progs/perftest.c: Use from Glibc syscall numbers.

[catacomb] / symm / gaead.c

/* -*-c-*-
 *
 * Generic authenticated encryption interface
 *
 * (c) 2018 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of Catacomb.
 *
 * Catacomb is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Library General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Catacomb is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with Catacomb.  If not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 * USA.
 */

/*----- Header files ------------------------------------------------------*/

#include "gaead.h"

/*----- Main code ---------------------------------------------------------*/

/* --- @gaead_szokcommon@ --- *
 *
 * Arguments:	@const gcaead *aec@ = pointer to AEAD class
 *		@size_t nsz@, @size_t hsz@, @size_t msz@, @size_t tsz@ =
 *			nonce, header, message, and tag sizes
 *
 * Returns:	Nonzero if the sizes are acceptable to the AEAD scheme in
 *		combination.
 *
 * Use:		Generic implementation for sensible AEAD schemes.
 */

int gaead_szokcommon(const gcaead *aec,
		     size_t nsz, size_t hsz, size_t msz, size_t tsz)
{
  if (keysz(nsz, aec->noncesz) != nsz) return (0);
  if (keysz(tsz, aec->tagsz) != tsz) return (0);
  if (hsz && (aec->f&AEADF_NOAAD)) return (0);
  return (1);
}

/* --- @gaead_encrypt@ --- *
 *
 * Arguments:	@const gaead_key *k@ = the AEAD key, already prepared
 *		@const void *n@, @size_t nsz@ = nonce
 *		@const void *h@, @size_t hsz@ = additional `header' data
 *		@const void *m@, @size_t msz@ = message input
 *		@void *c@, @size_t *csz_input@ = ciphertext output
 *		@void *t@, @size_t tsz@ = tag output
 *
 * Returns:	Zero on success, @-1@ if the output buffer is too small.
 *
 * Use:		Encrypts and authenticates a message in a single operation.
 *		This just saves a bunch of messing about with the various
 *		@gaead_...@ objects.
 *
 *		On entry, @*csz_inout@ should be the capacity of the
 *		ciphertext buffer; on exit, it will be updated with the
 *		actual size of ciphertext produced.  The function will not
 *		fail if @*csz_inout >= msz + k->c->ohd@.
 */

int gaead_encrypt(const gaead_key *k, const void *n, size_t nsz,
		  const void *h, size_t hsz,
		  const void *m, size_t msz,
		  void *c, size_t *csz_inout,
		  void *t, size_t tsz)
{
  gaead_enc *e = 0;
  gaead_aad *a = 0;
  buf b;
  int rc;

  buf_init(&b, c, *csz_inout);
  e = GAEAD_ENC(k, n, nsz, hsz, msz, tsz); if (!e) { rc = -1; goto end; }
  if (hsz) { a = GAEAD_AAD(e); GAEAD_HASH(a, h, hsz); }
  rc = GAEAD_ENCRYPT(e, m, msz, &b); if (rc) goto end;
  rc = GAEAD_DONE(e, a, &b, t, tsz);
end:
  if (rc >= 0) *csz_inout = BLEN(&b);
  if (e) GAEAD_DESTROY(e);
  if (a) GAEAD_DESTROY(a);
  return (rc);
}

/* --- @gaead_decrypt@ --- *
 *
 * Arguments:	@const gaead_key *k@ = the AEAD key, already prepared
 *		@const void *n@, @size_t nsz@ = nonce
 *		@const void *h@, @size_t hsz@ = additional `header' data
 *		@const void *c@, @size_t csz@ = ciphertext input
 *		@void *m@, @size_t *msz_inout@ = message output
 *		@const void *t@, @size_t tsz@ = tag input
 *
 * Returns:	@+1@ if everything is good; zero for authentication failure,
 *		@-1@ for other problems.
 *
 * Use:		Decrypts and verifies a message in a single operation.
 *		This just saves a bunch of messing about with the various
 *		@gaead_...@ objects.
 *
 *		On entry, @*msz_inout@ should be the capacity of the
 *		message buffer; on exit, it will be updated with the
 *		actual size of message produced.  The function will not
 *		fail if @*msz_inout >= csz@.
 */

int gaead_decrypt(const gaead_key *k, const void *n, size_t nsz,
		  const void *h, size_t hsz,
		  const void *c, size_t csz,
		  void *m, size_t *msz_inout,
		  const void *t, size_t tsz)
{
  gaead_dec *d = 0;
  gaead_aad *a = 0;
  buf b;
  int rc;

  buf_init(&b, m, *msz_inout);
  d = GAEAD_DEC(k, n, nsz, hsz, csz, tsz); if (!d) { rc = -1; goto end; }
  if (hsz) { a = GAEAD_AAD(d); GAEAD_HASH(a, h, hsz); }
  rc = GAEAD_DECRYPT(d, c, csz, &b); if (rc) goto end;
  rc = GAEAD_DONE(d, a, &b, t, tsz);
end:
  if (rc >= 0) *msz_inout = BLEN(&b);
  if (d) GAEAD_DESTROY(d);
  if (a) GAEAD_DESTROY(a);
  return (rc);
}

/*----- That's all, folks -------------------------------------------------*/