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/* cipher.c - cipher dispatcher
* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003
* 2005, 2007, 2008, 2009, 2011 Free Software Foundation, Inc.
* Copyright (C) 2013 g10 Code GmbH
*
* This file is part of Libgcrypt.
*
* Libgcrypt is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser general Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* Libgcrypt 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "g10lib.h"
#include "../src/gcrypt-testapi.h"
#include "cipher.h"
#include "./cipher-internal.h"
/* This is the list of the default ciphers, which are included in
libgcrypt. */
static gcry_cipher_spec_t * const cipher_list[] =
{
#if USE_BLOWFISH
&_gcry_cipher_spec_blowfish,
#endif
#if USE_DES
&_gcry_cipher_spec_des,
&_gcry_cipher_spec_tripledes,
#endif
#if USE_ARCFOUR
&_gcry_cipher_spec_arcfour,
#endif
#if USE_CAST5
&_gcry_cipher_spec_cast5,
#endif
#if USE_AES
&_gcry_cipher_spec_aes,
&_gcry_cipher_spec_aes192,
&_gcry_cipher_spec_aes256,
#endif
#if USE_TWOFISH
&_gcry_cipher_spec_twofish,
&_gcry_cipher_spec_twofish128,
#endif
#if USE_SERPENT
&_gcry_cipher_spec_serpent128,
&_gcry_cipher_spec_serpent192,
&_gcry_cipher_spec_serpent256,
#endif
#if USE_RFC2268
&_gcry_cipher_spec_rfc2268_40,
&_gcry_cipher_spec_rfc2268_128,
#endif
#if USE_SEED
&_gcry_cipher_spec_seed,
#endif
#if USE_CAMELLIA
&_gcry_cipher_spec_camellia128,
&_gcry_cipher_spec_camellia192,
&_gcry_cipher_spec_camellia256,
#endif
#ifdef USE_IDEA
&_gcry_cipher_spec_idea,
#endif
#if USE_SALSA20
&_gcry_cipher_spec_salsa20,
&_gcry_cipher_spec_salsa20r12,
#endif
#if USE_GOST28147
&_gcry_cipher_spec_gost28147,
&_gcry_cipher_spec_gost28147_mesh,
#endif
#if USE_CHACHA20
&_gcry_cipher_spec_chacha20,
#endif
#if USE_SM4
&_gcry_cipher_spec_sm4,
#endif
NULL
};
/* Cipher implementations starting with index 0 (enum gcry_cipher_algos) */
static gcry_cipher_spec_t * const cipher_list_algo0[] =
{
NULL, /* GCRY_CIPHER_NONE */
#ifdef USE_IDEA
&_gcry_cipher_spec_idea,
#else
NULL,
#endif
#if USE_DES
&_gcry_cipher_spec_tripledes,
#else
NULL,
#endif
#if USE_CAST5
&_gcry_cipher_spec_cast5,
#else
NULL,
#endif
#if USE_BLOWFISH
&_gcry_cipher_spec_blowfish,
#else
NULL,
#endif
NULL, /* GCRY_CIPHER_SAFER_SK128 */
NULL, /* GCRY_CIPHER_DES_SK */
#if USE_AES
&_gcry_cipher_spec_aes,
&_gcry_cipher_spec_aes192,
&_gcry_cipher_spec_aes256,
#else
NULL,
NULL,
NULL,
#endif
#if USE_TWOFISH
&_gcry_cipher_spec_twofish
#else
NULL
#endif
};
/* Cipher implementations starting with index 301 (enum gcry_cipher_algos) */
static gcry_cipher_spec_t * const cipher_list_algo301[] =
{
#if USE_ARCFOUR
&_gcry_cipher_spec_arcfour,
#else
NULL,
#endif
#if USE_DES
&_gcry_cipher_spec_des,
#else
NULL,
#endif
#if USE_TWOFISH
&_gcry_cipher_spec_twofish128,
#else
NULL,
#endif
#if USE_SERPENT
&_gcry_cipher_spec_serpent128,
&_gcry_cipher_spec_serpent192,
&_gcry_cipher_spec_serpent256,
#else
NULL,
NULL,
NULL,
#endif
#if USE_RFC2268
&_gcry_cipher_spec_rfc2268_40,
&_gcry_cipher_spec_rfc2268_128,
#else
NULL,
NULL,
#endif
#if USE_SEED
&_gcry_cipher_spec_seed,
#else
NULL,
#endif
#if USE_CAMELLIA
&_gcry_cipher_spec_camellia128,
&_gcry_cipher_spec_camellia192,
&_gcry_cipher_spec_camellia256,
#else
NULL,
NULL,
NULL,
#endif
#if USE_SALSA20
&_gcry_cipher_spec_salsa20,
&_gcry_cipher_spec_salsa20r12,
#else
NULL,
NULL,
#endif
#if USE_GOST28147
&_gcry_cipher_spec_gost28147,
#else
NULL,
#endif
#if USE_CHACHA20
&_gcry_cipher_spec_chacha20,
#else
NULL,
#endif
#if USE_GOST28147
&_gcry_cipher_spec_gost28147_mesh,
#else
NULL,
#endif
#if USE_SM4
&_gcry_cipher_spec_sm4,
#else
NULL,
#endif
};
static void _gcry_cipher_setup_mode_ops(gcry_cipher_hd_t c, int mode);
static int
map_algo (int algo)
{
return algo;
}
/* Return the spec structure for the cipher algorithm ALGO. For
an unknown algorithm NULL is returned. */
static gcry_cipher_spec_t *
spec_from_algo (int algo)
{
gcry_cipher_spec_t *spec = NULL;
algo = map_algo (algo);
if (algo >= 0 && algo < DIM(cipher_list_algo0))
spec = cipher_list_algo0[algo];
else if (algo >= 301 && algo < 301 + DIM(cipher_list_algo301))
spec = cipher_list_algo301[algo - 301];
if (spec)
gcry_assert (spec->algo == algo);
return spec;
}
/* Lookup a cipher's spec by its name. */
static gcry_cipher_spec_t *
spec_from_name (const char *name)
{
gcry_cipher_spec_t *spec;
int idx;
const char **aliases;
for (idx=0; (spec = cipher_list[idx]); idx++)
{
if (!stricmp (name, spec->name))
return spec;
if (spec->aliases)
{
for (aliases = spec->aliases; *aliases; aliases++)
if (!stricmp (name, *aliases))
return spec;
}
}
return NULL;
}
/* Lookup a cipher's spec by its OID. */
static gcry_cipher_spec_t *
spec_from_oid (const char *oid)
{
gcry_cipher_spec_t *spec;
gcry_cipher_oid_spec_t *oid_specs;
int idx, j;
for (idx=0; (spec = cipher_list[idx]); idx++)
{
oid_specs = spec->oids;
if (oid_specs)
{
for (j = 0; oid_specs[j].oid; j++)
if (!stricmp (oid, oid_specs[j].oid))
return spec;
}
}
return NULL;
}
/* Locate the OID in the oid table and return the spec or NULL if not
