From: Matthias Andree Date: Thu, 25 Apr 2013 19:29:46 +0000 (+0200) Subject: Make SSL_verify callback data local. X-Git-Url: http://pileus.org/git/?p=~andy%2Ffetchmail;a=commitdiff_plain;h=9f99b463d27294281c778c9be890499ee1d84799 Make SSL_verify callback data local. Use SSL_set_ex_data() to store a pointer to a local SSL verify state and config, to avoid global variables. Call SSL initialization only on first use of SSLOpen(). --- diff --git a/socket.c b/socket.c index 06a8efb5..23ec5f1c 100644 --- a/socket.c +++ b/socket.c @@ -1,7 +1,9 @@ /* * socket.c -- socket library functions * - * Copyright 1998 by Eric S. Raymond. + * Copyright 1998, 2004 by Eric S. Raymond. + * Copyright 2004, 2013 by Matthias Andree. + * * For license terms, see the file COPYING in this directory. */ @@ -48,6 +50,10 @@ extern int h_errno; # endif #endif /* ndef h_errno */ +/* used by SSL_get_ex_new_index, SSL_set_ex_data, SSL_get_ex_data, to communicate + options and state with the verify callback */ +static int global_mydata_index = -2; + static char *const *parse_plugin(const char *plugin, const char *host, const char *service) { char **argvec; @@ -510,14 +516,19 @@ int SockPeek(int sock) #ifdef SSL_ENABLE -static char *_ssl_server_cname = NULL; -static int _check_fp; -static char *_check_digest; -static char *_server_label; -static int _depth0ck; -static int _firstrun; -static int _prev_err; -static int _verify_ok; +struct ssl_callback_data { + char *ssl_server_cname; + char *check_digest; + char *server_label; + int check_fp; + int depth0ck; + int firstrun; + int prev_err; + int verify_ok; + int strict_mode; +}; + +typedef struct ssl_callback_data t_ssl_callback_data; SSL *SSLGetContext( int sock ) { @@ -531,7 +542,7 @@ SSL *SSLGetContext( int sock ) /* ok_return (preverify_ok) is 1 if this stage of certificate verification passed, or 0 if it failed. This callback lets us display informative errors, and perform additional validation (e.g. CN matches) */ -static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict ) +static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx) { #define SSLverbose (((outlevel) >= O_DEBUG) || ((outlevel) >= O_VERBOSE && (depth) == 0)) char buf[257]; @@ -543,7 +554,11 @@ static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict ) unsigned int dsz, esz; X509_NAME *subj, *issuer; char *tt; + t_ssl_callback_data *mydata; + SSL *ssl; + ssl = X509_STORE_CTX_get_ex_data(ctx, SSL_get_ex_data_X509_STORE_CTX_idx()); + mydata = SSL_get_ex_data(ssl, global_mydata_index); x509_cert = X509_STORE_CTX_get_current_cert(ctx); err = X509_STORE_CTX_get_error(ctx); depth = X509_STORE_CTX_get_error_depth(ctx); @@ -555,8 +570,8 @@ static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict ) if (depth == 0 && SSLverbose) report(stdout, GT_("Server certificate:\n")); else { - if (_firstrun) { - _firstrun = 0; + if (mydata->firstrun) { + mydata->firstrun = 0; if (SSLverbose) report(stdout, GT_("Certificate chain, from root to peer, starting at depth %d:\n"), depth); } else { @@ -603,14 +618,14 @@ static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict ) } if (depth == 0) { /* peer certificate */ - if (!