X-Git-Url: https://git.llucax.com/software/mutt-debian.git/blobdiff_plain/14c29200cb58d3c4a0830265f2433849781858d0..0ca86972afbf27082baed26631273e0fc78e8c6b:/mutt_ssl.c diff --git a/mutt_ssl.c b/mutt_ssl.c index 7883465..7de574e 100644 --- a/mutt_ssl.c +++ b/mutt_ssl.c @@ -22,6 +22,7 @@ #include #include +#include #include #include @@ -34,6 +35,7 @@ #include "mutt_menu.h" #include "mutt_curses.h" #include "mutt_ssl.h" +#include "mutt_idna.h" #if OPENSSL_VERSION_NUMBER >= 0x00904000L #define READ_X509_KEY(fp, key) PEM_read_X509(fp, key, NULL, NULL) @@ -58,6 +60,10 @@ static int entropy_byte_count = 0; #define HAVE_ENTROPY() (!access(DEVRANDOM, R_OK) || entropy_byte_count >= 16) #endif +/* keep a handle on accepted certificates in case we want to + * open up another connection to the same server in this session */ +static STACK_OF(X509) *SslSessionCerts = NULL; + typedef struct _sslsockdata { SSL_CTX *ctx; @@ -67,17 +73,19 @@ typedef struct _sslsockdata sslsockdata; /* local prototypes */ -int ssl_init (void); +static int ssl_init (void); static int add_entropy (const char *file); static int ssl_socket_read (CONNECTION* conn, char* buf, size_t len); static int ssl_socket_write (CONNECTION* conn, const char* buf, size_t len); static int ssl_socket_open (CONNECTION * conn); static int ssl_socket_close (CONNECTION * conn); static int tls_close (CONNECTION* conn); -static int ssl_check_certificate (sslsockdata * data); +static int ssl_cache_trusted_cert (X509 *cert); +static int ssl_check_certificate (CONNECTION *conn, sslsockdata * data); +static int interactive_check_cert (X509 *cert, int idx, int len); static void ssl_get_client_cert(sslsockdata *ssldata, CONNECTION *conn); static int ssl_passwd_cb(char *buf, int size, int rwflag, void *userdata); -static int ssl_negotiate (sslsockdata*); +static int ssl_negotiate (CONNECTION *conn, sslsockdata*); /* mutt_ssl_starttls: Negotiate TLS over an already opened connection. * TODO: Merge this code better with ssl_socket_open. */ @@ -111,7 +119,7 @@ int mutt_ssl_starttls (CONNECTION* conn) goto bail_ssl; } - if (ssl_negotiate (ssldata)) + if (ssl_negotiate (conn, ssldata)) goto bail_ssl; /* hmm. watch out if we're starting TLS over any method other than raw. */ @@ -145,7 +153,7 @@ int mutt_ssl_starttls (CONNECTION* conn) * versions also. (That's the reason for the ugly #ifdefs and macros, * otherwise I could have simply #ifdef'd the whole ssl_init funcion) */ -int ssl_init (void) +static int ssl_init (void) { char path[_POSIX_PATH_MAX]; static unsigned char init_complete = 0; @@ -290,7 +298,7 @@ static int ssl_socket_open (CONNECTION * conn) data->ssl = SSL_new (data->ctx); SSL_set_fd (data->ssl, conn->fd); - if (ssl_negotiate(data)) + if (ssl_negotiate(conn, data)) { mutt_socket_close (conn); return -1; @@ -304,7 +312,7 @@ static int ssl_socket_open (CONNECTION * conn) /* ssl_negotiate: After SSL state has been initialised, attempt to negotiate * SSL over the wire, including certificate checks. */ -static int ssl_negotiate (sslsockdata* ssldata) +static int ssl_negotiate (CONNECTION *conn, sslsockdata* ssldata) { int err; const char* errmsg; @@ -343,7 +351,7 @@ static int ssl_negotiate (sslsockdata* ssldata) return -1; } - if (!ssl_check_certificate (ssldata)) + if (!ssl_check_certificate (conn, ssldata)) return -1; mutt_message (_("SSL connection using %s (%s)"), @@ -450,7 +458,7 @@ static int check_certificate_by_signer (X509 *peercert) { X509_STORE_CTX xsc; X509_STORE *ctx; - int pass = 0; + int pass = 0, i; ctx = X509_STORE_new (); if (ctx == NULL) return 0; @@ -468,6 +476,9 @@ static int check_certificate_by_signer (X509 *peercert) else dprint (2, (debugfile, "X509_STORE_load_locations_failed\n")); + for (i = 0; i < sk_X509_num (SslSessionCerts); i++) + pass += (X509_STORE_add_cert (ctx, sk_X509_value (SslSessionCerts, i)) != 0); + if (pass == 0) { /* nothing to do */ @@ -475,7 +486,7 @@ static int check_certificate_by_signer (X509 *peercert) return 0; } - X509_STORE_CTX_init (&xsc, ctx, peercert, NULL); + X509_STORE_CTX_init (&xsc, ctx, peercert, SslSessionCerts); pass = (X509_verify_cert (&xsc) > 0); #ifdef DEBUG @@ -488,6 +499,7 @@ static int check_certificate_by_signer (X509 *peercert) snprintf (buf, sizeof (buf), "%s (%d)", X509_verify_cert_error_string(err), err); dprint (2, (debugfile, "X509_verify_cert: %s\n", buf)); + dprint (2, (debugfile, " [%s]\n", peercert->name)); } #endif X509_STORE_CTX_cleanup (&xsc); @@ -523,16 +535,17 @@ static int check_certificate_cache (X509 *peercert) unsigned char peermd[EVP_MAX_MD_SIZE]; unsigned int peermdlen; X509 *cert; - LIST *scert; + int i; - if (!X509_digest (peercert, EVP_sha1(), peermd, &peermdlen)) + if (!X509_digest (peercert, EVP_sha1(), peermd, &peermdlen) + || !SslSessionCerts) { return 0; } - for (scert = SslSessionCerts; scert; scert = scert->next) + for (i = sk_X509_num (SslSessionCerts); i-- > 0;) { - cert = *(X509**)scert->data; + cert = sk_X509_value (SslSessionCerts, i); if (!compare_certificates (cert, peercert, peermd, peermdlen)) { return 1; @@ -588,39 +601,241 @@ static int check_certificate_by_digest (X509 *peercert) return pass; } -static int ssl_check_certificate (sslsockdata * data) +/* port to mutt from msmtp's tls.c */ +static int hostname_match (const char *hostname, const char *certname) +{ + const char *cmp1, *cmp2; + + if (strncmp(certname, "*.", 2) == 0) + { + cmp1 = certname + 2; + cmp2 = strchr(hostname, '.'); + if (!cmp2) + { + return 0; + } + else + { + cmp2++; + } + } + else + { + cmp1 = certname; + cmp2 = hostname; + } + + if (*cmp1 == '\0' || *cmp2 == '\0') + { + return 0; + } + + if (strcasecmp(cmp1, cmp2) != 0) + { + return 0; + } + + return 1; +} + +/* port to mutt from msmtp's tls.c */ +static int check_host (X509 *x509cert, const char *hostname, char *err, size_t errlen) +{ + int i, rc = 0; + /* hostname in ASCII format: */ + char *hostname_ascii = NULL; + /* needed to get the common name: */ + X509_NAME *x509_subject; + char *buf = NULL; + int bufsize; + /* needed to get the DNS subjectAltNames: */ + STACK *subj_alt_names; + int subj_alt_names_count; + GENERAL_NAME *subj_alt_name; + /* did we find a name matching hostname? */ + int match_found; + + /* Check if 'hostname' matches the one of the subjectAltName extensions of + * type DNS or the Common Name (CN). */ + +#ifdef HAVE_LIBIDN + if (idna_to_ascii_lz(hostname, &hostname_ascii, 0) != IDNA_SUCCESS) + { + hostname_ascii = safe_strdup(hostname); + } +#else + hostname_ascii = safe_strdup(hostname); +#endif + + /* Try the DNS subjectAltNames. */ + match_found = 0; + if ((subj_alt_names = X509_get_ext_d2i(x509cert, NID_subject_alt_name, + NULL, NULL))) + { + subj_alt_names_count = sk_GENERAL_NAME_num(subj_alt_names); + for (i = 0; i < subj_alt_names_count; i++) + { + subj_alt_name = sk_GENERAL_NAME_value(subj_alt_names, i); + if (subj_alt_name->type == GEN_DNS) + { + if ((match_found = hostname_match(hostname_ascii, + (char *)(subj_alt_name->d.ia5->data)))) + { + break; + } + } + } + } + + if (!match_found) + { + /* Try the common name */ + if (!