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freebsd-skq/contrib/ldns/dane.c
des d300320fbe Upgrade LDNS to 1.7.0. 
I've been holding back on this because 1.7.0 requires OpenSSL 1.1.0 or
newer for full DANE support.  But we can't wait forever, and nothing in
base uses DANE anyway, so here we go.
2018-05-12 12:00:18 +00:00

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/*
* Verify or create TLS authentication with DANE (RFC6698)
*
* (c) NLnetLabs 2012
*
* See the file LICENSE for the license.
*
*/
#include <ldns/config.h>
#ifdef USE_DANE
#include <ldns/ldns.h>
#include <ldns/dane.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_SSL
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/x509v3.h>
#endif
ldns_status
ldns_dane_create_tlsa_owner(ldns_rdf** tlsa_owner, const ldns_rdf* name,
uint16_t port, ldns_dane_transport transport)
{
char buf[LDNS_MAX_DOMAINLEN];
size_t s;
assert(tlsa_owner != NULL);
assert(name != NULL);
assert(ldns_rdf_get_type(name) == LDNS_RDF_TYPE_DNAME);
s = (size_t)snprintf(buf, LDNS_MAX_DOMAINLEN, "X_%d", (int)port);
buf[0] = (char)(s - 1);
switch(transport) {
case LDNS_DANE_TRANSPORT_TCP:
s += snprintf(buf + s, LDNS_MAX_DOMAINLEN - s, "\004_tcp");
break;
case LDNS_DANE_TRANSPORT_UDP:
s += snprintf(buf + s, LDNS_MAX_DOMAINLEN - s, "\004_udp");
break;
case LDNS_DANE_TRANSPORT_SCTP:
s += snprintf(buf + s, LDNS_MAX_DOMAINLEN - s, "\005_sctp");
break;
default:
return LDNS_STATUS_DANE_UNKNOWN_TRANSPORT;
}
if (s + ldns_rdf_size(name) > LDNS_MAX_DOMAINLEN) {
return LDNS_STATUS_DOMAINNAME_OVERFLOW;
}
memcpy(buf + s, ldns_rdf_data(name), ldns_rdf_size(name));
*tlsa_owner = ldns_rdf_new_frm_data(LDNS_RDF_TYPE_DNAME,
s + ldns_rdf_size(name), buf);
if (*tlsa_owner == NULL) {
return LDNS_STATUS_MEM_ERR;
}
return LDNS_STATUS_OK;
}
#ifdef HAVE_SSL
ldns_status
ldns_dane_cert2rdf(ldns_rdf** rdf, X509* cert,
ldns_tlsa_selector selector,
ldns_tlsa_matching_type matching_type)
{
unsigned char* buf = NULL;
size_t len;
X509_PUBKEY* xpubkey;
EVP_PKEY* epubkey;
unsigned char* digest;
assert(rdf != NULL);
assert(cert != NULL);
switch(selector) {
case LDNS_TLSA_SELECTOR_FULL_CERTIFICATE:
len = (size_t)i2d_X509(cert, &buf);
break;
case LDNS_TLSA_SELECTOR_SUBJECTPUBLICKEYINFO:
#ifndef S_SPLINT_S
xpubkey = X509_get_X509_PUBKEY(cert);
#endif
if (! xpubkey) {
return LDNS_STATUS_SSL_ERR;
}
epubkey = X509_PUBKEY_get(xpubkey);
if (! epubkey) {
return LDNS_STATUS_SSL_ERR;
}
len = (size_t)i2d_PUBKEY(epubkey, &buf);
break;
default:
return LDNS_STATUS_DANE_UNKNOWN_SELECTOR;
}
switch(matching_type) {
case LDNS_TLSA_MATCHING_TYPE_NO_HASH_USED:
