X-Git-Url: https://git.llucax.com/software/mutt-debian.git/blobdiff_plain/19304f7c526fbe36ba0db2fb80bcaf3bd974d81d..9ae284163f491c64de122fcd555019040e0d4da7:/mutt_ssl_gnutls.c diff --git a/mutt_ssl_gnutls.c b/mutt_ssl_gnutls.c index d189841..dbac87e 100644 --- a/mutt_ssl_gnutls.c +++ b/mutt_ssl_gnutls.c @@ -33,6 +33,16 @@ #include "mutt_ssl.h" #include "mutt_regex.h" +/* certificate error bitmap values */ +#define CERTERR_VALID 0 +#define CERTERR_EXPIRED 1 +#define CERTERR_NOTYETVALID 2 +#define CERTERR_REVOKED 4 +#define CERTERR_NOTTRUSTED 8 +#define CERTERR_HOSTNAME 16 +#define CERTERR_SIGNERNOTCA 32 +#define CERTERR_INSECUREALG 64 + typedef struct _tlssockdata { gnutls_session state; @@ -265,6 +275,12 @@ static int tls_negotiate (CONNECTION * conn) SslClientCert, GNUTLS_X509_FMT_PEM); } +#if HAVE_DECL_GNUTLS_VERIFY_DISABLE_TIME_CHECKS + /* disable checking certificate activation/expiration times + in gnutls, we do the checks ourselves */ + gnutls_certificate_set_verify_flags(data->xcred, GNUTLS_VERIFY_DISABLE_TIME_CHECKS); +#endif + gnutls_init(&data->state, GNUTLS_CLIENT); /* set socket */ @@ -408,7 +424,7 @@ static int tls_compare_certificates (const gnutls_datum *peercert) } b64_data.size = fread(b64_data.data, 1, b64_data.size, fd1); - fclose(fd1); + safe_fclose (&fd1); do { ret = gnutls_pem_base64_decode_alloc(NULL, &b64_data, &cert); @@ -496,15 +512,15 @@ static int tls_check_stored_hostname (const gnutls_datum *cert, /* try checking against names stored in stored certs file */ if ((fp = fopen (SslCertFile, "r"))) { - if (regcomp(&preg, "^#H ([a-zA-Z0-9_\\.-]+) ([0-9A-F]{4}( [0-9A-F]{4}){7})[ \t]*$", REG_ICASE|REG_EXTENDED) != 0) + if (REGCOMP(&preg, "^#H ([a-zA-Z0-9_\\.-]+) ([0-9A-F]{4}( [0-9A-F]{4}){7})[ \t]*$", + REG_ICASE) != 0) { - regfree(&preg); return 0; } buf[0] = '\0'; tls_fingerprint (GNUTLS_DIG_MD5, buf, sizeof (buf), cert); - while ((linestr = mutt_read_line(linestr, &linestrsize, fp, &linenum)) != NULL) + while ((linestr = mutt_read_line(linestr, &linestrsize, fp, &linenum, 0)) != NULL) { if(linestr[0] == '#' && linestr[1] == 'H') { @@ -517,7 +533,7 @@ static int tls_check_stored_hostname (const gnutls_datum *cert, { regfree(&preg); FREE(&linestr); - fclose(fp); + safe_fclose (&fp); return 1; } } @@ -525,50 +541,30 @@ static int tls_check_stored_hostname (const gnutls_datum *cert, } regfree(&preg); - fclose(fp); + safe_fclose (&fp); } /* not found a matching name */ return 0; } -static int tls_check_one_certificate (const gnutls_datum_t *certdata, - gnutls_certificate_status certstat, - const char* hostname, int idx, int len) +static int tls_check_preauth (const gnutls_datum_t *certdata, + gnutls_certificate_status certstat, + const char *hostname, int chainidx, int* certerr, + int* savedcert) { gnutls_x509_crt cert; - int certerr_hostname = 0; - int certerr_expired = 0; - int certerr_notyetvalid = 0; - int certerr_nottrusted = 0; - int certerr_revoked = 0; - int certerr_signernotca = 0; - char buf[SHORT_STRING]; - char fpbuf[SHORT_STRING]; - size_t buflen; - char dn_common_name[SHORT_STRING]; - char dn_email[SHORT_STRING]; - char dn_organization[SHORT_STRING]; - char dn_organizational_unit[SHORT_STRING]; - char dn_locality[SHORT_STRING]; - char dn_province[SHORT_STRING]; - char dn_country[SHORT_STRING]; - time_t t; - char datestr[30]; - MUTTMENU *menu; - char