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-rw-r--r--libdane/dane.c1066
1 files changed, 1066 insertions, 0 deletions
diff --git a/libdane/dane.c b/libdane/dane.c
new file mode 100644
index 0000000..c9cbe84
--- /dev/null
+++ b/libdane/dane.c
@@ -0,0 +1,1066 @@
+/*
+ * Copyright (C) 2012 KU Leuven
+ * Copyright (C) 2013 Christian Grothoff
+ * Copyright (C) 2013 Nikos Mavrogiannopoulos
+ *
+ * Author: Nikos Mavrogiannopoulos
+ *
+ * This file is part of libdane.
+ *
+ * The libdane library is free software; you can redistribute it
+ * and/or modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>
+ *
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <arpa/inet.h>
+#include <unbound.h>
+#include <gnutls/dane.h>
+#include <gnutls/x509.h>
+#include <gnutls/abstract.h>
+#include <gnutls/crypto.h>
+#include "../lib/gnutls_int.h"
+
+#define MAX_DATA_ENTRIES 100
+
+#undef gnutls_assert
+#undef gnutls_assert_val
+
+#ifdef DEBUG
+#define gnutls_assert() fprintf(stderr, "ASSERT: %s: %d\n", __FILE__, __LINE__);
+#define gnutls_assert_val(x) gnutls_assert_val_int(x, __FILE__, __LINE__)
+static int gnutls_assert_val_int(int val, const char *file, int line)
+{
+ fprintf(stderr, "ASSERT: %s: %d\n", file, line);
+ return val;
+}
+#else
+#define gnutls_assert()
+#define gnutls_assert_val(x) (x)
+#endif
+
+struct dane_state_st {
+ struct ub_ctx *ctx;
+ unsigned int flags;
+};
+
+struct dane_query_st {
+ struct ub_result *result;
+ unsigned int data_entries;
+ dane_cert_usage_t usage[MAX_DATA_ENTRIES];
+ dane_cert_type_t type[MAX_DATA_ENTRIES];
+ dane_match_type_t match[MAX_DATA_ENTRIES];
+ gnutls_datum_t data[MAX_DATA_ENTRIES];
+ unsigned int flags;
+ dane_query_status_t status;
+};
+
+/**
+ * dane_query_status:
+ * @q: The query result structure
+ *
+ * This function will return the status of the query response.
+ * See %dane_query_status_t for the possible types.
+ *
+ * Returns: The status type.
+ **/
+dane_query_status_t dane_query_status(dane_query_t q)
+{
+ return q->status;
+}
+
+/**
+ * dane_query_entries:
+ * @q: The query result structure
+ *
+ * This function will return the number of entries in a query.
+ *
+ * Returns: The number of entries.
+ **/
+unsigned int dane_query_entries(dane_query_t q)
+{
+ return q->data_entries;
+}
+
+/**
+ * dane_query_data:
+ * @q: The query result structure
+ * @idx: The index of the query response.
+ * @usage: The certificate usage (see %dane_cert_usage_t)
+ * @type: The certificate type (see %dane_cert_type_t)
+ * @match: The DANE matching type (see %dane_match_type_t)
+ * @data: The DANE data.
+ *
+ * This function will provide the DANE data from the query
+ * response.
+ *
+ * Returns: On success, %DANE_E_SUCCESS (0) is returned, otherwise a
+ * negative error value.
+ **/
+int
+dane_query_data(dane_query_t q, unsigned int idx,
+ unsigned int *usage, unsigned int *type,
+ unsigned int *match, gnutls_datum_t * data)
+{
+ if (idx >= q->data_entries)
+ return
+ gnutls_assert_val(DANE_E_REQUESTED_DATA_NOT_AVAILABLE);
+
+ if (usage)
+ *usage = q->usage[idx];
+ if (type)
+ *type = q->type[idx];
+ if (match)
+ *match = q->match[idx];
+ if (data) {
+ data->data = q->data[idx].data;
+ data->size = q->data[idx].size;
+ }
+
+ return DANE_E_SUCCESS;
+}
+
+/**
+ * dane_query_to_raw_tlsa:
+ * @q: The query result structure
+ * @data_entries: Pointer set to the number of entries in the query
+ * @dane_data: Pointer to contain an array of DNS rdata items, terminated with a NULL pointer;
+ * caller must guarantee that the referenced data remains
+ * valid until dane_query_deinit() is called.
+ * @dane_data_len: Pointer to contain the length n bytes of the dane_data items
+ * @secure: Pointer set true if the result is validated securely, false if
+ * validation failed or the domain queried has no security info
+ * @bogus: Pointer set true if the result was not secure due to a security failure
+ *
+ * This function will provide the DANE data from the query
+ * response.
