1521 log_error(LOG_LEVEL_ERROR, "Writing certificate into file failed");
1527 * Freeing used structures
1529 mbedtls_x509write_crt_free(&cert);
1530 mbedtls_pk_free(&loaded_subject_key);
1531 mbedtls_pk_free(&loaded_issuer_key);
1532 mbedtls_mpi_free(&serial);
1533 mbedtls_x509_crt_free(&issuer_cert);
1535 freez(cert_opt.subject_key);
1536 freez(cert_opt.output_file);
1543 /*********************************************************************
1545 * Function : make_certs_path
1547 * Description : Creates path to file from three pieces. This function
1548 * takes parameters and puts them in one new mallocated
1549 * char * in correct order. Returned variable must be freed
1550 * by caller. This function is mainly used for creating
1551 * paths of certificates and keys files.
1554 * 1 : conf_dir = Name/path of directory where is the file.
1555 * '.' can be used for current directory.
1556 * 2 : file_name = Name of file in conf_dir without suffix.
1557 * 3 : suffix = Suffix of given file_name.
1559 * Returns : path => Path was built up successfully
1560 * NULL => Path can't be built up
1562 *********************************************************************/
1563 static char *make_certs_path(const char *conf_dir, const char *file_name,
1566 /* Test if all given parameters are valid */
1567 if (conf_dir == NULL || *conf_dir == '\0' || file_name == NULL ||
1568 *file_name == '\0' || suffix == NULL || *suffix == '\0')
1570 log_error(LOG_LEVEL_ERROR,
1571 "make_certs_path failed: bad input parameters");
1576 size_t path_size = strlen(conf_dir)
1577 + strlen(file_name) + strlen(suffix) + 2;
1579 /* Setting delimiter and editing path length */
1580 #if defined(_WIN32) || defined(__OS2__)
1581 char delim[] = "\\";
1583 #else /* ifndef _WIN32 || __OS2__ */
1585 #endif /* ifndef _WIN32 || __OS2__ */
1588 * Building up path from many parts
1591 if (*conf_dir != '/' && basedir && *basedir)
1594 * Replacing conf_dir with basedir. This new variable contains
1595 * absolute path to cwd.
1597 path_size += strlen(basedir) + 2;
1598 path = zalloc_or_die(path_size);
1600 strlcpy(path, basedir, path_size);
1601 strlcat(path, delim, path_size);
1602 strlcat(path, conf_dir, path_size);
1603 strlcat(path, delim, path_size);
1604 strlcat(path, file_name, path_size);
1605 strlcat(path, suffix, path_size);
1608 #endif /* defined unix */
1610 path = zalloc_or_die(path_size);
1612 strlcpy(path, conf_dir, path_size);
1613 strlcat(path, delim, path_size);
1614 strlcat(path, file_name, path_size);
1615 strlcat(path, suffix, path_size);
1622 /*********************************************************************
1624 * Function : get_certificate_mutex_id
1626 * Description : Computes mutex id from host name hash. This hash must
1627 * be already saved in csp structure
1630 * 1 : csp = Current client state (buffers, headers, etc...)
1632 * Returns : Mutex id for given host name
1634 *********************************************************************/
1635 static unsigned int get_certificate_mutex_id(struct client_state *csp) {
1636 #ifdef LIMIT_MUTEX_NUMBER
1637 return (unsigned int)(csp->http->hash_of_host[0] % 32);
1639 return (unsigned int)(csp->http->hash_of_host[1]
1640 + 256 * (int)csp->http->hash_of_host[0]);
1641 #endif /* LIMIT_MUTEX_NUMBER */
1645 /*********************************************************************
1647 * Function : get_certificate_serial
1649 * Description : Computes serial number for new certificate from host
1650 * name hash. This hash must be already saved in csp
1654 * 1 : csp = Current client state (buffers, headers, etc...)
1656 * Returns : Serial number for new certificate
1658 *********************************************************************/
1659 static unsigned long get_certificate_serial(struct client_state *csp) {
1660 unsigned long exp = 1;
1661 unsigned long serial = 0;
1663 int i = CERT_SERIAL_NUM_LENGTH;
1664 /* Length of hash is 16 bytes, we must avoid to read next chars */
1676 serial += exp * (unsigned)csp->http->hash_of_host[i];
1683 /*********************************************************************
1685 * Function : ssl_send_certificate_error
1687 * Description : Sends info about invalid server certificate to client.
1688 * Sent message is including all trusted chain certificates,
1689 * that can be downloaded in web browser.
1692 * 1 : csp = Current client state (buffers, headers, etc...)