found. An optional "oid." or "OID." prefix in OID is ignored, the
OID is expected to be in standard IETF dotted notation. A pointer
to the OID specification of the module implementing this algorithm
is return in OID_SPEC unless passed as NULL.*/
static gcry_cipher_spec_t *
search_oid (const char *oid, gcry_cipher_oid_spec_t *oid_spec)
{
gcry_cipher_spec_t *spec;
int i;
if (!oid)
return NULL;
if (!strncmp (oid, "oid.", 4) || !strncmp (oid, "OID.", 4))
oid += 4;
spec = spec_from_oid (oid);
if (spec && spec->oids)
{
for (i = 0; spec->oids[i].oid; i++)
if (!stricmp (oid, spec->oids[i].oid))
{
if (oid_spec)
*oid_spec = spec->oids[i];
return spec;
}
}
return NULL;
}
/* Map STRING to the cipher algorithm identifier. Returns the
algorithm ID of the cipher for the given name or 0 if the name is
not known. It is valid to pass NULL for STRING which results in a
return value of 0. */
int
_gcry_cipher_map_name (const char *string)
{
gcry_cipher_spec_t *spec;
if (!string)
return 0;
/* If the string starts with a digit (optionally prefixed with
either "OID." or "oid."), we first look into our table of ASN.1
object identifiers to figure out the algorithm */
spec = search_oid (string, NULL);
if (spec)
return spec->algo;
spec = spec_from_name (string);
if (spec)
return spec->algo;
return 0;
}
/* Given a STRING with an OID in dotted decimal notation, this
function returns the cipher mode (GCRY_CIPHER_MODE_*) associated
with that OID or 0 if no mode is known. Passing NULL for string
yields a return value of 0. */
int
_gcry_cipher_mode_from_oid (const char *string)
{
gcry_cipher_spec_t *spec;
gcry_cipher_oid_spec_t oid_spec;
if (!string)
return 0;
spec = search_oid (string, &oid_spec);
if (spec)
return oid_spec.mode;
return 0;
}
/* Map the cipher algorithm identifier ALGORITHM to a string
representing this algorithm. This string is the default name as
used by Libgcrypt. A "?" is returned for an unknown algorithm.
NULL is never returned. */
const char *
_gcry_cipher_algo_name (int algorithm)
{
gcry_cipher_spec_t *spec;
spec = spec_from_algo (algorithm);
return spec? spec->name : "?";
}
/* Flag the cipher algorithm with the identifier ALGORITHM as
disabled. There is no error return, the function does nothing for
unknown algorithms. Disabled algorithms are virtually not
available in Libgcrypt. This is not thread safe and should thus be
called early. */
static void
disable_cipher_algo (int algo)
{
gcry_cipher_spec_t *spec = spec_from_algo (algo);
if (spec)
spec->flags.disabled = 1;
}
/* Return 0 if the cipher algorithm with identifier ALGORITHM is
available. Returns a basic error code value if it is not
available. */
static gcry_err_code_t
check_cipher_algo (int algorithm)
{
gcry_cipher_spec_t *spec;
spec = spec_from_algo (algorithm);
if (spec && !spec->flags.disabled)
return 0;
return GPG_ERR_CIPHER_ALGO;
}
/* Return the standard length in bits of the key for the cipher
algorithm with the identifier ALGORITHM. */
static unsigned int
cipher_get_keylen (int algorithm)
{
gcry_cipher_spec_t *spec;
unsigned len = 0;
spec = spec_from_algo (algorithm);
if (spec)
{
len = spec->keylen;
if (!len)
log_bug ("cipher %d w/o key length\n", algorithm);
}
return len;
}
/* Return the block length of the cipher algorithm with the identifier
ALGORITHM. This function return 0 for an invalid algorithm. */
static unsigned int
cipher_get_blocksize (int algorithm)
{
gcry_cipher_spec_t *spec;
unsigned len = 0;
spec = spec_from_algo (algorithm);
if (spec)
{
len = spec->blocksize;
if (!len)
log_bug ("cipher %d w/o blocksize\n", algorithm);
}
return len;
}
/*
Open a cipher handle for use with cipher algorithm ALGORITHM, using
the cipher mode MODE (one of the GCRY_CIPHER_MODE_*) and return a
handle in HANDLE. Put NULL into HANDLE and return an error code if
something goes wrong. FLAGS may be used to modify the
operation. The defined flags are:
GCRY_CIPHER_SECURE: allocate all internal buffers in secure memory.
GCRY_CIPHER_ENABLE_SYNC: Enable the sync operation as used in OpenPGP.
GCRY_CIPHER_CBC_CTS: Enable CTS mode.
GCRY_CIPHER_CBC_MAC: Enable MAC mode.
Values for these flags may be combined using OR.
*/
gcry_err_code_t
_gcry_cipher_open (gcry_cipher_hd_t *handle,
int algo, int mode, unsigned int flags)
{
gcry_err_code_t rc;
gcry_cipher_hd_t h = NULL;
if (mode >= GCRY_CIPHER_MODE_INTERNAL)
rc = GPG_ERR_INV_CIPHER_MODE;
else
rc = _gcry_cipher_open_internal (&h, algo, mode, flags);
*handle = rc ? NULL : h;
return rc;
}
gcry_err_code_t
_gcry_cipher_open_internal (gcry_cipher_hd_t *handle,
int algo, int mode, unsigned int flags)
{
int secure = (flags & GCRY_CIPHER_SECURE);
gcry_cipher_spec_t *spec;
gcry_cipher_hd_t h = NULL;
gcry_err_code_t err;
/* If the application missed to call the random poll function, we do
it here to ensure that it is used once in a while. */
_gcry_fast_random_poll ();
spec = spec_from_algo (algo);
if (!spec)
err = GPG_ERR_CIPHER_ALGO;
else if (spec->flags.disabled)
err = GPG_ERR_CIPHER_ALGO;
else
err = 0;
/* check flags */
if ((! err)
&& ((flags & ~(0