+ *
+ * The pointers dane_data and dane_data_len are allocated with gnutls_malloc()
+ * to contain the data from the query result structure (individual
+ * @dane_data items simply point to the original data and are not allocated separately).
+ * The returned @dane_data are only valid during the lifetime of @q.
+ *
+ * Returns: On success, %DANE_E_SUCCESS (0) is returned, otherwise a
+ * negative error value.
+ */
+int
+dane_query_to_raw_tlsa(dane_query_t q, unsigned int *data_entries,
+ char ***dane_data, int **dane_data_len, int *secure, int *bogus)
+{
+ size_t data_sz;
+ char *data_buf;
+ unsigned int idx;
+
+ *data_entries = 0;
+ *dane_data = NULL;
+ *dane_data_len = NULL;
+
+ if (secure) {
+ if (q->status & DANE_QUERY_DNSSEC_VERIFIED)
+ *secure = 1;
+ else
+ *secure = 0;
+ }
+
+ if (bogus) {
+ if (q->status & DANE_QUERY_BOGUS)
+ *bogus = 1;
+ else
+ *bogus = 0;
+ }
+
+ /* pack dane_data pointer list followed by dane_data contents */
+ data_sz = sizeof (**dane_data) * (q->data_entries + 1);
+ for (idx = 0; idx < q->data_entries; idx++)
+ data_sz += 3 + q->data[idx].size;
+
+ *dane_data = gnutls_calloc (1, data_sz);
+ if (*dane_data == NULL)
+ return DANE_E_MEMORY_ERROR;
+ data_buf = (char *)*dane_data;
+ data_buf += sizeof (**dane_data) * (q->data_entries + 1);
+
+ *dane_data_len = gnutls_calloc (q->data_entries + 1, sizeof (**dane_data_len));
+ if (*dane_data_len == NULL) {
+ free(*dane_data);
+ *dane_data = NULL;
+ return DANE_E_MEMORY_ERROR;
+ }
+
+ for (idx = 0; idx < q->data_entries; idx++) {
+ (*dane_data)[idx] = data_buf;
+ (*dane_data)[idx][0] = q->usage[idx];
+ (*dane_data)[idx][1] = q->type[idx];
+ (*dane_data)[idx][2] = q->match[idx];
+ memcpy(&(*dane_data)[idx][3], q->data[idx].data, q->data[idx].size);
+ (*dane_data_len)[idx] = 3 + q->data[idx].size;
+ data_buf += 3 + q->data[idx].size;
+ }
+ (*dane_data)[idx] = NULL;
+ (*dane_data_len)[idx] = 0;
+ *data_entries = q->data_entries;
+
+ return DANE_E_SUCCESS;
+}
+
+/**
+ * dane_state_init:
+ * @s: The structure to be initialized
+ * @flags: flags from the %dane_state_flags enumeration
+ *
+ * This function will initialize the backend resolver. It is
+ * intended to be used in scenarios where multiple resolvings
+ * occur, to optimize against multiple re-initializations.
+ *
+ * Returns: On success, %DANE_E_SUCCESS (0) is returned, otherwise a
+ * negative error value.
+ **/
+int dane_state_init(dane_state_t * s, unsigned int flags)
+{
+ struct ub_ctx *ctx;
+ int ret;
+
+ *s = calloc(1, sizeof(struct dane_state_st));
+ if (*s == NULL)
+ return gnutls_assert_val(DANE_E_MEMORY_ERROR);
+
+ ctx = ub_ctx_create();
+ if (!ctx) {
+ gnutls_assert();
+ ret = DANE_E_INITIALIZATION_ERROR;
+ goto cleanup;
+ }
+ ub_ctx_debugout(ctx, stderr);
+
+ if (!(flags & DANE_F_IGNORE_LOCAL_RESOLVER)) {
+ if (ub_ctx_resolvconf(ctx, NULL) != 0) {
+ gnutls_assert();
+ ret = DANE_E_INITIALIZATION_ERROR;
+ goto cleanup;
+ }
+
+ if (ub_ctx_hosts(ctx, NULL) != 0) {
+ gnutls_assert();
+ ret = DANE_E_INITIALIZATION_ERROR;
+ goto cleanup;
+ }
+ }
+
+ /* read public keys for DNSSEC verification */
+ if (!(flags & DANE_F_IGNORE_DNSSEC)) {
+ if (ub_ctx_add_ta_file(ctx,
+ (char *) UNBOUND_ROOT_KEY_FILE) !=
+ 0) {
+ gnutls_assert();
+ ret = DANE_E_INITIALIZATION_ERROR;
+ goto cleanup;
+ }
+ }
+
+ (*s)->ctx = ctx;
+ (*s)->flags = flags;
+
+ return DANE_E_SUCCESS;
+ cleanup:
+
+ if (ctx)
+ ub_ctx_delete(ctx);
+ free(*s);
+
+ return ret;
+}
+
+/**
+ * dane_state_deinit:
+ * @s: The structure to be deinitialized
+ *
+ * This function will deinitialize a DANE query structure.