1696 *********************************************************************/
1697 extern void ssl_send_certificate_error(struct client_state *csp)
1699 size_t message_len = 0;
1701 struct certs_chain *cert = NULL;
1703 /* Header of message with certificate informations */
1704 const char message_begin[] =
1705 "HTTP/1.1 200 OK\r\n"
1706 "Content-Type: text/html\r\n"
1707 "Connection: close\r\n\r\n"
1708 "<html><body><h1>Invalid server certificate</h1><p>Reason: ";
1709 const char message_end[] = "</body></html>\r\n\r\n";
1710 char reason[INVALID_CERT_INFO_BUF_SIZE];
1711 memset(reason, 0, sizeof(reason));
1713 /* Get verification message from verification return code */
1714 mbedtls_x509_crt_verify_info(reason, sizeof(reason), " ",
1715 csp->server_cert_verification_result);
1718 * Computing total length of message with all certificates inside
1720 message_len = strlen(message_begin) + strlen(message_end)
1721 + strlen(reason) + strlen("</p>") + 1;
1723 cert = &(csp->server_certs_chain);
1724 while (cert->next != NULL)
1726 size_t base64_len = 4 * ((strlen(cert->file_buf) + 2) / 3) + 1;
1728 message_len += strlen(cert->text_buf) + strlen("<pre></pre>\n")
1729 + base64_len + strlen("<a href=\"data:application"
1730 "/x-x509-ca-cert;base64,\">Download certificate</a>");
1735 * Joining all blocks in one long message
1737 char message[message_len];
1738 memset(message, 0, message_len);
1740 strlcpy(message, message_begin, message_len);
1741 strlcat(message, reason , message_len);
1742 strlcat(message, "</p>" , message_len);
1744 cert = &(csp->server_certs_chain);
1745 while (cert->next != NULL)
1748 size_t base64_len = 4 * ((strlen(cert->file_buf) + 2) / 3) + 1; /* +1 for terminating null*/
1749 char base64_buf[base64_len];
1750 memset(base64_buf, 0, base64_len);
1752 /* Encoding certificate into base64 code */
1753 ret = mbedtls_base64_encode((unsigned char*)base64_buf,
1754 base64_len, &olen, (const unsigned char*)cert->file_buf,
1755 strlen(cert->file_buf));
1758 log_error(LOG_LEVEL_ERROR,
1759 "Encoding to base64 failed, buffer is to small");
1762 strlcat(message, "<pre>", message_len);
1763 strlcat(message, cert->text_buf, message_len);
1764 strlcat(message, "</pre>\n", message_len);
1768 strlcat(message, "<a href=\"data:application/x-x509-ca-cert;base64,",
1770 strlcat(message, base64_buf, message_len);
1771 strlcat(message, "\">Download certificate</a>", message_len);
1776 strlcat(message, message_end, message_len);
1779 * Sending final message to client
1781 ssl_send_data(&(csp->mbedtls_client_attr.ssl),
1782 (const unsigned char *)message, strlen(message));
1784 * Waiting before closing connection. Some browsers don't show received
1785 * message if there isn't this delay.
1789 free_certificate_chain(csp);
1793 /*********************************************************************
1795 * Function : ssl_verify_callback
1797 * Description : This is a callback function for certificate verification.
1798 * It's called for all certificates in server certificate
1799 * trusted chain and it's preparing information about this
1800 * certificates. Prepared informations can be used to inform
1801 * user about invalid certificates.
1804 * 1 : csp_void = Current client state (buffers, headers, etc...)
1805 * 2 : crt = certificate from trusted chain
1806 * 3 : depth = depth in trusted chain
1807 * 4 : flags = certificate flags
1809 * Returns : 0 on success and negative value on error
1811 *********************************************************************/
1812 static int ssl_verify_callback(void *csp_void, mbedtls_x509_crt *crt,
1813 int depth, uint32_t *flags)
1815 struct client_state *csp = (struct client_state *)csp_void;
1816 struct certs_chain *last = &(csp->server_certs_chain);
1821 * Searching for last item in certificates linked list
1823 while (last->next != NULL)
1829 * Preparing next item in linked list for next certificate
1831 last->next = malloc_or_die(sizeof(struct certs_chain));
1832 last->next->next = NULL;
1833 memset(last->next->text_buf, 0, sizeof(last->next->text_buf));
1834 memset(last->next->file_buf, 0, sizeof(last->next->file_buf));
1837 * Saving certificate file into buffer
1839 if ((ret = mbedtls_pem_write_buffer(PEM_BEGIN_CRT, PEM_END_CRT,
1840 crt->raw.p, crt->raw.len, (unsigned char *)last->file_buf,
1841 sizeof(last->file_buf)-1, &olen)) != 0)
1847 * Saving certificate information into buffer
1849 mbedtls_x509_crt_info(last->text_buf, sizeof(last->text_buf) - 1,
1850 CERT_INFO_PREFIX, crt);
1856 /*********************************************************************
1858 * Function : free_certificate_chain
1860 * Description : Frees certificates linked list. This linked list is
1861 * used to save informations about certificates in
1865 * 1 : csp = Current client state (buffers, headers, etc...)