helpstr[LONG_STRING]; - char title[STRING]; - FILE *fp; - gnutls_datum pemdata; - int i, row, done, ret; + + *certerr = CERTERR_VALID; + *savedcert = 0; if (gnutls_x509_crt_init (&cert) < 0) { mutt_error (_("Error initialising gnutls certificate data")); mutt_sleep (2); - return 0; + return -1; } - + if (gnutls_x509_crt_import (cert, certdata, GNUTLS_X509_FMT_DER) < 0) { mutt_error (_("Error processing certificate data")); @@ -576,94 +572,166 @@ static int tls_check_one_certificate (const gnutls_datum_t *certdata, gnutls_x509_crt_deinit (cert); return -1; } - - if (gnutls_x509_crt_get_expiration_time (cert) < time(NULL)) - certerr_expired = 1; - if (gnutls_x509_crt_get_activation_time (cert) > time(NULL)) - certerr_notyetvalid = 1; - if (!idx) + if (option (OPTSSLVERIFYDATES) != M_NO) { - if (!gnutls_x509_crt_check_hostname (cert, hostname) && - !tls_check_stored_hostname (certdata, hostname)) - certerr_hostname = 1; + if (gnutls_x509_crt_get_expiration_time (cert) < time(NULL)) + *certerr |= CERTERR_EXPIRED; + if (gnutls_x509_crt_get_activation_time (cert) > time(NULL)) + *certerr |= CERTERR_NOTYETVALID; } - + + if (chainidx == 0 && option (OPTSSLVERIFYHOST) != M_NO + && !gnutls_x509_crt_check_hostname (cert, hostname) + && !tls_check_stored_hostname (certdata, hostname)) + *certerr |= CERTERR_HOSTNAME; + /* see whether certificate is in our cache (certificates file) */ if (tls_compare_certificates (certdata)) { - if (certstat & GNUTLS_CERT_INVALID) + *savedcert = 1; + + if (chainidx == 0 && certstat & GNUTLS_CERT_INVALID) { /* doesn't matter - have decided is valid because server certificate is in our trusted cache */ certstat ^= GNUTLS_CERT_INVALID; } - - if (certstat & GNUTLS_CERT_SIGNER_NOT_FOUND) + + if (chainidx == 0 && certstat & GNUTLS_CERT_SIGNER_NOT_FOUND) { /* doesn't matter that we haven't found the signer, since certificate is in our trusted cache */ certstat ^= GNUTLS_CERT_SIGNER_NOT_FOUND; } - - if (certstat & GNUTLS_CERT_SIGNER_NOT_CA) + + if (chainidx <= 1 && certstat & GNUTLS_CERT_SIGNER_NOT_CA) { /* Hmm. Not really sure how to handle this, but let's say that we don't care if the CA certificate hasn't got the - correct X.509 basic constraints if server certificate is - in our cache. */ + correct X.509 basic constraints if server or first signer + certificate is in our cache. */ certstat ^= GNUTLS_CERT_SIGNER_NOT_CA; } + + if (chainidx == 0 && certstat & GNUTLS_CERT_INSECURE_ALGORITHM) + { + /* doesn't matter that it was signed using an insecure + algorithm, since certificate is in our trusted cache */ + certstat ^= GNUTLS_CERT_INSECURE_ALGORITHM; + } } if (certstat & GNUTLS_CERT_REVOKED) { - certerr_revoked = 1; + *certerr |= CERTERR_REVOKED; certstat ^= GNUTLS_CERT_REVOKED; } - + if (certstat & GNUTLS_CERT_INVALID) { - certerr_nottrusted = 1; + *certerr |= CERTERR_NOTTRUSTED; certstat ^= GNUTLS_CERT_INVALID; } - + if (certstat & GNUTLS_CERT_SIGNER_NOT_FOUND) { /* NB: already cleared if cert in cache */ - certerr_nottrusted = 1; + *certerr |= CERTERR_NOTTRUSTED; certstat ^= GNUTLS_CERT_SIGNER_NOT_FOUND; } - + if (certstat & GNUTLS_CERT_SIGNER_NOT_CA) { /* NB: already cleared if cert in cache */ - certerr_signernotca = 1; + *certerr |= CERTERR_SIGNERNOTCA; certstat ^= GNUTLS_CERT_SIGNER_NOT_CA; } - /* OK if signed by (or is) a trusted certificate */ - /* we've been zeroing the interesting bits in certstat - + if (certstat & GNUTLS_CERT_INSECURE_ALGORITHM) + { + /* NB: already cleared if cert in cache */ + *certerr |= CERTERR_INSECUREALG; + certstat ^= GNUTLS_CERT_INSECURE_ALGORITHM; + } + + gnutls_x509_crt_deinit (cert); + + /* we've been zeroing the interesting bits in certstat - don't return OK if there are any unhandled bits we don't understand */ - if (!