-// Copyright (c) 1996-2021 by the citadel.org team
+// Copyright (c) 1996-2022 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.
#include "webcit.h"
#include "webserver.h"
-/* where to find the keys */
-#define CTDL_CRYPTO_DIR ctdl_key_dir
-#define CTDL_KEY_PATH file_crpt_file_key
-#define CTDL_CSR_PATH file_crpt_file_csr
-#define CTDL_CER_PATH file_crpt_file_cer
-#define SIGN_DAYS 3650 // how long our self-signed certificate should live
SSL_CTX *ssl_ctx; // Global SSL context
+char key_file[PATH_MAX] = "";
+char cert_file[PATH_MAX] = "";
char *ssl_cipher_list = DEFAULT_SSL_CIPHER_LIST;
pthread_key_t ThreadSSL; // Per-thread SSL context
-void shutdown_ssl(void) {
- ERR_free_strings();
-}
-
-
-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) { // We already have a key -- don't generate a new one.
- 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(file_crpt_file_key, 0600);
- if (PEM_write_RSAPrivateKey(fp, // the file
- rsa, // the key
- NULL, // no enc
- NULL, // no passphrase
- 0, // no passphrase
- NULL, // no callback
- NULL // no callback
- ) != 1) {
- syslog(LOG_ERR, "crypto: cannot write key: %s", ERR_reason_error_string(ERR_get_error()));
- unlink(keyfilename);
- }
- fclose(fp);
- }
- // Free the memory we used
-free_all:
- RSA_free(rsa);
- BN_free(bne);
-}
+// Set the private key and certificate chain for the global SSL Context.
+// This is called during initialization, and can be called again later if the certificate changes.
+void bind_to_key_and_certificate(void) {
+ SSL_CTX *old_ctx, *new_ctx;
-// 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;
-
-#ifndef OPENSSL_NO_EGD
- if (!access("/var/run/egd-pool", F_OK)) {
- RAND_egd("/var/run/egd-pool");
+ if (IsEmptyStr(key_file)) {
+ snprintf(key_file, sizeof key_file, "%s/keys/citadel.key", ctdl_dir);
}
-#endif
-
- if (!RAND_status()) {
- syslog(LOG_WARNING, "PRNG not adequately seeded, won't do SSL/TLS");
- return;
+ if (IsEmptyStr(cert_file)) {
+ snprintf(cert_file, sizeof key_file, "%s/keys/citadel.cer", ctdl_dir);
}
- // Initialize SSL transport layer
- SSL_library_init();
- SSL_load_error_strings();
- ssl_method = SSLv23_server_method();
- if (!(ssl_ctx = SSL_CTX_new(ssl_method))) {
+ if (!(new_ctx = SSL_CTX_new(SSLv23_server_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))) {
+ if (!(SSL_CTX_set_cipher_list(new_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);
-
- // Before attempting to generate keys/certificates, first try
- // link to them from the Citadel server if it's on the same host.
- // We ignore any error return because it either meant that there
- // was nothing in Citadel to link from (in which case we just
- // generate new files) or the target files already exist (which
- // is not fatal either).
- if (!strcasecmp(ctdlhost, "uds")) {
- sprintf(buf, "%s/keys/citadel.key", ctdlport);
- rv = symlink(buf, CTDL_KEY_PATH);
- if (!rv) {
- syslog(LOG_DEBUG, "%s", strerror(errno));
- }
- sprintf(buf, "%s/keys/citadel.csr", ctdlport);
- rv = symlink(buf, CTDL_CSR_PATH);
- if (!rv) {
- syslog(LOG_DEBUG, "%s", strerror(errno));
- }
- sprintf(buf, "%s/keys/citadel.cer", ctdlport);
- rv = symlink(buf, CTDL_CER_PATH);
- if (!rv) {
- syslog(LOG_DEBUG, "%s", strerror(errno));
- }
- }
+ syslog(LOG_DEBUG, "crypto: [re]installing key \"%s\" and certificate \"%s\"", key_file, cert_file);
- // 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);
- }
+ SSL_CTX_use_certificate_chain_file(new_ctx, cert_file);
+ SSL_CTX_use_PrivateKey_file(new_ctx, key_file, SSL_FILETYPE_PEM);
- 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);
-
- // Tell it who we are
- env = getenv("O");
- if (env == NULL) {
- env = "Organization name";
- }
-
- X509_NAME_add_entry_by_txt(
- name, "O",
- MBSTRING_ASC,
- (unsigned char*)env,
- -1, -1, 0
- );
-
- env = getenv("OU");
- if (env == NULL) {
- env = "Citadel server";
- }
-
- X509_NAME_add_entry_by_txt(
- name, "OU",
