X-Git-Url: https://code.citadel.org/?a=blobdiff_plain;f=webcit%2Fcrypto.c;h=5df3e61a13111d676866ed24b6209d6d7505b839;hb=HEAD;hp=145beb79e9e7041b6dec101fed0725aaab5c64db;hpb=14bee768fb27483b355d98feef2a96de81d75017;p=citadel.git diff --git a/webcit/crypto.c b/webcit/crypto.c index 145beb79e..845113791 100644 --- a/webcit/crypto.c +++ b/webcit/crypto.c @@ -1,448 +1,251 @@ -/* $Id$ */ - +// 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. +// +// 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 "sysdep.h" #ifdef HAVE_OPENSSL - -#include -#include -#include -#include -#include -#include - -#include #include "webcit.h" -#include "webserver.h" -#define CTDL_CRYPTO_DIR "./keys" -#define CTDL_KEY_PATH CTDL_CRYPTO_DIR "/citadel.key" -#define CTDL_CSR_PATH CTDL_CRYPTO_DIR "/citadel.csr" -#define CTDL_CER_PATH CTDL_CRYPTO_DIR "/citadel.cer" -#define SIGN_DAYS 3650 /* Ten years */ -/* Shared Diffie-Hellman parameters */ -#define DH_P "1A74527AEE4EE2568E85D4FB2E65E18C9394B9C80C42507D7A6A0DBE9A9A54B05A9A96800C34C7AA5297095B69C88901EEFD127F969DCA26A54C0E0B5C5473EBAEB00957D2633ECAE3835775425DE66C0DE6D024DBB17445E06E6B0C78415E589B8814F08531D02FD43778451E7685541079CFFB79EF0D26EFEEBBB69D1E80383" -#define DH_G "2" -#define DH_L 1024 -#define CIT_CIPHERS "ALL:RC4+RSA:+SSLv2:@STRENGTH" /* see ciphers(1) */ +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; -SSL_CTX *ssl_ctx; /* SSL context */ -pthread_mutex_t **SSLCritters; /* Things needing locking */ +pthread_key_t ThreadSSL; // Per-thread SSL context -static unsigned long id_callback(void) -{ - return (unsigned long) pthread_self(); -} - /* - * Set up the cert things on the server side. We do need both the - * private key (in key_file) and the cert (in cert_file). - * Both files may be identical. - * - * This function is taken from OpenSSL apps/s_cb.c - */ - -static int ctdl_install_certificate(SSL_CTX * ctx, - const char *cert_file, const char *key_file) -{ - if (cert_file != NULL) { - if (SSL_CTX_use_certificate_file(ctx, cert_file, - SSL_FILETYPE_PEM) <= 0) { - lprintf(3, "unable to get certificate from '%s'", - cert_file); - return (0); - } - if (key_file == NULL) - key_file = cert_file; - if (SSL_CTX_use_PrivateKey_file(ctx, key_file, - SSL_FILETYPE_PEM) <= 0) { - lprintf(3, "unable to get private key from '%s'", - key_file); - return (0); - } - /* Now we know that a key and cert have been set against - * the SSL context */ - if (!SSL_CTX_check_private_key(ctx)) { - lprintf(3, - "Private key does not match the certificate public key"); - return (0); - } - } - return (1); -} +// 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; -void init_ssl(void) -{ - SSL_METHOD *ssl_method; - DH *dh; - 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; - - if (!access("/var/run/egd-pool", F_OK)) - RAND_egd("/var/run/egd-pool"); - - if (!RAND_status()) { - lprintf(3, - "PRNG not adequately seeded, won't do SSL/TLS\n"); - return; + if (IsEmptyStr(key_file)) { + snprintf(key_file, sizeof key_file, "%s/keys/citadel.key", ctdl_dir); } - SSLCritters = - malloc(CRYPTO_num_locks() * sizeof(pthread_mutex_t *)); - if (!SSLCritters) { - lprintf(1, "citserver: can't allocate memory!!\n"); - /* Nothing's been initialized, just die */ - exit(1); - } else { - int a; - - for (a = 0; a < CRYPTO_num_locks(); a++) { - SSLCritters[a] = malloc(sizeof(pthread_mutex_t)); - if (!SSLCritters[a]) { - lprintf(1, - "citserver: can't allocate memory!!