2 * Functions in this module handle SSL encryption when WebCit is running
5 * Copyright (c) 1996-2018 by the citadel.org team
7 * This program is open source software. You can redistribute it and/or
8 * modify it under the terms of the GNU General Public License, version 3.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
18 SSL_CTX *ssl_ctx; /* SSL context */
19 pthread_mutex_t **SSLCritters; /* Things needing locking */
20 char *ssl_cipher_list = DEFAULT_SSL_CIPHER_LIST;
21 void ssl_lock(int mode, int n, const char *file, int line);
25 * OpenSSL wants a callback function to identify the currently running thread.
26 * Since we are a pthreads program, we convert the output of pthread_self() to a long.
28 static unsigned long id_callback(void)
30 return (unsigned long) pthread_self();
35 * OpenSSL wants a callback function to set and clear various types of locks.
36 * Since we are a pthreads program, we use mutexes.
38 void ssl_lock(int mode, int n, const char *file, int line)
40 if (mode & CRYPTO_LOCK) {
41 pthread_mutex_lock(SSLCritters[n]);
44 pthread_mutex_unlock(SSLCritters[n]);
50 * Generate a private key for SSL
52 void generate_key(char *keyfilename)
58 unsigned long e = RSA_F4;
61 if (access(keyfilename, R_OK) == 0)
66 syslog(LOG_INFO, "crypto: generating RSA key pair");
70 ret = BN_set_word(bne,e);
77 ret = RSA_generate_key_ex(rsa, bits, bne, NULL);
84 fp = fopen(keyfilename, "w");
87 chmod(keyfilename, 0600);
88 if (PEM_write_RSAPrivateKey(fp, /* the file */
91 NULL, /* no passphr */
97 syslog(LOG_ERR, "crypto: cannot write key: %s", ERR_reason_error_string(ERR_get_error()));
111 * Initialize ssl engine, load certs and initialize openssl internals
115 const SSL_METHOD *ssl_method;
117 X509_REQ *req = NULL;
120 EVP_PKEY *req_pkey = NULL;
121 X509_NAME *name = NULL;
126 SSLCritters = malloc(CRYPTO_num_locks() * sizeof(pthread_mutex_t *));
129 syslog(LOG_ERR, "citserver: can't allocate memory!!");
135 for (a = 0; a < CRYPTO_num_locks(); a++)
137 SSLCritters[a] = malloc(sizeof(pthread_mutex_t));
140 syslog(LOG_INFO, "citserver: can't allocate memory!!");
143 pthread_mutex_init(SSLCritters[a], NULL);
148 * Initialize SSL transport layer
151 SSL_load_error_strings();
152 ssl_method = SSLv23_server_method();
153 if (!(ssl_ctx = SSL_CTX_new(ssl_method)))
155 syslog(LOG_WARNING, "SSL_CTX_new failed: %s", ERR_reason_error_string(ERR_get_error()));
159 syslog(LOG_INFO, "Requesting cipher list: %s", ssl_cipher_list);
160 if (!(SSL_CTX_set_cipher_list(ssl_ctx, ssl_cipher_list)))
162 syslog(LOG_WARNING, "SSL_CTX_set_cipher_list failed: %s", ERR_reason_error_string(ERR_get_error()));
166 CRYPTO_set_locking_callback(ssl_lock);
167 CRYPTO_set_id_callback(id_callback);
170 * Get our certificates in order.
171 * First, create the key/cert directory if it's not there already...
173 mkdir(CTDL_CRYPTO_DIR, 0700);
176 * If we still don't have a private key, generate one.
178 generate_key(CTDL_KEY_PATH);
181 * If there is no certificate file on disk, we will be generating a self-signed certificate
182 * in the next step. Therefore, if we have neither a CSR nor a certificate, generate
183 * the CSR in this step so that the next step may commence.
185 if ( (access(CTDL_CER_PATH, R_OK) != 0) && (access(CTDL_CSR_PATH, R_OK) != 0) )
187 syslog(LOG_INFO, "Generating a certificate signing request.");
190 * Read our key from the file. No, we don't just keep this
191 * in memory from the above key-generation function, because
192 * there is the possibility that the key was already on disk
193 * and we didn't just generate it now.
