/* 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_module_t cipher;
int ret, algorithm = 0;
if (! string)
return 0;
REGISTER_DEFAULT_CIPHERS;
/* 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 */
ath_mutex_lock (&ciphers_registered_lock);
ret = search_oid (string, &algorithm, NULL);
if (! ret)
{
cipher = gcry_cipher_lookup_name (string);
if (cipher)
{
algorithm = cipher->mod_id;
_gcry_module_release (cipher);
}
}
ath_mutex_unlock (&ciphers_registered_lock);
return algorithm;
}
/* 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;
/* Release module. */
ath_mutex_lock (&ciphers_registered_lock);
_gcry_module_release (h->module);
ath_mutex_unlock (&ciphers_registered_lock);
/* 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);
gcry_free ((char*)h - off);
}
/* Locate the OID in the oid table and return the index or -1 when not
found. An opitonal "oid." or "OID." prefix in OID is ignored, the
OID is expected to be in standard IETF dotted notation. The
internal algorithm number is returned in ALGORITHM unless it
ispassed as NULL. A pointer to the specification of the module
implementing this algorithm is return in OID_SPEC unless passed as
NULL.*/
static int
search_oid (const char *oid, int *algorithm, gcry_cipher_oid_spec_t *oid_spec)
{
gcry_module_t module;
int ret = 0;
if (oid && ((! strncmp (oid, "oid.", 4))
|| (! strncmp (oid, "OID.", 4))))
oid += 4;
module = gcry_cipher_lookup_oid (oid);
if (module)
{
gcry_cipher_spec_t *cipher = module->spec;
int i;
for (i = 0; cipher->oids[i].oid && !ret; i++)
if (! stricmp (oid, cipher->oids[i].oid))
{
if (algorithm)
*algorithm = module->mod_id;
if (oid_spec)
*oid_spec = cipher->oids[i];
ret = 1;
}
_gcry_module_release (module);
}
return ret;
}
/* Unregister the cipher identified by MODULE, which must have been
registered with gcry_cipher_register. */
void
_gcry_cipher_unregister (gcry_module_t module)
{
ath_mutex_lock (&ciphers_registered_lock);
_gcry_module_release (module);
ath_mutex_unlock (&ciphers_registered_lock);
}
/* 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_module_t module = NULL;
cipher_extra_spec_t *extraspec = NULL;
gcry_err_code_t ec = 0;
REGISTER_DEFAULT_CIPHERS;
ath_mutex_lock (&ciphers_registered_lock);
module = _gcry_module_lookup_id (ciphers_registered, algo);
if (module && !(module->flags & FLAG_MODULE_DISABLED))
extraspec = module->extraspec;
ath_mutex_unlock (&ciphers_registered_lock);
if (extraspec && extraspec->selftest)
ec = extraspec->selftest (algo, extended, report);
else
{
ec = GPG_ERR_CIPHER_ALGO;
if (report)
report ("cipher", algo, "module",
module && !(module->flags & FLAG_MODULE_DISABLED)?
