From fd3d8d6496f3dbfa2aad0e5b821706c7d1f9e0b6 Mon Sep 17 00:00:00 2001 From: Jon Simons Date: Fri, 25 May 2018 03:29:06 -0700 Subject: [PATCH] ecdh: fix SSH_MSG_KEXDH_REPLY for libgcrypt Ensure to provide the `ssh_string` pubkey blob to the buffer packing routine when computing the SSH_MSG_KEXDH_REPLY message, rather than the new `ssh_key` type. Introduced with 16217454d576511f37f39c3169963629f9d5082f. Testing done: with this change, the `pkd_hello` test is passing on a libgcrypt build for me. Previously it would segfault during pubkey exchange with "ecdh-sha2-nistp256". Signed-off-by: Jon Simons Reviewed-by: Andreas Schneider --- src/ecdh_gcrypt.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/src/ecdh_gcrypt.c b/src/ecdh_gcrypt.c index e4b73dc2..7bbccc25 100644 --- a/src/ecdh_gcrypt.c +++ b/src/ecdh_gcrypt.c @@ -268,6 +268,7 @@ int ssh_server_ecdh_init(ssh_session session, ssh_buffer packet) { /* SSH host keys (rsa,dsa,ecdsa) */ ssh_key privkey; ssh_string sig_blob = NULL; + ssh_string pubkey_blob = NULL; int rc = SSH_ERROR; const char *curve = NULL; @@ -333,14 +334,22 @@ int ssh_server_ecdh_init(ssh_session session, ssh_buffer packet) { goto out; } + rc = ssh_dh_get_next_server_publickey_blob(session, &pubkey_blob); + if (rc != SSH_OK) { + ssh_set_error(session, SSH_FATAL, "Could not export server public key"); + ssh_string_free(sig_blob); + goto out; + } + rc = ssh_buffer_pack(session->out_buffer, "bSSS", SSH2_MSG_KEXDH_REPLY, - session->next_crypto->server_pubkey, /* host's pubkey */ + pubkey_blob, /* host's pubkey */ q_s_string, /* ecdh public key */ sig_blob); /* signature blob */ ssh_string_free(sig_blob); + ssh_string_free(pubkey_blob); if (rc != SSH_OK) { ssh_set_error_oom(session);