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freebsd/contrib/ldns/dane.c
Dag-Erling Smørgrav 5afab0e5e5 ldns: Upgrade to 1.8.3. 
Merge commit 'cf3e3d5bd0a1fae39c74c7db5a4e8b10732d0766'

Reviewed by:	emaste
Differential Revision:	https://reviews.freebsd.org/D40226
2023-05-24 15:50:18 +00:00

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/*
* Verify or create TLS authentication with DANE (RFC6698)
*
* (c) NLnetLabs 2012-2020
*
* 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
/* OpenSSL context options. At the moment, disable SSLv2, SSLv3
* and Compression, if available. TLSv1.0 is allowed at the moment.
* TLSv1.1 is the first to provide elliptic curves, so it is usually
* allowed in a TLS stack. TLSv1.2 is the first to provide authentication
* modes of operation, like GCM. The defines below are a moving
* target based on OpenSSL library version. Grep is useful to find
* the defines: grep -IR SSL_OP_NO_ /usr/include/openssl.
*/
#ifdef HAVE_SSL
# ifdef SSL_OP_NO_SSLv2
const long NoOpenSSLv2 = SSL_OP_NO_SSLv2;
# else
const long NoOpenSSLv2 = 0L;
# endif
# ifdef SSL_OP_NO_SSLv3
const long NoOpenSSLv3 = SSL_OP_NO_SSLv3;
# else
const long NoOpenSSLv3 = 0L;
# endif
# ifdef SSL_OP_NO_TLSv1
const long NoOpenTLSv1 = SSL_OP_NO_TLSv1;
# else
const long NoOpenTLSv1 = 0L;
# endif
# ifdef SSL_OP_NO_DTLSv1
const long NoOpenDTLSv1 = SSL_OP_NO_DTLSv1;
# else
const long NoOpenDTLSv1 = 0L;
# endif
# ifdef SSL_OP_NO_COMPRESSION
const long NoOpenSSLCompression = SSL_OP_NO_COMPRESSION;
# else
const long NoOpenSSLCompression = 0L;
# endif
#endif
#if defined(USE_DANE_VERIFY) && defined(USE_DANE_TA_USAGE)
static SSL_CTX*
ldns_dane_new_ssl_context(void)
{
SSL_CTX* ssl_ctx;
ssl_ctx = SSL_CTX_new(TLS_client_method());
if (ssl_ctx != NULL)
{
/* ldns allows TLS and DTLS v1.0 at the moment. Some may disagree.
* Sometime in the future they may be disabled, too. Maybe
* --disable-tlsv1 and --disable-dtlsv1 should be configure options.
*/
long flags = NoOpenSSLv2 | NoOpenSSLv3 | NoOpenSSLCompression;
SSL_CTX_set_options(ssl_ctx, flags);
}
return ssl_ctx;
}
#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;
}
/* Ordinary 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 = ldns_dane_new_ssl_context()))
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 = ldns_dane_new_ssl_context()))
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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