diff options
Diffstat (limited to 'modules/ssl/ssl_engine_pphrase.c')
| -rw-r--r-- | modules/ssl/ssl_engine_pphrase.c | 616 |
1 files changed, 616 insertions, 0 deletions
diff --git a/modules/ssl/ssl_engine_pphrase.c b/modules/ssl/ssl_engine_pphrase.c new file mode 100644 index 0000000..8c29443 --- /dev/null +++ b/modules/ssl/ssl_engine_pphrase.c @@ -0,0 +1,616 @@ +/* Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/* _ _ + * _ __ ___ ___ __| | ___ ___| | mod_ssl + * | '_ ` _ \ / _ \ / _` | / __/ __| | Apache Interface to OpenSSL + * | | | | | | (_) | (_| | \__ \__ \ | + * |_| |_| |_|\___/ \__,_|___|___/___/_| + * |_____| + * ssl_engine_pphrase.c + * Pass Phrase Dialog + */ + /* ``Treat your password like your + toothbrush. Don't let anybody + else use it, and get a new one + every six months.'' + -- Clifford Stoll */ +#include "ssl_private.h" + +typedef struct { + server_rec *s; + apr_pool_t *p; + apr_array_header_t *aPassPhrase; + int nPassPhraseCur; + char *cpPassPhraseCur; + int nPassPhraseDialog; + int nPassPhraseDialogCur; + BOOL bPassPhraseDialogOnce; + const char *key_id; + const char *pkey_file; +} pphrase_cb_arg_t; + +#ifdef HAVE_ECC +static const char *key_types[] = {"RSA", "DSA", "ECC"}; +#else +static const char *key_types[] = {"RSA", "DSA"}; +#endif + +/* + * Return true if the named file exists and is readable + */ + +static apr_status_t exists_and_readable(const char *fname, apr_pool_t *pool, + apr_time_t *mtime) +{ + apr_status_t stat; + apr_finfo_t sbuf; + apr_file_t *fd; + + if ((stat = apr_stat(&sbuf, fname, APR_FINFO_MIN, pool)) != APR_SUCCESS) + return stat; + + if (sbuf.filetype != APR_REG) + return APR_EGENERAL; + + if ((stat = apr_file_open(&fd, fname, APR_READ, 0, pool)) != APR_SUCCESS) + return stat; + + if (mtime) { + *mtime = sbuf.mtime; + } + + apr_file_close(fd); + return APR_SUCCESS; +} + +/* + * reuse vhost keys for asn1 tables where keys are allocated out + * of s->process->pool to prevent "leaking" each time we format + * a vhost key. since the key is stored in a table with lifetime + * of s->process->pool, the key needs to have the same lifetime. + * + * XXX: probably seems silly to use a hash table with keys and values + * being the same, but it is easier than doing a linear search + * and will make it easier to remove keys if needed in the future. + * also have the problem with apr_array_header_t that if we + * underestimate the number of vhost keys when we apr_array_make(), + * the array will get resized when we push past the initial number + * of elts. this resizing in the s->process->pool means "leaking" + * since apr_array_push() will apr_alloc arr->nalloc * 2 elts, + * leaving the original arr->elts to waste. + */ +static const char *asn1_table_vhost_key(SSLModConfigRec *mc, apr_pool_t *p, + const char *id, int i) +{ + /* 'p' pool used here is cleared on restarts (or sooner) */ + char *key = apr_psprintf(p, "%s:%d", id, i); + void *keyptr = apr_hash_get(mc->tVHostKeys, key, + APR_HASH_KEY_STRING); + + if (!keyptr) { + /* make a copy out of s->process->pool */ + keyptr = apr_pstrdup(mc->pPool, key); + apr_hash_set(mc->tVHostKeys, keyptr, + APR_HASH_KEY_STRING, keyptr); + } + + return (char *)keyptr; +} + +/* _________________________________________________________________ +** +** Pass Phrase and Private Key Handling +** _________________________________________________________________ +*/ + +#define BUILTIN_DIALOG_BACKOFF 2 +#define BUILTIN_DIALOG_RETRIES 5 + +static apr_file_t *writetty = NULL; +static apr_file_t *readtty = NULL; + +int ssl_pphrase_Handle_CB(char *, int, int, void *); + +static char *pphrase_array_get(apr_array_header_t *arr, int idx) +{ + if ((idx < 0) || (idx >= arr->nelts)) { + return NULL; + } + + return ((char **)arr->elts)[idx]; +} + +apr_status_t ssl_load_encrypted_pkey(server_rec *s, apr_pool_t *p, int idx, + const char *pkey_file, + apr_array_header_t **pphrases) +{ + SSLModConfigRec *mc = myModConfig(s); + SSLSrvConfigRec *sc = mySrvConfig(s); + const char *key_id = asn1_table_vhost_key(mc, p, sc->vhost_id, idx); + EVP_PKEY *pPrivateKey = NULL; + ssl_asn1_t *asn1; + unsigned char *ucp; + long int length; + int nPassPhrase = (*pphrases)->nelts; + int nPassPhraseRetry = 0; + apr_time_t pkey_mtime = 0; + apr_status_t rv; + pphrase_cb_arg_t ppcb_arg; + + if (!pkey_file) { + ap_log_error(APLOG_MARK, APLOG_EMERG, 0, s, APLOGNO(02573) + "Init: No private key specified for %s", key_id); + return ssl_die(s); + } + else if ((rv = exists_and_readable(pkey_file, p, &pkey_mtime)) + != APR_SUCCESS ) { + ap_log_error(APLOG_MARK, APLOG_EMERG, rv, s, APLOGNO(02574) + "Init: Can't open server private key file %s", pkey_file); + return ssl_die(s); + } + + ppcb_arg.s = s; + ppcb_arg.p = p; + ppcb_arg.aPassPhrase = *pphrases; + ppcb_arg.nPassPhraseCur = 0; + ppcb_arg.cpPassPhraseCur = NULL; + ppcb_arg.nPassPhraseDialog = 0; + ppcb_arg.nPassPhraseDialogCur = 0; + ppcb_arg.bPassPhraseDialogOnce = TRUE; + ppcb_arg.key_id = key_id; + ppcb_arg.pkey_file = pkey_file; + + /* + * if the private key is encrypted and SSLPassPhraseDialog + * is configured to "builtin" it isn't possible to prompt for + * a password after httpd has detached from the tty. + * in this case if we already have a private key and the + * file name/mtime hasn't changed, then reuse the existing key. + * we also reuse existing private keys that were encrypted for + * exec: and pipe: dialogs to minimize chances to snoop the + * password. that and pipe: dialogs might prompt the user + * for password, which on win32 for example could happen 4 + * times at startup. twice for each child and twice within + * each since apache "restarts itself" on startup. + * of course this will not work for the builtin dialog if + * the server was started without LoadModule ssl_module + * configured, then restarted with it configured. + * but we fall through with a chance of success if the key + * is not encrypted or can be handled via exec or pipe dialog. + * and in the case of fallthrough, pkey_mtime and isatty() + * are used to give a better idea as to what failed. + */ + if (pkey_mtime) { + ssl_asn1_t *asn1 = ssl_asn1_table_get(mc->tPrivateKey, key_id); + if (asn1 && (asn1->source_mtime == pkey_mtime)) { + ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, APLOGNO(02575) + "Reusing existing private key from %s on restart", + ppcb_arg.pkey_file); + return APR_SUCCESS; + } + } + + ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, APLOGNO(02576) + "Attempting to load encrypted (?) private key %s", key_id); + + for (;;) { + /* + * Try to read the private key file with the help of + * the callback function which serves the pass + * phrases to OpenSSL + */ + + ppcb_arg.cpPassPhraseCur = NULL; + + /* Ensure that the error stack is empty; some SSL + * functions will fail spuriously if the error stack + * is not empty. */ + ERR_clear_error(); + + pPrivateKey = modssl_read_privatekey(ppcb_arg.pkey_file, NULL, + ssl_pphrase_Handle_CB, &ppcb_arg); + /* If the private key was successfully read, nothing more to + do here. */ + if (pPrivateKey != NULL) + break; + + /* + * when we have more remembered pass phrases + * try to reuse these first. + */ + if (ppcb_arg.nPassPhraseCur < nPassPhrase) { + ppcb_arg.nPassPhraseCur++; + continue; + } + + /* + * else it's not readable and we have no more + * remembered pass phrases. Then this has to mean + * that the callback function popped up the dialog + * but a wrong pass phrase was entered. We give the + * user (but not the dialog program) a few more + * chances... + */ +#ifndef WIN32 + if ((sc->server->pphrase_dialog_type == SSL_PPTYPE_BUILTIN + || sc->server->pphrase_dialog_type == SSL_PPTYPE_PIPE) +#else + if (sc->server->pphrase_dialog_type == SSL_PPTYPE_PIPE +#endif + && ppcb_arg.cpPassPhraseCur != NULL + && nPassPhraseRetry < BUILTIN_DIALOG_RETRIES ) { + apr_file_printf(writetty, "Apache:mod_ssl:Error: Pass phrase incorrect " + "(%d more retr%s permitted).\n", + (BUILTIN_DIALOG_RETRIES-nPassPhraseRetry), + (BUILTIN_DIALOG_RETRIES-nPassPhraseRetry) == 1 ? "y" : "ies"); + nPassPhraseRetry++; + if (nPassPhraseRetry > BUILTIN_DIALOG_BACKOFF) + apr_sleep((nPassPhraseRetry-BUILTIN_DIALOG_BACKOFF) + * 5 * APR_USEC_PER_SEC); + continue; + } +#ifdef WIN32 + if (sc->server->pphrase_dialog_type == SSL_PPTYPE_BUILTIN) { + ap_log_error(APLOG_MARK, APLOG_EMERG, 0, s, APLOGNO(02577) + "Init: SSLPassPhraseDialog builtin is not " + "supported on Win32 (key file " + "%s)", ppcb_arg.pkey_file); + return ssl_die(s); + } +#endif /* WIN32 */ + + /* + * Ok, anything else now means a fatal error. + */ + if (ppcb_arg.cpPassPhraseCur == NULL) { + if (ppcb_arg.nPassPhraseDialogCur && pkey_mtime && + !isatty(fileno(stdout))) /* XXX: apr_isatty() */ + { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, + s, APLOGNO(02578) + "Init: Unable to read pass phrase " + "[Hint: key introduced or changed " + "before restart?]"); + ssl_log_ssl_error(SSLLOG_MARK, APLOG_ERR, s); + } + else { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, + s, APLOGNO(02579) "Init: Private key not found"); + ssl_log_ssl_error(SSLLOG_MARK, APLOG_ERR, s); + } + if (writetty) { + apr_file_printf(writetty, "Apache:mod_ssl:Error: Private key not found.\n"); + apr_file_printf(writetty, "**Stopped\n"); + } + } + else { + ap_log_error(APLOG_MARK, APLOG_EMERG, 0, s, APLOGNO(02580) + "Init: Pass phrase incorrect for key %s", + key_id); + ssl_log_ssl_error(SSLLOG_MARK, APLOG_EMERG, s); + + if (writetty) { + apr_file_printf(writetty, "Apache:mod_ssl:Error: Pass phrase incorrect.\n"); + apr_file_printf(writetty, "**Stopped\n"); + } + } + return ssl_die(s); + } + + if (pPrivateKey == NULL) { + ap_log_error(APLOG_MARK, APLOG_EMERG, 0, s, APLOGNO(02581) + "Init: Unable to read server private key from file %s", + ppcb_arg.pkey_file); + ssl_log_ssl_error(SSLLOG_MARK, APLOG_EMERG, s); + return ssl_die(s); + } + + /* + * Log the type of reading + */ + if (ppcb_arg.nPassPhraseDialogCur == 0) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(02582) + "unencrypted %s private key - pass phrase not " + "required", key_id); + } + else { + if (ppcb_arg.cpPassPhraseCur != NULL) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, + s, APLOGNO(02583) + "encrypted %s private key - pass phrase " + "requested", key_id); + } + else { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, + s, APLOGNO(02584) + "encrypted %s private key - pass phrase" + " reused", key_id); + } + } + + /* + * Ok, when we have one more pass phrase store it + */ + if (ppcb_arg.cpPassPhraseCur != NULL) { + *(const char **)apr_array_push(ppcb_arg.aPassPhrase) = + ppcb_arg.cpPassPhraseCur; + nPassPhrase++; + } + + /* + * Insert private key into the global module configuration + * (we convert it to a stand-alone DER byte sequence + * because the SSL library uses static variables inside a + * RSA