core: Support reading the archive to decrypt/verify directly from a file

* src/engine-gpg.c (add_file_name_arg_or_data): New.
(gpg_decrypt): Use add_file_name_arg_or_data instead of add_data for the
ciphertext.
(gpg_verify): Use add_file_name_arg_or_data instead of add_data for the
signature and the signed text.

* tests/run-decrypt.c (show_usage): New option --direct-file-io.
(main): Parse new option. If option is given, then don't open input
file, create simple data object instead of data object from stream and
set input file name on input data.
* tests/run-verify.c (show_usage): New option --direct-file-io.
(main): Parse new option. If option is given, then don't open input
files, create simple data objects instead of data objects from stream
and set input file names on input data objects.
--

This change makes it possible to tell gpg (and gpgtar) to read the
input (i.e. the signed/encrypted data or the signature or the created
archive) directly from the files with given file names instead of from
streams piped through GpgME's Data IO.

GnuPG-bug-id: 6530

NEWS

@@ -5,6 +5,9 @@ Noteworthy changes in version 1.21.0 (unreleased)
    gpgme_op_sign* to allow writing the output directly to a
    file.  [T6530]
 
+ * Extended gpgme_op_decrypt* and gpgme_op_verify* to allow
+   reading the input data directly from files.  [T6530]
+
  * qt: Allow writing the created archives directly to a
    file.  [T6530]
 

doc/gpgme.texi

@@ -5592,8 +5592,9 @@ An error code describing the reason why the key was found invalid.
 
 @deftypefun gpgme_error_t gpgme_op_decrypt (@w{gpgme_ctx_t @var{ctx}}, @w{gpgme_data_t @var{cipher}}, @w{gpgme_data_t @var{plain}})
 The function @code{gpgme_op_decrypt} decrypts the ciphertext in the
-data object @var{cipher} and stores it into the data object
+data object @var{cipher} or, if a file name is set on the data object,
-@var{plain}.
+the ciphertext stored in the corresponding file.  The decrypted
+ciphertext is stored into the data object @var{plain}.
 
 The function returns the error code @code{GPG_ERR_NO_ERROR} if the
 ciphertext could be decrypted successfully, @code{GPG_ERR_INV_VALUE}
@@ -5806,7 +5807,10 @@ detached signature, then the signed text should be provided in
 Otherwise, if @var{sig} is a normal (or cleartext) signature,
 @var{signed_text} should be a null pointer and @var{plain} should be a
 writable data object that will contain the plaintext after successful
-verification.
+verification.  If a file name is set on the data object @var{sig} (or
+on the data object @var{signed_text}), then the data of the signature
+(resp. the data of the signed text) is not read from the data object
+but from the file with the given file name.
 
 The results of the individual signature verifications can be retrieved
 with @code{gpgme_op_verify_result}.

src/engine-gpg.c

@@ -365,6 +365,18 @@ add_data (engine_gpg_t gpg, gpgme_data_t data, int dup_to, int inbound)
   return add_data_ext (gpg, data, dup_to, inbound, 0);
 }
 
+
+static gpgme_error_t
+add_file_name_arg_or_data (engine_gpg_t gpg, gpgme_data_t data, int dup_to, int inbound)
+{
+  const char *file_name = gpgme_data_get_file_name (data);
+  if (file_name)
+    return add_arg (gpg, file_name);
+  else
+    return add_data (gpg, data, dup_to, inbound);
+}
+
+
 /* Return true if the engine's version is at least VERSION.  */
 static int
 have_gpg_version (engine_gpg_t gpg, const char *version)
@@ -1883,7 +1895,7 @@ gpg_decrypt (void *engine,
       if (!err)
         err = add_arg (gpg, "--");
       if (!err)
-        err = add_data (gpg, ciph, 0, 0);
+        err = add_file_name_arg_or_data (gpg, ciph, 0, 0);
     }
   else
     {
@@ -1898,7 +1910,7 @@ gpg_decrypt (void *engine,
       if (!err)
         err = add_arg (gpg, "--");
       if (!err)
-        err = add_data (gpg, ciph, -1, 0);
+        err = add_file_name_arg_or_data (gpg, ciph, -1, 0);
     }
 
   if (!err)
@@ -3707,7 +3719,7 @@ gpg_verify (void *engine, gpgme_verify_flags_t flags, gpgme_data_t sig,
       if (!err)
         err = add_arg (gpg, "--");
       if (!err)
-        err = add_data (gpg, sig, 0, 0);
+        err = add_file_name_arg_or_data (gpg, sig, 0, 0);
     }
   else if (plaintext)
     {
@@ -3720,7 +3732,7 @@ gpg_verify (void *engine, gpgme_verify_flags_t flags, gpgme_data_t sig,
       if (!err)
 	err = add_arg (gpg, "--");
       if (!err)
-	err = add_data (gpg, sig, -1, 0);
+	err = add_file_name_arg_or_data (gpg, sig, -1, 0);
       if (!err)
 	err = add_data (gpg, plaintext, 1, 1);
     }
@@ -3732,9 +3744,9 @@ gpg_verify (void *engine, gpgme_verify_flags_t flags, gpgme_data_t sig,
       if (!err)
 	err = add_arg (gpg, "--");
       if (!err)
-	err = add_data (gpg, sig, -1, 0);
+	err = add_file_name_arg_or_data (gpg, sig, -1, 0);
       if (!err && signed_text)
-	err = add_data (gpg, signed_text, -1, 0);
+	err = add_file_name_arg_or_data (gpg, signed_text, -1, 0);
     }
 
