plucky (3) shishi_decrypt.3.gz

Provided by: shishi-doc_1.0.3-5_all bug

NAME
       shishi_decrypt - API function


SYNOPSIS
       #include <shishi.h>

       int  shishi_decrypt(Shishi  * handle, Shishi_key * key, int keyusage, const char * in, size_t inlen, char
       ** out, size_t * outlen);


ARGUMENTS
       Shishi * handle
                   shishi handle as allocated by shishi_init().

       Shishi_key * key
                   key to decrypt with.

       int keyusage
                   integer specifying what this key is decrypting.

       const char * in
                   input array with data to decrypt.

       size_t inlen
                   size of input array with data to decrypt.

       char ** out output array with newly allocated decrypted data.

       size_t * outlen
                   output variable with size of newly allocated output array.


DESCRIPTION
       Decrypts data specified key.  The key actually used is derived using the key usage.  If key usage  is  0,
       no  key  derivation  is used.  The OUT buffer must be deallocated by the caller.  The default IV is used,
       see shishi_decrypt_iv if you need to alter it.  The next IV is lost, see shishi_decrypt_ivupdate  if  you
       need it.

       Note  that DECRYPT(ENCRYPT(data)) does not necessarily yield data exactly.  Some encryption types add pad
       to make the data fit into the block size of the  encryption  algorithm.   Furthermore,  the  pad  is  not
       guaranteed  to  look  in any special way, although existing implementations often pad with the zero byte.
       This means that you may have to "frame" data, so it is  possible  to  infer  the  original  length  after
       decryption.  Compare ASN.1 DER which contains such information.


RETURN VALUE
       Returns SHISHI_OK iff successful.


REPORTING BUGS
       Report  bugs  to <bug-shishi@gnu.org>.  GNU Shishi home page: http://www.gnu.org/software/shishi/ General
       help using GNU software: http://www.gnu.org/gethelp/


       Copyright © 2002-2022 Simon Josefsson.
       Copying and distribution of this file, with or without modification, are permitted in any medium  without
       royalty provided the copyright notice and this notice are preserved.


SEE ALSO
       The full documentation for shishi is maintained as a Texinfo manual.  If the info and shishi programs are
       properly installed at your site, the command

              info shishi

       should give you access to the complete manual.