+ *
+ **/
+void dane_state_deinit(dane_state_t s)
+{
+ ub_ctx_delete(s->ctx);
+ free(s);
+}
+
+/**
+ * dane_state_set_dlv_file:
+ * @s: The structure to be deinitialized
+ * @file: The file holding the DLV keys.
+ *
+ * This function will set a file with trusted keys
+ * for DLV (DNSSEC Lookaside Validation).
+ *
+ **/
+int dane_state_set_dlv_file(dane_state_t s, const char *file)
+{
+ int ret;
+
+ ret =
+ ub_ctx_set_option(s->ctx, (char *) "dlv-anchor-file:",
+ (void *) file);
+ if (ret != 0)
+ return gnutls_assert_val(DANE_E_FILE_ERROR);
+
+ return 0;
+}
+
+/**
+ * dane_query_deinit:
+ * @q: The structure to be deinitialized
+ *
+ * This function will deinitialize a DANE query result structure.
+ *
+ **/
+void dane_query_deinit(dane_query_t q)
+{
+ if (q->result)
+ ub_resolve_free(q->result);
+ free(q);
+}
+
+
+/**
+ * dane_raw_tlsa:
+ * @s: The DANE state structure
+ * @r: A structure to place the result
+ * @dane_data: array of DNS rdata items, terminated with a NULL pointer;
+ * caller must guarantee that the referenced data remains
+ * valid until dane_query_deinit() is called.
+ * @dane_data_len: the length n bytes of the dane_data items
+ * @secure: true if the result is validated securely, false if
+ * validation failed or the domain queried has no security info
+ * @bogus: if the result was not secure (secure = 0) due to a security failure,
+ * and the result is due to a security failure, bogus is true.
+ *
+ * This function will fill in the TLSA (DANE) structure from
+ * the given raw DNS record data. The @dane_data must be valid
+ * during the lifetime of the query.
+ *
+ * Returns: On success, %DANE_E_SUCCESS (0) is returned, otherwise a
+ * negative error value.
+ **/
+int
+dane_raw_tlsa(dane_state_t s, dane_query_t * r, char *const *dane_data,
+ const int *dane_data_len, int secure, int bogus)
+{
+ int ret = DANE_E_SUCCESS;
+ unsigned int i;
+
+ *r = calloc(1, sizeof(struct dane_query_st));
+ if (*r == NULL)
+ return gnutls_assert_val(DANE_E_MEMORY_ERROR);
+
+ (*r)->data_entries = 0;
+
+ for (i = 0; i < MAX_DATA_ENTRIES; i++) {
+ if (dane_data[i] == NULL)
+ break;
+
+ if (dane_data_len[i] <= 3)
+ return
+ gnutls_assert_val
+ (DANE_E_RECEIVED_CORRUPT_DATA);
+
+ (*r)->usage[i] = dane_data[i][0];
+ (*r)->type[i] = dane_data[i][1];
+ (*r)->match[i] = dane_data[i][2];
+ (*r)->data[i].data = (void *) &dane_data[i][3];
+ (*r)->data[i].size = dane_data_len[i] - 3;
+ (*r)->data_entries++;
+ }
+
+ if (!(s->flags & DANE_F_INSECURE) && !secure) {
+ if (bogus)
+ ret = gnutls_assert_val(DANE_E_INVALID_DNSSEC_SIG);
+ else
+ ret = gnutls_assert_val(DANE_E_NO_DNSSEC_SIG);
+ }
+
+ /* show security status */
+ if (secure) {
+ (*r)->status = DANE_QUERY_DNSSEC_VERIFIED;
+ } else if (bogus) {
+ gnutls_assert();
+ (*r)->status = DANE_QUERY_BOGUS;
+ } else {
+ gnutls_assert();
+ (*r)->status = DANE_QUERY_NO_DNSSEC;
+ }
+
+ return ret;
+}
+
+
+/**
+ * dane_query_tlsa:
+ * @s: The DANE state structure
+ * @r: A structure to place the result
+ * @host: The host name to resolve.
+ * @proto: The protocol type (tcp, udp, etc.)
