+++ /dev/null
-/*
- * Functions in this module handle SSL encryption when WebCit is running
- * as an HTTPS server.
- *
- * Copyright (c) 1996-2018 by the citadel.org team
- *
- * This program is open source software. You can redistribute it and/or
- * modify it under the terms of the GNU General Public License, version 3.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-
-#include "webcit.h"
-
-SSL_CTX *ssl_ctx; /* SSL context */
-pthread_mutex_t **SSLCritters; /* Things needing locking */
-char *ssl_cipher_list = DEFAULT_SSL_CIPHER_LIST;
-void ssl_lock(int mode, int n, const char *file, int line);
-
-
-/*
- * OpenSSL wants a callback function to identify the currently running thread.
- * Since we are a pthreads program, we convert the output of pthread_self() to a long.
- */
-static unsigned long id_callback(void)
-{
- return (unsigned long) pthread_self();
-}
-
-
-/*
- * OpenSSL wants a callback function to set and clear various types of locks.
- * Since we are a pthreads program, we use mutexes.
- */
-void ssl_lock(int mode, int n, const char *file, int line)
-{
- if (mode & CRYPTO_LOCK) {
- pthread_mutex_lock(SSLCritters[n]);
- } else {
- pthread_mutex_unlock(SSLCritters[n]);
- }
-}
-
-
-/*
- * Generate a private key for SSL
- */
-void generate_key(char *keyfilename)
-{
- int ret = 0;
- RSA *rsa = NULL;
- BIGNUM *bne = NULL;
- int bits = 2048;
- unsigned long e = RSA_F4;
- FILE *fp;
-
- if (access(keyfilename, R_OK) == 0) {
- return;
- }
-
- syslog(LOG_INFO, "crypto: generating RSA key pair");
-
- // generate rsa key
- bne = BN_new();
- ret = BN_set_word(bne, e);
- if (ret != 1) {
- goto free_all;
- }
-
- rsa = RSA_new();
- ret = RSA_generate_key_ex(rsa, bits, bne, NULL);
- if (ret != 1) {
- goto free_all;
- }
- // write the key file
- fp = fopen(keyfilename, "w");
- if (fp != NULL) {
- chmod(keyfilename, 0600);
- if (PEM_write_RSAPrivateKey(fp, /* the file */
- rsa, /* the key */
- NULL, /* no enc */
- NULL, /* no passphr */
- 0, /* no passphr */
- NULL, /* no callbk */
- NULL /* no callbk */
- ) != 1) {
- syslog(LOG_ERR, "crypto: cannot write key: %s", ERR_reason_error_string(ERR_get_error()));
- unlink(keyfilename);
- }
- fclose(fp);
- }
- // 4. free
- free_all:
- RSA_free(rsa);
- BN_free(bne);
-}
-
-
-/*
- * Initialize ssl engine, load certs and initialize openssl internals
- */
-void init_ssl(void)
-{
- const SSL_METHOD *ssl_method;
- RSA *rsa = NULL;
- X509_REQ *req = NULL;
- X509 *cer = NULL;
- EVP_PKEY *pk = NULL;
- EVP_PKEY *req_pkey = NULL;
- X509_NAME *name = NULL;
- FILE *fp;
- char buf[SIZ];
- int rv = 0;
-
- SSLCritters = malloc(CRYPTO_num_locks() * sizeof(pthread_mutex_t *));
- if (!SSLCritters) {
- syslog(LOG_ERR, "citserver: can't allocate memory!!");
- exit(1);
- } else {
- int a;
- for (a = 0; a < CRYPTO_num_locks(); a++) {
- SSLCritters[a] = malloc(sizeof(pthread_mutex_t));
- if (!SSLCritters[a]) {
- syslog(LOG_INFO, "citserver: can't allocate memory!!");
- exit(1);
- }
- pthread_mutex_init(SSLCritters[a], NULL);
- }
- }
-
- /*
- * Initialize SSL transport layer
- */
- SSL_library_init();
- SSL_load_error_strings();
- ssl_method = SSLv23_server_method();
- if (!(ssl_ctx = SSL_CTX_new(ssl_method))) {
- syslog(LOG_WARNING, "SSL_CTX_new failed: %s", ERR_reason_error_string(ERR_get_error()));
- return;
- }
-
- syslog(LOG_INFO, "Requesting cipher list: %s", ssl_cipher_list);
- if (!(SSL_CTX_set_cipher_list(ssl_ctx, ssl_cipher_list))) {
- syslog(LOG_WARNING, "SSL_CTX_set_cipher_list failed: %s", ERR_reason_error_string(ERR_get_error()));
- return;
- }
-
- CRYPTO_set_locking_callback(ssl_lock);
- CRYPTO_set_id_callback(id_callback);
-
- /*
- * Get our certificates in order.