- MBSTRING_ASC,
- (unsigned char*)env,
- -1, -1, 0
- );
-
- env = getenv("CN");
- if (env == NULL)
- env = "*";
-
- X509_NAME_add_entry_by_txt(
- name, "CN",
- MBSTRING_ASC,
- (unsigned char*)env,
- -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);
- ShutDownWebcit();
- exit(0);
- }
- }
-
- X509_REQ_free(req);
- }
- }
- RSA_free(rsa);
- }
- else {
- syslog(LOG_WARNING, "Unable to read private key.");
- }
+ if ( !SSL_CTX_check_private_key(new_ctx) ) {
+ syslog(LOG_WARNING, "crypto: cannot install certificate: %s", ERR_reason_error_string(ERR_get_error()));
}
- // 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.\n");
+ old_ctx = ssl_ctx;
+ ssl_ctx = new_ctx;
+ sleep(1);
+ SSL_CTX_free(old_ctx);
+}
- // 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);
- }
+// initialize ssl engine, load certs and initialize openssl internals
+void init_ssl(void) {
- fp = fopen(CTDL_CSR_PATH, "r");
- if (fp) {
- req = PEM_read_X509_REQ(fp, NULL, NULL, NULL);
- fclose(fp);
- }
+ // Initialize the OpenSSL library
+ SSL_load_error_strings();
+ ERR_load_crypto_strings();
+ OpenSSL_add_all_algorithms();
+ SSL_library_init();
- 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);
- ShutDownWebcit();
- exit(0);
- }
- }
- X509_free(cer);
- }
- }
- RSA_free(rsa);
- }
+ // Now try to bind to the key and certificate.
+ bind_to_key_and_certificate();
+}
+
+
+// Check the modification time of the key and certificate -- reload if either one changed
+void update_key_and_cert_if_needed(void) {
+ static time_t previous_mtime = 0;
+ struct stat keystat;
+ struct stat certstat;
+
+ if (stat(key_file, &keystat) != 0) {
+ syslog(LOG_ERR, "%s: %s", key_file, strerror(errno));
+ return;
+ }
+ if (stat(cert_file, &certstat) != 0) {
+ syslog(LOG_ERR, "%s: %s", cert_file, strerror(errno));
+ return;
}
- // 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, "crypto: cannot install certificate: %s", ERR_reason_error_string(ERR_get_error()));
+ if ((keystat.st_mtime + certstat.st_mtime) != previous_mtime) {
+ bind_to_key_and_certificate();
+ previous_mtime = keystat.st_mtime + certstat.st_mtime;
}
}
// starts SSL/TLS encryption for the current session.
int starttls(int sock) {
- int retval, bits, alg_bits;
SSL *newssl;
+ int retval, bits, alg_bits;
+ // Check the modification time of the key and certificate -- reload if they changed
+ update_key_and_cert_if_needed();
+
+ // SSL is a thread-specific thing, I think.
pthread_setspecific(ThreadSSL, NULL);
if (!ssl_ctx) {
errval = SSL_get_error(newssl, 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));
+ syslog(LOG_WARNING, "first SSL_accept failed: errval=%ld, retval=%d %s", errval, retval, strerror(errval));
}
else {
- syslog(LOG_WARNING, "SSL_accept failed: %s", ssl_error_reason);
+ syslog(LOG_WARNING, "first SSL_accept failed: %s", ssl_error_reason);
}
- sleeeeeeeeeep(1);
- retval = SSL_accept(newssl);
- }
- if (retval < 1) {
- long errval;
- const char *ssl_error_reason = NULL;
-
- errval = SSL_get_error(newssl, 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(newssl);
- newssl = NULL;
- return(4);
}
else {
syslog(LOG_INFO, "SSL_accept success");
}
- /*r = */BIO_set_close(SSL_get_rbio(newssl), BIO_NOCLOSE);
+ BIO_set_close(SSL_get_rbio(newssl), BIO_NOCLOSE);
bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(newssl), &alg_bits);
syslog(LOG_INFO, "SSL/TLS using %s on %s (%d of %d bits)",
SSL_CIPHER_get_name(SSL_get_current_cipher(newssl)),
sleeeeeeeeeep(1);
continue;
}
- syslog(LOG_WARNING, "SSL_write got error %ld, ret %d", errval, retval);
+ syslog(LOG_WARNING, "SSL_write: %s", ERR_reason_error_string(ERR_get_error()));
if (retval == -1) {
syslog(LOG_WARNING, "errno is %d\n", errno);
}
sleeeeeeeeeep(1);
continue;
}
- syslog(LOG_WARNING, "SSL_read got error %ld", errval);
+ syslog(LOG_WARNING, "SSL_read in client_read: %s", ERR_reason_error_string(ERR_get_error()));
endtls();
return (-1);
}