Hi,
Here is a patch to fetch sshfp DNS records using getdns instead of ldns.
Enable using --with-getdns. The original ldns code is still there.
Getdns solves two problem with ldns: it know where the root trust anchors
lives and it can handle recursive resolvers that are not dnssec-aware.
diff --git a/configure.ac b/configure.ac
index 9b05c30..7c0fd88 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1459,6 +1459,38 @@ int main() { ldns_status status = ldns_verify_trusted(NULL, NULL, NULL, NULL); s
]
)
+# Check whether user wants to use getdns
+GETDNS_MSG="no"
+AC_ARG_WITH(getdns,
+ [ --with-getdns[[=PATH]] Use getdns for DNSSEC support (optionally in PATH)],
+ [
+ if test "x$withval" != "xno" ; then
+
+ if test "x$withval" != "xyes" ; then
+ CPPFLAGS="$CPPFLAGS -I${withval}/include"
+ LDFLAGS="$LDFLAGS -L${withval}/lib"
+ fi
+
+ AC_DEFINE(HAVE_GETDNS, 1, [Define if you want getdns support])
+ LIBS="-lgetdns $LIBS"
+ GETDNS_MSG="yes"
+
+ AC_MSG_CHECKING([for getdns support])
+ AC_LINK_IFELSE(
+ [AC_LANG_SOURCE([[
+#include <getdns/getdns.h>
+int main() { getdns_context *this_context; getdns_return_t status = getdns_context_create(&this_context, 1); return (status == GETDNS_RETURN_GOOD ? 0 : 1); }
+ ]])
+ ],
+ [AC_MSG_RESULT(yes)],
+ [
+ AC_MSG_RESULT(no)
+ AC_MSG_ERROR([** Incomplete or missing getdns libraries.])
+ ])
+ fi
+ ]
+)
+
# Check whether user wants libedit support
LIBEDIT_MSG="no"
AC_ARG_WITH([libedit],
diff --git a/openbsd-compat/Makefile.in b/openbsd-compat/Makefile.in
index 3c5e3b7..24b52b3 100644
--- a/openbsd-compat/Makefile.in
+++ b/openbsd-compat/Makefile.in
@@ -18,7 +18,7 @@ LDFLAGS=-L. @LDFLAGS@
OPENBSD=base64.o basename.o bcrypt_pbkdf.o bindresvport.o blowfish.o daemon.o dirname.o fmt_scaled.o getcwd.o getgrouplist.o getopt_long.o getrrsetbyname.o glob.o inet_aton.o inet_ntoa.o inet_ntop.o mktemp.o pwcache.o readpassphrase.o reallocarray.o realpath.o rresvport.o setenv.o setproctitle.o sha1.o sha2.o rmd160.o md5.o sigact.o strlcat.o strlcpy.o strmode.o strnlen.o strptime.o strsep.o strtonum.o strtoll.o strtoul.o strtoull.o timingsafe_bcmp.o vis.o blowfish.o bcrypt_pbkdf.o explicit_bzero.o
-COMPAT=arc4random.o bsd-asprintf.o bsd-closefrom.o bsd-cray.o bsd-cygwin_util.o bsd-getpeereid.o getrrsetbyname-ldns.o bsd-misc.o bsd-nextstep.o bsd-openpty.o bsd-poll.o bsd-setres_id.o bsd-snprintf.o bsd-statvfs.o bsd-waitpid.o fake-rfc2553.o openssl-compat.o xmmap.o xcrypt.o kludge-fd_set.o
+COMPAT=arc4random.o bsd-asprintf.o bsd-closefrom.o bsd-cray.o bsd-cygwin_util.o bsd-getpeereid.o getrrsetbyname-getdns.o getrrsetbyname-ldns.o bsd-misc.o bsd-nextstep.o bsd-openpty.o bsd-poll.o bsd-setres_id.o bsd-snprintf.o bsd-statvfs.o bsd-waitpid.o fake-rfc2553.o openssl-compat.o xmmap.o xcrypt.o kludge-fd_set.o
PORTS=port-aix.o port-irix.o port-linux.o port-solaris.o port-tun.o port-uw.o
diff --git a/openbsd-compat/getrrsetbyname-getdns.c b/openbsd-compat/getrrsetbyname-getdns.c
new file mode 100644
index 0000000..a2dc147
--- /dev/null
+++ b/openbsd-compat/getrrsetbyname-getdns.c
@@ -0,0 +1,322 @@
+/* $OpenBSD$ */
+
+/*
+ * Copyright (c) 2015 Philip Homburg <philip@xxxxxxxxxxxxxxxx>
+ * Copyright (c) 2007 Simon Vallet / Genoscope <svallet@xxxxxxxxxxxxxxxx>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+
+#if !defined (HAVE_GETRRSETBYNAME) && defined (HAVE_GETDNS)
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <getdns/getdns.h>
+
+#include "getrrsetbyname.h"
+#include "log.h"
+#include "xmalloc.h"
+
+#define malloc(x) (xmalloc(x))
+#define calloc(x, y) (xcalloc((x),(y)))
+
+
+int
+getrrsetbyname(const char *hostname, unsigned int rdclass,
+ unsigned int rdtype, unsigned int flags,
+ struct rrsetinfo **res)
+{
+ int result, dnssec_status;
+ getdns_return_t this_ret; /* Holder for all function returns */
+ uint32_t this_error;
+ getdns_context *this_context = NULL;
+ getdns_dict * this_extensions = NULL;
+ getdns_dict * this_response = NULL;