(x509_subject = X509_get_subject_name(x509cert))) + { + if (err && errlen) + strfcpy (err, _("cannot get certificate subject"), errlen); + goto out; + } + + bufsize = X509_NAME_get_text_by_NID(x509_subject, NID_commonName, + NULL, 0); + bufsize++; + buf = safe_malloc((size_t)bufsize); + if (X509_NAME_get_text_by_NID(x509_subject, NID_commonName, + buf, bufsize) == -1) + { + if (err && errlen) + strfcpy (err, _("cannot get certificate common name"), errlen); + goto out; + } + match_found = hostname_match(hostname_ascii, buf); + } + + if (!match_found) + { + if (err && errlen) + snprintf (err, errlen, _("certificate owner does not match hostname %s"), + hostname); + goto out; + } + + rc = 1; + +out: + FREE(&buf); + FREE(&hostname_ascii); + + return rc; +} + +static int ssl_cache_trusted_cert (X509 *c) +{ + dprint (1, (debugfile, "trusted: %s\n", c->name)); + if (!SslSessionCerts) + SslSessionCerts = sk_new_null(); + return (sk_X509_push (SslSessionCerts, X509_dup(c))); +} + +/* check whether cert is preauthorized */ +static int ssl_check_preauth (X509 *cert, CONNECTION *conn) { - char *part[] = - {"/CN=", "/Email=", "/O=", "/OU=", "/L=", "/ST=", "/C="}; - char helpstr[LONG_STRING]; char buf[SHORT_STRING]; - MUTTMENU *menu; - int done, row, i; - FILE *fp; - char *name = NULL, *c; /* check session cache first */ - if (check_certificate_cache (data->cert)) + if (check_certificate_cache (cert)) { - dprint (1, (debugfile, "ssl_check_certificate: using cached certificate\n")); + dprint (2, (debugfile, "ssl_check_preauth: using cached certificate\n")); return 1; } - if (check_certificate_by_signer (data->cert)) + buf[0] = 0; + if (!check_host (cert, conn->account.host, buf, sizeof (buf))) + { + mutt_error (_("Certificate host check failed: %s"), buf); + mutt_sleep (2); + return -1; + } + dprint (2, (debugfile, "ssl_check_preauth: hostname check passed\n")); + + if (check_certificate_by_signer (cert)) { - dprint (1, (debugfile, "ssl_check_certificate: signer check passed\n")); + dprint (2, (debugfile, "ssl_check_preauth: signer check passed\n")); return 1; } /* automatic check from user's database */ - if (SslCertFile && check_certificate_by_digest (data->cert)) + if (SslCertFile && check_certificate_by_digest (cert)) { - dprint (1, (debugfile, "ssl_check_certificate: digest check passed\n")); + dprint (2, (debugfile, "ssl_check_preauth: digest check passed\n")); return 1; } - /* interactive check from user */ - menu = mutt_new_menu (); + return 0; +} + +static int ssl_check_certificate (CONNECTION *conn, sslsockdata *data) +{ + int i, preauthrc, chain_len; + STACK_OF(X509) *chain; + X509 *cert; + + if ((preauthrc = ssl_check_preauth (data->cert, conn)) > 0) + return preauthrc; + + chain = SSL_get_peer_cert_chain (data->ssl); + chain_len = sk_X509_num (chain); + if (!chain || (chain_len < 1)) + return interactive_check_cert (data->cert, 0, 0); + + /* check the chain from root to peer */ + for (i = chain_len-1; i >= 0; i--) + { + cert = sk_X509_value (chain, i); + if (check_certificate_cache (cert)) + dprint (2, (debugfile, "ssl chain: already cached: %s\n", cert->name)); + else if (i /* 0 is the peer */ || !preauthrc) + { + if (check_certificate_by_signer (cert)) + { + dprint (2, (debugfile, "ssl chain: checked by signer: %s\n", cert->name)); + ssl_cache_trusted_cert (cert); + return 1; + } + else if (SslCertFile && check_certificate_by_digest (cert)) + { + dprint (2, (debugfile, "ssl chain: trusted with file: %s\n", cert->name)); + ssl_cache_trusted_cert (cert); + return 1; + } + else /* allow users to shoot their foot */ + { + dprint (2, (debugfile, "ssl chain: check failed: %s\n", cert->name)); + if (interactive_check_cert (cert, i, chain_len)) + return 1; + } + } + else /* highly suspicious because (i==0 && preauthrc < 0) */ + if (interactive_check_cert (cert, i, chain_len)) + return 1; + } + + return 0; +} + +static int interactive_check_cert (X509 *cert, int