195 fp = fopen(CTDL_KEY_PATH, "r");
198 rsa = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
204 /* Create a public key from the private key */
205 if (pk=EVP_PKEY_new(), pk != NULL)
207 EVP_PKEY_assign_RSA(pk, rsa);
208 if (req = X509_REQ_new(), req != NULL)
211 /* Set the public key */
212 X509_REQ_set_pubkey(req, pk);
213 X509_REQ_set_version(req, 0L);
214 name = X509_REQ_get_subject_name(req);
215 X509_NAME_add_entry_by_txt(
216 name, "O", MBSTRING_ASC,
217 (unsigned char*)"Citadel Server",
220 X509_NAME_add_entry_by_txt(
221 name, "OU", MBSTRING_ASC,
222 (unsigned char*)"Default Certificate PLEASE CHANGE",
225 X509_NAME_add_entry_by_txt(
232 X509_REQ_set_subject_name(req, name);
235 if (!X509_REQ_sign(req, pk, EVP_md5()))
237 syslog(LOG_WARNING, "X509_REQ_sign(): error");
241 /* Write it to disk. */
242 fp = fopen(CTDL_CSR_PATH, "w");
245 chmod(CTDL_CSR_PATH, 0600);
246 PEM_write_X509_REQ(fp, req);
251 syslog(LOG_WARNING, "Cannot write key: %s", CTDL_CSR_PATH);
262 syslog(LOG_WARNING, "Unable to read private key.");
267 * Generate a self-signed certificate if we don't have one.
269 if (access(CTDL_CER_PATH, R_OK) != 0)
271 syslog(LOG_INFO, "Generating a self-signed certificate.");
273 /* Same deal as before: always read the key from disk because
274 * it may or may not have just been generated.
276 fp = fopen(CTDL_KEY_PATH, "r");
279 rsa = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
283 /* This also holds true for the CSR. */
289 if (pk=EVP_PKEY_new(), pk != NULL)
291 EVP_PKEY_assign_RSA(pk, rsa);
294 fp = fopen(CTDL_CSR_PATH, "r");
297 req = PEM_read_X509_REQ(fp, NULL, NULL, NULL);
303 if (cer = X509_new(), cer != NULL)
305 ASN1_INTEGER_set(X509_get_serialNumber(cer), 0);
306 X509_set_issuer_name(cer, X509_REQ_get_subject_name(req));
307 X509_set_subject_name(cer, X509_REQ_get_subject_name(req));
308 X509_gmtime_adj(X509_get_notBefore(cer), 0);
309 X509_gmtime_adj(X509_get_notAfter(cer),(long)60*60*24*SIGN_DAYS);
311 req_pkey = X509_REQ_get_pubkey(req);
312 X509_set_pubkey(cer, req_pkey);
313 EVP_PKEY_free(req_pkey);
316 if (!X509_sign(cer, pk, EVP_md5()))
318 syslog(LOG_WARNING, "X509_sign(): error");
321 { /* Write it to disk. */
322 fp = fopen(CTDL_CER_PATH, "w");
325 chmod(CTDL_CER_PATH, 0600);
326 PEM_write_X509(fp, cer);
331 syslog(LOG_WARNING, "Cannot write key: %s", CTDL_CER_PATH);
343 * Now try to bind to the key and certificate.
344 * Note that we use SSL_CTX_use_certificate_chain_file() which allows
345 * the certificate file to contain intermediate certificates.
347 SSL_CTX_use_certificate_chain_file(ssl_ctx, CTDL_CER_PATH);
348 SSL_CTX_use_PrivateKey_file(ssl_ctx, CTDL_KEY_PATH, SSL_FILETYPE_PEM);
349 if ( !SSL_CTX_check_private_key(ssl_ctx) )
351 syslog(LOG_WARNING, "Cannot install certificate: %s", ERR_reason_error_string(ERR_get_error()));
358 * starts SSL/TLS encryption for the current session.