+ getdns_list *replies_tree_list;
+ getdns_dict *reply_dict;
+ getdns_list *answer_list;
+ size_t num_answers, rec_count;
+ struct rrsetinfo *rrset = NULL;
+ struct rdatainfo *rdata;
+
+ /* don't allow flags yet, unimplemented */
+ if (flags) {
+ result = ERRSET_INVAL;
+ goto done;
+ }
+
+ if (rdclass != ns_c_in)
+ {
+ /* We only support class IN */
+ debug2("getdns: we only support class IN\n");
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ /* Create the DNS context for this call */
+ this_ret = getdns_context_create(&this_context, 1);
+ if (this_ret != GETDNS_RETURN_GOOD)
+ {
+ debug2("getdns: trying to create the context failed: %d\n",
+ this_ret);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ this_extensions = getdns_dict_create();
+ this_ret = getdns_dict_set_int(this_extensions,
+ "dnssec_return_status", GETDNS_EXTENSION_TRUE);
+ if (this_ret != GETDNS_RETURN_GOOD)
+ {
+ debug2("getdns: trying to set an extension for DNSSEC failed: %d", this_ret);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ /* Set up the getdns_sync_request call */
+ this_ret = getdns_general_sync(this_context, hostname, rdtype,
+ this_extensions, &this_response);
+ if (this_ret == GETDNS_RETURN_BAD_DOMAIN_NAME)
+ {
+ debug2("getdns: bad domain name was used: %s\n", hostname);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ /* Be sure the search returned something */
+ this_ret = getdns_dict_get_int(this_response, "status", &this_error);
+ if (this_ret != GETDNS_RETURN_GOOD)
+ {
+ debug2("getdns: getdns_dict_get_int failed for 'status': %d",
+ this_ret);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ if (this_error != GETDNS_RESPSTATUS_GOOD) // If the search didn't return "good"
+ {
+ debug2("getdns: the search had no results, and status %d",
+ this_error);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ this_ret = getdns_dict_get_list(this_response, "replies_tree",
+ &replies_tree_list);
+ if (this_ret != GETDNS_RETURN_GOOD)
+ {
+ debug2(
+ "getdns: getdns_dict_get_list failed for 'replies_tree': %d",
+ this_ret);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ /* Assume one reply */
+ this_ret = getdns_list_get_dict(replies_tree_list, 0, &reply_dict);
+ if (this_ret != GETDNS_RETURN_GOOD)
+ {
+ debug2("getdns: getdns_list_get_dict failed for '[0]': %d",
+ this_ret);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ this_ret = getdns_dict_get_int(reply_dict, "dnssec_status", &dnssec_status);
+ if (this_ret != GETDNS_RETURN_GOOD)
+ {
+ debug2(
+ "getdns: getdns_dict_get_int failed for 'dnssec_status': %d",
+ this_ret);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ this_ret = getdns_dict_get_list(reply_dict, "answer",
+ &answer_list);
+ if (this_ret != GETDNS_RETURN_GOOD)
+ {
+ debug2(
+ "getdns: getdns_dict_get_list failed for 'answer': %d",
+ this_ret);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ this_ret = getdns_list_get_length(answer_list, &num_answers);
+ if (this_ret != GETDNS_RETURN_GOOD)
+ {
+ debug2("getdns: getdns_list_get_length failed: %d",
+ this_ret);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ /* initialize rrset */
+ rrset = calloc(1, sizeof(struct rrsetinfo));
+ if (rrset == NULL) {
+ result = ERRSET_NOMEMORY;
+ goto done;
+ }
+ rrset->rri_nrdatas = num_answers;
+ if (!rrset->rri_nrdatas) {
+ result = ERRSET_NODATA;
+ goto done;
+ }
+
+ if (dnssec_status == GETDNS_DNSSEC_SECURE)
+ rrset->rri_flags |= RRSET_VALIDATED;
+
+ /* allocate memory for answers */
+ rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
+ sizeof(struct rdatainfo));
+
+ if (rrset->rri_rdatas == NULL) {
+ result = ERRSET_NOMEMORY;
+ goto done;
+ }
+
+
+ /* Go through each record */
+ rec_count= 0;
+ for ( size_t ans_count = 0; ans_count < num_answers; ++ans_count )
+ {
+ getdns_dict * this_answer;
+ getdns_dict *rdata_dict;
+ getdns_bindata *this_rdata_data;
+ int answer_type;
+
