1 files changed, 16 insertions, 2 deletions

diff --git a/authfd.c b/authfd.c
index 12bf1251f..a634bcb81 100644
--- a/authfd.c
+++ b/authfd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: authfd.c,v 1.99 2015/09/02 07:51:12 jsg Exp $ */
+/* $OpenBSD: authfd.c,v 1.100 2015/12/04 16:41:28 markus Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -426,11 +426,24 @@ ssh_decrypt_challenge(int sock, struct sshkey* key, BIGNUM *challenge,
 }
 #endif
 
+/* encode signature algoritm in flag bits, so we can keep the msg format */
+static u_int
+agent_encode_alg(struct sshkey *key, const char *alg)
+{
+        if (alg != NULL && key->type == KEY_RSA) {
+                if (strcmp(alg, "rsa-sha2-256") == 0)
+                        return SSH_AGENT_RSA_SHA2_256;
+                else if (strcmp(alg, "rsa-sha2-512") == 0)
+                        return SSH_AGENT_RSA_SHA2_512;
+        }
+        return 0;
+}
+
 /* ask agent to sign data, returns err.h code on error, 0 on success */
 int
 ssh_agent_sign(int sock, struct sshkey *key,
     u_char **sigp, size_t *lenp,
-    const u_char *data, size_t datalen, u_int compat)
+    const u_char *data, size_t datalen, const char *alg, u_int compat)
 {
         struct sshbuf *msg;
         u_char *blob = NULL, type;
@@ -449,6 +462,7 @@ ssh_agent_sign(int sock, struct sshkey *key,
                 return SSH_ERR_ALLOC_FAIL;
         if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
                 goto out;
+        flags |= agent_encode_alg(key, alg);
         if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_SIGN_REQUEST)) != 0 ||
             (r = sshbuf_put_string(msg, blob, blen)) != 0 ||
             (r = sshbuf_put_string(msg, data, datalen)) != 0 ||