+ * @port: The service port number (eg. 443).
+ *
+ * This function will query the DNS server for the TLSA (DANE)
+ * data for the given host.
+ *
+ * Returns: On success, %DANE_E_SUCCESS (0) is returned, otherwise a
+ * negative error value.
+ **/
+int
+dane_query_tlsa(dane_state_t s, dane_query_t * r, const char *host,
+ const char *proto, unsigned int port)
+{
+ char ns[1024];
+ int ret;
+ struct ub_result *result;
+
+ snprintf(ns, sizeof(ns), "_%u._%s.%s", port, proto, host);
+
+ /* query for webserver */
+ ret = ub_resolve(s->ctx, ns, 52, 1, &result);
+ if (ret != 0) {
+ return gnutls_assert_val(DANE_E_RESOLVING_ERROR);
+ }
+
+/* show first result */
+ if (!result->havedata) {
+ ub_resolve_free(result);
+ return gnutls_assert_val(DANE_E_NO_DANE_DATA);
+ }
+
+ ret =
+ dane_raw_tlsa(s, r, result->data, result->len, result->secure,
+ result->bogus);
+ if (*r == NULL) {
+ ub_resolve_free(result);
+ return ret;
+ }
+ (*r)->result = result;
+ return ret;
+}
+
+
+static unsigned int
+matches(const gnutls_datum_t * raw1, const gnutls_datum_t * raw2,
+ dane_match_type_t match)
+{
+ uint8_t digest[64];
+ int ret;
+
+ if (match == DANE_MATCH_EXACT) {
+ if (raw1->size != raw2->size)
+ return gnutls_assert_val(0);
+
+ if (memcmp(raw1->data, raw2->data, raw1->size) != 0)
+ return gnutls_assert_val(0);
+
+ return 1;
+ } else if (match == DANE_MATCH_SHA2_256) {
+
+ if (raw2->size != 32)
+ return gnutls_assert_val(0);
+
+ ret =
+ gnutls_hash_fast(GNUTLS_DIG_SHA256, raw1->data,
+ raw1->size, digest);
+ if (ret < 0)
+ return gnutls_assert_val(0);
+
+ if (memcmp(digest, raw2->data, 32) != 0)
+ return gnutls_assert_val(0);
+
+ return 1;
+ } else if (match == DANE_MATCH_SHA2_512) {
+ if (raw2->size != 64)
+ return gnutls_assert_val(0);
+
+ ret =
+ gnutls_hash_fast(GNUTLS_DIG_SHA512, raw1->data,
+ raw1->size, digest);
+ if (ret < 0)
+ return gnutls_assert_val(0);
+
+ if (memcmp(digest, raw2->data, 64) != 0)
+ return gnutls_assert_val(0);
+
+ return 1;
+ }
+
+ return gnutls_assert_val(0);
+}
+
+static int
+crt_to_pubkey(const gnutls_datum_t * raw_crt, gnutls_datum_t * out)
+{
+ gnutls_pubkey_t pub = NULL;
+ gnutls_x509_crt_t crt = NULL;
+ int ret;
+
+ out->data = NULL;
+
+ ret = gnutls_x509_crt_init(&crt);
+ if (ret < 0)
+ return gnutls_assert_val(DANE_E_PUBKEY_ERROR);
+
+ ret = gnutls_pubkey_init(&pub);
+ if (ret < 0) {
+ gnutls_assert();
+ ret = DANE_E_PUBKEY_ERROR;
+ goto cleanup;
+ }
+
+ ret = gnutls_x509_crt_import(crt, raw_crt, GNUTLS_X509_FMT_DER);
+ if (ret < 0) {
+ gnutls_assert();
+ ret = DANE_E_PUBKEY_ERROR;
+ goto cleanup;
+ }
+
+ ret = gnutls_pubkey_import_x509(pub, crt, 0);
+ if (ret < 0) {
+ gnutls_assert();
+ ret = DANE_E_PUBKEY_ERROR;
+ goto cleanup;
+ }
+
+ ret = gnutls_pubkey_export2(pub, GNUTLS_X509_FMT_DER, out);
+ if (ret < 0) {
+ gnutls_assert();
+ ret = DANE_E_PUBKEY_ERROR;
+ goto cleanup;
+ }
+
+ ret = 0;
+ goto clean_certs;
+
+ cleanup:
+ free(out->data);
+ out->data = NULL;
+ clean_certs:
+ if (pub)
+ gnutls_pubkey_deinit(pub);
+ if (crt)
+ gnutls_x509_crt_deinit(crt);
+
+ return ret;
+}
+
+static int
+verify_ca(const gnutls_datum_t * raw_crt, unsigned raw_crt_size,
+ gnutls_certificate_type_t crt_type,
+ dane_cert_type_t ctype,
+ dane_match_type_t match, gnutls_datum_t * data,