| GCRY_CIPHER_SECURE
| GCRY_CIPHER_ENABLE_SYNC
| GCRY_CIPHER_CBC_CTS
| GCRY_CIPHER_CBC_MAC))
|| ((flags & GCRY_CIPHER_CBC_CTS) && (flags & GCRY_CIPHER_CBC_MAC))))
err = GPG_ERR_CIPHER_ALGO;
/* check that a valid mode has been requested */
if (! err)
switch (mode)
{
case GCRY_CIPHER_MODE_CCM:
if (spec->blocksize != GCRY_CCM_BLOCK_LEN)
err = GPG_ERR_INV_CIPHER_MODE;
if (!spec->encrypt || !spec->decrypt)
err = GPG_ERR_INV_CIPHER_MODE;
break;
case GCRY_CIPHER_MODE_XTS:
if (spec->blocksize != GCRY_XTS_BLOCK_LEN)
err = GPG_ERR_INV_CIPHER_MODE;
if (!spec->encrypt || !spec->decrypt)
err = GPG_ERR_INV_CIPHER_MODE;
break;
case GCRY_CIPHER_MODE_ECB:
case GCRY_CIPHER_MODE_CBC:
case GCRY_CIPHER_MODE_CFB:
case GCRY_CIPHER_MODE_CFB8:
case GCRY_CIPHER_MODE_OFB:
case GCRY_CIPHER_MODE_CTR:
case GCRY_CIPHER_MODE_AESWRAP:
case GCRY_CIPHER_MODE_CMAC:
case GCRY_CIPHER_MODE_EAX:
case GCRY_CIPHER_MODE_GCM:
if (!spec->encrypt || !spec->decrypt)
err = GPG_ERR_INV_CIPHER_MODE;
break;
case GCRY_CIPHER_MODE_POLY1305:
if (!spec->stencrypt || !spec->stdecrypt || !spec->setiv)
err = GPG_ERR_INV_CIPHER_MODE;
else if (spec->algo != GCRY_CIPHER_CHACHA20)
err = GPG_ERR_INV_CIPHER_MODE;
break;
case GCRY_CIPHER_MODE_OCB:
/* Note that our implementation allows only for 128 bit block
length algorithms. Lower block lengths would be possible
but we do not implement them because they limit the
security too much. */
if (!spec->encrypt || !spec->decrypt)
err = GPG_ERR_INV_CIPHER_MODE;
else if (spec->blocksize != (128/8))
err = GPG_ERR_INV_CIPHER_MODE;
break;
case GCRY_CIPHER_MODE_STREAM:
if (!spec->stencrypt || !spec->stdecrypt)
err = GPG_ERR_INV_CIPHER_MODE;
break;
case GCRY_CIPHER_MODE_NONE:
/* This mode may be used for debugging. It copies the main
text verbatim to the ciphertext. We do not allow this in
fips mode or if no debug flag has been set. */
if (fips_mode () || !_gcry_get_debug_flag (0))
err = GPG_ERR_INV_CIPHER_MODE;
break;
default:
err = GPG_ERR_INV_CIPHER_MODE;
}
/* Perform selftest here and mark this with a flag in cipher_table?
No, we should not do this as it takes too long. Further it does
not make sense to exclude algorithms with failing selftests at
runtime: If a selftest fails there is something seriously wrong
with the system and thus we better die immediately. */
if (! err)
{
size_t size = (sizeof (*h)
+ 2 * spec->contextsize
- sizeof (cipher_context_alignment_t)
#ifdef NEED_16BYTE_ALIGNED_CONTEXT
+ 15 /* Space for leading alignment gap. */
#endif /*NEED_16BYTE_ALIGNED_CONTEXT*/
);
/* Space needed per mode. */
switch (mode)
{
case GCRY_CIPHER_MODE_XTS:
/* Additional cipher context for tweak. */
size += 2 * spec->contextsize + 15;
break;
default:
break;
}
if (secure)
h = xtrycalloc_secure (1, size);
else
h = xtrycalloc (1, size);
if (! h)
err = gpg_err_code_from_syserror ();
else
{
size_t off = 0;
char *tc;
#ifdef NEED_16BYTE_ALIGNED_CONTEXT
if ( ((uintptr_t)h & 0x0f) )
{
/* The malloced block is not aligned on a 16 byte
boundary. Correct for this. */
off = 16 - ((uintptr_t)h & 0x0f);
h = (void*)((char*)h + off);
}
#endif /*NEED_16BYTE_ALIGNED_CONTEXT*/
h->magic = secure ? CTX_MAGIC_SECURE : CTX_MAGIC_NORMAL;
h->actual_handle_size = size - off;
h->handle_offset = off;
h->spec = spec;
h->algo = algo;
h->mode = mode;
h->flags = flags;
/* Setup bulk encryption routines. */
switch (algo)
{
#ifdef USE_AES
case GCRY_CIPHER_AES128:
case GCRY_CIPHER_AES192:
case GCRY_CIPHER_AES256:
h->bulk.cfb_enc = _gcry_aes_cfb_enc;
h->bulk.cfb_dec = _gcry_aes_cfb_dec;
h->bulk.cbc_enc = _gcry_aes_cbc_enc;
h->bulk.cbc_dec = _gcry_aes_cbc_dec;
h->bulk.ctr_enc = _gcry_aes_ctr_enc;
h->bulk.ocb_crypt = _gcry_aes_ocb_crypt;
h->bulk.ocb_auth = _gcry_aes_ocb_auth;
h->bulk.xts_crypt = _gcry_aes_xts_crypt;
break;
#endif /*USE_AES*/
#ifdef USE_BLOWFISH
case GCRY_CIPHER_BLOWFISH:
h->bulk.cfb_dec = _gcry_blowfish_cfb_dec;
h->bulk.cbc_dec = _gcry_blowfish_cbc_dec;
h->bulk.ctr_enc = _gcry_blowfish_ctr_enc;
break;
#endif /*USE_BLOWFISH*/
#ifdef USE_CAST5
case GCRY_CIPHER_CAST5:
h->bulk.cfb_dec = _gcry_cast5_cfb_dec;
h->bulk.cbc_dec = _gcry_cast5_cbc_dec;
h->bulk.ctr_enc = _gcry_cast5_ctr_enc;
break;
#endif /*USE_CAMELLIA*/
#ifdef USE_CAMELLIA
case GCRY_CIPHER_CAMELLIA128:
case GCRY_CIPHER_CAMELLIA192:
case GCRY_CIPHER_CAMELLIA256:
h->bulk.cbc_dec = _gcry_camellia_cbc_dec;
h->bulk.cfb_dec = _gcry_camellia_cfb_dec;
h->bulk.ctr_enc = _gcry_camellia_ctr_enc;
h->bulk.ocb_crypt = _gcry_camellia_ocb_crypt;
h->bulk.ocb_auth = _gcry_camellia_ocb_auth;
break;
#endif /*USE_CAMELLIA*/
#ifdef USE_DES
case GCRY_CIPHER_3DES:
h->bulk.cbc_dec = _gcry_3des_cbc_dec;
h->bulk.cfb_dec = _gcry_3des_cfb_dec;
h->bulk.ctr_enc = _gcry_3des_ctr_enc;
break;
#endif /*USE_DES*/
#ifdef USE_SERPENT
case GCRY_CIPHER_SERPENT128:
case GCRY_CIPHER_SERPENT192:
case GCRY_CIPHER_SERPENT256:
h->bulk.cbc_dec = _gcry_serpent_cbc_dec;
h->bulk.cfb_dec = _gcry_serpent_cfb_dec;
h->bulk.ctr_enc = _gcry_serpent_ctr_enc;
h->bulk.ocb_crypt = _gcry_serpent_ocb_crypt;
h->bulk.ocb_auth = _gcry_serpent_ocb_auth;
break;