- * First, create the key/cert directory if it's not there already...
- */
- mkdir(CTDL_CRYPTO_DIR, 0700);
-
- /*
- * If we still don't have a private key, generate one.
- */
- generate_key(CTDL_KEY_PATH);
-
- /*
- * If there is no certificate file on disk, we will be generating a self-signed certificate
- * in the next step. Therefore, if we have neither a CSR nor a certificate, generate
- * the CSR in this step so that the next step may commence.
- */
- if ((access(CTDL_CER_PATH, R_OK) != 0) && (access(CTDL_CSR_PATH, R_OK) != 0)) {
- syslog(LOG_INFO, "Generating a certificate signing request.");
-
- /*
- * Read our key from the file. No, we don't just keep this
- * in memory from the above key-generation function, because
- * there is the possibility that the key was already on disk
- * and we didn't just generate it now.
- */
- fp = fopen(CTDL_KEY_PATH, "r");
- if (fp) {
- rsa = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
- fclose(fp);
- }
-
- if (rsa) {
- /* Create a public key from the private key */
- if (pk = EVP_PKEY_new(), pk != NULL) {
- EVP_PKEY_assign_RSA(pk, rsa);
- if (req = X509_REQ_new(), req != NULL) {
- const char *env;
- /* Set the public key */
- X509_REQ_set_pubkey(req, pk);
- X509_REQ_set_version(req, 0L);
- name = X509_REQ_get_subject_name(req);
- X509_NAME_add_entry_by_txt(name, "O", MBSTRING_ASC,
- (unsigned char *) "Citadel Server", -1, -1, 0);
- X509_NAME_add_entry_by_txt(name, "OU", MBSTRING_ASC,
- (unsigned char *) "Default Certificate PLEASE CHANGE",
- -1, -1, 0);
- X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC, (unsigned char *) "*", -1, -1, 0);
-
- X509_REQ_set_subject_name(req, name);
-
- /* Sign the CSR */
- if (!X509_REQ_sign(req, pk, EVP_md5())) {
- syslog(LOG_WARNING, "X509_REQ_sign(): error");
- } else {
- /* Write it to disk. */
- fp = fopen(CTDL_CSR_PATH, "w");
- if (fp != NULL) {
- chmod(CTDL_CSR_PATH, 0600);
- PEM_write_X509_REQ(fp, req);
- fclose(fp);
- } else {
- syslog(LOG_WARNING, "Cannot write key: %s", CTDL_CSR_PATH);
- exit(1);
- }
- }
- X509_REQ_free(req);
- }
- }
- RSA_free(rsa);
- } else {
- syslog(LOG_WARNING, "Unable to read private key.");
- }
- }
-
- /*
- * Generate a self-signed certificate if we don't have one.
- */
- if (access(CTDL_CER_PATH, R_OK) != 0) {
- syslog(LOG_INFO, "Generating a self-signed certificate.");
-
- /* Same deal as before: always read the key from disk because
- * it may or may not have just been generated.