structure which do not survive DSO reloads!) + */ + length = i2d_PrivateKey(pPrivateKey, NULL); + ucp = ssl_asn1_table_set(mc->tPrivateKey, key_id, length); + (void)i2d_PrivateKey(pPrivateKey, &ucp); /* 2nd arg increments */ + + if (ppcb_arg.nPassPhraseDialogCur != 0) { + /* remember mtime of encrypted keys */ + asn1 = ssl_asn1_table_get(mc->tPrivateKey, key_id); + asn1->source_mtime = pkey_mtime; + } + + /* + * Free the private key structure + */ + EVP_PKEY_free(pPrivateKey); + + /* + * Let the user know when we're successful. + */ + if ((ppcb_arg.nPassPhraseDialog > 0) && + (ppcb_arg.cpPassPhraseCur != NULL)) { + if (writetty) { + apr_file_printf(writetty, "\n" + "OK: Pass Phrase Dialog successful.\n"); + } + } + + /* Close the pipes if they were opened + */ + if (readtty) { + apr_file_close(readtty); + apr_file_close(writetty); + readtty = writetty = NULL; + } + + return APR_SUCCESS; +} + +static apr_status_t ssl_pipe_child_create(apr_pool_t *p, const char *progname) +{ + /* Child process code for 'ErrorLog "|..."'; + * may want a common framework for this, since I expect it will + * be common for other foo-loggers to want this sort of thing... + */ + apr_status_t rc; + apr_procattr_t *procattr; + apr_proc_t *procnew; + + if (((rc = apr_procattr_create(&procattr, p)) == APR_SUCCESS) && + ((rc = apr_procattr_io_set(procattr, + APR_FULL_BLOCK, + APR_FULL_BLOCK, + APR_NO_PIPE)) == APR_SUCCESS)) { + char **args; + + apr_tokenize_to_argv(progname, &args, p); + procnew = (apr_proc_t *)apr_pcalloc(p, sizeof(*procnew)); + rc = apr_proc_create(procnew, args[0], (const char * const *)args, + NULL, procattr, p); + if (rc == APR_SUCCESS) { + /* XXX: not sure if we aught to... + * apr_pool_note_subprocess(p, procnew, APR_KILL_AFTER_TIMEOUT); + */ + writetty = procnew->in; + readtty = procnew->out; + } + } + + return rc; +} + +static int pipe_get_passwd_cb(char *buf, int length, char *prompt, int verify) +{ + apr_status_t rc; + char *p; + + apr_file_puts(prompt, writetty); + + buf[0]='\0'; + rc = apr_file_gets(buf, length, readtty); + apr_file_puts(APR_EOL_STR, writetty); + + if (rc != APR_SUCCESS || apr_file_eof(readtty)) { + memset(buf, 0, length); + return 1; /* failure */ + } + if ((p = strchr(buf, '\n')) != NULL) { + *p = '\0'; + } +#ifdef WIN32 + /* XXX: apr_sometest */ + if ((p = strchr(buf, '\r')) != NULL) { + *p = '\0'; + } +#endif + return 0; +} + +int ssl_pphrase_Handle_CB(char *buf, int bufsize, int verify, void *srv) +{ + pphrase_cb_arg_t *ppcb_arg = (pphrase_cb_arg_t *)srv; + SSLSrvConfigRec *sc = mySrvConfig(ppcb_arg->s); + char *cpp; + int len = -1; + + ppcb_arg->nPassPhraseDialog++; + ppcb_arg->nPassPhraseDialogCur++; + + /* + * When remembered pass phrases are available use them... + */ + if ((cpp = pphrase_array_get(ppcb_arg->aPassPhrase, + ppcb_arg->nPassPhraseCur)) != NULL) { + apr_cpystrn(buf, cpp, bufsize); + len = strlen(buf); + return len; + } + + /* + * Builtin or Pipe dialog + */ + if (sc->server->pphrase_dialog_type == SSL_PPTYPE_BUILTIN + || sc->server->pphrase_dialog_type == SSL_PPTYPE_PIPE) { + char *prompt; + int i; + + if (sc->server->pphrase_dialog_type == SSL_PPTYPE_PIPE) { + if (!readtty) { + ap_log_error(APLOG_MARK, APLOG_INFO, 0, ppcb_arg->s, + APLOGNO(01965) + "Init: Creating pass phrase dialog pipe child " + "'%s'", sc->server->pphrase_dialog_path); + if (ssl_pipe_child_create(ppcb_arg->p, + sc->server->pphrase_dialog_path) + != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, ppcb_arg->s, + APLOGNO(01966) + "Init: Failed to create pass phrase pipe '%s'", + sc->server->pphrase_dialog_path); + PEMerr(PEM_F_PEM_DEF_CALLBACK, + PEM_R_PROBLEMS_GETTING_PASSWORD); + memset(buf, 0, (unsigned int)bufsize); + return (-1); + } + } + ap_log_error(APLOG_MARK, APLOG_INFO, 0, ppcb_arg->s, APLOGNO(01967) + "Init: Requesting pass phrase via piped dialog"); + } + else { /* sc->server->pphrase_dialog_type == SSL_PPTYPE_BUILTIN */ +#ifdef WIN32 + PEMerr(PEM_F_PEM_DEF_CALLBACK, PEM_R_PROBLEMS_GETTING_PASSWORD); + memset(buf, 0, (unsigned int)bufsize); + return (-1); +#else + /* + * stderr has already been redirected to the error_log. + * rather than attempting to temporarily rehook it to the terminal, + * we print the prompt to stdout before EVP_read_pw_string turns + * off tty echo + */ + apr_file_open_stdout(&writetty, ppcb_arg->p); + + ap_log_error(APLOG_MARK, APLOG_INFO, 0, ppcb_arg->s, APLOGNO(01968) + "Init: Requesting pass phrase via builtin terminal " + "dialog"); +#endif + } + + /* + * The first time display a header to inform the user about what + * program he actually speaks to, which module is responsible for + * this terminal dialog and why to the hell he has to enter + * something... + */ + if (ppcb_arg->nPassPhraseDialog == 1) { + apr_file_printf(writetty, "%s mod_ssl (Pass Phrase Dialog)\n", + AP_SERVER_BASEVERSION); + apr_file_printf(writetty, "Some of your private key files are encrypted for security reasons.\n"); + apr_file_printf(writetty, "In order to read them you have to provide the pass phrases.\n"); + } + if (ppcb_arg->bPassPhraseDialogOnce) { + ppcb_arg->bPassPhraseDialogOnce = FALSE; + apr_file_printf(writetty, "\n"); + apr_file_printf(writetty, "Private key %s (%s)\n", + ppcb_arg->key_id, ppcb_arg->pkey_file); + } + + /* + * Emulate the OpenSSL internal pass phrase dialog + * (see crypto/pem/pem_lib.c:def_callback() for details) + */ + prompt = "Enter pass phrase:"; + + for (;;) { + apr_file_puts(prompt, writetty); + if (sc->server->pphrase_dialog_type == SSL_PPTYPE_PIPE) { + i = pipe_get_passwd_cb(buf, bufsize, "", FALSE); + } + else { /* sc->server->pphrase_dialog_type == SSL_PPTYPE_BUILTIN */ + i = EVP_read_pw_string(buf, bufsize, "", FALSE); + } + if (i != 0) { + PEMerr(PEM_F_PEM_DEF_CALLBACK,PEM_R_PROBLEMS_GETTING_PASSWORD); + memset(buf, 0, (unsigned int)bufsize); + return (-1); + } + len = strlen(buf); + if (len < 1) + apr_file_printf(writetty, "Apache:mod_ssl:Error: Pass phrase empty (needs to be at least 1 character).\n"); + else + break; + } + } + + /* + * Filter program + */ + else if (sc->server->pphrase_dialog_type == SSL_PPTYPE_FILTER) { + const char *cmd = sc->server->pphrase_dialog_path; + const char **argv = apr_palloc(ppcb_arg->p, sizeof(char *) * 4); + const char *idx = ap_strrchr_c(ppcb_arg->key_id, ':') + 1; + char *result; + int i; + + ap_log_error(APLOG_MARK, APLOG_INFO, 0, ppcb_arg->s, APLOGNO(01969) + "Init: Requesting pass phrase from dialog filter " + "program (%s)", cmd); + + argv[0] = cmd; + argv[1] = apr_pstrndup(ppcb_arg->p, ppcb_arg->key_id, + idx-1 - ppcb_arg->key_id); + if ((i = atoi(idx)) < CERTKEYS_IDX_MAX+1) { + /* + * For compatibility with existing 2.4.x configurations, use + * "RSA", "DSA" and "ECC" strings for the first two/three keys + */ + argv[2] = key_types[i]; + } else { + /* Four and above: use the integer index */ + argv[2] = apr_pstrdup(ppcb_arg->p, idx); + } + argv[3] = NULL; + + result = ssl_util_readfilter(ppcb_arg->s, ppcb_arg->p, cmd, argv); + apr_cpystrn(buf, result, bufsize); + len = strlen(buf); + } + + /* + * Ok, we now have the pass phrase, so give it back + */ + ppcb_arg->cpPassPhraseCur = apr_pstrdup(ppcb_arg->p, buf); + + /* + * And return its length to OpenSSL... + */ + return (len); +} |