(certerr_expired || certerr_notyetvalid || - certerr_hostname || certerr_nottrusted) && certstat == 0) - { - gnutls_x509_crt_deinit (cert); + if (*certerr == CERTERR_VALID && certstat == 0) + return 0; + + return -1; +} + +static int tls_check_one_certificate (const gnutls_datum_t *certdata, + gnutls_certificate_status certstat, + const char* hostname, int idx, int len) +{ + int certerr, savedcert; + gnutls_x509_crt cert; + char buf[SHORT_STRING]; + char fpbuf[SHORT_STRING]; + size_t buflen; + char dn_common_name[SHORT_STRING]; + char dn_email[SHORT_STRING]; + char dn_organization[SHORT_STRING]; + char dn_organizational_unit[SHORT_STRING]; + char dn_locality[SHORT_STRING]; + char dn_province[SHORT_STRING]; + char dn_country[SHORT_STRING]; + time_t t; + char datestr[30]; + MUTTMENU *menu; + char helpstr[LONG_STRING]; + char title[STRING]; + FILE *fp; + gnutls_datum pemdata; + int i, row, done, ret; + + if (!tls_check_preauth (certdata, certstat, hostname, idx, &certerr, + &savedcert)) return 1; + + /* skip signers if insecure algorithm was used */ + if (idx && (certerr & CERTERR_INSECUREALG)) + { + if (idx == 1) + { + mutt_error (_("Warning: Server certificate was signed using an insecure algorithm")); + mutt_sleep (2); + } + return 0; } /* interactive check from user */ + if (gnutls_x509_crt_init (&cert) < 0) + { + mutt_error (_("Error initialising gnutls certificate data")); + mutt_sleep (2); + return 0; + } + + if (gnutls_x509_crt_import (cert, certdata, GNUTLS_X509_FMT_DER) < 0) + { + mutt_error (_("Error processing certificate data")); + mutt_sleep (2); + gnutls_x509_crt_deinit (cert); + return -1; + } + menu = mutt_new_menu (-1); menu->max = 25; menu->dialog = (char **) safe_calloc (1, menu->max * sizeof (char *)); for (i = 0; i < menu->max; i++) menu->dialog[i] = (char *) safe_calloc (1, SHORT_STRING * sizeof (char)); - + row = 0; strfcpy (menu->dialog[row], _("This certificate belongs to:"), SHORT_STRING); row++; - + buflen = sizeof (dn_common_name); if (gnutls_x509_crt_get_dn_by_oid (cert, GNUTLS_OID_X520_COMMON_NAME, 0, 0, dn_common_name, &buflen) != 0) @@ -692,17 +760,17 @@ static int tls_check_one_certificate (const gnutls_datum_t *certdata, if (gnutls_x509_crt_get_dn_by_oid (cert, GNUTLS_OID_X520_COUNTRY_NAME, 0, 0, dn_country, &buflen) != 0) dn_country[0] = '\0'; - + snprintf (menu->dialog[row++], SHORT_STRING, " %s %s", dn_common_name, dn_email); snprintf (menu->dialog[row++], SHORT_STRING, " %s", dn_organization); snprintf (menu->dialog[row++], SHORT_STRING, " %s", dn_organizational_unit); snprintf (menu->dialog[row++], SHORT_STRING, " %s %s %s", dn_locality, dn_province, dn_country); row++; - + strfcpy (menu->dialog[row], _("This certificate was issued by:"), SHORT_STRING); row++; - + buflen = sizeof (dn_common_name); if (gnutls_x509_crt_get_issuer_dn_by_oid (cert, GNUTLS_OID_X520_COMMON_NAME, 0, 0, dn_common_name, &buflen) != 0) @@ -731,52 +799,52 @@ static int