*rdf = ldns_rdf_new(LDNS_RDF_TYPE_HEX, len, buf);
return *rdf ? LDNS_STATUS_OK : LDNS_STATUS_MEM_ERR;
break;
case LDNS_TLSA_MATCHING_TYPE_SHA256:
digest = LDNS_XMALLOC(unsigned char, LDNS_SHA256_DIGEST_LENGTH);
if (digest == NULL) {
LDNS_FREE(buf);
return LDNS_STATUS_MEM_ERR;
}
(void) ldns_sha256(buf, (unsigned int)len, digest);
*rdf = ldns_rdf_new(LDNS_RDF_TYPE_HEX, LDNS_SHA256_DIGEST_LENGTH,
digest);
LDNS_FREE(buf);
return *rdf ? LDNS_STATUS_OK : LDNS_STATUS_MEM_ERR;
break;
case LDNS_TLSA_MATCHING_TYPE_SHA512:
digest = LDNS_XMALLOC(unsigned char, LDNS_SHA512_DIGEST_LENGTH);
if (digest == NULL) {
LDNS_FREE(buf);
return LDNS_STATUS_MEM_ERR;
}
(void) ldns_sha512(buf, (unsigned int)len, digest);
*rdf = ldns_rdf_new(LDNS_RDF_TYPE_HEX, LDNS_SHA512_DIGEST_LENGTH,
digest);
LDNS_FREE(buf);
return *rdf ? LDNS_STATUS_OK : LDNS_STATUS_MEM_ERR;
break;
default:
LDNS_FREE(buf);
return LDNS_STATUS_DANE_UNKNOWN_MATCHING_TYPE;
}
}
/* Ordinary PKIX validation of cert (with extra_certs to help)
* against the CA's in store
*/
static ldns_status
ldns_dane_pkix_validate(X509* cert, STACK_OF(X509)* extra_certs,
X509_STORE* store)
{
X509_STORE_CTX* vrfy_ctx;
ldns_status s;
if (! store) {
return LDNS_STATUS_DANE_PKIX_DID_NOT_VALIDATE;
}
vrfy_ctx = X509_STORE_CTX_new();
if (! vrfy_ctx) {
return LDNS_STATUS_SSL_ERR;
} else if (X509_STORE_CTX_init(vrfy_ctx, store,
cert, extra_certs) != 1) {
s = LDNS_STATUS_SSL_ERR;
} else if (X509_verify_cert(vrfy_ctx) == 1) {
s = LDNS_STATUS_OK;
} else {
s = LDNS_STATUS_DANE_PKIX_DID_NOT_VALIDATE;
}
X509_STORE_CTX_free(vrfy_ctx);
return s;
}
/* Orinary PKIX validation of cert (with extra_certs to help)
* against the CA's in store, but also return the validation chain.
*/
static ldns_status
ldns_dane_pkix_validate_and_get_chain(STACK_OF(X509)** chain, X509* cert,
STACK_OF(X509)* extra_certs, X509_STORE* store)
{
ldns_status s;
X509_STORE* empty_store = NULL;
X509_STORE_CTX* vrfy_ctx;
assert(chain != NULL);
if (! store) {
store = empty_store = X509_STORE_new();
}
s = LDNS_STATUS_SSL_ERR;
vrfy_ctx = X509_STORE_CTX_new();
if (! vrfy_ctx) {
goto exit_free_empty_store;
} else if (X509_STORE_CTX_init(vrfy_ctx, store,
cert, extra_certs) != 1) {
goto exit_free_vrfy_ctx;
} else if (X509_verify_cert(vrfy_ctx) == 1) {
s = LDNS_STATUS_OK;
} else {
s = LDNS_STATUS_DANE_PKIX_DID_NOT_VALIDATE;
}
*chain = X509_STORE_CTX_get1_chain(vrfy_ctx);
if (! *chain) {
s = LDNS_STATUS_SSL_ERR;
}
exit_free_vrfy_ctx:
X509_STORE_CTX_free(vrfy_ctx);
exit_free_empty_store:
if (empty_store) {
X509_STORE_free(empty_store);
}
return s;
}
/* Return the validation chain that can be build out of cert, with extra_certs.