\n"); - /* Nothing's been initialized, just die */ - exit(1); - } - pthread_mutex_init(SSLCritters[a], NULL); - } + 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))) { - lprintf(3, "SSL_CTX_new failed: %s\n", - ERR_reason_error_string(ERR_get_error())); + 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; } - if (!(SSL_CTX_set_cipher_list(ssl_ctx, CIT_CIPHERS))) { - lprintf(3, "SSL: No ciphers available\n"); - SSL_CTX_free(ssl_ctx); - ssl_ctx = NULL; - return; - } -#if 0 -#if SSLEAY_VERSION_NUMBER >= 0x00906000L - SSL_CTX_set_mode(ssl_ctx, SSL_CTX_get_mode(ssl_ctx) | - SSL_MODE_AUTO_RETRY); -#endif -#endif - - CRYPTO_set_locking_callback(ssl_lock); - CRYPTO_set_id_callback(id_callback); - - /* Load DH parameters into the context */ - dh = DH_new(); - if (!dh) { - lprintf(3, "init_ssl() can't allocate a DH object: %s\n", - ERR_reason_error_string(ERR_get_error())); - SSL_CTX_free(ssl_ctx); - ssl_ctx = NULL; - return; - } - if (!(BN_hex2bn(&(dh->p), DH_P))) { - lprintf(3, "init_ssl() can't assign DH_P: %s\n", - ERR_reason_error_string(ERR_get_error())); - SSL_CTX_free(ssl_ctx); - ssl_ctx = NULL; - return; - } - if (!(BN_hex2bn(&(dh->g), DH_G))) { - lprintf(3, "init_ssl() can't assign DH_G: %s\n", - ERR_reason_error_string(ERR_get_error())); - SSL_CTX_free(ssl_ctx); - ssl_ctx = NULL; + + syslog(LOG_INFO, "Requesting cipher list: %s", 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; } - dh->length = DH_L; - SSL_CTX_set_tmp_dh(ssl_ctx, dh); - DH_free(dh); - - /* Get our certificates in order. - * First, create the key/cert directory if it's not there already... - */ - mkdir(CTDL_CRYPTO_DIR, 0700); - - /* - * Generate a key pair if we don't have one. - */ - if (access(CTDL_KEY_PATH, R_OK) != 0) { - lprintf(5, "Generating RSA key pair.\n"); - rsa = RSA_generate_key(1024, /* modulus size */ - 65537, /* exponent */ - NULL, /* no callback */ - NULL); /* no callback */ - if (rsa == NULL) { - lprintf(3, "Key generation failed: %s\n", - ERR_reason_error_string(ERR_get_error())); - } - if (rsa != NULL) { - fp = fopen(CTDL_KEY_PATH, "w"); - if (fp != NULL) { - chmod(CTDL_KEY_PATH, 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) { - lprintf(3, "Cannot write key: %s\n", - ERR_reason_error_string(ERR_get_error())); - unlink(CTDL_KEY_PATH); - } - fclose(fp); - } - RSA_free(rsa); - } - } - - /* - * Generate a CSR if we don't have one. - */ - if (access(CTDL_CSR_PATH, R_OK) != 0) { - lprintf(5, "Generating a certificate signing request.\n"); - - /* - * 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) { - - /* 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 */ - - /* - X509_NAME_add_entry_by_txt(name, "C", - MBSTRING_ASC, "US", -1, -1, 0); - X509_NAME_add_entry_by_txt(name, "ST", - MBSTRING_ASC, "New York", -1, -1, 0); + syslog(LOG_DEBUG, "crypto: [re]installing key \"%s\" and certificate \"%s\"", key_file, cert_file); - X509_NAME_add_entry_by_txt(name, "L", - MBSTRING_ASC, "Mount Kisco", -1, -1, 0); - */ + SSL_CTX_use_certificate_chain_file(new_ctx, cert_file); + SSL_CTX_use_PrivateKey_file(new_ctx, key_file, SSL_FILETYPE_PEM); - X509_NAME_add_entry_by_txt(name, "O", - MBSTRING_ASC, "FIXME.FIXME.org", -1, -1, 0); - - X509_NAME_add_entry_by_txt(name, "OU", - MBSTRING_ASC, "Citadel server", -1, -1, 0); - - X509_NAME_add_entry_by_txt(name, "CN", - MBSTRING_ASC, "FIXME.FIXME.org", -1, -1, 0); - - X509_REQ_set_subject_name(req, name); - - /* Sign the CSR */ - if (!X509_REQ_sign(req, pk, EVP_md5())) { - lprintf(3, "X509_REQ_sign(): error\n"); - } - 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); - } - } - - X509_REQ_free(req); - } - } - - RSA_free(rsa); - } - - else { - lprintf(3, "Unable to read private key.\n"); - } + if ( !SSL_CTX_check_private_key(new_ctx) ) { + syslog(LOG_WARNING, "crypto: cannot install certificate: %s", ERR_reason_error_string(ERR_get_error())); } + old_ctx = ssl_ctx; + ssl_ctx = new_ctx; + sleep(1); + SSL_CTX_free(old_ctx); +} - /* - * Generate a self-signed certificate if we don't have one. - */ - if (access(CTDL_CER_PATH, R_OK) != 0) { - lprintf(5, "Generating a self-signed certificate.\n"); +// initialize ssl engine, load certs and initialize openssl internals +void init_ssl(void) { - /* 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); - } + // Initialize the OpenSSL library + SSL_load_error_strings(); + ERR_load_crypto_strings(); + OpenSSL_add_all_algorithms(); + SSL_library_init(); - /* 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); - } + // Now try to bind to the key and certificate. + bind_to_key_and_certificate(); +} - 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) { - - X509_set_issuer_name(cer, req->req_info->subject); - X509_set_subject_name(cer, req->req_info->subject); - 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())) { - lprintf(3, "X509_sign(): error\n"); - } - 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); - } - } - X509_free(cer); - } - } +// 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; - RSA_free(rsa); - } + if (stat(key_file, &keystat) != 0) { + syslog(LOG_ERR, "%s: %s", key_file, strerror(errno)); + return; } - - - /* - * Now try to bind to the key and certificate. - */ - if (ctdl_install_certificate(ssl_ctx, - CTDL_CER_PATH, - CTDL_KEY_PATH) != 1) - { - lprintf(3, "Cannot install certificate: %s\n", - ERR_reason_error_string(ERR_get_error())); + if (stat(cert_file, &certstat) != 0) { + syslog(LOG_ERR, "%s: %s", cert_file, strerror(errno)); + return; } + if ((keystat.st_mtime + certstat.st_mtime) != previous_mtime) { + bind_to_key_and_certificate(); + previous_mtime = keystat.st_mtime + certstat.st_mtime; + } } -/* - * starttls() starts SSL/TLS encryption for the current session. - */ -int starttls(void) { - +// starts SSL/TLS encryption for the current session. +int starttls(int sock) { + 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) { return(1); } - if (!(WC->ssl = SSL_new(ssl_ctx))) { - lprintf(3, "SSL_new failed: %s\n", - ERR_reason_error_string(ERR_get_error())); + if (!(newssl = SSL_new(ssl_ctx))) { + syslog(LOG_WARNING, "SSL_new failed: %s", ERR_reason_error_string(ERR_get_error())); return(2); } - if (!(SSL_set_fd(WC->ssl, WC->http_sock))) { - lprintf(3, "SSL_set_fd failed: %s\n", - ERR_reason_error_string(ERR_get_error())); - SSL_free(WC->ssl); - WC->ssl = NULL; + if (!(SSL_set_fd(newssl, sock))) { + syslog(LOG_WARNING, "SSL_set_fd failed: %s", ERR_reason_error_string(ERR_get_error())); + SSL_free(newssl); return(3); } - retval = SSL_accept(WC->ssl); + retval = SSL_accept(newssl); if (retval < 1) { - /* - * Can't notify the client of an error here; they will - * discover the problem at the SSL layer and should - * revert to unencrypted communications. - */ + // Can't notify the client of an error here; they will + // discover the problem at the SSL layer and should + // revert to unencrypted communications. long errval; + const char *ssl_error_reason = NULL; - errval = SSL_get_error(WC->ssl, retval); - lprintf(3, "SSL_accept failed: %s\n", - ERR_reason_error_string(ERR_get_error())); - SSL_free(WC->ssl); - WC->ssl = NULL; - return(4); + errval = SSL_get_error(newssl, retval); + ssl_error_reason = ERR_reason_error_string(ERR_get_error()); + if (ssl_error_reason == NULL) { + syslog(LOG_WARNING, "first SSL_accept failed: errval=%ld, retval=%d %s", errval, retval, strerror(errval)); + } + else { + syslog(LOG_WARNING, "first SSL_accept failed: %s", ssl_error_reason); + } + } + else { + syslog(LOG_INFO, "SSL_accept success"); } - BIO_set_close(WC->ssl->rbio, BIO_NOCLOSE); - bits = - SSL_CIPHER_get_bits(SSL_get_current_cipher(WC->ssl), - &alg_bits); - lprintf(5, "SSL/TLS using %s on %s (%d of %d bits)\n", - SSL_CIPHER_get_name(SSL_get_current_cipher(WC->ssl)), - SSL_CIPHER_get_version(SSL_get_current_cipher(WC->ssl)), + 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)), + SSL_CIPHER_get_version(SSL_get_current_cipher(newssl)), bits, alg_bits); + + pthread_setspecific(ThreadSSL, newssl); + syslog(LOG_INFO, "SSL started"); return(0); } +// shuts down the TLS connection +// +// WARNING: This may make your session vulnerable to a known plaintext +// attack in the current implmentation. +void endtls(void) { -/* - * endtls() shuts down the TLS connection - * - * WARNING: This may make your session vulnerable to a known plaintext - * attack in the current implmentation. - */ -void endtls(void) -{ - lprintf(5, "Ending SSL/TLS\n"); - SSL_shutdown(WC->ssl); - SSL_free(WC->ssl); - WC->ssl = NULL; + if (THREADSSL == NULL) { + return; + } + + syslog(LOG_INFO, "Ending SSL/TLS"); + SSL_shutdown(THREADSSL); + SSL_get_SSL_CTX(THREADSSL); + SSL_free(THREADSSL); + pthread_setspecific(ThreadSSL, NULL); } -/* - * ssl_lock() callback for OpenSSL mutex locks - */ -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]); +// Send binary data to the client encrypted. +int client_write_ssl(const StrBuf *Buf) { + const char *buf; + int retval; + int nremain; + long nbytes; + char junk[1]; + + if (THREADSSL == NULL) return -1; + + nbytes = nremain = StrLength(Buf); + buf = ChrPtr(Buf); + + while (nremain > 0) { + if (SSL_want_write(THREADSSL)) { + if ((SSL_read(THREADSSL, junk, 0)) < 1) { + syslog(LOG_WARNING, "SSL_read in client_write: %s", ERR_reason_error_string(ERR_get_error())); + } + } + retval = SSL_write(THREADSSL, &buf[nbytes - nremain], nremain); + if (retval < 1) { + long errval; + + errval = SSL_get_error(THREADSSL, retval); + if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) { + sleeeeeeeeeep(1); + continue; + } + syslog(LOG_WARNING, "SSL_write: %s", ERR_reason_error_string(ERR_get_error())); + if (retval == -1) { + syslog(LOG_WARNING, "errno is %d\n", errno); + } + endtls(); + return -1; + } + nremain -= retval; + } + return 0; +} + + +// read data from the encrypted layer. +int client_read_sslbuffer(StrBuf *buf, int timeout) { + char sbuf[16384]; // OpenSSL communicates in 16k blocks, so let's speak its native tongue. + int rlen; + char junk[1]; + SSL *pssl = THREADSSL; + + if (pssl == NULL) return(-1); + + while (1) { + if (SSL_want_read(pssl)) { + if ((SSL_write(pssl, junk, 0)) < 1) { + syslog(LOG_WARNING, "SSL_write in client_read"); + } + } + rlen = SSL_read(pssl, sbuf, sizeof(sbuf)); + if (rlen < 1) { + long errval; + + errval = SSL_get_error(pssl, rlen); + if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) { + sleeeeeeeeeep(1); + continue; + } + syslog(LOG_WARNING, "SSL_read in client_read: %s", ERR_reason_error_string(ERR_get_error())); + endtls(); + return (-1); + } + StrBufAppendBufPlain(buf, sbuf, rlen, 0); + return rlen; + } + return (0); } #endif /* HAVE_OPENSSL */