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, 23 insertions, 1 deletions

diff --git a/src/gpgme.h.in b/src/gpgme.h.in
index e9ee6e2f..b6c14064 100644
--- a/src/gpgme.h.in
+++ b/src/gpgme.h.in
@@ -1238,7 +1238,8 @@ typedef enum
     GPGME_ENCRYPT_EXPECT_SIGN = 8,
     GPGME_ENCRYPT_NO_COMPRESS = 16,
     GPGME_ENCRYPT_SYMMETRIC = 32,
-    GPGME_ENCRYPT_THROW_KEYIDS = 64
+    GPGME_ENCRYPT_THROW_KEYIDS = 64,
+    GPGME_ENCRYPT_WRAP = 128
   }
 gpgme_encrypt_flags_t;
 
@@ -1317,6 +1318,14 @@ typedef struct _gpgme_op_decrypt_result *gpgme_decrypt_result_t;
 /* Retrieve a pointer to the result of the decrypt operation.  */
 gpgme_decrypt_result_t gpgme_op_decrypt_result (gpgme_ctx_t ctx);
 
+/* The valid decryption flags.  */
+typedef enum
+  {
+    GPGME_DECRYPT_VERIFY = 1,
+    GPGME_DECRYPT_UNWRAP = 128
+  }
+gpgme_decrypt_flags_t;
+
 /* Decrypt ciphertext CIPHER within CTX and store the resulting
    plaintext in PLAIN.  */
 gpgme_error_t gpgme_op_decrypt_start (gpgme_ctx_t ctx, gpgme_data_t cipher,
@@ -1332,6 +1341,19 @@ gpgme_error_t gpgme_op_decrypt_verify_start (gpgme_ctx_t ctx,
 gpgme_error_t gpgme_op_decrypt_verify (gpgme_ctx_t ctx, gpgme_data_t cipher,
 				       gpgme_data_t plain);
 
+/* Decrypt ciphertext CIPHER within CTX and store the resulting
+ * plaintext in PLAIN.  With the flag GPGME_DECRYPT_VERIFY also do a
+ * signature verification pn the plaintext.  */
+gpgme_error_t gpgme_op_decrypt_ext_start (gpgme_ctx_t ctx,
+                                          gpgme_decrypt_flags_t flags,
+                                          gpgme_data_t cipher,
+                                          gpgme_data_t plain);
+gpgme_error_t gpgme_op_decrypt_ext (gpgme_ctx_t ctx,
+                                    gpgme_decrypt_flags_t flags,
+                                    gpgme_data_t cipher,
+                                    gpgme_data_t plain);
+
+
 
 /*
  * Signing.