#endif /*USE_SERPENT*/
#ifdef USE_SM4
case GCRY_CIPHER_SM4:
h->bulk.cbc_dec = _gcry_sm4_cbc_dec;
h->bulk.cfb_dec = _gcry_sm4_cfb_dec;
h->bulk.ctr_enc = _gcry_sm4_ctr_enc;
h->bulk.ocb_crypt = _gcry_sm4_ocb_crypt;
h->bulk.ocb_auth = _gcry_sm4_ocb_auth;
break;
#endif /*USE_SM4*/
#ifdef USE_TWOFISH
case GCRY_CIPHER_TWOFISH:
case GCRY_CIPHER_TWOFISH128:
h->bulk.cbc_dec = _gcry_twofish_cbc_dec;
h->bulk.cfb_dec = _gcry_twofish_cfb_dec;
h->bulk.ctr_enc = _gcry_twofish_ctr_enc;
h->bulk.ocb_crypt = _gcry_twofish_ocb_crypt;
h->bulk.ocb_auth = _gcry_twofish_ocb_auth;
break;
#endif /*USE_TWOFISH*/
default:
break;
}
/* Setup mode routines. */
_gcry_cipher_setup_mode_ops(h, mode);
/* Setup defaults depending on the mode. */
switch (mode)
{
case GCRY_CIPHER_MODE_OCB:
h->u_mode.ocb.taglen = 16; /* Bytes. */
break;
case GCRY_CIPHER_MODE_XTS:
tc = h->context.c + spec->contextsize * 2;
tc += (16 - (uintptr_t)tc % 16) % 16;
h->u_mode.xts.tweak_context = tc;
break;
default:
break;
}
}
}
/* Done. */
*handle = err ? NULL : h;
return err;
}
/* Release all resources associated with the cipher handle H. H may be
NULL in which case this is a no-operation. */
void
_gcry_cipher_close (gcry_cipher_hd_t h)
{
size_t off;
if (!h)
return;
if ((h->magic != CTX_MAGIC_SECURE)
&& (h->magic != CTX_MAGIC_NORMAL))
_gcry_fatal_error(GPG_ERR_INTERNAL,
"gcry_cipher_close: already closed/invalid handle");
else
h->magic = 0;
/* We always want to wipe out the memory even when the context has
been allocated in secure memory. The user might have disabled
secure memory or is using his own implementation which does not
do the wiping. To accomplish this we need to keep track of the
actual size of this structure because we have no way to known
how large the allocated area was when using a standard malloc. */
off = h->handle_offset;
wipememory (h, h->actual_handle_size);
xfree ((char*)h - off);
}
/* Set the key to be used for the encryption context C to KEY with
length KEYLEN. The length should match the required length. */
static gcry_err_code_t
cipher_setkey (gcry_cipher_hd_t c, byte *key, size_t keylen)
{
gcry_err_code_t rc;
if (c->mode == GCRY_CIPHER_MODE_XTS)
{
/* XTS uses two keys. */
if (keylen % 2)
return GPG_ERR_INV_KEYLEN;
keylen /= 2;
if (fips_mode ())
{
/* Reject key if subkeys Key_1 and Key_2 are equal.
See "Implementation Guidance for FIPS 140-2, A.9 XTS-AES
Key Generation Requirements" for details. */
if (buf_eq_const (key, key + keylen, keylen))
return GPG_ERR_WEAK_KEY;
}
}
rc = c->spec->setkey (&c->context.c, key, keylen, c);
if (!rc || (c->marks.allow_weak_key && rc == GPG_ERR_WEAK_KEY))
{
/* Duplicate initial context. */
memcpy ((void *) ((char *) &c->context.c + c->spec->contextsize),
(void *) &c->context.c,
c->spec->contextsize);
c->marks.key = 1;
switch (c->mode)
{
case GCRY_CIPHER_MODE_CMAC:
rc = _gcry_cipher_cmac_set_subkeys (c);
break;
case GCRY_CIPHER_MODE_EAX:
rc = _gcry_cipher_eax_setkey (c);
break;
case GCRY_CIPHER_MODE_GCM:
_gcry_cipher_gcm_setkey (c);
break;
case GCRY_CIPHER_MODE_OCB:
_gcry_cipher_ocb_setkey (c);
break;
case GCRY_CIPHER_MODE_POLY1305:
_gcry_cipher_poly1305_setkey (c);
break;
case GCRY_CIPHER_MODE_XTS:
/* Setup tweak cipher with second part of XTS key. */
rc = c->spec->setkey (c->u_mode.xts.tweak_context, key + keylen,
keylen, c);
if (!rc || (c->marks.allow_weak_key && rc == GPG_ERR_WEAK_KEY))
{
/* Duplicate initial tweak context. */
memcpy (c->u_mode.xts.tweak_context + c->spec->contextsize,
c->u_mode.xts.tweak_context, c->spec->contextsize);
}
else
c->marks.key = 0;
break;
default:
break;
};
}
else
c->marks.key = 0;
return rc;
}
/* Set the IV to be used for the encryption context C to IV with
length IVLEN. The length should match the required length. */
static gcry_err_code_t
cipher_setiv (gcry_cipher_hd_t c, const byte *iv, size_t ivlen)
{
/* If the cipher has its own IV handler, we use only this one. This
is currently used for stream ciphers requiring a nonce. */
if (c->spec->setiv)
{
c->spec->setiv (&c->context.c, iv, ivlen);
return 0;
}
memset (c->u_iv.iv, 0, c->spec->blocksize);
if (iv)
{
if (ivlen != c->spec->blocksize)
{
log_info ("WARNING: cipher_setiv: ivlen=%u blklen=%u\n",
(unsigned int)ivlen, (unsigned int)c->spec->blocksize);
fips_signal_error ("IV length does not match blocklength");
}
if (ivlen > c->spec->blocksize)
ivlen = c->spec->blocksize;
memcpy (c->u_iv.iv, iv, ivlen);
c->marks.iv = 1;
}
else
c->marks.iv = 0;
c->unused = 0;
return 0;
}
/* Reset the cipher context to the initial context. This is basically
the same as an release followed by a new. */
static void
cipher_reset (gcry_cipher_hd_t c)
{
unsigned int marks_key, marks_allow_weak_key;
marks_key = c->marks.key;
marks_allow_weak_key = c->marks.allow_weak_key;
memcpy (&c->context.c,
(char *) &c->context.c + c->spec->contextsize,
c->spec->contextsize);
memset (&c->marks, 0, sizeof c->marks);
memset (c->u_iv.iv, 0, c->spec->blocksize);
memset (c->lastiv, 0, c->spec->blocksize);
memset (c->u_ctr.ctr, 0, c->spec->blocksize);
c->unused = 0;