*/
static ldns_status
ldns_dane_pkix_get_chain(STACK_OF(X509)** chain,
X509* cert, STACK_OF(X509)* extra_certs)
{
ldns_status s;
X509_STORE* empty_store = NULL;
X509_STORE_CTX* vrfy_ctx;
assert(chain != NULL);
empty_store = X509_STORE_new();
s = LDNS_STATUS_SSL_ERR;
vrfy_ctx = X509_STORE_CTX_new();
if (! vrfy_ctx) {
goto exit_free_empty_store;
} else if (X509_STORE_CTX_init(vrfy_ctx, empty_store,
cert, extra_certs) != 1) {
goto exit_free_vrfy_ctx;
}
(void) X509_verify_cert(vrfy_ctx);
*chain = X509_STORE_CTX_get1_chain(vrfy_ctx);
if (! *chain) {
s = LDNS_STATUS_SSL_ERR;
} else {
s = LDNS_STATUS_OK;
}
exit_free_vrfy_ctx:
X509_STORE_CTX_free(vrfy_ctx);
exit_free_empty_store:
X509_STORE_free(empty_store);
return s;
}
/* Pop n+1 certs and return the last popped.
*/
static ldns_status
ldns_dane_get_nth_cert_from_validation_chain(
X509** cert, STACK_OF(X509)* chain, int n, bool ca)
{
if (n >= sk_X509_num(chain) || n < 0) {
return LDNS_STATUS_DANE_OFFSET_OUT_OF_RANGE;
}
*cert = sk_X509_pop(chain);
while (n-- > 0) {
X509_free(*cert);
*cert = sk_X509_pop(chain);
}
if (ca && ! X509_check_ca(*cert)) {
return LDNS_STATUS_DANE_NON_CA_CERTIFICATE;
}
return LDNS_STATUS_OK;
}
/* Create validation chain with cert and extra_certs and returns the last
* self-signed (if present).
*/
static ldns_status
ldns_dane_pkix_get_last_self_signed(X509** out_cert,
X509* cert, STACK_OF(X509)* extra_certs)
{
ldns_status s;
X509_STORE* empty_store = NULL;
X509_STORE_CTX* vrfy_ctx;
assert(out_cert != NULL);
empty_store = X509_STORE_new();
s = LDNS_STATUS_SSL_ERR;
vrfy_ctx = X509_STORE_CTX_new();
if (! vrfy_ctx) {
goto exit_free_empty_store;
} else if (X509_STORE_CTX_init(vrfy_ctx, empty_store,
cert, extra_certs) != 1) {
goto exit_free_vrfy_ctx;
}
(void) X509_verify_cert(vrfy_ctx);
if (X509_STORE_CTX_get_error(vrfy_ctx) == X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN ||
X509_STORE_CTX_get_error(vrfy_ctx) == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT){
*out_cert = X509_STORE_CTX_get_current_cert( vrfy_ctx);
s = LDNS_STATUS_OK;
} else {
s = LDNS_STATUS_DANE_PKIX_NO_SELF_SIGNED_TRUST_ANCHOR;
}
exit_free_vrfy_ctx:
X509_STORE_CTX_free(vrfy_ctx);
exit_free_empty_store:
X509_STORE_free(empty_store);
return s;
}
ldns_status
ldns_dane_select_certificate(X509** selected_cert,
X509* cert, STACK_OF(X509)* extra_certs,
X509_STORE* pkix_validation_store,
ldns_tlsa_certificate_usage cert_usage, int offset)
{
ldns_status s;
STACK_OF(X509)* pkix_validation_chain = NULL;
assert(selected_cert != NULL);
assert(cert != NULL);
/* With PKIX validation explicitly turned off (pkix_validation_store
* == NULL), treat the "CA constraint" and "Service certificate
* constraint" the same as "Trust anchor assertion" and "Domain issued
* certificate" respectively.
*/
if (pkix_validation_store == NULL) {
switch (cert_usage) {
case LDNS_TLSA_USAGE_CA_CONSTRAINT:
cert_usage = LDNS_TLSA_USAGE_TRUST_ANCHOR_ASSERTION;
break;
case LDNS_TLSA_USAGE_SERVICE_CERTIFICATE_CONSTRAINT:
cert_usage = LDNS_TLSA_USAGE_DOMAIN_ISSUED_CERTIFICATE;
break;
default:
break;
}
}
/* Now what to do with each Certificate usage...