+ unsigned int *verify)
+{
+ gnutls_datum_t pubkey = { NULL, 0 };
+ int ret, i;
+ unsigned int vstatus = 0;
+ gnutls_x509_crt_t crt = NULL, ca = NULL;
+ unsigned is_ok = 0;
+
+ if (raw_crt_size < 2) /* we cannot verify the CA */
+ return gnutls_assert_val(DANE_E_UNKNOWN_DANE_DATA);
+
+ if (ctype == DANE_CERT_X509 && crt_type == GNUTLS_CRT_X509) {
+ is_ok = 0;
+ for (i=raw_crt_size-1;i>=1;i--) {
+ if (matches(&raw_crt[i], data, match)) {
+ is_ok = 1;
+ break;
+ }
+ }
+
+ if (is_ok == 0) {
+ gnutls_assert();
+ *verify |= DANE_VERIFY_CA_CONSTRAINTS_VIOLATED;
+ }
+
+ } else if (ctype == DANE_CERT_PK && crt_type == GNUTLS_CRT_X509) {
+ is_ok = 0;
+
+ for (i=raw_crt_size-1;i>=1;i--) {
+ ret = crt_to_pubkey(&raw_crt[i], &pubkey);
+ if (ret < 0) {
+ gnutls_assert();
+ goto cleanup;
+ }
+
+ if (matches(&pubkey, data, match)) {
+ is_ok = 1;
+ break;
+ }
+
+ free(pubkey.data);
+ pubkey.data = NULL;
+ }
+
+ if (is_ok == 0) {
+ gnutls_assert();
+ *verify |= DANE_VERIFY_CA_CONSTRAINTS_VIOLATED;
+ }
+ } else {
+ ret = gnutls_assert_val(DANE_E_UNKNOWN_DANE_DATA);
+ goto cleanup;
+ }
+
+ /* check if the certificate chain is actually a chain */
+ ret = gnutls_x509_crt_init(&crt);
+ if (ret < 0) {
+ ret = gnutls_assert_val(DANE_E_CERT_ERROR);
+ goto cleanup;
+ }
+
+ ret =
+ gnutls_x509_crt_import(crt, &raw_crt[0], GNUTLS_X509_FMT_DER);
+ if (ret < 0) {
+ ret = gnutls_assert_val(DANE_E_CERT_ERROR);
+ goto cleanup;
+ }
+
+ for (i=raw_crt_size-1;i>=1;i--) {
+ ret = gnutls_x509_crt_init(&ca);
+ if (ret < 0) {
+ ret = gnutls_assert_val(DANE_E_CERT_ERROR);
+ goto cleanup;
+ }
+
+ ret = gnutls_x509_crt_import(ca, &raw_crt[i], GNUTLS_X509_FMT_DER);
+ if (ret < 0) {
+ ret = gnutls_assert_val(DANE_E_CERT_ERROR);
+ goto cleanup;
+ }
+
+ ret = gnutls_x509_crt_check_issuer(crt, ca);
+ if (ret != 0)
+ break;
+
+ gnutls_x509_crt_deinit(ca);
+ ca = NULL;
+ }
+
+ if (ca == NULL) {
+ gnutls_assert();
+ *verify |= DANE_VERIFY_CA_CONSTRAINTS_VIOLATED;
+ } else {
+ ret = gnutls_x509_crt_verify(crt, &ca, 1, 0, &vstatus);
+ if (ret < 0) {
+ ret = gnutls_assert_val(DANE_E_CERT_ERROR);
+ goto cleanup;
+ }
+
+ if (vstatus != 0)
+ *verify |= DANE_VERIFY_CA_CONSTRAINTS_VIOLATED;
+ }
+
+ ret = 0;
+ cleanup:
+ free(pubkey.data);
+ if (crt != NULL)
+ gnutls_x509_crt_deinit(crt);
+ if (ca != NULL)
+ gnutls_x509_crt_deinit(ca);
+ return ret;
+}
+
+static int
+verify_ee(const gnutls_datum_t * raw_crt,
+ gnutls_certificate_type_t crt_type, dane_cert_type_t ctype,
+ dane_match_type_t match, gnutls_datum_t * data,
+ unsigned int *verify)
+{
+ gnutls_datum_t pubkey = { NULL, 0 };
+ int ret;
+
+ if (ctype == DANE_CERT_X509 && crt_type == GNUTLS_CRT_X509) {
+
+ if (!matches(raw_crt, data, match)) {
+ gnutls_assert();
+ *verify |= DANE_VERIFY_CERT_DIFFERS;
+ }
+
+ } else if (ctype == DANE_CERT_PK && crt_type == GNUTLS_CRT_X509) {
+
+ ret = crt_to_pubkey(raw_crt, &pubkey);
+ if (ret < 0) {
+ gnutls_assert();
+ goto cleanup;
+ }
+
+ if (!matches(&pubkey, data, match)) {
+ gnutls_assert();
+ *verify |= DANE_VERIFY_CERT_DIFFERS;
+ }
+ } else {
+ ret = gnutls_assert_val(DANE_E_UNKNOWN_DANE_DATA);
+ goto cleanup;
+ }
+
+ ret = 0;
+ cleanup:
+ free(pubkey.data);
+ return ret;
+}
+
+#define CHECK_VRET(ret, checked, record_status, status) \
+ if (ret == DANE_E_UNKNOWN_DANE_DATA) { \
