/* md.c - message digest dispatcher
* Copyright (C) 1998, 1999, 2002, 2003, 2006,
* 2008 Free Software Foundation, Inc.
* Copyright (C) 2013, 2014 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 "cipher.h"
/* This is the list of the digest implementations included in
libgcrypt. */
static gcry_md_spec_t *digest_list[] =
{
#if USE_CRC
&_gcry_digest_spec_crc32,
&_gcry_digest_spec_crc32_rfc1510,
&_gcry_digest_spec_crc24_rfc2440,
#endif
#if USE_SHA1
&_gcry_digest_spec_sha1,
#endif
#if USE_SHA256
&_gcry_digest_spec_sha256,
&_gcry_digest_spec_sha224,
#endif
#if USE_SHA512
&_gcry_digest_spec_sha512,
&_gcry_digest_spec_sha384,
#endif
#if USE_SHA3
&_gcry_digest_spec_sha3_224,
&_gcry_digest_spec_sha3_256,
&_gcry_digest_spec_sha3_384,
&_gcry_digest_spec_sha3_512,
&_gcry_digest_spec_shake128,
&_gcry_digest_spec_shake256,
#endif
#if USE_GOST_R_3411_94
&_gcry_digest_spec_gost3411_94,
&_gcry_digest_spec_gost3411_cp,
#endif
#if USE_GOST_R_3411_12
&_gcry_digest_spec_stribog_256,
&_gcry_digest_spec_stribog_512,
#endif
#if USE_WHIRLPOOL
&_gcry_digest_spec_whirlpool,
#endif
#if USE_RMD160
&_gcry_digest_spec_rmd160,
#endif
#if USE_TIGER
&_gcry_digest_spec_tiger,
&_gcry_digest_spec_tiger1,
&_gcry_digest_spec_tiger2,
#endif
#if USE_MD5
&_gcry_digest_spec_md5,
#endif
#if USE_MD4
&_gcry_digest_spec_md4,
#endif
#if USE_MD2
&_gcry_digest_spec_md2,
#endif
#if USE_BLAKE2
&_gcry_digest_spec_blake2b_512,
&_gcry_digest_spec_blake2b_384,
&_gcry_digest_spec_blake2b_256,
&_gcry_digest_spec_blake2b_160,
&_gcry_digest_spec_blake2s_256,
&_gcry_digest_spec_blake2s_224,
&_gcry_digest_spec_blake2s_160,
&_gcry_digest_spec_blake2s_128,
#endif
NULL
};
typedef struct gcry_md_list
{
gcry_md_spec_t *spec;
struct gcry_md_list *next;
size_t actual_struct_size; /* Allocated size of this structure. */
PROPERLY_ALIGNED_TYPE context;
} GcryDigestEntry;
/* This structure is put right after the gcry_md_hd_t buffer, so that
* only one memory block is needed. */
struct gcry_md_context
{
int magic;
size_t actual_handle_size; /* Allocated size of this handle. */
FILE *debug;
struct {
unsigned int secure: 1;
unsigned int finalized:1;
unsigned int bugemu1:1;
unsigned int hmac:1;
} flags;
GcryDigestEntry *list;
};
#define CTX_MAGIC_NORMAL 0x11071961
#define CTX_MAGIC_SECURE 0x16917011
static gcry_err_code_t md_enable (gcry_md_hd_t hd, int algo);
static void md_close (gcry_md_hd_t a);
static void md_write (gcry_md_hd_t a, const void *inbuf, size_t inlen);
static byte *md_read( gcry_md_hd_t a, int algo );
static int md_get_algo( gcry_md_hd_t a );
static int md_digest_length( int algo );
static void md_start_debug ( gcry_md_hd_t a, const char *suffix );
static void md_stop_debug ( gcry_md_hd_t a );
static int
map_algo (int algo)
{
return algo;
}
/* Return the spec structure for the hash algorithm ALGO. For an
unknown algorithm NULL is returned. */
static gcry_md_spec_t *
spec_from_algo (int algo)
{
int idx;
gcry_md_spec_t *spec;
algo = map_algo (algo);
for (idx = 0; (spec = digest_list[idx]); idx++)
if (algo == spec->algo)
return spec;
return NULL;
}
/* Lookup a hash's spec by its name. */
static gcry_md_spec_t *
spec_from_name (const char *name)
{
gcry_md_spec_t *spec;
int idx;
for (idx=0; (spec = digest_list[idx]); idx++)
{
if (!stricmp (name, spec->name))
return spec;
}
return NULL;
}
/* Lookup a hash's spec by its OID. */
static gcry_md_spec_t *
spec_from_oid (const char *oid)
{
gcry_md_spec_t *spec;
gcry_md_oid_spec_t *oid_specs;
int idx, j;
for (idx=0; (spec = digest_list[idx]); idx++)
{
oid_specs = spec->oids;
if (oid_specs)
{
for (j = 0; oid_specs[j].oidstring; j++)
if (!stricmp (oid, oid_specs[j].oidstring))
return spec;
}
}
return NULL;
}
static gcry_md_spec_t *
search_oid (const char *oid, gcry_md_oid_spec_t *oid_spec)
{
gcry_md_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].oidstring; i++)
if (!stricmp (oid, spec->oids[i].oidstring))
{
if (oid_spec)
*oid_spec = spec->oids[i];
return spec;
}
}
return NULL;
}
/****************
* Map a string to the digest algo
*/
int
_gcry_md_map_name (const char *string)
{
gcry_md_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;
/* Not found, search a matching digest name. */
spec = spec_from_name (string);
if (spec)
return spec->algo;
return 0;
}
/****************
* This function simply returns the name of the algorithm or some constant
* string when there is no algo. It will never return NULL.