1869 *********************************************************************/
1870 static void free_certificate_chain(struct client_state *csp)
1872 struct certs_chain *cert = csp->server_certs_chain.next;
1874 /* Cleaning buffers */
1875 memset(csp->server_certs_chain.text_buf, 0,
1876 sizeof(csp->server_certs_chain.text_buf));
1877 memset(csp->server_certs_chain.file_buf, 0,
1878 sizeof(csp->server_certs_chain.file_buf));
1879 csp->server_certs_chain.next = NULL;
1881 /* Freeing memory in whole linked list */
1886 struct certs_chain *cert_for_free = cert;
1888 freez(cert_for_free);
1889 } while (cert != NULL);
1894 /*********************************************************************
1896 * Function : file_exists
1898 * Description : Tests if file exists and is readable.
1901 * 1 : path = Path to tested file.
1903 * Returns : 1 => File exists and is readable.
1904 * 0 => File doesn't exist or is not readable.
1906 *********************************************************************/
1907 static int file_exists(const char *path)
1910 if ((f = fopen(path, "r")) != NULL)
1920 /*********************************************************************
1922 * Function : host_to_hash
1924 * Description : Creates MD5 hash from host name. Host name is loaded
1925 * from structure csp and saved again into it.
1928 * 1 : csp = Current client state (buffers, headers, etc...)
1930 * Returns : 1 => Error while creating hash
1931 * 0 => Hash created successfully
1933 *********************************************************************/
1934 static int host_to_hash(struct client_state *csp)
1938 #if !defined(MBEDTLS_MD5_C)
1939 log_error(LOG_LEVEL_ERROR, "MBEDTLS_MD5_C is not defined. Can't create"
1940 "MD5 hash for certificate and key name.");
1943 memset(csp->http->hash_of_host, 0, sizeof(csp->http->hash_of_host));
1944 mbedtls_md5((unsigned char *)csp->http->host, strlen(csp->http->host),
1945 csp->http->hash_of_host);
1947 /* Converting hash into string with hex */
1951 if ((ret = sprintf((char *)csp->http->hash_of_host_hex + 2 * i, "%02x",
1952 csp->http->hash_of_host[i])) < 0)
1954 log_error(LOG_LEVEL_ERROR, "Sprintf return value: %d", ret);
1960 #endif /* MBEDTLS_MD5_C */
1964 /*********************************************************************
1966 * Function : tunnel_established_successfully
1968 * Description : Check if parent proxy server response contains
1969 * informations about successfully created connection with
1970 * destination server. (HTTP/... 2xx ...)
1973 * 1 : server_response = Buffer with parent proxy server response
1974 * 2 : response_len = Length of server_response
1976 * Returns : 1 => Connection created successfully
1977 * 0 => Connection wasn't created successfully
1979 *********************************************************************/
1980 extern int tunnel_established_successfully(const char *server_response,
1981 unsigned int response_len)
1983 unsigned int pos = 0;
1985 if (server_response == NULL)
1990 /* Tests if "HTTP/" string is at the begin of received response */
1991 if (strncmp(server_response, "HTTP/", 5) != 0)
1996 for (pos = 0; pos < response_len; pos++)
1998 if (server_response[pos] == ' ')
2005 * response_len -3 because of buffer end, response structure and 200 code.
2006 * There must be at least 3 chars after space.
2007 * End of buffer: ... 2xx'\0'
2010 if (pos >= (response_len - 3))
2015 /* Test HTTP status code */
2016 if (server_response[pos + 1] != '2')
2025 /*********************************************************************
2027 * Function : seed_rng
2029 * Description : Seeding the RNG for all SSL uses
2032 * 1 : csp = Current client state (buffers, headers, etc...)
2034 * Returns : -1 => RNG wasn't seed successfully
2035 * 0 => RNG is seeded successfully
2037 *********************************************************************/
2038 static int seed_rng(struct client_state *csp)
2041 char err_buf[ERROR_BUF_SIZE];
2043 if (rng_seeded == 0)
2045 privoxy_mutex_lock(&rng_mutex);
2046 if (rng_seeded == 0)
2048 mbedtls_ctr_drbg_init(&ctr_drbg);
2049 mbedtls_entropy_init(&entropy);
2050 ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func,
2054 mbedtls_strerror(ret, err_buf, sizeof(err_buf));
2055 log_error(LOG_LEVEL_ERROR,
2056 "mbedtls_ctr_drbg_seed failed: %s", err_buf);
2057 privoxy_mutex_unlock(&rng_mutex);
2062 privoxy_mutex_unlock(&rng_mutex);