+ /* skip that entry */ \
+ continue; \
+ } else if (ret < 0) { \
+ gnutls_assert(); \
+ goto cleanup; \
+ } \
+ checked = 1; \
+ if (record_status == 0) { \
+ status = 0; \
+ break; \
+ } else { \
+ status |= record_status; \
+ }
+
+/**
+ * dane_verify_crt_raw:
+ * @s: A DANE state structure (may be NULL)
+ * @chain: A certificate chain
+ * @chain_size: The size of the chain
+ * @chain_type: The type of the certificate chain
+ * @r: DANE data to check against
+ * @sflags: Flags for the initialization of @s (if NULL)
+ * @vflags: Verification flags; an OR'ed list of %dane_verify_flags_t.
+ * @verify: An OR'ed list of %dane_verify_status_t.
+ *
+ * This is the low-level function of dane_verify_crt(). See the
+ * high level function for documentation.
+ *
+ * This function does not perform any resolving, it utilizes
+ * cached entries from @r.
+ *
+ * Returns: a negative error code on error and %DANE_E_SUCCESS (0)
+ * when the DANE entries were successfully parsed, irrespective of
+ * whether they were verified (see @verify for that information). If
+ * no usable entries were encountered %DANE_E_REQUESTED_DATA_NOT_AVAILABLE
+ * will be returned.
+ *
+ **/
+int
+dane_verify_crt_raw(dane_state_t s,
+ const gnutls_datum_t * chain, unsigned chain_size,
+ gnutls_certificate_type_t chain_type,
+ dane_query_t r,
+ unsigned int sflags, unsigned int vflags,
+ unsigned int *verify)
+{
+ int ret;
+ unsigned checked = 0;
+ unsigned int usage, type, match, idx;
+ gnutls_datum_t data;
+
+ if (chain_type != GNUTLS_CRT_X509)
+ return gnutls_assert_val(DANE_E_INVALID_REQUEST);
+
+ if (chain_size == 0)
+ return gnutls_assert_val(DANE_E_NO_CERT);
+
+ *verify = 0;
+ idx = 0;
+ do {
+ unsigned int record_verify = 0;
+
+ ret =
+ dane_query_data(r, idx++, &usage, &type, &match,
+ &data);
+ if (ret == DANE_E_REQUESTED_DATA_NOT_AVAILABLE)
+ break;
+
+ if (ret < 0) {
+ gnutls_assert();
+ goto cleanup;
+ }
+
+ if (!(vflags & DANE_VFLAG_ONLY_CHECK_EE_USAGE)
+ && (usage == DANE_CERT_USAGE_LOCAL_CA
+ || usage == DANE_CERT_USAGE_CA)) {
+ ret =
+ verify_ca(chain, chain_size, chain_type, type,
+ match, &data, &record_verify);
+ CHECK_VRET(ret, checked, record_verify, *verify);
+
+ } else if (!(vflags & DANE_VFLAG_ONLY_CHECK_CA_USAGE)
+ && (usage == DANE_CERT_USAGE_LOCAL_EE
+ || usage == DANE_CERT_USAGE_EE)) {
+ ret =
+ verify_ee(&chain[0], chain_type, type, match,
+ &data, &record_verify);
+ CHECK_VRET(ret, checked, record_verify, *verify);
+ }
+ }
+ while (1);
+
+ if ((vflags & DANE_VFLAG_FAIL_IF_NOT_CHECKED) && checked == 0) {
+ ret =
+ gnutls_assert_val(DANE_E_REQUESTED_DATA_NOT_AVAILABLE);
+ } else if (checked == 0) {
+ *verify |= DANE_VERIFY_UNKNOWN_DANE_INFO;
+ } else {
+ ret = 0;
+ }
+
+ cleanup:
+ return ret;
+}
+
+
+/**
+ * dane_verify_crt:
+ * @s: A DANE state structure (may be NULL)
+ * @chain: A certificate chain
+ * @chain_size: The size of the chain
+ * @chain_type: The type of the certificate chain
+ * @hostname: The hostname associated with the chain
+ * @proto: The protocol of the service connecting (e.g. tcp)
+ * @port: The port of the service connecting (e.g. 443)
+ * @sflags: Flags for the initialization of @s (if NULL)
+ * @vflags: Verification flags; an OR'ed list of %dane_verify_flags_t.
