[PATCH 4/4] Disallow encryption/decryption if key is not set

[Jussi Kivilinna]

* cipher/cipher.c (cipher_encrypt, cipher_decrypt): If mode is not
NONE, make sure that key is set.
* cipher/cipher-ccm.c (_gcry_cipher_ccm_set_nonce): Do not clear
'marks.key' when reseting state.
--

Reported-by: Andreas Metzler <ametzler at bebt.de>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna at iki.fi>
---
 cipher/cipher-ccm.c |    3 +++
 cipher/cipher.c     |   12 ++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/cipher/cipher-ccm.c b/cipher/cipher-ccm.c
index 4d8f816..d7f14d8 100644
--- a/cipher/cipher-ccm.c
+++ b/cipher/cipher-ccm.c
@@ -110,6 +110,7 @@ gcry_err_code_t
 _gcry_cipher_ccm_set_nonce (gcry_cipher_hd_t c, const unsigned char *nonce,
                             size_t noncelen)
 {
+  unsigned int marks_key;
   size_t L = 15 - noncelen;
   size_t L_;
 
@@ -122,12 +123,14 @@ _gcry_cipher_ccm_set_nonce (gcry_cipher_hd_t c, const unsigned char *nonce,
     return GPG_ERR_INV_LENGTH;
 
   /* Reset state */
+  marks_key = c->marks.key;
   memset (&c->u_mode, 0, sizeof(c->u_mode));
   memset (&c->marks, 0, sizeof(c->marks));
   memset (&c->u_iv, 0, sizeof(c->u_iv));
   memset (&c->u_ctr, 0, sizeof(c->u_ctr));
   memset (c->lastiv, 0, sizeof(c->lastiv));
   c->unused = 0;
+  c->marks.key = marks_key;
 
   /* Setup CTR */
   c->u_ctr.ctr[0] = L_;
diff --git a/cipher/cipher.c b/cipher/cipher.c
index 2b7bf21..ff3340f 100644
--- a/cipher/cipher.c
+++ b/cipher/cipher.c
@@ -818,6 +818,12 @@ cipher_encrypt (gcry_cipher_hd_t c, byte *outbuf, size_t outbuflen,
 {
   gcry_err_code_t rc;
 
+  if (c->mode != GCRY_CIPHER_MODE_NONE && !c->marks.key)
+    {
+      log_error ("cipher_encrypt: key not set\n");
+      return GPG_ERR_MISSING_KEY;
+    }
+
   switch (c->mode)
     {
     case GCRY_CIPHER_MODE_ECB:
@@ -935,6 +941,12 @@ cipher_decrypt (gcry_cipher_hd_t c, byte *outbuf, size_t outbuflen,
 {
   gcry_err_code_t rc;
 
+  if (c->mode != GCRY_CIPHER_MODE_NONE && !c->marks.key)
+    {
+      log_error ("cipher_decrypt: key not set\n");
+      return GPG_ERR_MISSING_KEY;
+    }
+
   switch (c->mode)
     {
     case GCRY_CIPHER_MODE_ECB: