X-Git-Url: https://code.citadel.org/?a=blobdiff_plain;f=webcit%2Fcrypto.c;h=5df3e61a13111d676866ed24b6209d6d7505b839;hb=HEAD;hp=1515ff39762e4a195f00d1435947dd4151d00acf;hpb=9d9f8bb7bfee22a9748f8a23c204286391cd5b17;p=citadel.git diff --git a/webcit/crypto.c b/webcit/crypto.c index 1515ff397..845113791 100644 --- a/webcit/crypto.c +++ b/webcit/crypto.c @@ -1,437 +1,195 @@ -/* - * $Id$ - */ -/** - * \defgroup https Provides HTTPS, when the OpenSSL library is available. - * \ingroup WebcitHttpServer - */ - -/*@{*/ +// 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 "webcit.h" -#include "webserver.h" -/** \todo dirify */ -/** where to find the keys */ -#define CTDL_CRYPTO_DIR "./keys" -#define CTDL_KEY_PATH file_crpt_file_key /**< the key */ -#define CTDL_CSR_PATH file_crpt_file_csr /**< the csr file */ -#define CTDL_CER_PATH file_crpt_file_cer /**< the cer file */ -#define SIGN_DAYS 365 /**< how long our certificate should live */ - -SSL_CTX *ssl_ctx; /**< SSL context */ -pthread_mutex_t **SSLCritters; /**< Things needing locking */ - -pthread_key_t ThreadSSL; /**< Per-thread SSL context */ - -/** - * \brief what????? - * \return thread id??? - */ -static unsigned long id_callback(void) -{ - return (unsigned long) pthread_self(); -} -/** - * \brief initialize ssl engine - * load certs and initialize openssl internals - */ -void init_ssl(void) -{ - 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]; - - 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; - } - 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(WC_EXIT_SSL); - } 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(WC_EXIT_SSL); - } - 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))) { - lprintf(3, "SSL_CTX_new failed: %s\n", - 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. \todo dirify. this is a setup job. - * 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). \todo dirify - */ - if (!strcasecmp(ctdlhost, "uds")) { - sprintf(buf, "%s/keys/citadel.key", ctdlport); - symlink(buf, CTDL_KEY_PATH); - sprintf(buf, "%s/keys/citadel.csr", ctdlport); - symlink(buf, CTDL_CSR_PATH); - sprintf(buf, "%s/keys/citadel.cer", ctdlport); - symlink(buf, CTDL_CER_PATH); - } +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; - /** - * If we still don't have a private key, generate 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); - } - } +pthread_key_t ThreadSSL; // Per-thread SSL context - /** - * 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) { +// 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) { - /** 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) { + SSL_CTX *old_ctx, *new_ctx; - /** 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 */ - - /* \todo whats this? - 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); - - X509_NAME_add_entry_by_txt(name, "L", - MBSTRING_ASC, "Mount Kisco", -1, -1, 0); - */ - - X509_NAME_add_entry_by_txt(name, "O", - MBSTRING_ASC, "Organization name", -1, -1, 0); - - X509_NAME_add_entry_by_txt(name, "OU", - MBSTRING_ASC, "Citadel server", -1, -1, 0); + if (IsEmptyStr(key_file)) { + snprintf(key_file, sizeof key_file, "%s/keys/citadel.key", ctdl_dir); + } + if (IsEmptyStr(cert_file)) { + snprintf(cert_file, sizeof key_file, "%s/keys/citadel.cer", ctdl_dir); + } - X509_NAME_add_entry_by_txt(name, "CN", - MBSTRING_ASC, "*", -1, -1, 0); - - X509_REQ_set_subject_name(req, name); + 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; + } - /** 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); - } - } + 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; + } - X509_REQ_free(req); - } - } + syslog(LOG_DEBUG, "crypto: [re]installing key \"%s\" and certificate \"%s\"", key_file, cert_file); - RSA_free(rsa); - } + SSL_CTX_use_certificate_chain_file(new_ctx, cert_file); + SSL_CTX_use_PrivateKey_file(new_ctx, key_file, SSL_FILETYPE_PEM); - 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) { - - ASN1_INTEGER_set(X509_get_serialNumber(cer), 0); - 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; + } + 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) ) { - lprintf(3, "Cannot install certificate: %s\n", - 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; } - } -/** - * \brief starts SSL/TLS encryption for the current session. - * \param sock the socket connection - * \return Zero if the SSL/TLS handshake succeeded, non-zero otherwise. - */ +// 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) { return(1); } if (!(newssl = SSL_new(ssl_ctx))) { - lprintf(3, "SSL_new failed: %s\n", - ERR_reason_error_string(ERR_get_error())); + syslog(LOG_WARNING, "SSL_new failed: %s", ERR_reason_error_string(ERR_get_error())); return(2); } if (!