+ * @verify: An OR'ed list of %dane_verify_status_t.
+ *
+ * This function will verify the given certificate chain against the
+ * CA constrains and/or the certificate available via DANE.
+ * If no information via DANE can be obtained the flag %DANE_VERIFY_NO_DANE_INFO
+ * is set. If a DNSSEC signature is not available for the DANE
+ * record then the verify flag %DANE_VERIFY_NO_DNSSEC_DATA is set.
+ *
+ * Due to the many possible options of DANE, there is no single threat
+ * model countered. When notifying the user about DANE verification results
+ * it may be better to mention: DANE verification did not reject the certificate,
+ * rather than mentioning a successful DANE verication.
+ *
+ * Note that this function is designed to be run in addition to
+ * PKIX - certificate chain - verification. To be run independently
+ * the %DANE_VFLAG_ONLY_CHECK_EE_USAGE flag should be specified;
+ * then the function will check whether the key of the peer matches the
+ * key advertized in the DANE entry.
+ *
+ * Returns: a negative error code on error and %DANE_E_SUCCESS (0)
+ * when the DANE entries were successfully parsed, irrespective of
+ * whether they were verified (see @verify for that information). If
+ * no usable entries were encountered %DANE_E_REQUESTED_DATA_NOT_AVAILABLE
+ * will be returned.
+ *
+ **/
+int
+dane_verify_crt(dane_state_t s,
+ const gnutls_datum_t * chain, unsigned chain_size,
+ gnutls_certificate_type_t chain_type,
+ const char *hostname, const char *proto, unsigned int port,
+ unsigned int sflags, unsigned int vflags,
+ unsigned int *verify)
+{
+ dane_state_t state = NULL;
+ dane_query_t r = NULL;
+ int ret;
+
+ *verify = 0;
+ if (s == NULL) {
+ ret = dane_state_init(&state, sflags);
+ if (ret < 0) {
+ gnutls_assert();
+ return ret;
+ }
+ } else
+ state = s;
+
+ ret = dane_query_tlsa(state, &r, hostname, proto, port);
+ if (ret < 0) {
+ gnutls_assert();
+ goto cleanup;
+ }
+ ret = dane_verify_crt_raw(state, chain, chain_size, chain_type,
+ r, sflags, vflags, verify);
+ cleanup:
+ if (state != s)
+ dane_state_deinit(state);
+ if (r != NULL)
+ dane_query_deinit(r);
+ return ret;
+}
+
+/**
+ * dane_verify_session_crt:
+ * @s: A DANE state structure (may be NULL)
+ * @session: A gnutls session
+ * @hostname: The hostname associated with the chain
+ * @proto: The protocol of the service connecting (e.g. tcp)
+ * @port: The port of the service connecting (e.g. 443)
+ * @sflags: Flags for the initialization of @s (if NULL)
+ * @vflags: Verification flags; an OR'ed list of %dane_verify_flags_t.
+ * @verify: An OR'ed list of %dane_verify_status_t.
+ *
+ * This function will verify session's certificate chain against the
+ * CA constrains and/or the certificate available via DANE.
+ * See dane_verify_crt() for more information.
+ *
+ * This will not verify the chain for validity; unless the DANE
+ * verification is restricted to end certificates, this must be
+ * be performed separately using gnutls_certificate_verify_peers3().
+ *
+ * Returns: a negative error code on error and %DANE_E_SUCCESS (0)
+ * when the DANE entries were successfully parsed, irrespective of
+ * whether they were verified (see @verify for that information). If
+ * no usable entries were encountered %DANE_E_REQUESTED_DATA_NOT_AVAILABLE
+ * will be returned.