idx, int len) +{ + char *part[] = + {"/CN=", "/Email=", "/O=", "/OU=", "/L=", "/ST=", "/C="}; + char helpstr[LONG_STRING]; + char buf[STRING]; + char title[STRING]; + MUTTMENU *menu = mutt_new_menu (-1); + int done, row, i; + FILE *fp; + char *name = NULL, *c; + + dprint (2, (debugfile, "interactive_check_cert: %s\n", cert->name)); + menu->max = 19; menu->dialog = (char **) safe_calloc (1, menu->max * sizeof (char *)); for (i = 0; i < menu->max; i++) @@ -629,8 +844,10 @@ static int ssl_check_certificate (sslsockdata * data) row = 0; strfcpy (menu->dialog[row], _("This certificate belongs to:"), SHORT_STRING); row++; - name = X509_NAME_oneline (X509_get_subject_name (data->cert), + name = X509_NAME_oneline (X509_get_subject_name (cert), buf, sizeof (buf)); + dprint (2, (debugfile, "oneline: %s\n", name)); + for (i = 0; i < 5; i++) { c = x509_get_part (name, part[i]); @@ -640,7 +857,7 @@ static int ssl_check_certificate (sslsockdata * data) row++; strfcpy (menu->dialog[row], _("This certificate was issued by:"), SHORT_STRING); row++; - name = X509_NAME_oneline (X509_get_issuer_name (data->cert), + name = X509_NAME_oneline (X509_get_issuer_name (cert), buf, sizeof (buf)); for (i = 0; i < 5; i++) { @@ -651,18 +868,21 @@ static int ssl_check_certificate (sslsockdata * data) row++; snprintf (menu->dialog[row++], SHORT_STRING, _("This certificate is valid")); snprintf (menu->dialog[row++], SHORT_STRING, _(" from %s"), - asn1time_to_string (X509_get_notBefore (data->cert))); + asn1time_to_string (X509_get_notBefore (cert))); snprintf (menu->dialog[row++], SHORT_STRING, _(" to %s"), - asn1time_to_string (X509_get_notAfter (data->cert))); + asn1time_to_string (X509_get_notAfter (cert))); row++; buf[0] = '\0'; - x509_fingerprint (buf, sizeof (buf), data->cert); + x509_fingerprint (buf, sizeof (buf), cert); snprintf (menu->dialog[row++], SHORT_STRING, _("Fingerprint: %s"), buf); - menu->title = _("SSL Certificate check"); - if (SslCertFile && X509_cmp_current_time (X509_get_notAfter (data->cert)) >= 0 - && X509_cmp_current_time (X509_get_notBefore (data->cert)) < 0) + snprintf (title, sizeof (title), + _("SSL Certificate check (certificate %d of %d in chain)"), + len - idx, len); + menu->title = title; + if (SslCertFile && X509_cmp_current_time (X509_get_notAfter (cert)) >= 0 + && X509_cmp_current_time (X509_get_notBefore (cert)) < 0) { menu->prompt = _("(r)eject, accept (o)nce, (a)ccept always"); menu->keys = _("roa"); @@ -695,7 +915,7 @@ static int ssl_check_certificate (sslsockdata * data) done = 0; if ((fp = fopen (SslCertFile, "a"))) { - if (PEM_write_X509 (fp, data->cert)) + if (PEM_write_X509 (fp, cert)) done = 1; fclose (fp); } @@ -712,15 +932,13 @@ static int ssl_check_certificate (sslsockdata * data) /* fall through */ case OP_MAX + 2: /* accept once */ done = 2; - /* keep a handle on accepted certificates in case we want to - * open up another connection to the same server in this session */ - SslSessionCerts = mutt_add_list_n (SslSessionCerts, &data->cert, - sizeof (X509 **)); + ssl_cache_trusted_cert (cert); break; } } unset_option(OPTUNBUFFEREDINPUT); mutt_menuDestroy (&menu); + dprint (2, (debugfile, "ssl interactive_check_cert: done=%d\n", done)); return (done == 2); } @@ -733,6 +951,9 @@ static void ssl_get_client_cert(sslsockdata *ssldata, CONNECTION *conn) SSL_CTX_set_default_passwd_cb(ssldata->ctx, ssl_passwd_cb); SSL_CTX_use_certificate_file(ssldata->ctx, SslClientCert, SSL_FILETYPE_PEM); SSL_CTX_use_PrivateKey_file(ssldata->ctx, SslClientCert, SSL_FILETYPE_PEM); + + /* if we are using a client cert, SASL may expect an external auth name */ + mutt_account_getuser (&conn->account); } }