Be more careful about destroying sensitive data after private key

[u/mdw/putty] / sshdes.c

diff --git a/sshdes.c b/sshdes.c
index ad4beb6..9cb9cfa 100644 (file)
--- a/sshdes.c
+++ b/sshdes.c
@@ -840,6 +840,7 @@ void des3_decrypt_pubkey(unsigned char *key, unsigned char *blk, int len)
     des_key_setup(GET_32BIT_MSB_FIRST(key),
                  GET_32BIT_MSB_FIRST(key + 4), &ourkeys[2]);
     des_3cbc_decrypt(blk, blk, len, ourkeys);
+    memset(ourkeys, 0, sizeof(ourkeys));
 }
 
 void des3_encrypt_pubkey(unsigned char *key, unsigned char *blk, int len)
@@ -852,6 +853,39 @@ void des3_encrypt_pubkey(unsigned char *key, unsigned char *blk, int len)
     des_key_setup(GET_32BIT_MSB_FIRST(key),
                  GET_32BIT_MSB_FIRST(key + 4), &ourkeys[2]);
     des_3cbc_encrypt(blk, blk, len, ourkeys);
+    memset(ourkeys, 0, sizeof(ourkeys));
+}
+
+void des3_decrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
+                             unsigned char *blk, int len)
+{
+    DESContext ourkeys[3];
+    des_key_setup(GET_32BIT_MSB_FIRST(key),
+                 GET_32BIT_MSB_FIRST(key + 4), &ourkeys[0]);
+    des_key_setup(GET_32BIT_MSB_FIRST(key + 8),
+                 GET_32BIT_MSB_FIRST(key + 12), &ourkeys[1]);
+    des_key_setup(GET_32BIT_MSB_FIRST(key + 16),
+                 GET_32BIT_MSB_FIRST(key + 20), &ourkeys[2]);
+    ourkeys[0].div0 = GET_32BIT_MSB_FIRST(iv);
+    ourkeys[0].div1 = GET_32BIT_MSB_FIRST(iv+4);
+    des_cbc3_decrypt(blk, blk, len, ourkeys);
+    memset(ourkeys, 0, sizeof(ourkeys));
+}
+
+void des3_encrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
+                             unsigned char *blk, int len)
+{
+    DESContext ourkeys[3];
+    des_key_setup(GET_32BIT_MSB_FIRST(key),
+                 GET_32BIT_MSB_FIRST(key + 4), &ourkeys[0]);
+    des_key_setup(GET_32BIT_MSB_FIRST(key + 8),
+                 GET_32BIT_MSB_FIRST(key + 12), &ourkeys[1]);
+    des_key_setup(GET_32BIT_MSB_FIRST(key + 16),
+                 GET_32BIT_MSB_FIRST(key + 20), &ourkeys[2]);
+    ourkeys[0].eiv0 = GET_32BIT_MSB_FIRST(iv);
+    ourkeys[0].eiv1 = GET_32BIT_MSB_FIRST(iv+4);
+    des_cbc3_encrypt(blk, blk, len, ourkeys);
+    memset(ourkeys, 0, sizeof(ourkeys));
 }
 
 static const struct ssh2_cipher ssh_3des_ssh2 = {