/* Finds an issuer of the certificate. If multiple issuers
* are present, returns one that is activated and not expired.
*/
static inline gnutls_x509_crt_t
find_issuer (gnutls_x509_crt_t cert,
const gnutls_x509_crt_t * trusted_cas, int tcas_size)
{
int i;
gnutls_x509_crt_t issuer = NULL;
/* this is serial search.
*/
for (i = 0; i < tcas_size; i++)
{
if (is_issuer (cert, trusted_cas[i]) == 1)
{
if (issuer == NULL)
{
issuer = trusted_cas[i];
}
else
{
time_t now = gnutls_time(0);
if (now < gnutls_x509_crt_get_expiration_time(trusted_cas[i]) &&
now >= gnutls_x509_crt_get_activation_time(trusted_cas[i]))
{
issuer = trusted_cas[i];
}
}
}
}
return issuer;
}
static inline gnutls_x509_crt_t
find_issuer (gnutls_x509_crt_t cert,
const gnutls_x509_crt_t * trusted_cas, int tcas_size)
{
int i;
/* this is serial search.
*/
for (i = 0; i < tcas_size; i++)
{
if (is_issuer (cert, trusted_cas[i]) == 1)
return trusted_cas[i];
}
gnutls_assert ();
return NULL;
}
/**
* gnutls_x509_crt_check_issuer:
* @cert: is the certificate to be checked
* @issuer: is the certificate of a possible issuer
*
* This function will check if the given certificate was issued by the
* given issuer. It checks the DN fields and the authority
* key identifier and subject key identifier fields match.
*
* Returns: It will return true (1) if the given certificate is issued
* by the given issuer, and false (0) if not. A negative error code is
* returned in case of an error.
**/
int
gnutls_x509_crt_check_issuer (gnutls_x509_crt_t cert,
gnutls_x509_crt_t issuer)
{
return is_issuer (cert, issuer);
}
/*
* Verifies the given certificate again a certificate list of
* trusted CAs.
*
* Returns only 0 or 1. If 1 it means that the certificate
* was successfuly verified.
*
* 'flags': an OR of the gnutls_certificate_verify_flags enumeration.
*
* Output will hold some extra information about the verification
* procedure. Issuer will hold the actual issuer from the trusted list.
*/
static int
_gnutls_verify_certificate2 (gnutls_x509_crt_t cert,
const gnutls_x509_crt_t * trusted_cas,
int tcas_size, unsigned int flags,
unsigned int *output,
gnutls_x509_crt_t * _issuer,
time_t now,
gnutls_verify_output_function func)
{
gnutls_datum_t cert_signed_data = { NULL, 0 };
gnutls_datum_t cert_signature = { NULL, 0 };
gnutls_x509_crt_t issuer = NULL;
int issuer_version, result, hash_algo;
unsigned int out = 0;
if (output)
*output = 0;
if (tcas_size >= 1)
issuer = find_issuer (cert, trusted_cas, tcas_size);
else
{
gnutls_assert ();
out = GNUTLS_CERT_SIGNER_NOT_FOUND | GNUTLS_CERT_INVALID;
if (output)
*output |= out;
result = 0;
goto cleanup;
}
/* issuer is not in trusted certificate
* authorities.
*/
if (issuer == NULL)
{
out = GNUTLS_CERT_SIGNER_NOT_FOUND | GNUTLS_CERT_INVALID;
if (output)
*output |= out;
gnutls_assert ();
result = 0;
goto cleanup;
}
if (_issuer != NULL)
*_issuer = issuer;
issuer_version = gnutls_x509_crt_get_version (issuer);
if (issuer_version < 0)
{
gnutls_assert ();
return issuer_version;
}
if (!(flags & GNUTLS_VERIFY_DISABLE_CA_SIGN) &&
((flags & GNUTLS_VERIFY_DO_NOT_ALLOW_X509_V1_CA_CRT)
|| issuer_version != 1))
{
if (check_if_ca (cert, issuer, flags) == 0)
{
gnutls_assert ();
out = GNUTLS_CERT_SIGNER_NOT_CA | GNUTLS_CERT_INVALID;
if (output)
*output |= out;
result = 0;
goto cleanup;
}
}
result =
_gnutls_x509_get_signed_data (cert->cert, "tbsCertificate",
&cert_signed_data);
if (result < 0)
{
gnutls_assert ();
goto cleanup;
}
result =
_gnutls_x509_get_signature (cert->cert, "signature", &cert_signature);
if (result < 0)
{
gnutls_assert ();
goto cleanup;
}
result = _gnutls_x509_get_signature_algorithm(cert->cert, "signatureAlgorithm.algorithm");
if (result < 0)
{
gnutls_assert ();
goto cleanup;
}
hash_algo = gnutls_sign_get_hash_algorithm(result);
result =
_gnutls_x509_verify_data (hash_algo, &cert_signed_data, &cert_signature,
issuer);
if (result == GNUTLS_E_PK_SIG_VERIFY_FAILED)
{
gnutls_assert ();
out |= GNUTLS_CERT_INVALID | GNUTLS_CERT_SIGNATURE_FAILURE;
/* error. ignore it */
if (output)
*output |= out;
result = 0;
}
else if (result < 0)
{
gnutls_assert();
goto cleanup;
}
/* If the certificate is not self signed check if the algorithms
* used are secure. If the certificate is self signed it doesn't
* really matter.