"no selftest available" :
module? "algorithm disabled" : "algorithm not found");
}
if (module)
{
ath_mutex_lock (&ciphers_registered_lock);
_gcry_module_release (module);
ath_mutex_unlock (&ciphers_registered_lock);
}
return gpg_error (ec);
}
/* 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 vitually not available
in Libgcrypt. */
static void
disable_cipher_algo (int algorithm)
{
gcry_module_t cipher;
REGISTER_DEFAULT_CIPHERS;
ath_mutex_lock (&ciphers_registered_lock);
cipher = _gcry_module_lookup_id (ciphers_registered, algorithm);
if (cipher)
{
if (! (cipher->flags & FLAG_MODULE_DISABLED))
cipher->flags |= FLAG_MODULE_DISABLED;
_gcry_module_release (cipher);
}
ath_mutex_unlock (&ciphers_registered_lock);
}
/* Map the cipher algorithm identifier ALGORITHM to a string
representing this algorithm. This string is the default name as
used by Libgcrypt. NULL is returned for an unknown algorithm. */
static const char *
cipher_algo_to_string (int algorithm)
{
gcry_module_t cipher;
const char *name = NULL;
REGISTER_DEFAULT_CIPHERS;
ath_mutex_lock (&ciphers_registered_lock);
cipher = _gcry_module_lookup_id (ciphers_registered, algorithm);
if (cipher)
{
name = ((gcry_cipher_spec_t *) cipher->spec)->name;
_gcry_module_release (cipher);
}
ath_mutex_unlock (&ciphers_registered_lock);
return name;
}
/* 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_module_t cipher;
unsigned len = 0;
REGISTER_DEFAULT_CIPHERS;
ath_mutex_lock (&ciphers_registered_lock);
cipher = _gcry_module_lookup_id (ciphers_registered, algorithm);
if (cipher)
{
len = ((gcry_cipher_spec_t *) cipher->spec)->blocksize;
if (! len)
log_bug ("cipher %d w/o blocksize\n", algorithm);
_gcry_module_release (cipher);
}
ath_mutex_unlock (&ciphers_registered_lock);
return len;
}
/* 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_err_code_t err = GPG_ERR_NO_ERROR;
gcry_module_t cipher;
REGISTER_DEFAULT_CIPHERS;
ath_mutex_lock (&ciphers_registered_lock);
cipher = _gcry_module_lookup_id (ciphers_registered, algorithm);
if (cipher)
{
if (cipher->flags & FLAG_MODULE_DISABLED)
err = GPG_ERR_CIPHER_ALGO;
_gcry_module_release (cipher);
}
else
err = GPG_ERR_CIPHER_ALGO;
ath_mutex_unlock (&ciphers_registered_lock);
return err;
}
/*
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_error_t
gcry_cipher_open (gcry_cipher_hd_t *handle,
int algo, int mode, unsigned int flags)
{
int secure = (flags & GCRY_CIPHER_SECURE);
gcry_cipher_spec_t *cipher = NULL;
cipher_extra_spec_t *extraspec = NULL;
gcry_module_t module = NULL;
gcry_cipher_hd_t h = NULL;
gcry_err_code_t err = 0;
/* 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 ();
REGISTER_DEFAULT_CIPHERS;
/* Fetch the according module and check whether the cipher is marked
available for use. */
ath_mutex_lock (&ciphers_registered_lock);
module = _gcry_module_lookup_id (ciphers_registered, algo);
if (module)
{
/* Found module. */
if (module->flags & FLAG_MODULE_DISABLED)
{
/* Not available for use. */
err = GPG_ERR_CIPHER_ALGO;
}
else
{
cipher = (gcry_cipher_spec_t *) module->spec;
extraspec = module->extraspec;
}
}
else
err = GPG_ERR_CIPHER_ALGO;
ath_mutex_unlock (&ciphers_registered_lock);
/* 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 & 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_ECB:
case GCRY_CIPHER_MODE_CBC:
case GCRY_CIPHER_MODE_CFB:
case GCRY_CIPHER_MODE_OFB:
case GCRY_CIPHER_MODE_CTR:
case GCRY_CIPHER_MODE_AESWRAP:
if ((cipher->encrypt == dummy_encrypt_block)
|| (cipher->decrypt == dummy_decrypt_block))
err = GPG_ERR_INV_CIPHER_MODE;
break;
case GCRY_CIPHER_MODE_STREAM:
