Different VPN servers may use different tls-auth keys. For this
reason it is convenient to make tls-auth a per-connection-block
option so that the user is allowed to specify one key per remote.
If no tls-auth option is specified in a given connection block,
the global one, if any, is used.
If persist-key is specified, tls-auth keys are pre-loaded during
startup (same as they were embeeded in the config file) so that
later there is no need to access the key files.
Trac: #720
Cc: Steffan Karger <stef...@karger.me>
Signed-off-by: Antonio Quartulli <a...@unstable.cc>
---
v2:
- convert tls-auth keyfile to inline key if persist-key was specified
doc/openvpn.8 | 2 +
src/openvpn/init.c | 10 ++---
src/openvpn/options.c | 90 +++++++++++++++++++++++++++++++++++--------
src/openvpn/options.h | 5 +++
4 files changed, 85 insertions(+), 22 deletions(-)
diff --git a/doc/openvpn.8 b/doc/openvpn.8
index 4114f408..8006ba29 100644
--- a/doc/openvpn.8
+++ b/doc/openvpn.8
@@ -361,6 +361,7 @@ block:
.B fragment,
.B http\-proxy,
.B http\-proxy\-option,
+.B key\-direction,
.B link\-mtu,
.B local,
.B lport,
@@ -372,6 +373,7 @@ block:
.B remote,
.B rport,
.B socks\-proxy,
+.B tls\-auth,
.B tun\-mtu and
.B tun\-mtu\-extra.
diff --git a/src/openvpn/init.c b/src/openvpn/init.c
index 15fef08d..22a74e36 100644
--- a/src/openvpn/init.c
+++ b/src/openvpn/init.c
@@ -2504,7 +2504,7 @@ do_init_tls_wrap_key(struct context *c)
const struct options *options = &c->options;
/* TLS handshake authentication (--tls-auth) */
- if (options->tls_auth_file)
+ if (options->ce.tls_auth_file)
{
/* Initialize key_type for tls-auth with auth only */
CLEAR(c->c1.ks.tls_auth_key_type);
@@ -2522,9 +2522,9 @@ do_init_tls_wrap_key(struct context *c)
crypto_read_openvpn_key(&c->c1.ks.tls_auth_key_type,
&c->c1.ks.tls_wrap_key,
- options->tls_auth_file,
- options->tls_auth_file_inline,
- options->key_direction,
+ options->ce.tls_auth_file,
+ options->ce.tls_auth_file_inline,
+ options->ce.key_direction,
"Control Channel Authentication", "tls-auth");
}
@@ -2803,7 +2803,7 @@ do_init_crypto_tls(struct context *c, const unsigned int
flags)
#endif
/* TLS handshake authentication (--tls-auth) */
- if (options->tls_auth_file)
+ if (options->ce.tls_auth_file)
{
to.tls_wrap.mode = TLS_WRAP_AUTH;
to.tls_wrap.opt.key_ctx_bi = c->c1.ks.tls_wrap_key;
diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index 426057ab..7357f189 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -1506,6 +1506,10 @@ show_connection_entry(const struct connection_entry *o)
#ifdef ENABLE_OCC
SHOW_INT(explicit_exit_notification);
#endif
+
+ SHOW_STR(tls_auth_file);
+ SHOW_PARM(key_direction, keydirection2ascii(o->key_direction, false, true),
+ "%s");
}
@@ -1786,7 +1790,6 @@ show_settings(const struct options *o)
SHOW_BOOL(push_peer_info);
SHOW_BOOL(tls_exit);
- SHOW_STR(tls_auth_file);
SHOW_STR(tls_crypt_file);
#ifdef ENABLE_PKCS11
@@ -2869,6 +2872,23 @@ options_postprocess_mutate_ce(struct options *o, struct
connection_entry *ce)
}
}
+ /*
+ * Set per-connection block tls-auth fields if no other method was defined
+ */
+ if (!ce->tls_auth_file)
+ {
+ ce->tls_auth_file = o->tls_auth_file;
+ ce->tls_auth_file_inline = o->tls_auth_file_inline;
+ ce->key_direction = o->key_direction;
+ }
+
+ /* pre-cache tls-auth key file if persist-key was specified */
+ if (ce->tls_auth_file && !ce->tls_auth_file_inline && o->persist_key)
+ {
+ struct buffer in = keyfile_to_buffer(ce->tls_auth_file, 2048, &o->gc);
+ ce->tls_auth_file = INLINE_FILE_TAG;