(SSL_set_fd(newssl, sock))) { - lprintf(3, "SSL_set_fd failed: %s\n", - ERR_reason_error_string(ERR_get_error())); + syslog(LOG_WARNING, "SSL_set_fd failed: %s", ERR_reason_error_string(ERR_get_error())); SSL_free(newssl); return(3); } 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(newssl, retval); - lprintf(3, "SSL_accept failed: %s\n", - ERR_reason_error_string(ERR_get_error())); - SSL_free(newssl); - newssl = NULL; - return(4); + 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(newssl->rbio, BIO_NOCLOSE); + BIO_set_close(SSL_get_rbio(newssl), BIO_NOCLOSE); bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(newssl), &alg_bits); - lprintf(5, "SSL/TLS using %s on %s (%d of %d bits)\n", + 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) { -/** - * \brief shuts down the TLS connection - * - * WARNING: This may make your session vulnerable to a known plaintext - * attack in the current implmentation. - */ -void endtls(void) -{ - SSL_CTX *ctx = NULL; - - if (THREADSSL == NULL) return; + if (THREADSSL == NULL) { + return; + } - lprintf(5, "Ending SSL/TLS\n"); + syslog(LOG_INFO, "Ending SSL/TLS"); SSL_shutdown(THREADSSL); - ctx = SSL_get_SSL_CTX(THREADSSL); - - /** I don't think this is needed, and it crashes the server anyway - * - * if (ctx != NULL) { - * lprintf(9, "Freeing CTX at %x\n", (int)ctx ); - * SSL_CTX_free(ctx); - * } - */ - + SSL_get_SSL_CTX(THREADSSL); SSL_free(THREADSSL); pthread_setspecific(ThreadSSL, NULL); } -/** - * \brief callback for OpenSSL mutex locks - * \param mode which mode?????? - * \param n how many??? - * \param file which filename ??? - * \param line what line???? - */ -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]); -} - -/** - * \brief Send binary data to the client encrypted. - * \param buf chars to send to the client - * \param nbytes how many chars - */ -void client_write_ssl(char *buf, int nbytes) -{ +// 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; + if (THREADSSL == NULL) return -1; - nremain = nbytes; + nbytes = nremain = StrLength(Buf); + buf = ChrPtr(Buf); while (nremain > 0) { if (SSL_want_write(THREADSSL)) { if ((SSL_read(THREADSSL, junk, 0)) < 1) { - lprintf(9, "SSL_read in client_write: %s\n", - ERR_reason_error_string(ERR_get_error())); + syslog(LOG_WARNING, "SSL_read in client_write: %s", ERR_reason_error_string(ERR_get_error())); } } retval = SSL_write(THREADSSL, &buf[nbytes - nremain], nremain); @@ -439,87 +197,55 @@ void client_write_ssl(char *buf, int nbytes) long errval; errval = SSL_get_error(THREADSSL, retval); - if (errval == SSL_ERROR_WANT_READ || - errval == SSL_ERROR_WANT_WRITE) { - sleep(1); + if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) { + sleeeeeeeeeep(1); continue; } - lprintf(9, "SSL_write got error %ld, ret %d\n", errval, retval); + syslog(LOG_WARNING, "SSL_write: %s", ERR_reason_error_string(ERR_get_error())); if (retval == -1) { - lprintf(9, "errno is %d\n", errno); + syslog(LOG_WARNING, "errno is %d\n", errno); } endtls(); - return; + return -1; } nremain -= retval; } + return 0; } -/** - * \brief read data from the encrypted layer. - * \param buf charbuffer to read to - * \param bytes how many - * \param timeout how long should we wait? - * \returns what??? - */ -int client_read_ssl(char *buf, int bytes, int timeout) -{ -#if 0 - fd_set rfds; - struct timeval tv; - int retval; - int s; -#endif - int len, rlen; +// 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 (THREADSSL == NULL) return(0); - - len = 0; - while (len < bytes) { -#if 0 - /** - * This code is disabled because we don't need it when - * using blocking reads (which we are). -IO - */ - FD_ZERO(&rfds); - s = BIO_get_fd(THREADSSL->rbio, NULL); - FD_SET(s, &rfds); - tv.tv_sec = timeout; - tv.tv_usec = 0; - - retval = select(s + 1, &rfds, NULL, NULL, &tv); - - if (FD_ISSET(s, &rfds) == 0) { - return (0); - } + if (pssl == NULL) return(-1); -#endif - if (SSL_want_read(THREADSSL)) { - if ((SSL_write(THREADSSL, junk, 0)) < 1) { - lprintf(9, "SSL_write in client_read: %s\n", ERR_reason_error_string(ERR_get_error())); + 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(THREADSSL, &buf[len], bytes - len); + rlen = SSL_read(pssl, sbuf, sizeof(sbuf)); if (rlen < 1) { long errval; - errval = SSL_get_error(THREADSSL, rlen); - if (errval == SSL_ERROR_WANT_READ || - errval == SSL_ERROR_WANT_WRITE) { - sleep(1); + errval = SSL_get_error(pssl, rlen); + if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) { + sleeeeeeeeeep(1); continue; } - lprintf(9, "SSL_read got error %ld\n", errval); + syslog(LOG_WARNING, "SSL_read in client_read: %s", ERR_reason_error_string(ERR_get_error())); endtls(); - return (0); + return (-1); } - len += rlen; + StrBufAppendBufPlain(buf, sbuf, rlen, 0); + return rlen; } - return (1); + return (0); } - #endif /* HAVE_OPENSSL */ -/*@}*/