if ((cipher->stencrypt == dummy_encrypt_stream)
|| (cipher->stdecrypt == dummy_decrypt_stream))
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 * cipher->contextsize
- sizeof (cipher_context_alignment_t)
#ifdef NEED_16BYTE_ALIGNED_CONTEXT
+ 15 /* Space for leading alignment gap. */
#endif /*NEED_16BYTE_ALIGNED_CONTEXT*/
);
if (secure)
h = gcry_calloc_secure (1, size);
else
h = gcry_calloc (1, size);
if (! h)
err = gpg_err_code_from_syserror ();
else
{
size_t off = 0;
#ifdef NEED_16BYTE_ALIGNED_CONTEXT
if ( ((unsigned long)h & 0x0f) )
{
/* The malloced block is not aligned on a 16 byte
boundary. Correct for this. */
off = 16 - ((unsigned long)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->cipher = cipher;
h->extraspec = extraspec;
h->module = module;
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;
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;
break;
#endif /*USE_CAMELLIA*/
#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;
break;
#endif /*USE_SERPENT*/
#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;
break;
#endif /*USE_TWOFISH*/
default:
break;
}
}
}
/* Done. */
if (err)
{
if (module)
{
/* Release module. */
ath_mutex_lock (&ciphers_registered_lock);
_gcry_module_release (module);
ath_mutex_unlock (&ciphers_registered_lock);
}
}
*handle = err ? NULL : h;
return gcry_error (err);
}
/*
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_error_t
gcry_cipher_open (gcry_cipher_hd_t *handle,
int algo, int mode, unsigned int flags)
{
int secure = (flags & GCRY_CIPHER_SECURE);
gcry_cipher_spec_t *cipher = NULL;
gcry_module_t module = NULL;
gcry_cipher_hd_t h = NULL;
gcry_err_code_t err = 0;
/* 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 ();
REGISTER_DEFAULT_CIPHERS;
/* Fetch the according module and check wether the cipher is marked
available for use. */
ath_mutex_lock (&ciphers_registered_lock);
module = _gcry_module_lookup_id (ciphers_registered, algo);
if (module)
{
/* Found module. */
if (module->flags & FLAG_MODULE_DISABLED)
{
/* Not available for use. */
err = GPG_ERR_CIPHER_ALGO;
_gcry_module_release (module);
}
else
cipher = (gcry_cipher_spec_t *) module->spec;
}
else
err = GPG_ERR_CIPHER_ALGO;
ath_mutex_unlock (&ciphers_registered_lock);
/* 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 & 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_ECB:
case GCRY_CIPHER_MODE_CBC:
case GCRY_CIPHER_MODE_CFB:
case GCRY_CIPHER_MODE_CTR:
if ((cipher->encrypt == dummy_encrypt_block)
|| (cipher->decrypt == dummy_decrypt_block))
err = GPG_ERR_INV_CIPHER_MODE;
break;
case GCRY_CIPHER_MODE_STREAM:
if ((cipher->stencrypt == dummy_encrypt_stream)
|| (cipher->stdecrypt == dummy_decrypt_stream))
err = GPG_ERR_INV_CIPHER_MODE;
break;
case GCRY_CIPHER_MODE_NONE:
/* FIXME: issue a warning when this mode is used */
break;
default:
err = GPG_ERR_INV_CIPHER_MODE;
}
/* ? FIXME: perform selftest here and mark this with a flag in
cipher_table ? */
if (! err)
{
size_t size = (sizeof (*h)
+ 2 * cipher->contextsize
- sizeof (PROPERLY_ALIGNED_TYPE));
if (secure)
h = gcry_calloc_secure (1, size);
else
h = gcry_calloc (1, size);
if (! h)
err = gpg_err_code_from_errno (errno);
else
{
h->magic = secure ? CTX_MAGIC_SECURE : CTX_MAGIC_NORMAL;
h->actual_handle_size = size;
h->cipher = cipher;
h->module = module;
h->mode = mode;
h->flags = flags;
}
}
/* Done. */
if (err)
{
if (module)
{
/* Release module. */
ath_mutex_lock (&ciphers_registered_lock);
_gcry_module_release (module);
ath_mutex_unlock (&ciphers_registered_lock);
}
}
*handle = err ? NULL : h;
return gcry_error (err);
}