*/
if (is_issuer (cert, cert) == 0)
{
int sigalg;
sigalg = gnutls_x509_crt_get_signature_algorithm (cert);
if (((sigalg == GNUTLS_SIGN_RSA_MD2) &&
!(flags & GNUTLS_VERIFY_ALLOW_SIGN_RSA_MD2)) ||
((sigalg == GNUTLS_SIGN_RSA_MD5) &&
!(flags & GNUTLS_VERIFY_ALLOW_SIGN_RSA_MD5)))
{
out = GNUTLS_CERT_INSECURE_ALGORITHM | GNUTLS_CERT_INVALID;
if (output)
*output |= out;
result = 0;
}
}
/* Check activation/expiration times
*/
if (!(flags & GNUTLS_VERIFY_DISABLE_TIME_CHECKS))
{
/* check the time of the issuer first */
if (!(flags & GNUTLS_VERIFY_DISABLE_TRUSTED_TIME_CHECKS))
{
out |= check_time (issuer, now);
if (out != 0)
{
result = 0;
if (output) *output |= out;
}
}
out |= check_time (cert, now);
if (out != 0)
{
result = 0;
if (output) *output |= out;
}
}
cleanup:
if (result >= 0 && func) func(cert, issuer, NULL, out);
_gnutls_free_datum (&cert_signed_data);
_gnutls_free_datum (&cert_signature);
return result;
}
/*
* Verifies the given certificate against a certificate list of
* trusted CAs.
*
* Returns only 0 or 1. If 1 it means that the certificate
* was successfuly verified.
*
* 'flags': an OR of the gnutls_certificate_verify_flags enumeration.
*
* Output will hold some extra information about the verification
* procedure.
*/
static unsigned
verify_crt(gnutls_x509_crt_t cert,
const gnutls_x509_crt_t * trusted_cas,
int tcas_size, unsigned int flags,
unsigned int *output,
verify_state_st *vparams,
unsigned end_cert)
{
gnutls_datum_t cert_signed_data = { NULL, 0 };
gnutls_datum_t cert_signature = { NULL, 0 };
gnutls_x509_crt_t issuer = NULL;
int issuer_version, hash_algo;
unsigned result = 1;
const mac_entry_st * me;
unsigned int out = 0, usage;
int sigalg, ret;
if (output)
*output = 0;
if (vparams->max_path == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
/* bail immediately, to avoid inconistency */
goto cleanup;
}
vparams->max_path--;
if (tcas_size >= 1)
issuer = find_issuer(cert, trusted_cas, tcas_size);
ret =
_gnutls_x509_get_signed_data(cert->cert, &cert->der, "tbsCertificate",
&cert_signed_data);
if (ret < 0) {
MARK_INVALID(0);
cert_signed_data.data = NULL;
}
ret =
_gnutls_x509_get_signature(cert->cert, "signature",
&cert_signature);
if (ret < 0) {
MARK_INVALID(0);
cert_signature.data = NULL;
}
ret =
_gnutls_x509_get_signature_algorithm(cert->cert,
"signatureAlgorithm.algorithm");
if (ret < 0) {
MARK_INVALID(0);
}
sigalg = ret;
/* issuer is not in trusted certificate
* authorities.
