NAME

       shishi_decrypt_etype - API function

SYNOPSIS

       #include <shishi.h>

       int shishi_decrypt_etype(Shishi * handle, Shishi_key * key, int keyusage, int32_t etype, 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.

       int32_t etype
                   integer specifying what cipher to use.

       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  as per encryption method using 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_etype if you need to alter it.  The next IV is
       lost, see shishi_decrypt_ivupdate_etype 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

       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.

shishi                                                1.0.3                              shishi_decrypt_etype(3)