From 448de134ac1439e1cbbed02ad344c37d9450d6d7 Mon Sep 17 00:00:00 2001 From: Jon Simons Date: Fri, 25 May 2018 03:39:21 -0700 Subject: [PATCH] ecdh: fix SSH_MSG_KEXDH_REPLY for mbedTLS 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 mbedTLS 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_mbedcrypto.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/src/ecdh_mbedcrypto.c b/src/ecdh_mbedcrypto.c index d4e7a774..aebc7bac 100644 --- a/src/ecdh_mbedcrypto.c +++ b/src/ecdh_mbedcrypto.c @@ -181,6 +181,7 @@ int ssh_server_ecdh_init(ssh_session session, ssh_buffer packet) mbedtls_ecp_group grp; ssh_key privkey = NULL; ssh_string sig_blob = NULL; + ssh_string pubkey_blob = NULL; int rc; mbedtls_ecp_group_id curve; @@ -256,12 +257,21 @@ 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, - q_s_string, - sig_blob); + SSH2_MSG_KEXDH_REPLY, + 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);