   if (!err)

tests/run-decrypt.c

@@ -94,6 +94,7 @@ show_usage (int ex)
          "  --archive        extract files from an encrypted archive\n"
          "  --directory DIR  extract the files into the directory DIR\n"
          "  --diagnostics    print diagnostics\n"
+         "  --direct-file-io pass FILE instead of stream with content of FILE to backend\n"
          , stderr);
   exit (ex);
 }
@@ -122,6 +123,7 @@ main (int argc, char **argv)
   int large_buffers = 0;
   int sensitive = 0;
   int diagnostics = 0;
+  int direct_file_io = 0;
 
   if (argc)
     { argc--; argv++; }
@@ -221,6 +223,11 @@ main (int argc, char **argv)
           directory = *argv;
           argc--; argv++;
         }
+      else if (!strcmp (*argv, "--direct-file-io"))
+        {
+          direct_file_io = 1;
+          argc--; argv++;
+        }
       else if (!strncmp (*argv, "--", 2))
         show_usage (1);
 
@@ -229,6 +236,8 @@ main (int argc, char **argv)
   if (argc < 1 || argc > 2)
     show_usage (1);
 
+  if (!direct_file_io)
+    {
       fp_in = fopen (argv[0], "rb");
       if (!fp_in)
         {
@@ -237,6 +246,7 @@ main (int argc, char **argv)
                    argv[0], gpgme_strerror (err));
           exit (1);
         }
+    }
 
   init_gpgme (protocol);
 
@@ -303,6 +313,9 @@ main (int argc, char **argv)
         }
     }
 
+  if (direct_file_io)
+    err = gpgme_data_new (&in);
+  else
     err = gpgme_data_new_from_stream (&in, fp_in);
   if (err)
     {
@@ -310,6 +323,16 @@ main (int argc, char **argv)
                gpgme_strerror (err));
       exit (1);
     }
+  if (direct_file_io)
+    {
+      err = gpgme_data_set_file_name (in, argv[0]);
+      if (err)
+        {
+          fprintf (stderr, PGM ": error setting file name (in): %s\n",
+                   gpgme_strerror (err));
+          exit (1);
+        }
+    }
 
   err = gpgme_data_new (&out);
   if (err)

tests/run-verify.c

@@ -239,6 +239,7 @@ show_usage (int ex)
          "  --archive        extract files from a signed archive FILE\n"
          "  --directory DIR  extract the files into the directory DIR\n"
          "  --diagnostics    print diagnostics\n"
+         "  --direct-file-io pass file names instead of streams with content of files to backend\n"
          , stderr);
   exit (ex);
 }
@@ -258,6 +259,7 @@ main (int argc, char **argv)
   int auto_key_import = 0;
   gpgme_data_encoding_t encoding = GPGME_DATA_ENCODING_NONE;
   int diagnostics = 0;
+  int direct_file_io = 0;
   int repeats = 1;
   int i;
 
@@ -343,6 +345,11 @@ main (int argc, char **argv)
           diagnostics = 1;
           argc--; argv++;
         }
+      else if (!strcmp (*argv, "--direct-file-io"))
+        {
+          direct_file_io = 1;
+          argc--; argv++;
+        }
       else if (!strncmp (*argv, "--", 2))
         show_usage (1);
 
@@ -369,6 +376,8 @@ main (int argc, char **argv)
           printf ("Repeat: %i\n", i);
         }
 
+      if (!direct_file_io)
+        {
           fp_sig = fopen (argv[0], "rb");
           if (!fp_sig)
             {
@@ -388,6 +397,7 @@ main (int argc, char **argv)
                   exit (1);
                 }
             }
+        }
 
       err = gpgme_new (&ctx);
       fail_if_err (err);
@@ -429,6 +439,9 @@ main (int argc, char **argv)
           fail_if_err (err);
         }
 
+      if (direct_file_io)
+        err = gpgme_data_new (&sig);
+      else
         err = gpgme_data_new_from_stream (&sig, fp_sig);
       if (err)
         {
@@ -437,8 +450,21 @@ main (int argc, char **argv)
           exit (1);
         }
       gpgme_data_set_encoding (sig, encoding);
-      if (fp_msg)
+      if (direct_file_io)
         {
+          err = gpgme_data_set_file_name (sig, argv[0]);
+          if (err)
+            {
+              fprintf (stderr, PGM ": error setting file name (sig): %s\n",
+                       gpgme_strerror (err));
+              exit (1);
+            }
+        }
+      if (argc > 1)
+        {
+          if (direct_file_io)
+            err = gpgme_data_new (&msg);
+          else
             err = gpgme_data_new_from_stream (&msg, fp_msg);
           if (err)
             {
@@ -446,6 +472,16 @@ main (int argc, char **argv)
                        gpgme_strerror (err));
               exit (1);
             }
+          if (direct_file_io)
+            {
+              err = gpgme_data_set_file_name (msg, argv[1]);
+              if (err)
+                {
+                  fprintf (stderr, PGM ": error setting file name (msg): %s\n",
+                           gpgme_strerror (err));
+                  exit (1);
+                }
+            }
         }
 
       if (directory && (flags & GPGME_VERIFY_ARCHIVE))