- */
- fp = fopen(CTDL_KEY_PATH, "r");
- if (fp) {
- rsa = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
- fclose(fp);
- }
-
- /* This also holds true for the CSR. */
- req = NULL;
- cer = NULL;
- pk = NULL;
- if (rsa) {
- if (pk = EVP_PKEY_new(), pk != NULL) {
- EVP_PKEY_assign_RSA(pk, rsa);
- }
-
- fp = fopen(CTDL_CSR_PATH, "r");
- if (fp) {
- req = PEM_read_X509_REQ(fp, NULL, NULL, NULL);
- fclose(fp);
- }
-
- if (req) {
- if (cer = X509_new(), cer != NULL) {
- ASN1_INTEGER_set(X509_get_serialNumber(cer), 0);
- X509_set_issuer_name(cer, X509_REQ_get_subject_name(req));
- X509_set_subject_name(cer, X509_REQ_get_subject_name(req));
- X509_gmtime_adj(X509_get_notBefore(cer), 0);
- X509_gmtime_adj(X509_get_notAfter(cer), (long) 60 * 60 * 24 * SIGN_DAYS);
-
- req_pkey = X509_REQ_get_pubkey(req);
- X509_set_pubkey(cer, req_pkey);
- EVP_PKEY_free(req_pkey);
-
- /* Sign the cert */
- if (!X509_sign(cer, pk, EVP_md5())) {
- syslog(LOG_WARNING, "X509_sign(): error");
- } else { /* Write it to disk. */
- fp = fopen(CTDL_CER_PATH, "w");
- if (fp != NULL) {
- chmod(CTDL_CER_PATH, 0600);
- PEM_write_X509(fp, cer);
- fclose(fp);
- } else {
- syslog(LOG_WARNING, "Cannot write key: %s", CTDL_CER_PATH);
- exit(1);
- }
- }
- X509_free(cer);
- }
- }
- RSA_free(rsa);
- }
- }
-
- /*
- * Now try to bind to the key and certificate.
- * Note that we use SSL_CTX_use_certificate_chain_file() which allows
- * the certificate file to contain intermediate certificates.
- */
- SSL_CTX_use_certificate_chain_file(ssl_ctx, CTDL_CER_PATH);
- SSL_CTX_use_PrivateKey_file(ssl_ctx, CTDL_KEY_PATH, SSL_FILETYPE_PEM);
- if (!SSL_CTX_check_private_key(ssl_ctx)) {
- syslog(LOG_WARNING, "Cannot install certificate: %s", ERR_reason_error_string(ERR_get_error()));
- }
-
-}
-
-
-/*
- * starts SSL/TLS encryption for the current session.
- */
-void starttls(struct client_handle *ch)
-{
- int retval, bits, alg_bits;
-
- if (!ssl_ctx) {
- return;
- }
- if (!(ch->ssl_handle = SSL_new(ssl_ctx))) {
- syslog(LOG_WARNING, "SSL_new failed: %s", ERR_reason_error_string(ERR_get_error()));
- return;
- }
- if (!(SSL_set_fd(ch->ssl_handle, ch->sock))) {
- syslog(LOG_WARNING, "SSL_set_fd failed: %s", ERR_reason_error_string(ERR_get_error()));
- SSL_free(ch->ssl_handle);
- return;
- }
- retval = SSL_accept(ch->ssl_handle);
- if (retval < 1) {
- long errval;
- const char *ssl_error_reason = NULL;
-
- errval = SSL_get_error(ch->ssl_handle, retval);
- ssl_error_reason = ERR_reason_error_string(ERR_get_error());
- if (ssl_error_reason == NULL) {
- syslog(LOG_WARNING, "SSL_accept failed: errval=%ld, retval=%d %s", errval, retval, strerror(errval));
- } else {
- syslog(LOG_WARNING, "SSL_accept failed: %s\n", ssl_error_reason);
- }
- sleep(1);
- retval = SSL_accept(ch->ssl_handle);
- }
- if (retval < 1) {
- long errval;
- const char *ssl_error_reason = NULL;