*/
switch (cert_usage) {
case LDNS_TLSA_USAGE_CA_CONSTRAINT:
s = ldns_dane_pkix_validate_and_get_chain(
&pkix_validation_chain,
cert, extra_certs,
pkix_validation_store);
if (! pkix_validation_chain) {
return s;
}
if (s == LDNS_STATUS_OK) {
if (offset == -1) {
offset = 0;
}
s = ldns_dane_get_nth_cert_from_validation_chain(
selected_cert, pkix_validation_chain,
offset, true);
}
sk_X509_pop_free(pkix_validation_chain, X509_free);
return s;
break;
case LDNS_TLSA_USAGE_SERVICE_CERTIFICATE_CONSTRAINT:
*selected_cert = cert;
return ldns_dane_pkix_validate(cert, extra_certs,
pkix_validation_store);
break;
case LDNS_TLSA_USAGE_TRUST_ANCHOR_ASSERTION:
if (offset == -1) {
s = ldns_dane_pkix_get_last_self_signed(
selected_cert, cert, extra_certs);
return s;
} else {
s = ldns_dane_pkix_get_chain(
&pkix_validation_chain,
cert, extra_certs);
if (s == LDNS_STATUS_OK) {
s =
ldns_dane_get_nth_cert_from_validation_chain(
selected_cert, pkix_validation_chain,
offset, false);
} else if (! pkix_validation_chain) {
return s;
}
sk_X509_pop_free(pkix_validation_chain, X509_free);
return s;
}
break;
case LDNS_TLSA_USAGE_DOMAIN_ISSUED_CERTIFICATE:
*selected_cert = cert;
return LDNS_STATUS_OK;
break;
default:
return LDNS_STATUS_DANE_UNKNOWN_CERTIFICATE_USAGE;
break;
}
}
ldns_status
ldns_dane_create_tlsa_rr(ldns_rr** tlsa,
ldns_tlsa_certificate_usage certificate_usage,
ldns_tlsa_selector selector,
ldns_tlsa_matching_type matching_type,
X509* cert)
{
ldns_rdf* rdf;
ldns_status s;
assert(tlsa != NULL);
assert(cert != NULL);
/* create rr */
*tlsa = ldns_rr_new_frm_type(LDNS_RR_TYPE_TLSA);
if (*tlsa == NULL) {
return LDNS_STATUS_MEM_ERR;
}
rdf = ldns_native2rdf_int8(LDNS_RDF_TYPE_INT8,
(uint8_t)certificate_usage);
if (rdf == NULL) {
goto memerror;
}
(void) ldns_rr_set_rdf(*tlsa, rdf, 0);
rdf = ldns_native2rdf_int8(LDNS_RDF_TYPE_INT8, (uint8_t)selector);
if (rdf == NULL) {
goto memerror;
}
(void) ldns_rr_set_rdf(*tlsa, rdf, 1);
rdf = ldns_native2rdf_int8(LDNS_RDF_TYPE_INT8, (uint8_t)matching_type);
if (rdf == NULL) {
goto memerror;
}
(void) ldns_rr_set_rdf(*tlsa, rdf, 2);
s = ldns_dane_cert2rdf(&rdf, cert, selector, matching_type);
if (s == LDNS_STATUS_OK) {
(void) ldns_rr_set_rdf(*tlsa, rdf, 3);
return LDNS_STATUS_OK;
}
ldns_rr_free(*tlsa);
*tlsa = NULL;
return s;
memerror:
ldns_rr_free(*tlsa);
*tlsa = NULL;
return LDNS_STATUS_MEM_ERR;
}
#ifdef USE_DANE_VERIFY
/* Return tlsas that actually are TLSA resource records with known values
* for the Certificate usage, Selector and Matching type rdata fields.