c->marks.key = marks_key;
c->marks.allow_weak_key = marks_allow_weak_key;
switch (c->mode)
{
case GCRY_CIPHER_MODE_CMAC:
_gcry_cmac_reset(&c->u_mode.cmac);
break;
case GCRY_CIPHER_MODE_EAX:
_gcry_cmac_reset(&c->u_mode.eax.cmac_header);
_gcry_cmac_reset(&c->u_mode.eax.cmac_ciphertext);
break;
case GCRY_CIPHER_MODE_GCM:
/* Only clear head of u_mode, keep ghash_key and gcm_table. */
{
byte *u_mode_pos = (void *)&c->u_mode;
byte *ghash_key_pos = c->u_mode.gcm.u_ghash_key.key;
size_t u_mode_head_length = ghash_key_pos - u_mode_pos;
memset (&c->u_mode, 0, u_mode_head_length);
}
break;
case GCRY_CIPHER_MODE_POLY1305:
memset (&c->u_mode.poly1305, 0, sizeof c->u_mode.poly1305);
break;
case GCRY_CIPHER_MODE_CCM:
memset (&c->u_mode.ccm, 0, sizeof c->u_mode.ccm);
break;
case GCRY_CIPHER_MODE_OCB:
/* Do not clear precalculated L-values */
{
byte *u_mode_head_pos = (void *)&c->u_mode.ocb;
byte *u_mode_tail_pos = (void *)&c->u_mode.ocb.tag;
size_t u_mode_head_length = u_mode_tail_pos - u_mode_head_pos;
size_t u_mode_tail_length = sizeof(c->u_mode.ocb) - u_mode_head_length;
memset (u_mode_tail_pos, 0, u_mode_tail_length);
/* Setup default taglen. */
c->u_mode.ocb.taglen = 16;
}
break;
case GCRY_CIPHER_MODE_XTS:
memcpy (c->u_mode.xts.tweak_context,
c->u_mode.xts.tweak_context + c->spec->contextsize,
c->spec->contextsize);
break;
default:
break; /* u_mode unused by other modes. */
}
}
static gcry_err_code_t
do_ecb_crypt (gcry_cipher_hd_t c,
unsigned char *outbuf, size_t outbuflen,
const unsigned char *inbuf, size_t inbuflen,
gcry_cipher_encrypt_t crypt_fn)
{
unsigned int blocksize = c->spec->blocksize;
size_t n, nblocks;
unsigned int burn, nburn;
if (outbuflen < inbuflen)
return GPG_ERR_BUFFER_TOO_SHORT;
if ((inbuflen % blocksize))
return GPG_ERR_INV_LENGTH;
nblocks = inbuflen / blocksize;
burn = 0;
for (n=0; n < nblocks; n++ )
{
nburn = crypt_fn (&c->context.c, outbuf, inbuf);
burn = nburn > burn ? nburn : burn;
inbuf += blocksize;
outbuf += blocksize;
}
if (burn > 0)
_gcry_burn_stack (burn + 4 * sizeof(void *));
return 0;
}
static gcry_err_code_t
do_ecb_encrypt (gcry_cipher_hd_t c,
unsigned char *outbuf, size_t outbuflen,
const unsigned char *inbuf, size_t inbuflen)
{
return do_ecb_crypt (c, outbuf, outbuflen, inbuf, inbuflen, c->spec->encrypt);
}
static gcry_err_code_t
do_ecb_decrypt (gcry_cipher_hd_t c,
unsigned char *outbuf, size_t outbuflen,
const unsigned char *inbuf, size_t inbuflen)
{
return do_ecb_crypt (c, outbuf, outbuflen, inbuf, inbuflen, c->spec->decrypt);
}
static gcry_err_code_t
do_stream_encrypt (gcry_cipher_hd_t c,
unsigned char *outbuf, size_t outbuflen,
const unsigned char *inbuf, size_t inbuflen)
{
(void)outbuflen;
c->spec->stencrypt (&c->context.c, outbuf, (void *)inbuf, inbuflen);
return 0;
}
static gcry_err_code_t
do_stream_decrypt (gcry_cipher_hd_t c,
unsigned char *outbuf, size_t outbuflen,
const unsigned char *inbuf, size_t inbuflen)
{
(void)outbuflen;
c->spec->stdecrypt (&c->context.c, outbuf, (void *)inbuf, inbuflen);
return 0;
}
static gcry_err_code_t
do_encrypt_none_unknown (gcry_cipher_hd_t c, byte *outbuf, size_t outbuflen,
const byte *inbuf, size_t inbuflen)
{
gcry_err_code_t rc;
(void)outbuflen;
switch (c->mode)
{
case GCRY_CIPHER_MODE_CMAC:
rc = GPG_ERR_INV_CIPHER_MODE;
break;
case GCRY_CIPHER_MODE_NONE:
if (fips_mode () || !_gcry_get_debug_flag (0))
{
fips_signal_error ("cipher mode NONE used");
rc = GPG_ERR_INV_CIPHER_MODE;
}
else
{
if (inbuf != outbuf)
memmove (outbuf, inbuf, inbuflen);
rc = 0;
}
break;
default:
log_fatal ("cipher_encrypt: invalid mode %d\n", c->mode );
rc = GPG_ERR_INV_CIPHER_MODE;
break;
}
return rc;
}
static gcry_err_code_t
do_decrypt_none_unknown (gcry_cipher_hd_t c, byte *outbuf, size_t outbuflen,
const byte *inbuf, size_t inbuflen)
{
gcry_err_code_t rc;
(void)outbuflen;
switch (c->mode)
{
case GCRY_CIPHER_MODE_CMAC:
rc = GPG_ERR_INV_CIPHER_MODE;
break;
case GCRY_CIPHER_MODE_NONE:
if (fips_mode () || !_gcry_get_debug_flag (0))
{
fips_signal_error ("cipher mode NONE used");
rc = GPG_ERR_INV_CIPHER_MODE;
}
else
{
if (inbuf != outbuf)
memmove (outbuf, inbuf, inbuflen);
rc = 0;
}
break;
default:
log_fatal ("cipher_decrypt: invalid mode %d\n", c->mode );
rc = GPG_ERR_INV_CIPHER_MODE;
break;
}
return rc;
}
/****************
* Encrypt IN and write it to OUT. If IN is NULL, in-place encryption has
* been requested.
*/
gcry_err_code_t
_gcry_cipher_encrypt (gcry_cipher_hd_t h, void *out, size_t outsize,
const void *in, size_t inlen)
{
gcry_err_code_t rc;
if (!in) /* Caller requested in-place encryption. */
{
in = out;
inlen = outsize;
}
if (h->mode != GCRY_CIPHER_MODE_NONE && !h->marks.key)
{
log_error ("cipher_encrypt: key not set\n");
return GPG_ERR_MISSING_KEY;
}
rc = h->mode_ops.encrypt (h, out, outsize, in, inlen);
/* Failsafe: Make sure that the plaintext will never make it into
OUT if the encryption returned an error. */
if (rc && out)
memset (out, 0x42, outsize);
return rc;
}
/****************
* Decrypt IN and write it to OUT. If IN is NULL, in-place encryption has
* been requested.