+ *
+ **/
+int
+dane_verify_session_crt(dane_state_t s,
+ gnutls_session_t session,
+ const char *hostname, const char *proto,
+ unsigned int port, unsigned int sflags,
+ unsigned int vflags, unsigned int *verify)
+{
+ const gnutls_datum_t *cert_list;
+ unsigned int cert_list_size = 0;
+ unsigned int type;
+ gnutls_x509_crt_t crt, ca;
+ gnutls_certificate_credentials_t sc;
+ int ret;
+
+ cert_list = gnutls_certificate_get_peers(session, &cert_list_size);
+ if (cert_list_size == 0) {
+ return gnutls_assert_val(DANE_E_NO_CERT);
+ }
+
+ type = gnutls_certificate_type_get(session);
+
+ /* this list may be incomplete, try to get the self-signed CA if any */
+ ret = gnutls_x509_crt_init(&crt);
+ if (ret < 0) {
+ gnutls_assert();
+ goto failsafe;
+ }
+
+ ret = gnutls_x509_crt_import(crt, &cert_list[cert_list_size-1], GNUTLS_X509_FMT_DER);
+ if (ret < 0) {
+ gnutls_assert();
+ gnutls_x509_crt_deinit(crt);
+ goto failsafe;
+ }
+
+ /* if it is already self signed continue normally */
+ ret = gnutls_x509_crt_check_issuer(crt, crt);
+ if (ret != 0) {
+ gnutls_assert();
+ gnutls_x509_crt_deinit(crt);
+ goto failsafe;
+ }
+
+ /* chain does not finish in a self signed cert, try to obtain the issuer */
+ ret = gnutls_credentials_get(session, GNUTLS_CRD_CERTIFICATE, (void**)&sc);
+ if (ret < 0) {
+ gnutls_assert();
+ gnutls_x509_crt_deinit(crt);
+ goto failsafe;
+ }
+
+ ret = gnutls_certificate_get_issuer(sc, crt, &ca, 0);
+ if (ret < 0) {
+ gnutls_assert();
+ gnutls_x509_crt_deinit(crt);
+ goto failsafe;
+ }
+
+ /* make the new list */
+ gnutls_datum_t *new_cert_list;
+
+ new_cert_list = gnutls_malloc((cert_list_size + 1) * sizeof(gnutls_datum_t));
+ if (new_cert_list == NULL) {
+ gnutls_assert();
+ gnutls_x509_crt_deinit(crt);
+ goto failsafe;
+ }
+
+ memcpy(new_cert_list, cert_list, cert_list_size*sizeof(gnutls_datum_t));
+
+ ret = gnutls_x509_crt_export2(ca, GNUTLS_X509_FMT_DER, &new_cert_list[cert_list_size]);
+ if (ret < 0) {
+ gnutls_assert();
+ free(new_cert_list);
+ gnutls_x509_crt_deinit(crt);
+ goto failsafe;
+ }
+
+ ret = dane_verify_crt(s, new_cert_list, cert_list_size+1, type,
+ hostname, proto, port, sflags, vflags,
+ verify);
+ if (ret < 0) {
+ gnutls_assert();
+ }
+ gnutls_free(new_cert_list[cert_list_size].data);
+ free(new_cert_list);
+ return ret;
+
+ failsafe:
+ return dane_verify_crt(s, cert_list, cert_list_size, type,
+ hostname, proto, port, sflags, vflags,
+ verify);
+}
+
+/**
+ * dane_verification_status_print:
+ * @status: The status flags to be printed
+ * @type: The certificate type
+ * @out: Newly allocated datum with (0) terminated string.
+ * @flags: should be zero
+ *
+ * This function will pretty print the status of a verification
+ * process -- eg. the one obtained by dane_verify_crt().
+ *
+ * The output @out needs to be deallocated using gnutls_free().
+ *
+ * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
+ * negative error value.
+ **/
+int
+dane_verification_status_print(unsigned int status,
+ gnutls_datum_t * out, unsigned int flags)
+{
+ gnutls_buffer_st str;
+
+ _gnutls_buffer_init(&str);
+
+ if (status == 0)
+ _gnutls_buffer_append_str(&str,
+ _("Certificate matches. "));
+ else
+ _gnutls_buffer_append_str(&str,
+ _("Verification failed. "));
+
+ if (status & DANE_VERIFY_CA_CONSTRAINTS_VIOLATED)
+ _gnutls_buffer_append_str(&str,
+ _
+ ("CA constrains were violated. "));
+
+ if (status & DANE_VERIFY_CERT_DIFFERS)
+ _gnutls_buffer_append_str(&str,
+ _("The certificate differs. "));
+
+ if (status & DANE_VERIFY_NO_DANE_INFO)
+ _gnutls_buffer_append_str(&str,
+ _
+ ("There were no DANE information. "));
+
+ return _gnutls_buffer_to_datum(&str, out, 1);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 08:30:34 +0000