Decryption streaming

Coffman, Beth C Beth.C.Coffman at
Tue May 12 17:09:45 CEST 2009

Thanks.  Does documentation exist anywhere for the individual methods
within the libraries?  What about examples?  I'm not sure what methods
to use from GPGME to accomplish my task.  There is a lot of gnupg
documentation in general, but not on using the individual methods within
the libraries.

It looks like 
minip12.c  decrypt_block from gnupg-2.0.11 might do what I need, but I
don't see anything documenting what the "salt" and "pw" parameters are
supposed to be.

What I am looking to do is read and decrypt a small subset of data from
a file at a time, process it, delete it, and move on to decrypting the
next subset.


-----Original Message-----
From: David Shaw [mailto:dshaw at] 
Sent: Tuesday, May 12, 2009 9:20 AM
To: Coffman, Beth C
Cc: gnupg-users at
Subject: Re: Decryption streaming

On May 8, 2009, at 5:30 PM, Coffman, Beth C wrote:

> What is a good way to write a C++ app to decrypt multiple large PGP- 
> encrypted files simultaneously into memory?  I cannot have the 
> plaintext output in a file on disk at any time.  Preferably, one block

> of data from the file will be decrypted at a time.  Therefore, the 
> entire file or files will not need to reside in memory.

GPG (the program) can decrypt as a stream.  You can either write a
program that wraps around it, or use the GPGME library to do the work
for you.



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