_depth0ck) { - _depth0ck = 1; + if (!mydata->depth0ck) { + mydata->depth0ck = 1; } if ((i = X509_NAME_get_text_by_NID(subj, NID_commonName, buf, sizeof(buf))) != -1) { - if (_ssl_server_cname != NULL) { + if (mydata->ssl_server_cname != NULL) { char *p1 = buf; - char *p2 = _ssl_server_cname; + char *p2 = mydata->ssl_server_cname; int matched = 0; STACK_OF(GENERAL_NAME) *gens; @@ -623,7 +638,7 @@ static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict ) const GENERAL_NAME *gn = sk_GENERAL_NAME_value(gens, j); if (gn->type == GEN_DNS) { char *pp1 = (char *)gn->d.ia5->data; - char *pp2 = _ssl_server_cname; + char *pp2 = mydata->ssl_server_cname; if (outlevel >= O_VERBOSE) { report(stdout, GT_("Subject Alternative Name: %s\n"), (tt = sdump(pp1, (size_t)gn->d.ia5->length))); xfree(tt); @@ -646,32 +661,32 @@ static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict ) matched = 1; } if (!matched) { - if (strict || SSLverbose) { + if (mydata->strict_mode || SSLverbose) { report(stderr, GT_("Server CommonName mismatch: %s != %s\n"), - (tt = sdump(buf, i)), _ssl_server_cname ); + (tt = sdump(buf, i)), mydata->ssl_server_cname); xfree(tt); } ok_return = 0; } } else if (ok_return) { report(stderr, GT_("Server name not set, could not verify certificate!\n")); - if (strict) return (0); + if (mydata->strict_mode) return (0); } } else { if (outlevel >= O_VERBOSE) report(stdout, GT_("Unknown Server CommonName\n")); - if (ok_return && strict) { + if (ok_return && mydata->strict_mode) { report(stderr, GT_("Server name not specified in certificate!\n")); return (0); } } /* Print the finger print. Note that on errors, we might print it more than once * normally; we kluge around that by using a global variable. */ - if (_check_fp == 1) { + if (1 == mydata->check_fp) { unsigned dp; - _check_fp = -1; + mydata->check_fp = -1; digest_tp = EVP_md5(); if (digest_tp == NULL) { report(stderr, GT_("EVP_md5() failed!\n")); @@ -692,23 +707,23 @@ static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict ) tp += esz; } if (outlevel > O_NORMAL) - report(stdout, GT_("%s key fingerprint: %s\n"), _server_label, text); - if (_check_digest != NULL) { - if (strcasecmp(text, _check_digest) == 0) { + report(stdout, GT_("%s certificate MD5 fingerprint: %s\n"), mydata->server_label, text); + if (mydata->check_digest != NULL) { + if (strcasecmp(text, mydata->check_digest) == 0) { if (outlevel > O_NORMAL) - report(stdout, GT_("%s fingerprints match.\n"), _server_label); + report(stdout, GT_("%s fingerprints match.\n"), mydata->server_label); } else { - report(stderr, GT_("%s fingerprints do not match!\n"), _server_label); + report(stderr, GT_("%s fingerprints do not match!\n"), mydata->server_label); return (0); } } /* if (_check_digest != NULL) */ } /* if (_check_fp) */ } /* if (depth == 0 && !_depth0ck) */ - if (err != X509_V_OK && err != _prev_err && !(_check_fp != 0 && _check_digest && !strict)) { + if (err != X509_V_OK && err != mydata->prev_err && !(mydata->check_fp != 0 && mydata->check_digest && !mydata->strict_mode)) { char *tmp; int did_rep_err = 0; - _prev_err = err; + mydata->prev_err = err; report(stderr, GT_("Server certificate verification error: %s\n"), X509_verify_cert_error_string(err)); /* We gave the error code, but maybe we can add some more details for debugging */ @@ -753,23 +768,12 @@ static int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx, int strict ) * If not in strict checking mode (--sslcertck), override this * and pretend that verification had succeeded. */ - _verify_ok &= ok_return; - if (!strict) + mydata->verify_ok &= ok_return; + if (!mydata->strict_mode) ok_return = 1; - return (ok_return); -} - -static int SSL_nock_verify_callback( int ok_return, X509_STORE_CTX *ctx ) -{ - return SSL_verify_callback(ok_return, ctx, 0); -} - -static int