+ this_ret = getdns_list_get_dict(answer_list, ans_count,
+ &this_answer);
+ if (this_ret != GETDNS_RETURN_GOOD)
+ {
+ debug2(
+ "getdns: getdns_list_get_dict failed for '[%d]': %d",
+ ans_count, this_ret);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ this_ret= getdns_dict_get_int(this_answer, "type",
+ &answer_type);
+ if (this_ret != GETDNS_RETURN_GOOD)
+ {
+ debug2(
+ "getdns: getdns_dict_get_int failed for 'type': %d",
+ this_ret);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ if ((unsigned)answer_type != rdtype)
+ continue;
+
+ this_ret = getdns_dict_get_dict(this_answer, "rdata",
+ &rdata_dict);
+ if (this_ret != GETDNS_RETURN_GOOD)
+ {
+ debug2(
+ "getdns: getdns_dict_get_dict failed for 'rdata': %d",
+ this_ret);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ this_ret = getdns_dict_get_bindata(rdata_dict, "rdata_raw",
+ &this_rdata_data); // Ignore any error
+ if (this_ret != GETDNS_RETURN_GOOD)
+ {
+ debug2(
+ "getdns: getdns_dict_get_bindata failed for 'rdata_raw': %d",
+ this_ret);
+ result = ERRSET_FAIL;
+ goto done;
+ }
+
+ rdata = &rrset->rri_rdatas[rec_count];
+ rdata->rdi_length = this_rdata_data->size;
+
+ rdata->rdi_data = malloc(rdata->rdi_length);
+ if (rdata->rdi_data == NULL) {
+ result = ERRSET_NOMEMORY;
+ goto done;
+ }
+
+ memcpy(rdata->rdi_data, this_rdata_data->data,
+ rdata->rdi_length);
+
+ rec_count++;
+ }
+
+ rrset->rri_nrdatas = rec_count;
+
+ *res = rrset;
+ rrset= NULL;
+ result = ERRSET_SUCCESS;
+
+done:
+ getdns_dict_destroy(this_response);
+ getdns_dict_destroy(this_extensions);
+ getdns_context_destroy(this_context);
+ freerrset(rrset);
+
+ return result;
+}
+
+
+void
+freerrset(struct rrsetinfo *rrset)
+{
+ u_int16_t i;
+
+ if (rrset == NULL)
+ return;
+
+ if (rrset->rri_rdatas) {
+ for (i = 0; i < rrset->rri_nrdatas; i++) {
+ if (rrset->rri_rdatas[i].rdi_data == NULL)
+ break;
+ free(rrset->rri_rdatas[i].rdi_data);
+ }
+ free(rrset->rri_rdatas);
+ }
+
+ if (rrset->rri_sigs) {
+ for (i = 0; i < rrset->rri_nsigs; i++) {
+ if (rrset->rri_sigs[i].rdi_data == NULL)
+ break;
+ free(rrset->rri_sigs[i].rdi_data);
+ }
+ free(rrset->rri_sigs);
+ }
+
+ if (rrset->rri_name)
+ free(rrset->rri_name);
+ free(rrset);
+}
+
+
+#endif /* !defined (HAVE_GETRRSETBYNAME) && defined (HAVE_LDNS) */
diff --git a/openbsd-compat/getrrsetbyname.c b/openbsd-compat/getrrsetbyname.c
index dc6fe05..f9ca5df 100644
--- a/openbsd-compat/getrrsetbyname.c
+++ b/openbsd-compat/getrrsetbyname.c
@@ -47,7 +47,7 @@
#include "includes.h"
-#if !defined (HAVE_GETRRSETBYNAME) && !defined (HAVE_LDNS)
+#if !defined (HAVE_GETRRSETBYNAME) && !defined (HAVE_LDNS) && !defined(HAVE_GETDNS)
#include <stdlib.h>
#include <string.h>
diff --git a/sshconnect.c b/sshconnect.c
index f41960c..9f1eafa 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -71,6 +71,7 @@ char *server_version_string = NULL;
Key *previous_host_key = NULL;
static int matching_host_key_dns = 0;
+static int dns_secure = 0;
static pid_t proxy_command_pid = 0;
@@ -972,13 +973,18 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
fatal("%s: sshkey_fingerprint fail", __func__);
msg2[0] = '\0';
if (options.verify_host_key_dns) {
- if (matching_host_key_dns)
+ if (!matching_host_key_dns)
snprintf(msg2, sizeof(msg2),
- "Matching host key fingerprint"
+ "No matching host key fingerprint"
" found in DNS.\n");
+ else if (!dns_secure)
+ snprintf(msg2, sizeof(msg2),
+ "The DNS lookup was not secure,"
+ " however a matching host key"
+ " fingerprint was found in DNS.\n");
else
snprintf(msg2, sizeof(msg2),
- "No matching host key fingerprint"
+ "Matching host key fingerprint"
" found in DNS.\n");
}
snprintf(msg, sizeof(msg),
@@ -1295,6 +1301,9 @@ verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
r = 0;
goto out;
}
+ if (flags & DNS_VERIFY_SECURE) {
+ dns_secure = 1;
+ }
if (flags & DNS_VERIFY_MATCH) {
matching_host_key_dns = 1;
} else {
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