behavior of gcrypt depending on input data: "conflicting use"

[Christof Schulze]

Hello everyone,

currentrly I am writing a program to sign a given data string using a
secret key and verifying it using a public key.
I followed the documentation and did things like in the tests from
libgcrypt.
Yet Some strings (like "Hello World!") can be signed and verified ok
while other strings (like "Objekt1") lead to errors like "invalid
object" or "conflicting use" 
I cannot make anything out of these error codes so I am turning to this
mailinglist. Also google did not turn up anything.

I am guessing that sometimes gcry_mpi_scan (in
make_sign_parameters) returns something and sometimes it does not but I
am only guessing because nscanned sometimes - even when the string is
signed successfully - is 0.
I am at a loss and I would greatly appreciate some input on this matter.

I am using this code:
testlog.c http://pastebin.com/f6051a825
logging.c: http://pastebin.com/f4bf4f55f
logging.h: http://pastebin.com/f5e601a0f

kind Regards

Christof Schulze
-- 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 196 bytes
Desc: not available
URL: </pipermail/attachments/20090119/ff135186/attachment.pgp>