*/
static ldns_rr_list*
ldns_dane_filter_unusable_records(const ldns_rr_list* tlsas)
{
size_t i;
ldns_rr_list* r = ldns_rr_list_new();
ldns_rr* tlsa_rr;
if (! r) {
return NULL;
}
for (i = 0; i < ldns_rr_list_rr_count(tlsas); i++) {
tlsa_rr = ldns_rr_list_rr(tlsas, i);
if (ldns_rr_get_type(tlsa_rr) == LDNS_RR_TYPE_TLSA &&
ldns_rr_rd_count(tlsa_rr) == 4 &&
ldns_rdf2native_int8(ldns_rr_rdf(tlsa_rr, 0)) <= 3 &&
ldns_rdf2native_int8(ldns_rr_rdf(tlsa_rr, 1)) <= 1 &&
ldns_rdf2native_int8(ldns_rr_rdf(tlsa_rr, 2)) <= 2) {
if (! ldns_rr_list_push_rr(r, tlsa_rr)) {
ldns_rr_list_free(r);
return NULL;
}
}
}
return r;
}
#if !defined(USE_DANE_TA_USAGE)
/* Return whether cert/selector/matching_type matches data.
*/
static ldns_status
ldns_dane_match_cert_with_data(X509* cert, ldns_tlsa_selector selector,
ldns_tlsa_matching_type matching_type, ldns_rdf* data)
{
ldns_status s;
ldns_rdf* match_data;
s = ldns_dane_cert2rdf(&match_data, cert, selector, matching_type);
if (s == LDNS_STATUS_OK) {
if (ldns_rdf_compare(data, match_data) != 0) {
s = LDNS_STATUS_DANE_TLSA_DID_NOT_MATCH;
}
ldns_rdf_free(match_data);
}
return s;
}
/* Return whether any certificate from the chain with selector/matching_type
* matches data.
* ca should be true if the certificate has to be a CA certificate too.
*/
static ldns_status
ldns_dane_match_any_cert_with_data(STACK_OF(X509)* chain,
ldns_tlsa_selector selector,
ldns_tlsa_matching_type matching_type,
ldns_rdf* data, bool ca)
{
ldns_status s = LDNS_STATUS_DANE_TLSA_DID_NOT_MATCH;
size_t n, i;
X509* cert;
n = (size_t)sk_X509_num(chain);
for (i = 0; i < n; i++) {
cert = sk_X509_pop(chain);
if (! cert) {
s = LDNS_STATUS_SSL_ERR;
break;
}
s = ldns_dane_match_cert_with_data(cert,
selector, matching_type, data);
if (ca && s == LDNS_STATUS_OK && ! X509_check_ca(cert)) {
s = LDNS_STATUS_DANE_NON_CA_CERTIFICATE;
}
X509_free(cert);
if (s != LDNS_STATUS_DANE_TLSA_DID_NOT_MATCH) {
break;
}
/* when s == LDNS_STATUS_DANE_TLSA_DID_NOT_MATCH,
* try to match the next certificate
*/
}
return s;
}
#endif /* !defined(USE_DANE_TA_USAGE) */
#endif /* USE_DANE_VERIFY */
#ifdef USE_DANE_VERIFY
ldns_status
ldns_dane_verify_rr(const ldns_rr* tlsa_rr,
X509* cert, STACK_OF(X509)* extra_certs,
X509_STORE* pkix_validation_store)
{
#if defined(USE_DANE_TA_USAGE)
SSL_CTX *ssl_ctx = NULL;
SSL *ssl = NULL;
X509_STORE_CTX *store_ctx = NULL;
#else
STACK_OF(X509)* pkix_validation_chain = NULL;
#endif
ldns_status s = LDNS_STATUS_OK;
ldns_tlsa_certificate_usage usage;
ldns_tlsa_selector selector;
ldns_tlsa_matching_type mtype;
ldns_rdf* data;
if (! tlsa_rr || ldns_rr_get_type(tlsa_rr) != LDNS_RR_TYPE_TLSA ||
ldns_rr_rd_count(tlsa_rr) != 4 ||
ldns_rdf2native_int8(ldns_rr_rdf(tlsa_rr, 0)) > 3 ||
ldns_rdf2native_int8(ldns_rr_rdf(tlsa_rr, 1)) > 1 ||
ldns_rdf2native_int8(ldns_rr_rdf(tlsa_rr, 2)) > 2 ) {
/* No (usable) TLSA, so regular PKIX validation
*/
return ldns_dane_pkix_validate(cert, extra_certs,
pkix_validation_store);
}
usage = ldns_rdf2native_int8(ldns_rr_rdf(tlsa_rr, 0));
selector = ldns_rdf2native_int8(ldns_rr_rdf(tlsa_rr, 1));
mtype = ldns_rdf2native_int8(ldns_rr_rdf(tlsa_rr, 2));
data = ldns_rr_rdf(tlsa_rr, 3) ;
#if defined(USE_DANE_TA_USAGE)
/* Rely on OpenSSL dane functions.