*/
gcry_err_code_t
_gcry_cipher_decrypt (gcry_cipher_hd_t h, void *out, size_t outsize,
const void *in, size_t inlen)
{
if (!in) /* Caller requested in-place encryption. */
{
in = out;
inlen = outsize;
}
if (h->mode != GCRY_CIPHER_MODE_NONE && !h->marks.key)
{
log_error ("cipher_decrypt: key not set\n");
return GPG_ERR_MISSING_KEY;
}
return h->mode_ops.decrypt (h, out, outsize, in, inlen);
}
/****************
* Used for PGP's somewhat strange CFB mode. Only works if
* the corresponding flag is set.
*/
static void
cipher_sync (gcry_cipher_hd_t c)
{
if ((c->flags & GCRY_CIPHER_ENABLE_SYNC) && c->unused)
{
memmove (c->u_iv.iv + c->unused,
c->u_iv.iv, c->spec->blocksize - c->unused);
memcpy (c->u_iv.iv,
c->lastiv + c->spec->blocksize - c->unused, c->unused);
c->unused = 0;
}
}
gcry_err_code_t
_gcry_cipher_setkey (gcry_cipher_hd_t hd, const void *key, size_t keylen)
{
return cipher_setkey (hd, (void*)key, keylen);
}
gcry_err_code_t
_gcry_cipher_setiv (gcry_cipher_hd_t hd, const void *iv, size_t ivlen)
{
return hd->mode_ops.setiv (hd, iv, ivlen);
}
/* Set counter for CTR mode. (CTR,CTRLEN) must denote a buffer of
block size length, or (NULL,0) to set the CTR to the all-zero
block. */
gpg_err_code_t
_gcry_cipher_setctr (gcry_cipher_hd_t hd, const void *ctr, size_t ctrlen)
{
if (ctr && ctrlen == hd->spec->blocksize)
{
memcpy (hd->u_ctr.ctr, ctr, hd->spec->blocksize);
hd->unused = 0;
}
else if (!ctr || !ctrlen)
{
memset (hd->u_ctr.ctr, 0, hd->spec->blocksize);
hd->unused = 0;
}
else
return GPG_ERR_INV_ARG;
return 0;
}
gpg_err_code_t
_gcry_cipher_getctr (gcry_cipher_hd_t hd, void *ctr, size_t ctrlen)
{
if (ctr && ctrlen == hd->spec->blocksize)
memcpy (ctr, hd->u_ctr.ctr, hd->spec->blocksize);
else
return GPG_ERR_INV_ARG;
return 0;
}
gcry_err_code_t
_gcry_cipher_authenticate (gcry_cipher_hd_t hd, const void *abuf,
size_t abuflen)
{
gcry_err_code_t rc;
if (hd->mode_ops.authenticate)
{
rc = hd->mode_ops.authenticate (hd, abuf, abuflen);
}
else
{
log_error ("gcry_cipher_authenticate: invalid mode %d\n", hd->mode);
rc = GPG_ERR_INV_CIPHER_MODE;
}
return rc;
}
gcry_err_code_t
_gcry_cipher_gettag (gcry_cipher_hd_t hd, void *outtag, size_t taglen)
{
gcry_err_code_t rc;
if (hd->mode_ops.get_tag)
{
rc = hd->mode_ops.get_tag (hd, outtag, taglen);
}
else
{
log_error ("gcry_cipher_gettag: invalid mode %d\n", hd->mode);
rc = GPG_ERR_INV_CIPHER_MODE;
}
return rc;
}
gcry_err_code_t
_gcry_cipher_checktag (gcry_cipher_hd_t hd, const void *intag, size_t taglen)
{
gcry_err_code_t rc;
if (hd->mode_ops.check_tag)
{
rc = hd->mode_ops.check_tag (hd, intag, taglen);
}
else
{
log_error ("gcry_cipher_checktag: invalid mode %d\n", hd->mode);
rc = GPG_ERR_INV_CIPHER_MODE;
}
return rc;
}
static void
_gcry_cipher_setup_mode_ops(gcry_cipher_hd_t c, int mode)
{
/* Setup encryption and decryption routines. */
switch (mode)
{
case GCRY_CIPHER_MODE_STREAM:
c->mode_ops.encrypt = do_stream_encrypt;
c->mode_ops.decrypt = do_stream_decrypt;
break;
case GCRY_CIPHER_MODE_ECB:
c->mode_ops.encrypt = do_ecb_encrypt;
c->mode_ops.decrypt = do_ecb_decrypt;
break;
case GCRY_CIPHER_MODE_CBC:
if (!(c->flags & GCRY_CIPHER_CBC_CTS))
{
c->mode_ops.encrypt = _gcry_cipher_cbc_encrypt;
c->mode_ops.decrypt = _gcry_cipher_cbc_decrypt;
}
else
{
c->mode_ops.encrypt = _gcry_cipher_cbc_cts_encrypt;
c->mode_ops.decrypt = _gcry_cipher_cbc_cts_decrypt;
}
break;
case GCRY_CIPHER_MODE_CFB:
c->mode_ops.encrypt = _gcry_cipher_cfb_encrypt;
c->mode_ops.decrypt = _gcry_cipher_cfb_decrypt;
break;
case GCRY_CIPHER_MODE_CFB8:
c->mode_ops.encrypt = _gcry_cipher_cfb8_encrypt;
c->mode_ops.decrypt = _gcry_cipher_cfb8_decrypt;
break;
case GCRY_CIPHER_MODE_OFB:
c->mode_ops.encrypt = _gcry_cipher_ofb_encrypt;
c->mode_ops.decrypt = _gcry_cipher_ofb_encrypt;
break;
case GCRY_CIPHER_MODE_CTR:
c->mode_ops.encrypt = _gcry_cipher_ctr_encrypt;
c->mode_ops.decrypt = _gcry_cipher_ctr_encrypt;
break;
case GCRY_CIPHER_MODE_AESWRAP:
c->mode_ops.encrypt = _gcry_cipher_aeswrap_encrypt;
c->mode_ops.decrypt = _gcry_cipher_aeswrap_decrypt;
break;
case GCRY_CIPHER_MODE_CCM:
c->mode_ops.encrypt = _gcry_cipher_ccm_encrypt;
c->mode_ops.decrypt = _gcry_cipher_ccm_decrypt;
break;
case GCRY_CIPHER_MODE_EAX:
c->mode_ops.encrypt = _gcry_cipher_eax_encrypt;
c->mode_ops.decrypt = _gcry_cipher_eax_decrypt;
break;
case GCRY_CIPHER_MODE_GCM:
c->mode_ops.encrypt = _gcry_cipher_gcm_encrypt;
c->mode_ops.decrypt = _gcry_cipher_gcm_decrypt;
break;
case GCRY_CIPHER_MODE_POLY1305:
c->mode_ops.encrypt = _gcry_cipher_poly1305_encrypt;
c->mode_ops.decrypt = _gcry_cipher_poly1305_decrypt;