*/
if (issuer == NULL) {
MARK_INVALID(GNUTLS_CERT_SIGNER_NOT_FOUND);
} else {
if (vparams->nc != NULL) {
/* append the issuer's constraints */
ret = gnutls_x509_crt_get_name_constraints(issuer, vparams->nc,
GNUTLS_NAME_CONSTRAINTS_FLAG_APPEND, NULL);
if (ret < 0 && ret != GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto nc_done;
}
/* only check name constraints in server certificates, not CAs */
if (end_cert != 0) {
ret = gnutls_x509_name_constraints_check_crt(vparams->nc, GNUTLS_SAN_DNSNAME, cert);
if (ret == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto nc_done;
}
ret = gnutls_x509_name_constraints_check_crt(vparams->nc, GNUTLS_SAN_RFC822NAME, cert);
if (ret == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto nc_done;
}
ret = gnutls_x509_name_constraints_check_crt(vparams->nc, GNUTLS_SAN_DN, cert);
if (ret == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto nc_done;
}
ret = gnutls_x509_name_constraints_check_crt(vparams->nc, GNUTLS_SAN_URI, cert);
if (ret == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto nc_done;
}
ret = gnutls_x509_name_constraints_check_crt(vparams->nc, GNUTLS_SAN_IPADDRESS, cert);
if (ret == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto nc_done;
}
}
}
nc_done:
if (vparams->tls_feat != NULL) {
/* append the issuer's constraints */
ret = gnutls_x509_crt_get_tlsfeatures(issuer, vparams->tls_feat, GNUTLS_EXT_FLAG_APPEND, NULL);
if (ret < 0 && ret != GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto feat_done;
}
ret = gnutls_x509_tlsfeatures_check_crt(vparams->tls_feat, cert);
if (ret == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto feat_done;
}
}
feat_done:
issuer_version = gnutls_x509_crt_get_version(issuer);
if (issuer_version < 0) {
MARK_INVALID(0);
} else if (!(flags & GNUTLS_VERIFY_DISABLE_CA_SIGN) &&
((flags & GNUTLS_VERIFY_DO_NOT_ALLOW_X509_V1_CA_CRT)
|| issuer_version != 1)) {
if (check_if_ca(cert, issuer, &vparams->max_path, flags) != 1) {
MARK_INVALID(GNUTLS_CERT_SIGNER_NOT_CA);
}
ret =
gnutls_x509_crt_get_key_usage(issuer, &usage, NULL);
if (ret != GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
if (ret < 0) {
MARK_INVALID(0);
} else if (!(usage & GNUTLS_KEY_KEY_CERT_SIGN)) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
}
}
}
if (sigalg >= 0) {
hash_algo = gnutls_sign_get_hash_algorithm(sigalg);
me = mac_to_entry(hash_algo);
} else {
me = NULL;
}
if (me == NULL) {
MARK_INVALID(0);
} else if (cert_signed_data.data != NULL &&
cert_signature.data != NULL) {
ret =
_gnutls_x509_verify_data(me,
&cert_signed_data,
&cert_signature,
issuer);
if (ret == GNUTLS_E_PK_SIG_VERIFY_FAILED) {
MARK_INVALID(GNUTLS_CERT_SIGNATURE_FAILURE);
} else if (ret < 0) {
MARK_INVALID(0);
}
}
}
/* we always check the issuer for unsupported critical extensions */
if (issuer && check_for_unknown_exts(issuer) != 0) {
if (!(flags & GNUTLS_VERIFY_IGNORE_UNKNOWN_CRIT_EXTENSIONS)) {
MARK_INVALID(GNUTLS_CERT_UNKNOWN_CRIT_EXTENSIONS);
}
}
/* we only check the end-certificate for critical extensions; that
* way do not perform this check twice on the certificates when
* verifying a large list */
if (end_cert && check_for_unknown_exts(cert) != 0) {
if (!(flags & GNUTLS_VERIFY_IGNORE_UNKNOWN_CRIT_EXTENSIONS)) {
MARK_INVALID(GNUTLS_CERT_UNKNOWN_CRIT_EXTENSIONS);
}
}
if (sigalg >= 0) {
if (is_level_acceptable(cert, issuer, sigalg, flags) == 0) {
MARK_INVALID(GNUTLS_CERT_INSECURE_ALGORITHM);
}
/* If the certificate is not self signed check if the algorithms
* used are secure. If the certificate is self signed it doesn't
* really matter.
