#ifndef _PRIV_CRYPTO_H_4aa002c2_
#define _PRIV_CRYPTO_H_4aa002c2_

/* This file is in the public domain. */

/*
 * Support routines for the crypto applied to the private portions of
 *  public-key crypto keys.  This is the code that encrypts and
 *  decrypts private keys based on passphrases.
 */

/*
 * Wrap a private key.  This takes the unencrypted public-key private
 *  data blob and encrypts it with the given passphrase, returning an
 *  encrypted data blob.  (A zero-length passphrase produces no
 *  encryption; this is suitable for, eg, host keys.  "No passphrase
 *  available, please prompt" is indicated by a nil pointer for the
 *  passphrase.)  Arguments:
 *
 *	const void *in_ptr
 *	int in_len
 *	void **out_ptr
 *	int *out_len
 *	const char *passphrase
 */
extern void priv_wrap(const void *, int, void **, int *, const char *);

/*
 * Unwrap a private key.  This takes the encrypted public-key private
 *  data blob and decrypts it with the given passphrase, returning an
 *  unencrypted data blob.  If the private data blob is not encrypted,
 *  the passphrase argument is ignored; otherwise, it must decrypt the
 *  data blob correctly (there is a signature in encrypted data blobs
 *  to make it extremely unlikely that an incorrect decryption will go
 *  undetected).  Arguments:
 *
 *	const void *in_ptr
 *	int in_len
 *	const char *comment
 *	void **out_ptr
 *	int *out_len
 *	const char *passphrase
 *
 * comment is the key comment, used to provide meaningful passphrase
 *  prompts if prompting is done.  A nil passphrase pointer means that
 *  no passphrase is available, and prompting should be done;
 *  NO_PASSPHRASE also means that no passphrase is available, but
 *  indicates that if the data blob is encrypted, an error return
 *  should be produced.
 */
extern int priv_unwrap(const void *, int, const char *, void **, int *, const char *);
extern const char priv_unwrap__no_pp;
#define NO_PASSPHRASE (&priv_unwrap__no_pp)

/*
 * Tests whether a data blob has no passphrase set on it, returning
 *  true if it does, false if not.
 */
extern int priv_no_pp(const void *, int);

#endif