break;
case GCRY_CIPHER_MODE_OCB:
c->mode_ops.encrypt = _gcry_cipher_ocb_encrypt;
c->mode_ops.decrypt = _gcry_cipher_ocb_decrypt;
break;
case GCRY_CIPHER_MODE_XTS:
c->mode_ops.encrypt = _gcry_cipher_xts_encrypt;
c->mode_ops.decrypt = _gcry_cipher_xts_decrypt;
break;
default:
c->mode_ops.encrypt = do_encrypt_none_unknown;
c->mode_ops.decrypt = do_decrypt_none_unknown;
break;
}
/* Setup IV setting routine. */
switch (mode)
{
case GCRY_CIPHER_MODE_CCM:
c->mode_ops.setiv = _gcry_cipher_ccm_set_nonce;
break;
case GCRY_CIPHER_MODE_EAX:
c->mode_ops.setiv = _gcry_cipher_eax_set_nonce;
break;
case GCRY_CIPHER_MODE_GCM:
c->mode_ops.setiv = _gcry_cipher_gcm_setiv;
break;
case GCRY_CIPHER_MODE_POLY1305:
c->mode_ops.setiv = _gcry_cipher_poly1305_setiv;
break;
case GCRY_CIPHER_MODE_OCB:
c->mode_ops.setiv = _gcry_cipher_ocb_set_nonce;
break;
default:
c->mode_ops.setiv = cipher_setiv;
break;
}
/* Setup authentication routines for AEAD modes. */
switch (mode)
{
case GCRY_CIPHER_MODE_CCM:
c->mode_ops.authenticate = _gcry_cipher_ccm_authenticate;
c->mode_ops.get_tag = _gcry_cipher_ccm_get_tag;
c->mode_ops.check_tag = _gcry_cipher_ccm_check_tag;
break;
case GCRY_CIPHER_MODE_CMAC:
c->mode_ops.authenticate = _gcry_cipher_cmac_authenticate;
c->mode_ops.get_tag = _gcry_cipher_cmac_get_tag;
c->mode_ops.check_tag = _gcry_cipher_cmac_check_tag;
break;
case GCRY_CIPHER_MODE_EAX:
c->mode_ops.authenticate = _gcry_cipher_eax_authenticate;
c->mode_ops.get_tag = _gcry_cipher_eax_get_tag;
c->mode_ops.check_tag = _gcry_cipher_eax_check_tag;
break;
case GCRY_CIPHER_MODE_GCM:
c->mode_ops.authenticate = _gcry_cipher_gcm_authenticate;
c->mode_ops.get_tag = _gcry_cipher_gcm_get_tag;
c->mode_ops.check_tag = _gcry_cipher_gcm_check_tag;
break;
case GCRY_CIPHER_MODE_POLY1305:
c->mode_ops.authenticate = _gcry_cipher_poly1305_authenticate;
c->mode_ops.get_tag = _gcry_cipher_poly1305_get_tag;
c->mode_ops.check_tag = _gcry_cipher_poly1305_check_tag;
break;
case GCRY_CIPHER_MODE_OCB:
c->mode_ops.authenticate = _gcry_cipher_ocb_authenticate;
c->mode_ops.get_tag = _gcry_cipher_ocb_get_tag;
c->mode_ops.check_tag = _gcry_cipher_ocb_check_tag;
break;
default:
c->mode_ops.authenticate = NULL;
c->mode_ops.get_tag = NULL;
c->mode_ops.check_tag = NULL;
break;
}
}
gcry_err_code_t
_gcry_cipher_ctl (gcry_cipher_hd_t h, int cmd, void *buffer, size_t buflen)
{
gcry_err_code_t rc = 0;
switch (cmd)
{
case GCRYCTL_RESET:
cipher_reset (h);
break;
case GCRYCTL_FINALIZE:
if (!h || buffer || buflen)
return GPG_ERR_INV_ARG;
h->marks.finalize = 1;
break;
case GCRYCTL_CFB_SYNC:
cipher_sync( h );
break;
case GCRYCTL_SET_CBC_CTS:
if (buflen)
if (h->flags & GCRY_CIPHER_CBC_MAC)
rc = GPG_ERR_INV_FLAG;
else
h->flags |= GCRY_CIPHER_CBC_CTS;
else
h->flags &= ~GCRY_CIPHER_CBC_CTS;
break;
case GCRYCTL_SET_CBC_MAC:
if (buflen)
if (h->flags & GCRY_CIPHER_CBC_CTS)
rc = GPG_ERR_INV_FLAG;
else
h->flags |= GCRY_CIPHER_CBC_MAC;
else
h->flags &= ~GCRY_CIPHER_CBC_MAC;
break;
case GCRYCTL_SET_CCM_LENGTHS:
{
u64 params[3];
size_t encryptedlen;
size_t aadlen;
size_t authtaglen;
if (h->mode != GCRY_CIPHER_MODE_CCM)
return GPG_ERR_INV_CIPHER_MODE;
if (!buffer || buflen != 3 * sizeof(u64))
return GPG_ERR_INV_ARG;
/* This command is used to pass additional length parameters needed
by CCM mode to initialize CBC-MAC. */
memcpy (params, buffer, sizeof(params));
encryptedlen = params[0];
aadlen = params[1];
authtaglen = params[2];
rc = _gcry_cipher_ccm_set_lengths (h, encryptedlen, aadlen, authtaglen);
}
break;
case GCRYCTL_SET_TAGLEN:
if (!h || !buffer || buflen != sizeof(int) )
return GPG_ERR_INV_ARG;
switch (h->mode)
{
case GCRY_CIPHER_MODE_OCB:
switch (*(int*)buffer)
{
case 8: case 12: case 16:
h->u_mode.ocb.taglen = *(int*)buffer;
break;
default:
rc = GPG_ERR_INV_LENGTH; /* Invalid tag length. */
break;
}
break;
default:
rc =GPG_ERR_INV_CIPHER_MODE;
break;
}
break;
case GCRYCTL_DISABLE_ALGO:
/* This command expects NULL for H and BUFFER to point to an
integer with the algo number. */
if( h || !buffer || buflen != sizeof(int) )
return GPG_ERR_CIPHER_ALGO;
disable_cipher_algo( *(int*)buffer );
break;
case PRIV_CIPHERCTL_DISABLE_WEAK_KEY: /* (private) */
if (h->spec->set_extra_info)
rc = h->spec->set_extra_info
(&h->context.c, CIPHER_INFO_NO_WEAK_KEY, NULL, 0);
else
rc = GPG_ERR_NOT_SUPPORTED;
break;
case PRIV_CIPHERCTL_GET_INPUT_VECTOR: /* (private) */
/* This is the input block as used in CFB and OFB mode which has
initially been set as IV. The returned format is:
1 byte Actual length of the block in bytes.
n byte The block.