*/
if (gnutls_sign_is_secure(sigalg) == 0 &&
_gnutls_is_broken_sig_allowed(sigalg, flags) == 0 &&
is_issuer(cert, cert) == 0) {
MARK_INVALID(GNUTLS_CERT_INSECURE_ALGORITHM);
}
}
/* Check activation/expiration times
*/
if (!(flags & GNUTLS_VERIFY_DISABLE_TIME_CHECKS)) {
/* check the time of the issuer first */
if (issuer != NULL &&
!(flags & GNUTLS_VERIFY_DISABLE_TRUSTED_TIME_CHECKS)) {
out |= check_time_status(issuer, vparams->now);
if (out != 0) {
gnutls_assert();
result = 0;
}
}
out |= check_time_status(cert, vparams->now);
if (out != 0) {
gnutls_assert();
result = 0;
}
}
cleanup:
if (output)
*output |= out;
if (vparams->func) {
if (result == 0) {
out |= GNUTLS_CERT_INVALID;
}
vparams->func(cert, issuer, NULL, out);
}
_gnutls_free_datum(&cert_signed_data);
_gnutls_free_datum(&cert_signature);
return result;
}
/*
* Verifies the given certificate again a certificate list of
* trusted CAs.
*
* Returns only 0 or 1. If 1 it means that the certificate
* was successfuly verified.
*
* 'flags': an OR of the gnutls_certificate_verify_flags enumeration.
*
* Output will hold some extra information about the verification
* procedure. Issuer will hold the actual issuer from the trusted list.
*/
static int
_gnutls_verify_certificate2 (gnutls_x509_crt_t cert,
const gnutls_x509_crt_t * trusted_cas,
int tcas_size, unsigned int flags,
unsigned int *output,
gnutls_x509_crt_t * _issuer)
{
gnutls_datum_t cert_signed_data = { NULL, 0 };
gnutls_datum_t cert_signature = { NULL, 0 };
gnutls_x509_crt_t issuer = NULL;
int issuer_version, result;
if (output)
*output = 0;
if (tcas_size >= 1)
issuer = find_issuer (cert, trusted_cas, tcas_size);
else
{
gnutls_assert ();
if (output)
*output |= GNUTLS_CERT_SIGNER_NOT_FOUND | GNUTLS_CERT_INVALID;
return 0;
}
/* issuer is not in trusted certificate
* authorities.
*/
if (issuer == NULL)
{
if (output)
*output |= GNUTLS_CERT_SIGNER_NOT_FOUND | GNUTLS_CERT_INVALID;
gnutls_assert ();
return 0;
}
if (_issuer != NULL)
*_issuer = issuer;
issuer_version = gnutls_x509_crt_get_version (issuer);
if (issuer_version < 0)
{
gnutls_assert ();
return issuer_version;
}
if (!(flags & GNUTLS_VERIFY_DISABLE_CA_SIGN) &&
((flags & GNUTLS_VERIFY_DO_NOT_ALLOW_X509_V1_CA_CRT)
|| issuer_version != 1))
{
if (check_if_ca (cert, issuer, flags) == 0)
{
gnutls_assert ();
if (output)
*output |= GNUTLS_CERT_SIGNER_NOT_CA | GNUTLS_CERT_INVALID;
return 0;
}
}
result =
_gnutls_x509_get_signed_data (cert->cert, "tbsCertificate",
&cert_signed_data);
if (result < 0)
{
gnutls_assert ();
goto cleanup;
}
result =
_gnutls_x509_get_signature (cert->cert, "signature", &cert_signature);
if (result < 0)
{
gnutls_assert ();
goto cleanup;
}
result =
_gnutls_x509_verify_signature (&cert_signed_data, NULL, &cert_signature,
issuer);
if (result == GNUTLS_E_PK_SIG_VERIFY_FAILED)
{
gnutls_assert ();
/* error. ignore it */
if (output)
*output |= GNUTLS_CERT_INVALID;
result = 0;
}
else if (result < 0)
{
gnutls_assert();
goto cleanup;
}
/* If the certificate is not self signed check if the algorithms
* used are secure. If the certificate is self signed it doesn't
* really matter.
*/
if (is_issuer (cert, cert) == 0)
{
int sigalg;
sigalg = gnutls_x509_crt_get_signature_algorithm (cert);
if (((sigalg == GNUTLS_SIGN_RSA_MD2) &&
!(flags & GNUTLS_VERIFY_ALLOW_SIGN_RSA_MD2)) ||
((sigalg == GNUTLS_SIGN_RSA_MD5) &&
!(flags & GNUTLS_VERIFY_ALLOW_SIGN_RSA_MD5)))
{
if (output)
*output |= GNUTLS_CERT_INSECURE_ALGORITHM | GNUTLS_CERT_INVALID;
result = 0;
}
}
cleanup:
_gnutls_free_datum (&cert_signed_data);
_gnutls_free_datum (&cert_signature);
return result;
}