360 void starttls(struct client_handle *ch)
362 int retval, bits, alg_bits;
368 if (!(ch->ssl_handle = SSL_new(ssl_ctx)))
370 syslog(LOG_WARNING, "SSL_new failed: %s", ERR_reason_error_string(ERR_get_error()));
373 if (!(SSL_set_fd(ch->ssl_handle, ch->sock)))
375 syslog(LOG_WARNING, "SSL_set_fd failed: %s", ERR_reason_error_string(ERR_get_error()));
376 SSL_free(ch->ssl_handle);
379 retval = SSL_accept(ch->ssl_handle);
383 const char *ssl_error_reason = NULL;
385 errval = SSL_get_error(ch->ssl_handle, retval);
386 ssl_error_reason = ERR_reason_error_string(ERR_get_error());
387 if (ssl_error_reason == NULL)
389 syslog(LOG_WARNING, "SSL_accept failed: errval=%ld, retval=%d %s", errval, retval, strerror(errval));
393 syslog(LOG_WARNING, "SSL_accept failed: %s\n", ssl_error_reason);
396 retval = SSL_accept(ch->ssl_handle);
401 const char *ssl_error_reason = NULL;
403 errval = SSL_get_error(ch->ssl_handle, retval);
404 ssl_error_reason = ERR_reason_error_string(ERR_get_error());
405 if (ssl_error_reason == NULL)
407 syslog(LOG_WARNING, "SSL_accept failed: errval=%ld, retval=%d (%s)", errval, retval, strerror(errval));
411 syslog(LOG_WARNING, "SSL_accept failed: %s", ssl_error_reason);
413 SSL_free(ch->ssl_handle);
414 ch->ssl_handle = NULL;
419 syslog(LOG_INFO, "SSL_accept success");
421 bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(ch->ssl_handle), &alg_bits);
422 syslog(LOG_INFO, "SSL/TLS using %s on %s (%d of %d bits)",
423 SSL_CIPHER_get_name(SSL_get_current_cipher(ch->ssl_handle)),
424 SSL_CIPHER_get_version(SSL_get_current_cipher(ch->ssl_handle)),
427 syslog(LOG_INFO, "SSL started");
432 * shuts down the TLS connection
434 void endtls(struct client_handle *ch)
436 syslog(LOG_INFO, "Ending SSL/TLS");
437 if (ch->ssl_handle != NULL)
439 SSL_shutdown(ch->ssl_handle);
440 SSL_get_SSL_CTX(ch->ssl_handle);
441 SSL_free(ch->ssl_handle);
443 ch->ssl_handle = NULL;
448 * Send binary data to the client encrypted.
450 int client_write_ssl(struct client_handle *ch, char *buf, int nbytes)
456 if (ch->ssl_handle == NULL) return(-1);
461 if (SSL_want_write(ch->ssl_handle))
463 if ((SSL_read(ch->ssl_handle, junk, 0)) < 1)
465 syslog(LOG_WARNING, "SSL_read in client_write: %s", ERR_reason_error_string(ERR_get_error()));
468 retval = SSL_write(ch->ssl_handle, &buf[nbytes - nremain], nremain);
473 errval = SSL_get_error(ch->ssl_handle, retval);
474 if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE)
479 syslog(LOG_WARNING, "SSL_write got error %ld, ret %d", errval, retval);
482 syslog(LOG_WARNING, "errno is %d", errno);
494 * read data from the encrypted layer.
496 int client_read_ssl(struct client_handle *ch, char *buf, int nbytes)
502 if (ch->ssl_handle == NULL) return(-1);
504 while (bytes_read < nbytes)
506 if (SSL_want_read(ch->ssl_handle))
508 if ((SSL_write(ch->ssl_handle, junk, 0)) < 1)
510 syslog(LOG_WARNING, "SSL_write in client_read");
513 rlen = SSL_read(ch->ssl_handle, &buf[bytes_read], nbytes-bytes_read);
517 errval = SSL_get_error(ch->ssl_handle, rlen);
518 if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE)
523 syslog(LOG_WARNING, "SSL_read error %ld", errval);