If the provided buffer is too short, an error is returned. */
if (buflen < (1 + h->spec->blocksize))
rc = GPG_ERR_TOO_SHORT;
else
{
unsigned char *ivp;
unsigned char *dst = buffer;
int n = h->unused;
if (!n)
n = h->spec->blocksize;
gcry_assert (n <= h->spec->blocksize);
*dst++ = n;
ivp = h->u_iv.iv + h->spec->blocksize - n;
while (n--)
*dst++ = *ivp++;
}
break;
case GCRYCTL_SET_SBOX:
if (h->spec->set_extra_info)
rc = h->spec->set_extra_info
(&h->context.c, GCRYCTL_SET_SBOX, buffer, buflen);
else
rc = GPG_ERR_NOT_SUPPORTED;
break;
case GCRYCTL_SET_ALLOW_WEAK_KEY:
/* Expecting BUFFER to be NULL and buflen to be on/off flag (0 or 1). */
if (!h || buffer || buflen > 1)
return GPG_ERR_CIPHER_ALGO;
h->marks.allow_weak_key = buflen ? 1 : 0;
break;
default:
rc = GPG_ERR_INV_OP;
}
return rc;
}
/* Return information about the cipher handle H. CMD is the kind of
* information requested.
*
* CMD may be one of:
*
* GCRYCTL_GET_TAGLEN:
* Return the length of the tag for an AE algorithm mode. An
* error is returned for modes which do not support a tag.
* BUFFER must be given as NULL. On success the result is stored
* at NBYTES. The taglen is returned in bytes.
*
* The function returns 0 on success or an error code.
*/
gcry_err_code_t
_gcry_cipher_info (gcry_cipher_hd_t h, int cmd, void *buffer, size_t *nbytes)
{
gcry_err_code_t rc = 0;
switch (cmd)
{
case GCRYCTL_GET_TAGLEN:
if (!h || buffer || !nbytes)
rc = GPG_ERR_INV_ARG;
else
{
switch (h->mode)
{
case GCRY_CIPHER_MODE_OCB:
*nbytes = h->u_mode.ocb.taglen;
break;
case GCRY_CIPHER_MODE_CCM:
*nbytes = h->u_mode.ccm.authlen;
break;
case GCRY_CIPHER_MODE_EAX:
*nbytes = h->spec->blocksize;
break;
case GCRY_CIPHER_MODE_GCM:
*nbytes = GCRY_GCM_BLOCK_LEN;
break;
case GCRY_CIPHER_MODE_POLY1305:
*nbytes = POLY1305_TAGLEN;
break;
default:
rc = GPG_ERR_INV_CIPHER_MODE;
break;
}
}
break;
default:
rc = GPG_ERR_INV_OP;
}
return rc;
}
/* Return information about the given cipher algorithm ALGO.
WHAT select the kind of information returned:
GCRYCTL_GET_KEYLEN:
Return the length of the key. If the algorithm ALGO
supports multiple key lengths, the maximum supported key length
is returned. The key length is returned as number of octets.
BUFFER and NBYTES must be zero.
GCRYCTL_GET_BLKLEN:
Return the blocklength of the algorithm ALGO counted in octets.
BUFFER and NBYTES must be zero.
GCRYCTL_TEST_ALGO:
Returns 0 if the specified algorithm ALGO is available for use.
BUFFER and NBYTES must be zero.
Note: Because this function is in most cases used to return an
integer value, we can make it easier for the caller to just look at
the return value. The caller will in all cases consult the value
and thereby detecting whether a error occurred or not (i.e. while
checking the block size)
*/
gcry_err_code_t
_gcry_cipher_algo_info (int algo, int what, void *buffer, size_t *nbytes)
{
gcry_err_code_t rc = 0;
unsigned int ui;
switch (what)
{
case GCRYCTL_GET_KEYLEN:
if (buffer || (! nbytes))
rc = GPG_ERR_CIPHER_ALGO;
else
{
ui = cipher_get_keylen (algo);
if ((ui > 0) && (ui <= 512))
*nbytes = (size_t) ui / 8;
else
/* The only reason for an error is an invalid algo. */
rc = GPG_ERR_CIPHER_ALGO;
}
break;
case GCRYCTL_GET_BLKLEN:
if (buffer || (! nbytes))
rc = GPG_ERR_CIPHER_ALGO;
else
{
ui = cipher_get_blocksize (algo);
if ((ui > 0) && (ui < 10000))
*nbytes = ui;
else
{
/* The only reason is an invalid algo or a strange
blocksize. */
rc = GPG_ERR_CIPHER_ALGO;
}
}
break;
case GCRYCTL_TEST_ALGO:
if (buffer || nbytes)
rc = GPG_ERR_INV_ARG;
else
rc = check_cipher_algo (algo);
break;
default:
rc = GPG_ERR_INV_OP;
}
return rc;
}
/* This function returns length of the key for algorithm ALGO. If the
algorithm supports multiple key lengths, the maximum supported key
length is returned. On error 0 is returned. The key length is
returned as number of octets.
This is a convenience functions which should be preferred over
gcry_cipher_algo_info because it allows for proper type
checking. */
size_t
_gcry_cipher_get_algo_keylen (int algo)
{
size_t n;
if (_gcry_cipher_algo_info (algo, GCRYCTL_GET_KEYLEN, NULL, &n))
n = 0;
return n;
}
/* This functions returns the blocklength of the algorithm ALGO
counted in octets. On error 0 is returned.
This is a convenience functions which should be preferred over
gcry_cipher_algo_info because it allows for proper type
checking. */
size_t
_gcry_cipher_get_algo_blklen (int algo)
{
size_t n;
if (_gcry_cipher_algo_info( algo, GCRYCTL_GET_BLKLEN, NULL, &n))
n = 0;
return n;
}
/* Explicitly initialize this module. */
gcry_err_code_t
_gcry_cipher_init (void)
{
if (fips_mode())
{
/* disable algorithms that are disallowed in fips */
int idx;
gcry_cipher_spec_t *spec;
for (idx = 0; (spec = cipher_list[idx]); idx++)
if (!spec->flags.fips)
spec->flags.disabled = 1;
}
return 0;
}
/* Run the selftests for cipher algorithm ALGO with optional reporting
function REPORT. */
gpg_error_t
_gcry_cipher_selftest (int algo, int extended, selftest_report_func_t report)
{
gcry_err_code_t ec = 0;
gcry_cipher_spec_t *spec;
spec = spec_from_algo (algo);
if (spec && !spec->flags.disabled && spec->selftest)
ec = spec->selftest (algo, extended, report);
else
{
ec = GPG_ERR_CIPHER_ALGO;
if (report)
report ("cipher", algo, "module",
(spec && !spec->flags.disabled)?
"no selftest available" :
spec? "algorithm disabled" : "algorithm not found");
}
return gpg_error (ec);
}

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