core: New flags GPGME_DECRYPT_UNWRAP and GPGME_ENCRYPT_WRAP.

* src/gpgme.h.in (GPGME_ENCRYPT_WRAP): New const.
(gpgme_decrypt_flags_t): New enum.
(GPGME_DECRYPT_VERIFY): New const
(GPGME_DECRYPT_UNWRAP): New const
(gpgme_op_decrypt_ext_start): New func.
(gpgme_op_decrypt_ext): New func.
* src/decrypt-verify.c (gpgme_op_decrypt_ext_start): New.
(gpgme_op_decrypt_ext): New.
(decrypt_verify_start): Add arg FLAGS.  Replace call to
engine_op_decrypt_verify by the plain decrypt with the flag set.
(gpgme_op_decrypt_verify_start): Pass the flag.
(gpgme_op_decrypt_verify): Pass the flag.
* src/decrypt.c (decrypt_start): Rename to ...
(_gpgme_decrypt_start): this.  Add arg FLAGS.  Pass FLAGS to
engine_op_decrypt.
(gpgme_op_decrypt_start): Adjust for chnage pass 0 for FLAG.
(gpgme_op_decrypt_start): Ditto.
* src/engine.c (_gpgme_engine_op_decrypt_verify): Remove.
(_gpgme_engine_op_decrypt): Add arg FLAGS.
* src/gpgme.def, src/libgpgme.vers: Add new functions.
* src/engine-backend.h (struct engine_ops): Remove member
'decrypt_verify'.  Add FLAGS to 'decrypt'.  Adjust all initialization.
* src/engine-uiserver.c (uiserver_decrypt): Remove.
(uiserver_decrypt_verify): Remove.
(_uiserver_decrypt): Rename to ...
(uiserver_decrypt): this.  Replace arg VERIFY by new arg FLAGS.
* src/engine-gpg.c (gpg_decrypt): Support GPGME_DECRYPT_UNWRAP.
(gpg_encrypt): Support GPGME_ENCRYPT_WRAP.

* tests/run-decrypt.c (main): New option --unwrap.
* tests/run-encrypt.c (main): New option --wrap.
--

Manual testing of that wrap/unwrap feature can be done this way:

 ./run-encrypt --verbose --key Alice /etc/motd > x
 ./run-decrypt --verbose --unwrap x > y
 ./run-encrypt --verbose --key Bob --wrap y > z

1. The message was first encrypted to Alice.
2. Alice decrypts the message receiving a valid OpenPGP message.
3. Alice encrypt that message to Bob

This will also work with encrypted and signed messages; the signature
will be kept intact during re-encryption.  Requires GnuPG 2.1.12.

Signed-off-by: Werner Koch <[email protected]>

1 files changed, 16 insertions, 2 deletions

diff --git a/tests/run-decrypt.c b/tests/run-decrypt.c
index 8bcca0e5..0fcacf88 100644
--- a/tests/run-decrypt.c
+++ b/tests/run-decrypt.c
@@ -80,6 +80,7 @@ show_usage (int ex)
          "  --cms            use the CMS protocol\n"
          "  --export-session-key            show the session key\n"
          "  --override-session-key STRING   use STRING as session key\n"
+         "  --unwrap         remove only the encryption layer\n"
          , stderr);
   exit (ex);
 }
@@ -92,6 +93,7 @@ main (int argc, char **argv)
   gpgme_error_t err;
   gpgme_ctx_t ctx;
   gpgme_protocol_t protocol = GPGME_PROTOCOL_OpenPGP;
+  gpgme_decrypt_flags_t flags = 0;
   FILE *fp_in = NULL;
   gpgme_data_t in = NULL;
   gpgme_data_t out = NULL;
@@ -99,6 +101,7 @@ main (int argc, char **argv)
   int print_status = 0;
   int export_session_key = 0;
   const char *override_session_key = NULL;
+  int raw_output = 0;
 
   if (argc)
     { argc--; argv++; }
@@ -146,6 +149,12 @@ main (int argc, char **argv)
           override_session_key = *argv;
           argc--; argv++;
         }
+      else if (!strcmp (*argv, "--unwrap"))
+        {
+          flags |= GPGME_DECRYPT_UNWRAP;
+          raw_output = 1;
+          argc--; argv++;
+        }
       else if (!strncmp (*argv, "--", 2))
         show_usage (1);
 
@@ -211,7 +220,7 @@ main (int argc, char **argv)
       exit (1);
     }
 
-  err = gpgme_op_decrypt (ctx, in, out);
+  err = gpgme_op_decrypt_ext (ctx, flags, in, out);
   result = gpgme_op_decrypt_result (ctx);
   if (err)
     {
@@ -220,8 +229,13 @@ main (int argc, char **argv)
     }
   if (result)
     {
-      print_result (result);
+      if (!raw_output)
+        print_result (result);
+      if (!raw_output)
+        fputs ("Begin Output:\n", stdout);
       print_data (out);
+      if (!raw_output)
+        fputs ("End Output.\n", stdout);
     }
 
   gpgme_data_release (out);