*
* OpenSSL does not provide offline dane verification. The dane unit
* tests within openssl use the undocumented SSL_get0_dane() and
* X509_STORE_CTX_set0_dane() to convey dane parameters set on SSL and
* SSL_CTX to a X509_STORE_CTX that can be used to do offline
* verification. We use these undocumented means with the ldns
* dane function prototypes which did only offline dane verification.
*/
if (!(ssl_ctx = SSL_CTX_new(TLS_client_method())))
s = LDNS_STATUS_MEM_ERR;
else if (SSL_CTX_dane_enable(ssl_ctx) <= 0)
s = LDNS_STATUS_SSL_ERR;
else if (SSL_CTX_dane_set_flags(
ssl_ctx, DANE_FLAG_NO_DANE_EE_NAMECHECKS),
!(ssl = SSL_new(ssl_ctx)))
s = LDNS_STATUS_MEM_ERR;
else if (SSL_set_connect_state(ssl),
(SSL_dane_enable(ssl, NULL) <= 0))
s = LDNS_STATUS_SSL_ERR;
else if (SSL_dane_tlsa_add(ssl, usage, selector, mtype,
ldns_rdf_data(data), ldns_rdf_size(data)) <= 0)
s = LDNS_STATUS_SSL_ERR;
else if (!(store_ctx = X509_STORE_CTX_new()))
s = LDNS_STATUS_MEM_ERR;
else if (!X509_STORE_CTX_init(store_ctx, pkix_validation_store, cert, extra_certs))
s = LDNS_STATUS_SSL_ERR;
else {
int ret;
X509_STORE_CTX_set_default(store_ctx,
SSL_is_server(ssl) ? "ssl_client" : "ssl_server");
X509_VERIFY_PARAM_set1(X509_STORE_CTX_get0_param(store_ctx),
SSL_get0_param(ssl));
X509_STORE_CTX_set0_dane(store_ctx, SSL_get0_dane(ssl));
if (SSL_get_verify_callback(ssl))
X509_STORE_CTX_set_verify_cb(store_ctx, SSL_get_verify_callback(ssl));
ret = X509_verify_cert(store_ctx);
if (!ret) {
if (X509_STORE_CTX_get_error(store_ctx) == X509_V_ERR_DANE_NO_MATCH)
s = LDNS_STATUS_DANE_TLSA_DID_NOT_MATCH;
else
s = LDNS_STATUS_DANE_PKIX_DID_NOT_VALIDATE;
}
X509_STORE_CTX_cleanup(store_ctx);
}
if (store_ctx)
X509_STORE_CTX_free(store_ctx);
if (ssl)
SSL_free(ssl);
if (ssl_ctx)
SSL_CTX_free(ssl_ctx);
return s;
#else
switch (usage) {
case LDNS_TLSA_USAGE_CA_CONSTRAINT:
s = ldns_dane_pkix_validate_and_get_chain(
&pkix_validation_chain,
cert, extra_certs,
pkix_validation_store);
if (! pkix_validation_chain) {
return s;
}
if (s == LDNS_STATUS_DANE_PKIX_DID_NOT_VALIDATE) {
/*
* NO PKIX validation. We still try to match *any*
* certificate from the chain, so we return
* TLSA errors over PKIX errors.
*
* i.e. When the TLSA matches no certificate, we return
* TLSA_DID_NOT_MATCH and not PKIX_DID_NOT_VALIDATE
*/
s = ldns_dane_match_any_cert_with_data(
pkix_validation_chain,
selector, mtype, data, true);
if (s == LDNS_STATUS_OK) {
/* A TLSA record did match a cert from the
* chain, thus the error is failed PKIX
* validation.
*/
s = LDNS_STATUS_DANE_PKIX_DID_NOT_VALIDATE;
}
} else if (s == LDNS_STATUS_OK) {
/* PKIX validated, does the TLSA match too? */
s = ldns_dane_match_any_cert_with_data(
pkix_validation_chain,
selector, mtype, data, true);
}
sk_X509_pop_free(pkix_validation_chain, X509_free);
return s;
break;
case LDNS_TLSA_USAGE_SERVICE_CERTIFICATE_CONSTRAINT:
s = ldns_dane_match_cert_with_data(cert,
selector, mtype, data);
if (s == LDNS_STATUS_OK) {
return ldns_dane_pkix_validate(cert, extra_certs,
pkix_validation_store);
}
return s;
break;
case LDNS_TLSA_USAGE_TRUST_ANCHOR_ASSERTION:
#if 0
s = ldns_dane_pkix_get_chain(&pkix_validation_chain,
cert, extra_certs);
if (s == LDNS_STATUS_OK) {
s = ldns_dane_match_any_cert_with_data(
pkix_validation_chain,
selector, mtype, data, false);
} else if (! pkix_validation_chain) {
return s;
}
sk_X509_pop_free(pkix_validation_chain, X509_free);
return s;
#else
return LDNS_STATUS_DANE_NEED_OPENSSL_GE_1_1_FOR_DANE_TA;
#endif
break;
case LDNS_TLSA_USAGE_DOMAIN_ISSUED_CERTIFICATE:
return ldns_dane_match_cert_with_data(cert,
selector, mtype, data);
break;
default:
break;
}
#endif
return LDNS_STATUS_DANE_UNKNOWN_CERTIFICATE_USAGE;
}
ldns_status
ldns_dane_verify(const ldns_rr_list* tlsas,
X509* cert, STACK_OF(X509)* extra_certs,
X509_STORE* pkix_validation_store)
{
#if defined(USE_DANE_TA_USAGE)
SSL_CTX *ssl_ctx = NULL;
ldns_rdf *basename_rdf = NULL;
char *basename = NULL;
SSL *ssl = NULL;
X509_STORE_CTX *store_ctx = NULL;
#else
ldns_status ps;
#endif
size_t i;
ldns_rr* tlsa_rr;
ldns_rr_list *usable_tlsas;
ldns_status s = LDNS_STATUS_OK;
assert(cert != NULL);
if (! tlsas || ldns_rr_list_rr_count(tlsas) == 0)
/* No TLSA's, so regular PKIX validation
*/
return ldns_dane_pkix_validate(cert, extra_certs,
pkix_validation_store);
/* To enable name checks (which we don't) */
#if defined(USE_DANE_TA_USAGE) && 0
else if (!(basename_rdf = ldns_dname_clone_from(
ldns_rr_list_owner(tlsas), 2)))
/* Could nog get DANE base name */
s = LDNS_STATUS_ERR;
else if (!(basename = ldns_rdf2str(basename_rdf)))
s = LDNS_STATUS_MEM_ERR;
else if (strlen(basename) && (basename[strlen(basename)-1] = 0))
s = LDNS_STATUS_ERR; /* Intended to be unreachable */
#endif
else if (!(usable_tlsas = ldns_dane_filter_unusable_records(tlsas)))
return LDNS_STATUS_MEM_ERR;
else if (ldns_rr_list_rr_count(usable_tlsas) == 0) {
/* No TLSA's, so regular PKIX validation
*/
ldns_rr_list_free(usable_tlsas);
return ldns_dane_pkix_validate(cert, extra_certs,
pkix_validation_store);
}
#if defined(USE_DANE_TA_USAGE)
/* Rely on OpenSSL dane functions.
*
* OpenSSL does not provide offline dane verification. The dane unit
* tests within openssl use the undocumented SSL_get0_dane() and
* X509_STORE_CTX_set0_dane() to convey dane parameters set on SSL and
* SSL_CTX to a X509_STORE_CTX that can be used to do offline
* verification. We use these undocumented means with the ldns
* dane function prototypes which did only offline dane verification.
