diff options
Diffstat (limited to 'dirmngr/validate.c')
| -rw-r--r-- | dirmngr/validate.c | 84 |
1 files changed, 45 insertions, 39 deletions
diff --git a/dirmngr/validate.c b/dirmngr/validate.c index b3dc9d8c6..68e1bb387 100644 --- a/dirmngr/validate.c +++ b/dirmngr/validate.c @@ -371,7 +371,8 @@ validate_cert_chain (ctrl_t ctrl, ksba_cert_t cert, ksba_isotime_t r_exptime, int depth, maxdepth; char *issuer = NULL; char *subject = NULL; - ksba_cert_t subject_cert = NULL, issuer_cert = NULL; + ksba_cert_t subject_cert = NULL; + ksba_cert_t issuer_cert = NULL; ksba_isotime_t current_time; ksba_isotime_t exptime; int any_expired = 0; @@ -438,7 +439,7 @@ validate_cert_chain (ctrl_t ctrl, ksba_cert_t cert, ksba_isotime_t r_exptime, /* We walk up the chain until we find a trust anchor. */ subject_cert = cert; - maxdepth = 10; + maxdepth = 10; /* Sensible limit on the length of the chain. */ chain = NULL; depth = 0; for (;;) @@ -520,7 +521,7 @@ validate_cert_chain (ctrl_t ctrl, ksba_cert_t cert, ksba_isotime_t r_exptime, goto leave; /* Is this a self-signed certificate? */ - if (is_root_cert ( subject_cert, issuer, subject)) + if (is_root_cert (subject_cert, issuer, subject)) { /* Yes, this is our trust anchor. */ if (check_cert_sig (subject_cert, subject_cert) ) @@ -630,9 +631,9 @@ validate_cert_chain (ctrl_t ctrl, ksba_cert_t cert, ksba_isotime_t r_exptime, dump_cert ("issuer", issuer_cert); } - /* Now check the signature of the certificate. Well, we - should delay this until later so that faked certificates - can't be turned into a DoS easily. */ + /* Now check the signature of the certificate. FIXME: we should + * delay this until later so that faked certificates can't be + * turned into a DoS easily. */ err = check_cert_sig (issuer_cert, subject_cert); if (err) { @@ -669,14 +670,14 @@ validate_cert_chain (ctrl_t ctrl, ksba_cert_t cert, ksba_isotime_t r_exptime, } } #endif - /* We give a more descriptive error code than the one - returned from the signature checking. */ + /* Return a more descriptive error code than the one + * returned from the signature checking. */ err = gpg_error (GPG_ERR_BAD_CERT_CHAIN); goto leave; } /* Check that the length of the chain is not longer than allowed - by the CA. */ + * by the CA. */ { int chainlen; @@ -722,9 +723,11 @@ validate_cert_chain (ctrl_t ctrl, ksba_cert_t cert, ksba_isotime_t r_exptime, issuer_cert = NULL; } + /* Even if we have no error here we need to check whether we + * encountered an error somewhere during the checks. Set the error + * code to the most critical one. */ if (!err) - { /* If we encountered an error somewhere during the checks, set - the error code to the most critical one */ + { if (any_expired) err = gpg_error (GPG_ERR_CERT_EXPIRED); else if (any_no_policy_match) @@ -742,19 +745,19 @@ validate_cert_chain (ctrl_t ctrl, ksba_cert_t cert, ksba_isotime_t r_exptime, if (!err && mode != VALIDATE_MODE_CRL) { /* Now that everything is fine, walk the chain and check each - certificate for revocations. - - 1. item in the chain - The root certificate. - 2. item - the CA below the root - last item - the target certificate. - - Now for each certificate in the chain check whether it has - been included in a CRL and thus be revoked. We don't do OCSP - here because this does not seem to make much sense. This - might become a recursive process and we should better cache - our validity results to avoid double work. Far worse a - catch-22 may happen for an improper setup hierarchy and we - need a way to break up such a deadlock. */ + * certificate for revocations. + * + * 1. item in the chain - The root certificate. + * 2. item - the CA below the root + * last item - the target certificate. + * + * Now for each certificate in the chain check whether it has + * been included in a CRL and thus be revoked. We don't do OCSP + * here because this does not seem to make much sense. This + * might become a recursive process and we should better cache + * our validity results to avoid double work. Far worse a + * catch-22 may happen for an improper setup hierarchy and we + * need a way to break up such a deadlock. */ err = check_revocations (ctrl, chain); } @@ -773,11 +776,11 @@ validate_cert_chain (ctrl_t ctrl, ksba_cert_t cert, ksba_isotime_t r_exptime, if (!err && !(r_trust_anchor && *r_trust_anchor)) { /* With no error we can update the validation cache. We do this - for all certificates in the chain. Note that we can't use - the cache if the caller requested to check the trustiness of - the root certificate himself. Adding such a feature would - require us to also store the fingerprint of root - certificate. */ + * for all certificates in the chain. Note that we can't use + * the cache if the caller requested to check the trustiness of + * the root certificate himself. Adding such a feature would + * require us to also store the fingerprint of root + * certificate. */ chain_item_t citem; time_t validated_at = gnupg_get_time (); @@ -853,8 +856,8 @@ pk_algo_from_sexp (gcry_sexp_t pkey) /* Check the signature on CERT using the ISSUER_CERT. This function - does only test the cryptographic signature and nothing else. It is - assumed that the ISSUER_CERT is valid. */ + * does only test the cryptographic signature and nothing else. It is + * assumed that the ISSUER_CERT is valid. */ static gpg_error_t check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert) { @@ -952,20 +955,23 @@ check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert) /* Prepare the values for signature verification. At this point we - have these values: - - S_PKEY - S-expression with the issuer's public key. - S_SIG - Signature value as given in the certrificate. - MD - Finalized hash context with hash of the certificate. - ALGO_NAME - Lowercase hash algorithm name + * have these values: + * + * S_PKEY - S-expression with the issuer's public key. + * S_SIG - Signature value as given in the certificate. + * MD - Finalized hash context with hash of the certificate. + * ALGO_NAME - Lowercase hash algorithm name */ digestlen = gcry_md_get_algo_dlen (algo); digest = gcry_md_read (md, algo); if (pk_algo_from_sexp (s_pkey) == GCRY_PK_DSA) { + /* NB.: We support only SHA-1 here because we had problems back + * then to get test data for DSA-2. Meanwhile DSA has been + * replaced by ECDSA which we do not yet support. */ if (digestlen != 20) { - log_error (_("DSA requires the use of a 160 bit hash algorithm\n")); + log_error ("DSA requires the use of a 160 bit hash algorithm\n"); gcry_md_close (md); gcry_sexp_release (s_sig); gcry_sexp_release (s_pkey); @@ -975,7 +981,7 @@ check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert) (int)digestlen, digest) ) BUG (); } - else /* Not DSA. */ + else /* Not DSA - we assume RSA */ { if ( gcry_sexp_build (&s_hash, NULL, "(data(flags pkcs1)(hash %s %b))", algo_name, (int)digestlen, digest) ) |