[PATCH 3/4] dh: plug pubkey_blob leak in ssh_server_dh_process_init

[Jon Simons <jon@xxxxxxxxxxxxx>]

Ensure to `SSH_STRING_FREE` the pubkey_blob local in
`ssh_server_dh_process_init`.  The leak can be seen with
valgrind and the pkd tests with:

    valgrind \
      --leak-check=full \
      --show-leak-kinds=definite \
      ./pkd_hello -i1 -t torture_pkd_openssh_rsa_rsa_diffie_hellman_group14_sha1

Signed-off-by: Jon Simons <jon@xxxxxxxxxxxxx>
---
 src/dh.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/dh.c b/src/dh.c
index 9deea8d5..b4b988d9 100644
--- a/src/dh.c
+++ b/src/dh.c
@@ -690,7 +690,8 @@ int ssh_server_dh_process_init(ssh_session session, ssh_buffer packet)
                          pubkey_blob,
                          session->next_crypto->f,
                          sig_blob);
-    ssh_string_free(sig_blob);
+    SSH_STRING_FREE(sig_blob);
+    SSH_STRING_FREE(pubkey_blob);
     if(rc != SSH_OK) {
         ssh_set_error_oom(session);
         ssh_buffer_reinit(session->out_buffer);
@@ -717,6 +718,8 @@ error:
     if (!bignum_ctx_invalid(ctx)) {
         bignum_ctx_free(ctx);
     }
+    SSH_STRING_FREE(sig_blob);
+    SSH_STRING_FREE(pubkey_blob);
 
     session->session_state = SSH_SESSION_STATE_ERROR;
     ssh_dh_cleanup(session->next_crypto);
-- 
2.19.1.593.gc670b1f