shishi_decrypt_iv_etype(3)
NAME
shishi_decrypt_iv_etype - API function
SYNOPSIS
#include <shishi.h> int shishi_decrypt_iv_etype(Shishi * handle, Shishi_key * key, int keyusage, int32_t etype, const char * iv, size_t ivlen, 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 * iv
- input array with initialization vector
- size_t ivlen
- size of input array with initialization vector.
- 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 initialization
vector and 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 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@josefsson.org>.
COPYRIGHT
Copyright © 2002-2008 Simon Josefsson.
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
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.