From c6eb54c39e4663c8f9ea82e8bf29bfdb3c8d945a Mon Sep 17 00:00:00 2001
From: Andreas Schneider <mail@cynapses.org>
Date: Thu, 16 Apr 2009 14:50:53 +0000
Subject: [PATCH] Improve dh_import() functions.

git-svn-id: svn+ssh://svn.berlios.de/svnroot/repos/libssh/trunk@505 7dcaeef0-15fb-0310-b436-a5af3365683c
---
 include/libssh/priv.h |  4 ++--
 libssh/client.c       |  6 +++++-
 libssh/dh.c           | 22 +++++++++++++++++-----
 libssh/server.c       |  5 ++++-
 4 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/include/libssh/priv.h b/include/libssh/priv.h
index 1deff590..4fe54a9e 100644
--- a/include/libssh/priv.h
+++ b/include/libssh/priv.h
@@ -525,8 +525,8 @@ void ssh_crypto_finalize(void);
 
 STRING *dh_get_e(SSH_SESSION *session);
 STRING *dh_get_f(SSH_SESSION *session);
-void dh_import_f(SSH_SESSION *session,STRING *f_string);
-void dh_import_e(SSH_SESSION *session, STRING *e_string);
+int dh_import_f(SSH_SESSION *session,STRING *f_string);
+int dh_import_e(SSH_SESSION *session, STRING *e_string);
 void dh_import_pubkey(SSH_SESSION *session,STRING *pubkey_string);
 void dh_build_k(SSH_SESSION *session);
 int make_sessionid(SSH_SESSION *session);
diff --git a/libssh/client.c b/libssh/client.c
index 70956c98..166eb3a7 100644
--- a/libssh/client.c
+++ b/libssh/client.c
@@ -251,7 +251,11 @@ static int dh_handshake(SSH_SESSION *session) {
         rc = SSH_ERROR;
         goto error;
       }
-      dh_import_f(session, f);
+      if (dh_import_f(session, f) < 0) {
+        ssh_set_error(session, SSH_FATAL, "Cannot import f number");
+        rc = SSH_ERROR;
+        goto error;
+      }
       string_burn(f);
       string_free(f);
 
diff --git a/libssh/dh.c b/libssh/dh.c
index 9eb4810e..4f37615f 100644
--- a/libssh/dh.c
+++ b/libssh/dh.c
@@ -380,19 +380,31 @@ void dh_import_pubkey(SSH_SESSION *session, STRING *pubkey_string) {
   session->next_crypto->server_pubkey = pubkey_string;
 }
 
-void dh_import_f(SSH_SESSION *session,STRING *f_string){
-    session->next_crypto->f=make_string_bn(f_string);
+int dh_import_f(SSH_SESSION *session, STRING *f_string) {
+  session->next_crypto->f = make_string_bn(f_string);
+  if (session->next_crypto->f == NULL) {
+    return -1;
+  }
+
 #ifdef DEBUG_CRYPTO
-    ssh_print_bignum("f",session->next_crypto->f);
+  ssh_print_bignum("f",session->next_crypto->f);
 #endif
+
+  return 0;
 }
 
 /* used by the server implementation */
-void dh_import_e(SSH_SESSION *session, STRING *e_string){
-    session->next_crypto->e=make_string_bn(e_string);
+int dh_import_e(SSH_SESSION *session, STRING *e_string) {
+  session->next_crypto->e = make_string_bn(e_string);
+  if (session->next_crypto->e == NULL) {
+    return -1;
+  }
+
 #ifdef DEBUG_CRYPTO
     ssh_print_bignum("e",session->next_crypto->e);
 #endif
+
+  return 0;
 }
 
 void dh_build_k(SSH_SESSION *session){
diff --git a/libssh/server.c b/libssh/server.c
index 2809a8ec..7b3602b9 100644
--- a/libssh/server.c
+++ b/libssh/server.c
@@ -272,7 +272,10 @@ static int dh_handshake_server(SSH_SESSION *session){
         ssh_set_error(session,SSH_FATAL,"No e number in client request");
         return -1;
     }
-    dh_import_e(session,e);
+    if (dh_import_e(session, e) < 0) {
+      ssh_set_error(session,SSH_FATAL,"Cannot import e number");
+      return -1;
+    }
     free(e);
     if (dh_generate_y(session) < 0) {
       ssh_set_error(session,SSH_FATAL,"Could not create y number");