4 files changed, 28 insertions, 13 deletions

diff --git a/authfd.c b/authfd.c
index a5162790f..1f0cd2ab3 100644
--- a/authfd.c
+++ b/authfd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: authfd.c,v 1.117 2019/09/03 08:29:15 djm Exp $ */
+/* $OpenBSD: authfd.c,v 1.118 2019/10/31 21:19:14 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -423,7 +423,8 @@ ssh_agent_sign(int sock, const struct sshkey *key,
 
 
 static int
-encode_constraints(struct sshbuf *m, u_int life, u_int confirm, u_int maxsign)
+encode_constraints(struct sshbuf *m, u_int life, u_int confirm, u_int maxsign,
+    const char *provider)
 {
         int r;
 
@@ -441,6 +442,14 @@ encode_constraints(struct sshbuf *m, u_int life, u_int confirm, u_int maxsign)
                     (r = sshbuf_put_u32(m, maxsign)) != 0)
                         goto out;
         }
+        if (provider != NULL) {
+                if ((r = sshbuf_put_u8(m,
+                    SSH_AGENT_CONSTRAIN_EXTENSION)) != 0 ||
+                    (r = sshbuf_put_cstring(m,
+                    "sk-provider@openssh.com")) != 0 ||
+                    (r = sshbuf_put_cstring(m, provider)) != 0)
+                        goto out;
+        }
         r = 0;
  out:
         return r;
@@ -452,10 +461,11 @@ encode_constraints(struct sshbuf *m, u_int life, u_int confirm, u_int maxsign)
  */
 int
 ssh_add_identity_constrained(int sock, struct sshkey *key,
-    const char *comment, u_int life, u_int confirm, u_int maxsign)
+    const char *comment, u_int life, u_int confirm, u_int maxsign,
+    const char *provider)
 {
         struct sshbuf *msg;
-        int r, constrained = (life || confirm || maxsign);
+        int r, constrained = (life || confirm || maxsign || provider);
         u_char type;
 
         if ((msg = sshbuf_new()) == NULL)
@@ -469,6 +479,8 @@ ssh_add_identity_constrained(int sock, struct sshkey *key,
         case KEY_DSA_CERT:
         case KEY_ECDSA:
         case KEY_ECDSA_CERT:
+        case KEY_ECDSA_SK:
+        case KEY_ECDSA_SK_CERT:
 #endif
         case KEY_ED25519:
         case KEY_ED25519_CERT:
@@ -488,7 +500,8 @@ ssh_add_identity_constrained(int sock, struct sshkey *key,
                 goto out;
         }
         if (constrained &&
-            (r = encode_constraints(msg, life, confirm, maxsign)) != 0)
+            (r = encode_constraints(msg, life, confirm, maxsign,
+            provider)) != 0)
                 goto out;
         if ((r = ssh_request_reply(sock, msg, msg)) != 0)
                 goto out;
@@ -566,7 +579,7 @@ ssh_update_card(int sock, int add, const char *reader_id, const char *pin,
             (r = sshbuf_put_cstring(msg, pin)) != 0)
                 goto out;
         if (constrained &&
-            (r = encode_constraints(msg, life, confirm, 0)) != 0)
+            (r = encode_constraints(msg, life, confirm, 0, NULL)) != 0)
                 goto out;
         if ((r = ssh_request_reply(sock, msg, msg)) != 0)
                 goto out;
diff --git a/authfd.h b/authfd.h
index 579076504..443771a00 100644
--- a/authfd.h
+++ b/authfd.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: authfd.h,v 1.46 2019/09/03 08:29:15 djm Exp $ */
+/* $OpenBSD: authfd.h,v 1.47 2019/10/31 21:19:15 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -30,7 +30,8 @@ int	ssh_lock_agent(int sock, int lock, const char *password);
 int     ssh_fetch_identitylist(int sock, struct ssh_identitylist **idlp);
 void    ssh_free_identitylist(struct ssh_identitylist *idl);
 int     ssh_add_identity_constrained(int sock, struct sshkey *key,
-            const char *comment, u_int life, u_int confirm, u_int maxsign);
+            const char *comment, u_int life, u_int confirm, u_int maxsign,
+            const char *provider);
 int     ssh_agent_has_key(int sock, struct sshkey *key);
 int     ssh_remove_identity(int sock, struct sshkey *key);
 int     ssh_update_card(int sock, int add, const char *reader_id,
@@ -77,6 +78,7 @@ int	ssh_agent_sign(int sock, const struct sshkey *key,
 #define SSH_AGENT_CONSTRAIN_LIFETIME            1
 #define SSH_AGENT_CONSTRAIN_CONFIRM             2
 #define SSH_AGENT_CONSTRAIN_MAXSIGN             3
+#define SSH_AGENT_CONSTRAIN_EXTENSION           255
 
 /* extended failure messages */
 #define SSH2_AGENT_FAILURE                      30
diff --git a/ssh-add.c b/ssh-add.c
index ebfb8a32b..2c65d0272 100644
--- a/ssh-add.c
+++ b/ssh-add.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-add.c,v 1.141 2019/09/06 05:23:55 djm Exp $ */
+/* $OpenBSD: ssh-add.c,v 1.142 2019/10/31 21:19:15 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -311,7 +311,7 @@ add_file(int agent_fd, const char *filename, int key_only, int qflag)
         }
 
         if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
-            lifetime, confirm, maxsign)) == 0) {
+            lifetime, confirm, maxsign, NULL)) == 0) {
                 ret = 0;
                 if (!qflag) {
                         fprintf(stderr, "Identity added: %s (%s)\n",
@@ -364,7 +364,7 @@ add_file(int agent_fd, const char *filename, int key_only, int qflag)
         sshkey_free(cert);
 
         if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
-            lifetime, confirm, maxsign)) != 0) {
+            lifetime, confirm, maxsign, NULL)) != 0) {
                 error("Certificate %s (%s) add failed: %s", certpath,
                     private->cert->key_id, ssh_err(r));
                 goto out;
diff --git a/sshconnect.c b/sshconnect.c
index 6230dad32..223074bd6 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.c,v 1.319 2019/09/13 04:31:19 djm Exp $ */
+/* $OpenBSD: sshconnect.c,v 1.320 2019/10/31 21:19:15 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1426,7 +1426,7 @@ maybe_add_key_to_agent(char *authfile, struct sshkey *private,
         }
 
         if ((r = ssh_add_identity_constrained(auth_sock, private, comment, 0,
-            (options.add_keys_to_agent == 3), 0)) == 0)
+            (options.add_keys_to_agent == 3), 0, NULL)) == 0)
                 debug("identity added to agent: %s", authfile);
         else
                 debug("could not add identity to agent: %s (%d)", authfile, r);