* Use the macro gcry_md_test_algo() to check whether the algorithm
* is valid.
*/
const char *
_gcry_md_algo_name (int algorithm)
{
gcry_md_spec_t *spec;
spec = spec_from_algo (algorithm);
return spec ? spec->name : "?";
}
static gcry_err_code_t
check_digest_algo (int algorithm)
{
gcry_md_spec_t *spec;
spec = spec_from_algo (algorithm);
if (spec && !spec->flags.disabled)
return 0;
return GPG_ERR_DIGEST_ALGO;
}
/****************
* Open a message digest handle for use with algorithm ALGO.
* More algorithms may be added by md_enable(). The initial algorithm
* may be 0.
*/
static gcry_err_code_t
md_open (gcry_md_hd_t *h, int algo, unsigned int flags)
{
gcry_err_code_t err = 0;
int secure = !!(flags & GCRY_MD_FLAG_SECURE);
int hmac = !!(flags & GCRY_MD_FLAG_HMAC);
int bufsize = secure ? 512 : 1024;
struct gcry_md_context *ctx;
gcry_md_hd_t hd;
size_t n;
/* Allocate a memory area to hold the caller visible buffer with it's
* control information and the data required by this module. Set the
* context pointer at the beginning to this area.
* We have to use this strange scheme because we want to hide the
* internal data but have a variable sized buffer.
*
* +---+------+---........------+-------------+
* !ctx! bctl ! buffer ! private !
* +---+------+---........------+-------------+
* ! ^
* !---------------------------!
*
* We have to make sure that private is well aligned.
*/
n = sizeof (struct gcry_md_handle) + bufsize;
n = ((n + sizeof (PROPERLY_ALIGNED_TYPE) - 1)
/ sizeof (PROPERLY_ALIGNED_TYPE)) * sizeof (PROPERLY_ALIGNED_TYPE);
/* Allocate and set the Context pointer to the private data */
if (secure)
hd = xtrymalloc_secure (n + sizeof (struct gcry_md_context));
else
hd = xtrymalloc (n + sizeof (struct gcry_md_context));
if (! hd)
err = gpg_err_code_from_errno (errno);
if (! err)
{
hd->ctx = ctx = (void *) ((char *) hd + n);
/* Setup the globally visible data (bctl in the diagram).*/
hd->bufsize = n - sizeof (struct gcry_md_handle) + 1;
hd->bufpos = 0;
/* Initialize the private data. */
memset (hd->ctx, 0, sizeof *hd->ctx);
ctx->magic = secure ? CTX_MAGIC_SECURE : CTX_MAGIC_NORMAL;
ctx->actual_handle_size = n + sizeof (struct gcry_md_context);
ctx->flags.secure = secure;
ctx->flags.hmac = hmac;
ctx->flags.bugemu1 = !!(flags & GCRY_MD_FLAG_BUGEMU1);
}
if (! err)
{
/* Hmmm, should we really do that? - yes [-wk] */
_gcry_fast_random_poll ();
if (algo)
{
err = md_enable (hd, algo);
if (err)
md_close (hd);
}
}
if (! err)
*h = hd;
return err;
}
/* Create a message digest object for algorithm ALGO. FLAGS may be
given as an bitwise OR of the gcry_md_flags values. ALGO may be
given as 0 if the algorithms to be used are later set using
gcry_md_enable. H is guaranteed to be a valid handle or NULL on
error. */
gcry_err_code_t
_gcry_md_open (gcry_md_hd_t *h, int algo, unsigned int flags)
{
gcry_err_code_t rc;
gcry_md_hd_t hd;
if ((flags & ~(GCRY_MD_FLAG_SECURE
| GCRY_MD_FLAG_HMAC
| GCRY_MD_FLAG_BUGEMU1)))
rc = GPG_ERR_INV_ARG;
else
rc = md_open (&hd, algo, flags);
*h = rc? NULL : hd;
return rc;
}
static gcry_err_code_t
md_enable (gcry_md_hd_t hd, int algorithm)
{
struct gcry_md_context *h = hd->ctx;
gcry_md_spec_t *spec;
GcryDigestEntry *entry;
gcry_err_code_t err = 0;
for (entry = h->list; entry; entry = entry->next)
if (entry->spec->algo == algorithm)
return 0; /* Already enabled */
spec = spec_from_algo (algorithm);
if (!spec)
{
log_debug ("md_enable: algorithm %d not available\n", algorithm);