SSL_ck_verify_callback( int ok_return, X509_STORE_CTX *ctx ) -{ - return SSL_verify_callback(ok_return, ctx, 1); + return ok_return; } - /* get commonName from certificate set in file. * commonName is stored in buffer namebuffer, limited with namebufferlen */ @@ -811,9 +815,19 @@ int SSLOpen(int sock, char *mycert, char *mykey, const char *myproto, int certck struct stat randstat; int i; - SSL_load_error_strings(); - SSL_library_init(); - OpenSSL_add_all_algorithms(); /* see Debian Bug#576430 and manpage */ + static int ssl_lib_init = 0; + + if (!ssl_lib_init) { + SSL_load_error_strings(); + SSL_library_init(); + OpenSSL_add_all_algorithms(); /* see Debian Bug#576430 and manpage */ + ssl_lib_init = 1; + } + + if (-2 == global_mydata_index) { + global_mydata_index = SSL_get_ex_new_index(0, "fetchmail SSL callback data", NULL, NULL, NULL); + if (-1 == global_mydata_index) return PS_UNDEFINED; + } if (stat("/dev/random", &randstat) && stat("/dev/urandom", &randstat)) { @@ -859,15 +873,7 @@ int SSLOpen(int sock, char *mycert, char *mykey, const char *myproto, int certck } SSL_CTX_set_options(_ctx[sock], (SSL_OP_ALL | SSL_OP_NO_SSLv2) & ~SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS); - - if (certck) { - SSL_CTX_set_verify(_ctx[sock], SSL_VERIFY_PEER, SSL_ck_verify_callback); - } else { - /* In this case, we do not fail if verification fails. However, - * we provide the callback for output and possible fingerprint - * checks. */ - SSL_CTX_set_verify(_ctx[sock], SSL_VERIFY_PEER, SSL_nock_verify_callback); - } + SSL_CTX_set_verify(_ctx[sock], SSL_VERIFY_PEER, SSL_verify_callback); /* Check which trusted X.509 CA certificate store(s) to load */ { @@ -896,15 +902,19 @@ int SSLOpen(int sock, char *mycert, char *mykey, const char *myproto, int certck return(-1); } - /* This static is for the verify callback */ - _ssl_server_cname = servercname; - _server_label = label; - _check_fp = 1; - _check_digest = fingerprint; - _depth0ck = 0; - _firstrun = 1; - _verify_ok = 1; - _prev_err = -1; + t_ssl_callback_data mydata; + memset(&mydata, 0, sizeof(mydata)); + + /* This data is for the verify callback */ + mydata.ssl_server_cname = servercname; + mydata.server_label = label; + mydata.check_fp = 1; + mydata.check_digest = fingerprint; + mydata.depth0ck = 0; + mydata.firstrun = 1; + mydata.verify_ok = 1; + mydata.prev_err = -1; + mydata.strict_mode = certck; if( mycert || mykey ) { @@ -927,6 +937,8 @@ int SSLOpen(int sock, char *mycert, char *mykey, const char *myproto, int certck SSL_use_RSAPrivateKey_file(_ssl_context[sock], mykey, SSL_FILETYPE_PEM); } + SSL_set_ex_data(_ssl_context[sock], global_mydata_index, &mydata); + if (SSL_set_fd(_ssl_context[sock], sock) == 0 || SSL_connect(_ssl_context[sock]) < 1) { ERR_print_errors_fp(stderr); @@ -938,7 +950,7 @@ int SSLOpen(int sock, char *mycert, char *mykey, const char *myproto, int certck } /* Paranoia: was the callback not called as we expected? */ - if (!_depth0ck) { + if (!mydata.depth0ck) { report(stderr, GT_("Certificate/fingerprint verification was somehow skipped!\n")); if (fingerprint != NULL || certck) { @@ -955,7 +967,7 @@ int SSLOpen(int sock, char *mycert, char *mykey, const char *myproto, int certck } if (!certck && !fingerprint && - (SSL_get_verify_result(_ssl_context[sock]) != X509_V_OK || !_verify_ok)) { + (SSL_get_verify_result(_ssl_context[sock]) != X509_V_OK || !mydata.verify_ok)) { report(stderr, GT_("Warning: the connection is insecure, continuing anyways. (Better use --sslcertck!)\n")); }