core: Implement context flag "override-session-key".

* src/gpgme.c (gpgme_set_ctx_flag): Add flags "export-session-key" and
"override-session-key".
(gpgme_get_ctx_flag): Ditto.
(gpgme_set_export_session_keys): Remove.
(gpgme_get_export_session_keys): Remove.
* src/gpgme.def, src/libgpgme.vers: Remove them.
* src/context.h (struct gpgme_context): Add field
override_session_key.
* src/decrypt-verify.c (decrypt_verify_start): Pass
override_session_key value to the engine.
* src/decrypt.c (decrypt_start): Ditto.
* src/engine.c (_gpgme_engine_op_decrypt): Ditto.
(_gpgme_engine_op_decrypt_verify): Ditto.
* src/engine-backend.h (struct engine_ops): Extend DECRYPT and
DECRYPT_VERIFY_START with override_session_key.
* src/engine-uiserver.c (_uiserver_decrypt): Add stub arg
override_session_key.
(uiserver_decrypt): Ditto.
(uiserver_decrypt_verify): Ditto.
* src/engine-gpgsm.c (gpgsm_decrypt): Ditto.
* src/engine-gpg.c (gpg_decrypt): Add arg override_session_key and set
corresponding gpg option.

* tests/run-decrypt.c (print_result): Print the session key if
available.
(main): Add options --export-session-key and --override-session-key.

--

To keep the number of context manipulation functions at bay, this
patches removes the just added gpgme_set_export_session_keys and
gpgme_get_export_session_keys by flags for the generic context
function.

The patch also implements the --override-session-key feature.

GnuPG-bug-id: 2754
Signed-off-by: Werner Koch <[email protected]>

1 files changed, 21 insertions, 25 deletions

diff --git a/src/gpgme.c b/src/gpgme.c
index 32abc282..1a10fd91 100644
--- a/src/gpgme.c
+++ b/src/gpgme.c
@@ -247,6 +247,7 @@ gpgme_release (gpgme_ctx_t ctx)
   free (ctx->signers);
   free (ctx->lc_ctype);
   free (ctx->lc_messages);
+  free (ctx->override_session_key);
   _gpgme_engine_info_release (ctx->engine_info);
   ctx->engine_info = NULL;
   DESTROY_LOCK (ctx->lock);
@@ -515,6 +516,17 @@ gpgme_set_ctx_flag (gpgme_ctx_t ctx, const char *name, const char *value)
     {
       ctx->raw_description = abool;
     }
+  else if (!strcmp (name, "export-session-key"))
+    {
+      ctx->export_session_keys = abool;
+    }
+  else if (!strcmp (name, "override-session-key"))
+    {
+      free (ctx->override_session_key);
+      ctx->override_session_key = strdup (value);
+      if (!ctx->override_session_key)
+        err = gpg_error_from_syserror ();
+    }
   else
     err = gpg_error (GPG_ERR_UNKNOWN_NAME);
 
@@ -526,7 +538,7 @@ gpgme_set_ctx_flag (gpgme_ctx_t ctx, const char *name, const char *value)
  * of valid names.  If the NAME is unknown NULL is returned.  For a
  * boolean flag an empty string is returned for False and the string
  * "1" for True; thus either atoi or a simple string test can be
- * used. */
+ * used.  */
 const char *
 gpgme_get_ctx_flag (gpgme_ctx_t ctx, const char *name)
 {
@@ -540,35 +552,19 @@ gpgme_get_ctx_flag (gpgme_ctx_t ctx, const char *name)
     {
       return ctx->raw_description? "1":"";
     }
+  else if (!strcmp (name, "export-session-key"))
+    {
+      return ctx->export_session_keys? "1":"";
+    }
+  else if (!strcmp (name, "override-session-key"))
+    {
+      return ctx->override_session_key? ctx->override_session_key : "";
+    }
   else
     return NULL;
 }
 
 
-/* Enable or disable the exporting session keys upon decryption.  */
-void
-gpgme_set_export_session_keys (gpgme_ctx_t ctx, int export_session_keys)
-{
-  TRACE2 (DEBUG_CTX, "gpgme_set_export_session_keys", ctx, "export_session_keys=%i (%s)",
-	  export_session_keys, export_session_keys ? "yes" : "no");
-
-  if (!ctx)
-    return;
-
-  ctx->export_session_keys = !!export_session_keys;
-}
-
-
-/* Return whether this context will export session keys upon decryption.  */
-int
-gpgme_get_export_session_keys (gpgme_ctx_t ctx)
-{
-  TRACE2 (DEBUG_CTX, "gpgme_get_export_session_keys", ctx, "ctx->export_session_keys=%i (%s)",
-	  ctx->export_session_keys, ctx->export_session_keys ? "yes" : "no");
-  return ctx->export_session_keys;
-}
-
-
 /* Enable or disable the use of the special textmode.  Textmode is for
   example used for the RFC2015 signatures; note that the updated RFC
   3156 mandates that the MUA does some preparations so that textmode