tls_check_one_certificate (const gnutls_datum_t *certdata, if (gnutls_x509_crt_get_issuer_dn_by_oid (cert, GNUTLS_OID_X520_COUNTRY_NAME, 0, 0, dn_country, &buflen) != 0) dn_country[0] = '\0'; - + snprintf (menu->dialog[row++], SHORT_STRING, " %s %s", dn_common_name, dn_email); snprintf (menu->dialog[row++], SHORT_STRING, " %s", dn_organization); snprintf (menu->dialog[row++], SHORT_STRING, " %s", dn_organizational_unit); snprintf (menu->dialog[row++], SHORT_STRING, " %s %s %s", dn_locality, dn_province, dn_country); row++; - + snprintf (menu->dialog[row++], SHORT_STRING, _("This certificate is valid")); - + t = gnutls_x509_crt_get_activation_time (cert); - snprintf (menu->dialog[row++], SHORT_STRING, _(" from %s"), + snprintf (menu->dialog[row++], SHORT_STRING, _(" from %s"), tls_make_date (t, datestr, 30)); - + t = gnutls_x509_crt_get_expiration_time (cert); - snprintf (menu->dialog[row++], SHORT_STRING, _(" to %s"), + snprintf (menu->dialog[row++], SHORT_STRING, _(" to %s"), tls_make_date (t, datestr, 30)); - + fpbuf[0] = '\0'; tls_fingerprint (GNUTLS_DIG_SHA, fpbuf, sizeof (fpbuf), certdata); snprintf (menu->dialog[row++], SHORT_STRING, _("SHA1 Fingerprint: %s"), fpbuf); fpbuf[0] = '\0'; tls_fingerprint (GNUTLS_DIG_MD5, fpbuf, sizeof (fpbuf), certdata); snprintf (menu->dialog[row++], SHORT_STRING, _("MD5 Fingerprint: %s"), fpbuf); - - if (certerr_notyetvalid) + + if (certerr & CERTERR_NOTYETVALID) { row++; strfcpy (menu->dialog[row], _("WARNING: Server certificate is not yet valid"), SHORT_STRING); } - if (certerr_expired) + if (certerr & CERTERR_EXPIRED) { row++; strfcpy (menu->dialog[row], _("WARNING: Server certificate has expired"), SHORT_STRING); } - if (certerr_revoked) + if (certerr & CERTERR_REVOKED) { row++; strfcpy (menu->dialog[row], _("WARNING: Server certificate has been revoked"), SHORT_STRING); } - if (certerr_hostname) + if (certerr & CERTERR_HOSTNAME) { row++; strfcpy (menu->dialog[row], _("WARNING: Server hostname does not match certificate"), SHORT_STRING); } - if (certerr_signernotca) + if (certerr & CERTERR_SIGNERNOTCA) { row++; strfcpy (menu->dialog[row], _("WARNING: Signer of server certificate is not a CA"), SHORT_STRING); @@ -788,7 +856,9 @@ static int tls_check_one_certificate (const gnutls_datum_t *certdata, menu->title = title; /* certificates with bad dates, or that are revoked, must be accepted manually each and every time */ - if (SslCertFile && !certerr_expired && !certerr_notyetvalid && !certerr_revoked) + if (SslCertFile && !savedcert + && !(certerr & (CERTERR_EXPIRED | CERTERR_NOTYETVALID + | CERTERR_REVOKED))) { menu->prompt = _("(r)eject, accept (o)nce, (a)ccept always"); menu->keys = _("roa"); @@ -798,14 +868,14 @@ static int tls_check_one_certificate (const gnutls_datum_t *certdata, menu->prompt = _("(r)eject, accept (o)nce"); menu->keys = _("ro"); } - + helpstr[0] = '\0'; mutt_make_help (buf, sizeof (buf), _("Exit "), MENU_GENERIC, OP_EXIT); safe_strcat (helpstr, sizeof (helpstr), buf); mutt_make_help (buf, sizeof (buf), _("Help"), MENU_GENERIC, OP_HELP); safe_strcat (helpstr, sizeof (helpstr), buf); menu->help = helpstr; - + done = 0; set_option (OPTUNBUFFEREDINPUT); while (!done) @@ -822,12 +892,12 @@ static int tls_check_one_certificate (const gnutls_datum_t *certdata, if ((fp = fopen (SslCertFile, "a"))) { /* save hostname if necessary */ - if (certerr_hostname) + if (certerr & CERTERR_HOSTNAME) { fprintf(fp, "#H %s %s\n", hostname, fpbuf); done = 1; } - if (certerr_nottrusted) + if (certerr & CERTERR_NOTTRUSTED) { done = 0; ret = gnutls_pem_base64_encode_alloc ("CERTIFICATE", certdata, @@ -841,7 +911,7 @@ static int tls_check_one_certificate (const gnutls_datum_t *certdata, gnutls_free (pemdata.data); } } - fclose (fp); + safe_fclose (&fp); } if (!done) { @@ -866,23 +936,14 @@ static int tls_check_one_certificate (const gnutls_datum_t *certdata, return (done == 2); } -static int tls_check_certificate (CONNECTION* conn) +/* sanity-checking wrapper for gnutls_certificate_verify_peers */ +static gnutls_certificate_status tls_verify_peers (gnutls_session tlsstate) { - tlssockdata *data = conn->sockdata; - gnutls_session state = data->state; - const gnutls_datum *cert_list; - unsigned int cert_list_size = 0; gnutls_certificate_status certstat; - int i, rc; - - if (gnutls_auth_get_type (state) != GNUTLS_CRD_CERTIFICATE) - { - mutt_error (_("Unable to get certificate from peer")); - mutt_sleep (2); - return 0; - } - certstat = gnutls_certificate_verify_peers (state); + certstat = gnutls_certificate_verify_peers (tlsstate); + if (!certstat) + return certstat; if (certstat == GNUTLS_E_NO_CERTIFICATE_FOUND) { @@ -899,13 +960,34 @@ static int tls_check_certificate (CONNECTION* conn) } /* We only support X.509 certificates (not OpenPGP) at the moment */ - if (gnutls_certificate_type_get (state) != GNUTLS_CRT_X509) + if (gnutls_certificate_type_get (tlsstate) != GNUTLS_CRT_X509) { mutt_error (_("Certificate is not X.509")); mutt_sleep (2); return 0; } + return certstat; +} + +static int tls_check_certificate (CONNECTION* conn) +{ + tlssockdata *data = conn->sockdata; + gnutls_session state = data->state; + const gnutls_datum *cert_list; + unsigned int cert_list_size = 0; + gnutls_certificate_status certstat; + int certerr, i, preauthrc, savedcert, rc = 0; + + if (gnutls_auth_get_type (state) != GNUTLS_CRD_CERTIFICATE) + { + mutt_error (_("Unable to get certificate from peer")); + mutt_sleep (2); + return 0; + } + + certstat = tls_verify_peers (state); + cert_list = gnutls_certificate_get_peers (state, &cert_list_size); if (!cert_list) { @@ -914,13 +996,42 @@ static int tls_check_certificate (CONNECTION* conn) return 0; } + /* tls_verify_peers doesn't check hostname or expiration, so walk + * from most specific to least checking these. If we see a saved certificate, + * its status short-circuits the remaining checks. */ + preauthrc = 0; + for (i = 0; i < cert_list_size; i++) { + rc = tls_check_preauth(&cert_list[i], certstat, conn->account.host, i, + &certerr, &savedcert); + preauthrc += rc; + + if (savedcert) + { + if (!preauthrc) + return 1; + else + break; + } + } + + /* then check interactively, starting from chain root */ for (i = cert_list_size - 1; i >= 0; i--) { rc = tls_check_one_certificate (&cert_list[i], certstat, conn->account.host, i, cert_list_size); - if (rc) - return rc; + + /* add signers to trust set, then reverify */ + if (i && rc) { + rc = gnutls_certificate_set_x509_trust_mem (data->xcred, &cert_list[i], + GNUTLS_X509_FMT_DER); + if (rc != 1) + dprint (1, (debugfile, "error trusting certificate %d: %d\n", i, rc)); + + certstat = tls_verify_peers (state); + if (!certstat) + return 1; + } } - return 0; + return rc; }