+ ce->tls_auth_file_inline = (char *)in.data;
+ }
}
#ifdef _WIN32
@@ -3285,12 +3305,20 @@ options_postprocess_filechecks(struct options *options)
options->crl_file, R_OK,
"--crl-verify");
}
- errs |= check_file_access(CHKACC_FILE|CHKACC_INLINE|CHKACC_PRIVATE,
- options->tls_auth_file, R_OK, "--tls-auth");
+ ASSERT(options->connection_list);
+ for (int i = 0; i < options->connection_list->len; ++i)
+ {
+ struct connection_entry *ce = options->connection_list->array[i];
+
+ errs |= check_file_access(CHKACC_FILE|CHKACC_INLINE|CHKACC_PRIVATE,
+ ce->tls_auth_file, R_OK, "--tls-auth");
+ }
+
errs |= check_file_access(CHKACC_FILE|CHKACC_INLINE|CHKACC_PRIVATE,
options->tls_crypt_file, R_OK, "--tls-crypt");
errs |= check_file_access(CHKACC_FILE|CHKACC_INLINE|CHKACC_PRIVATE,
options->shared_secret_file, R_OK, "--secret");
+
errs |= check_file_access(CHKACC_DIRPATH|CHKACC_FILEXSTWR,
options->packet_id_file, R_OK|W_OK,
"--replay-persist");
@@ -3647,7 +3675,7 @@ options_string(const struct options *o,
{
if (TLS_CLIENT || TLS_SERVER)
{
- if (o->tls_auth_file)
+ if (o->ce.tls_auth_file)
{
buf_printf(&out, ",tls-auth");
}
@@ -7420,10 +7448,19 @@ add_option(struct options *options,
{
int key_direction;
+ VERIFY_PERMISSION(OPT_P_GENERAL|OPT_P_CONNECTION);
+
key_direction = ascii2keydirection(msglevel, p[1]);
if (key_direction >= 0)
{
- options->key_direction = key_direction;
+ if (permission_mask & OPT_P_GENERAL)
+ {
+ options->key_direction = key_direction;
+ }
+ else if (permission_mask & OPT_P_CONNECTION)
+ {
+ options->ce.key_direction = key_direction;
+ }
}
else
{
@@ -7992,26 +8029,45 @@ add_option(struct options *options,
}
else if (streq(p[0], "tls-auth") && p[1] && !p[3])
{
- VERIFY_PERMISSION(OPT_P_GENERAL);
- if (streq(p[1], INLINE_FILE_TAG) && p[2])
+ int key_direction = -1;
+
+ VERIFY_PERMISSION(OPT_P_GENERAL|OPT_P_CONNECTION);
+
+ if (permission_mask & OPT_P_GENERAL)
{
- options->tls_auth_file_inline = p[2];
+ if (streq(p[1], INLINE_FILE_TAG) && p[2])
+ {
+ options->tls_auth_file_inline = p[2];
+ }
+ else if (p[2])
+ {
+ key_direction = ascii2keydirection(msglevel, p[2]);
+ if (key_direction < 0)
+ {
+ goto err;
+ }
+ options->key_direction = key_direction;
+ }
+ options->tls_auth_file = p[1];
}
- else if (p[2])
+ else if (permission_mask & OPT_P_CONNECTION)
{
- int key_direction;
-
- key_direction = ascii2keydirection(msglevel, p[2]);
- if (key_direction >= 0)
+ options->ce.key_direction = KEY_DIRECTION_BIDIRECTIONAL;
+ if (streq(p[1], INLINE_FILE_TAG) && p[2])
{
- options->key_direction = key_direction;
+ options->ce.tls_auth_file_inline = p[2];
}
- else
+ else if (p[2])
{
- goto err;
+ key_direction = ascii2keydirection(msglevel, p[2]);
+ if (key_direction < 0)
+ {
+ goto err;
+ }
+ options->ce.key_direction = key_direction;
}
+ options->ce.tls_auth_file = p[1];
}
- options->tls_auth_file = p[1];
}
else if (streq(p[0], "tls-crypt") && p[1] && !p[3])
{
diff --git a/src/openvpn/options.h b/src/openvpn/options.h
index f7d0145a..77c963d2 100644
--- a/src/openvpn/options.h
+++ b/src/openvpn/options.h
@@ -130,6 +130,11 @@ struct connection_entry
#define CE_MAN_QUERY_REMOTE_MASK (0x07)
#define CE_MAN_QUERY_REMOTE_SHIFT (2)
unsigned int flags;
+
+ /* Shared secret used for TLS control channel authentication */
+ const char *tls_auth_file;
+ const char *tls_auth_file_inline;
+ int key_direction;
};
struct remote_entry
--
2.17.1
------------------------------------------------------------------------------
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