*/
if (!(ssl_ctx = SSL_CTX_new(TLS_client_method())))
s = LDNS_STATUS_MEM_ERR;
else if (SSL_CTX_dane_enable(ssl_ctx) <= 0)
s = LDNS_STATUS_SSL_ERR;
else if (SSL_CTX_dane_set_flags(
ssl_ctx, DANE_FLAG_NO_DANE_EE_NAMECHECKS),
!(ssl = SSL_new(ssl_ctx)))
s = LDNS_STATUS_MEM_ERR;
else if (SSL_set_connect_state(ssl),
(SSL_dane_enable(ssl, basename) <= 0))
s = LDNS_STATUS_SSL_ERR;
else for (i = 0; i < ldns_rr_list_rr_count(usable_tlsas); i++) {
ldns_tlsa_certificate_usage usage;
ldns_tlsa_selector selector;
ldns_tlsa_matching_type mtype;
ldns_rdf* data;
tlsa_rr = ldns_rr_list_rr(usable_tlsas, i);
usage = ldns_rdf2native_int8(ldns_rr_rdf(tlsa_rr,0));
selector= ldns_rdf2native_int8(ldns_rr_rdf(tlsa_rr,1));
mtype = ldns_rdf2native_int8(ldns_rr_rdf(tlsa_rr,2));
data = ldns_rr_rdf(tlsa_rr,3) ;
if (SSL_dane_tlsa_add(ssl, usage, selector, mtype,
ldns_rdf_data(data),
ldns_rdf_size(data)) <= 0) {
s = LDNS_STATUS_SSL_ERR;
break;
}
}
if (!s && !(store_ctx = X509_STORE_CTX_new()))
s = LDNS_STATUS_MEM_ERR;
else if (!X509_STORE_CTX_init(store_ctx, pkix_validation_store, cert, extra_certs))
s = LDNS_STATUS_SSL_ERR;
else {
int ret;
X509_STORE_CTX_set_default(store_ctx,
SSL_is_server(ssl) ? "ssl_client" : "ssl_server");
X509_VERIFY_PARAM_set1(X509_STORE_CTX_get0_param(store_ctx),
SSL_get0_param(ssl));
X509_STORE_CTX_set0_dane(store_ctx, SSL_get0_dane(ssl));
if (SSL_get_verify_callback(ssl))
X509_STORE_CTX_set_verify_cb(store_ctx, SSL_get_verify_callback(ssl));
ret = X509_verify_cert(store_ctx);
if (!ret) {
if (X509_STORE_CTX_get_error(store_ctx) == X509_V_ERR_DANE_NO_MATCH)
s = LDNS_STATUS_DANE_TLSA_DID_NOT_MATCH;
else
s = LDNS_STATUS_DANE_PKIX_DID_NOT_VALIDATE;
}
X509_STORE_CTX_cleanup(store_ctx);
}
if (store_ctx)
X509_STORE_CTX_free(store_ctx);
if (ssl)
SSL_free(ssl);
if (ssl_ctx)
SSL_CTX_free(ssl_ctx);
if (basename)
free(basename);
ldns_rdf_deep_free(basename_rdf);
#else
for (i = 0; i < ldns_rr_list_rr_count(usable_tlsas); i++) {
tlsa_rr = ldns_rr_list_rr(usable_tlsas, i);
ps = s;
s = ldns_dane_verify_rr(tlsa_rr, cert, extra_certs,
pkix_validation_store);
if (s != LDNS_STATUS_DANE_TLSA_DID_NOT_MATCH &&
s != LDNS_STATUS_DANE_PKIX_DID_NOT_VALIDATE &&
s != LDNS_STATUS_DANE_NEED_OPENSSL_GE_1_1_FOR_DANE_TA) {
/* which would be LDNS_STATUS_OK (match)
* or some fatal error preventing use from
* trying the next TLSA record.
*/
break;
}
s = (s > ps ? s : ps); /* pref NEED_OPENSSL_GE_1_1_FOR_DANE_TA
* over PKIX_DID_NOT_VALIDATE
* over TLSA_DID_NOT_MATCH
*/
}
#endif
ldns_rr_list_free(usable_tlsas);
return s;
}
#endif /* USE_DANE_VERIFY */
#endif /* HAVE_SSL */
#endif /* USE_DANE */
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