core: New data flags "io-buffer-size" and "sensitive".

* src/data.c (_gpgme_data_release): Free buffers.
(gpgme_data_seek): Adjust from renamed fields.
(gpgme_data_set_flag): Implement new flags.
(_gpgme_data_inbound_handler): Allow the use of a malloced buffer.
(_gpgme_data_outbound_handler): Ditto.
* src/data.h (BUFFER_SIZE): Move out of the struct definition.
(struct gpgme_data): Remove pending filed and introduce inbound and
outbound fields.

* src/conversion.c (_gpgme_wipememory): New.  Taken from GnuPG.
* src/cJSON.c (wipememory): Use this here too.

* tests/run-decrypt.c (main): Add options "--large-buffers" and
"--sensitive".
--

GnuPG-bug-id: 5478
Signed-off-by: Werner Koch <[email protected]>

1 files changed, 16 insertions, 0 deletions

diff --git a/doc/gpgme.texi b/doc/gpgme.texi
index ea6693ef..b9908170 100644
--- a/doc/gpgme.texi
+++ b/doc/gpgme.texi
@@ -2253,6 +2253,22 @@ the data.  If this is set the OpenPGP engine may use this to decide on
 buffer allocation strategies and to provide a total value for its
 progress information.
 
+@item io-buffer-size
+The value is a decimal number with the length of internal buffers to
+used for internal I/O operations.  The value is capped at 1048576 (1
+MiB).  In certain environments large buffers can yield a performance
+boost for callback bases data object, but the details depend a lot on
+the circumstances and the operating system.  This flag may only be set
+once and must be set before any actual I/O happens ion the data
+objects.
+
+@item sensitive
+If the numeric value is not 0 the data object is considered to contain
+sensitive information like passwords or key material.  If this is set
+the internal buffers are securely overwritten with zeroes by
+gpgme_data_release.
+
+
 @end table
 
 This function returns @code{0} on success.