-
- errval = SSL_get_error(ch->ssl_handle, retval);
- ssl_error_reason = ERR_reason_error_string(ERR_get_error());
- if (ssl_error_reason == NULL) {
- syslog(LOG_WARNING, "SSL_accept failed: errval=%ld, retval=%d (%s)", errval, retval, strerror(errval));
- } else {
- syslog(LOG_WARNING, "SSL_accept failed: %s", ssl_error_reason);
- }
- SSL_free(ch->ssl_handle);
- ch->ssl_handle = NULL;
- return;
- } else {
- syslog(LOG_INFO, "SSL_accept success");
- }
- bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(ch->ssl_handle), &alg_bits);
- syslog(LOG_INFO, "SSL/TLS using %s on %s (%d of %d bits)",
- SSL_CIPHER_get_name(SSL_get_current_cipher(ch->ssl_handle)),
- SSL_CIPHER_get_version(SSL_get_current_cipher(ch->ssl_handle)), bits, alg_bits);
-
- syslog(LOG_INFO, "SSL started");
-}
-
-
-/*
- * shuts down the TLS connection
- */
-void endtls(struct client_handle *ch)
-{
- syslog(LOG_INFO, "Ending SSL/TLS");
- if (ch->ssl_handle != NULL) {
- SSL_shutdown(ch->ssl_handle);
- SSL_get_SSL_CTX(ch->ssl_handle);
- SSL_free(ch->ssl_handle);
- }
- ch->ssl_handle = NULL;
-}
-
-
-/*
- * Send binary data to the client encrypted.
- */
-int client_write_ssl(struct client_handle *ch, char *buf, int nbytes)
-{
- int retval;
- int nremain;
- char junk[1];
-
- if (ch->ssl_handle == NULL)
- return (-1);
-
- nremain = nbytes;
- while (nremain > 0) {
- if (SSL_want_write(ch->ssl_handle)) {
- if ((SSL_read(ch->ssl_handle, junk, 0)) < 1) {
- syslog(LOG_WARNING, "SSL_read in client_write: %s", ERR_reason_error_string(ERR_get_error()));
- }
- }
- retval = SSL_write(ch->ssl_handle, &buf[nbytes - nremain], nremain);
- if (retval < 1) {
- long errval;
-
- errval = SSL_get_error(ch->ssl_handle, retval);
- if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
- sleep(1);
- continue;
- }
- syslog(LOG_WARNING, "SSL_write got error %ld, ret %d", errval, retval);
- if (retval == -1) {
- syslog(LOG_WARNING, "errno is %d", errno);
- endtls(ch);
- }
- return -1;
- }
- nremain -= retval;
- }
- return 0;
-}
-
-
-/*
- * read data from the encrypted layer.
- */
-int client_read_ssl(struct client_handle *ch, char *buf, int nbytes)
-{
- int bytes_read = 0;
- int rlen = 0;
- char junk[1];
-
- if (ch->ssl_handle == NULL)
- return (-1);
-
- while (bytes_read < nbytes) {
- if (SSL_want_read(ch->ssl_handle)) {
- if ((SSL_write(ch->ssl_handle, junk, 0)) < 1) {
- syslog(LOG_WARNING, "SSL_write in client_read");
- }
- }
- rlen = SSL_read(ch->ssl_handle, &buf[bytes_read], nbytes - bytes_read);
- if (rlen < 1) {
- long errval;
- errval = SSL_get_error(ch->ssl_handle, rlen);
- if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
- sleep(1);
- continue;
- }
- syslog(LOG_WARNING, "SSL_read error %ld", errval);
- endtls(ch);
- return (-1);
- }
- bytes_read += rlen;
- }
- return (bytes_read);
-}
projects / citadel.git / blobdiff