err = GPG_ERR_DIGEST_ALGO;
}
if (!err && algorithm == GCRY_MD_MD5 && fips_mode ())
{
_gcry_inactivate_fips_mode ("MD5 used");
if (_gcry_enforced_fips_mode () )
{
/* We should never get to here because we do not register
MD5 in enforced fips mode. But better throw an error. */
err = GPG_ERR_DIGEST_ALGO;
}
}
if (!err && h->flags.hmac && spec->read == NULL)
{
/* Expandable output function cannot act as part of HMAC. */
err = GPG_ERR_DIGEST_ALGO;
}
if (!err)
{
size_t size = (sizeof (*entry)
+ spec->contextsize * (h->flags.hmac? 3 : 1)
- sizeof (entry->context));
/* And allocate a new list entry. */
if (h->flags.secure)
entry = xtrymalloc_secure (size);
else
entry = xtrymalloc (size);
if (! entry)
err = gpg_err_code_from_errno (errno);
else
{
entry->spec = spec;
entry->next = h->list;
entry->actual_struct_size = size;
h->list = entry;
/* And init this instance. */
entry->spec->init (&entry->context.c,
h->flags.bugemu1? GCRY_MD_FLAG_BUGEMU1:0);
}
}
return err;
}
gcry_err_code_t
_gcry_md_enable (gcry_md_hd_t hd, int algorithm)
{
return md_enable (hd, algorithm);
}
static gcry_err_code_t
md_copy (gcry_md_hd_t ahd, gcry_md_hd_t *b_hd)
{
gcry_err_code_t err = 0;
struct gcry_md_context *a = ahd->ctx;
struct gcry_md_context *b;
GcryDigestEntry *ar, *br;
gcry_md_hd_t bhd;
size_t n;
if (ahd->bufpos)
md_write (ahd, NULL, 0);
n = (char *) ahd->ctx - (char *) ahd;
if (a->flags.secure)
bhd = xtrymalloc_secure (n + sizeof (struct gcry_md_context));
else
bhd = xtrymalloc (n + sizeof (struct gcry_md_context));
if (!bhd)
{
err = gpg_err_code_from_syserror ();
goto leave;
}
bhd->ctx = b = (void *) ((char *) bhd + n);
/* No need to copy the buffer due to the write above. */
gcry_assert (ahd->bufsize == (n - sizeof (struct gcry_md_handle) + 1));
bhd->bufsize = ahd->bufsize;
bhd->bufpos = 0;
gcry_assert (! ahd->bufpos);
memcpy (b, a, sizeof *a);
b->list = NULL;
b->debug = NULL;
/* Copy the complete list of algorithms. The copied list is
reversed, but that doesn't matter. */
for (ar = a->list; ar; ar = ar->next)
{
if (a->flags.secure)
br = xtrymalloc_secure (ar->actual_struct_size);
else
br = xtrymalloc (ar->actual_struct_size);
if (!br)
{
err = gpg_err_code_from_syserror ();
md_close (bhd);
goto leave;
}
memcpy (br, ar, ar->actual_struct_size);
br->next = b->list;
b->list = br;
}
if (a->debug)
md_start_debug (bhd, "unknown");
*b_hd = bhd;
leave:
return err;
}
gcry_err_code_t
_gcry_md_copy (gcry_md_hd_t *handle, gcry_md_hd_t hd)
{
gcry_err_code_t rc;
rc = md_copy (hd, handle);
if (rc)
*handle = NULL;
return rc;
}
/*
* Reset all contexts and discard any buffered stuff. This may be used
* instead of a md_close(); md_open().
*/
void
_gcry_md_reset (gcry_md_hd_t a)
{
GcryDigestEntry *r;
/* Note: We allow this even in fips non operational mode. */
a->bufpos = a->ctx->flags.finalized = 0;
if (a->ctx->flags.hmac)
for (r = a->ctx->list; r; r = r->next)
{
memcpy (r->context.c, r->context.c + r->spec->contextsize,
r->spec->contextsize);
}
else
for (r = a->ctx->list; r; r = r->next)
{
memset (r->context.c, 0, r->spec->contextsize);
(*r->spec->init) (&r->context.c,
a->ctx->flags.bugemu1? GCRY_MD_FLAG_BUGEMU1:0);
}
}
static void
md_close (gcry_md_hd_t a)
{
GcryDigestEntry *r, *r2;
if (! a)
return;
if (a->ctx->debug)
md_stop_debug (a);
for (r = a->ctx->list; r; r = r2)
{
r2 = r->next;
wipememory (r, r->actual_struct_size);
xfree (r);
}
wipememory (a, a->ctx->actual_handle_size);
xfree(a);
}
void
_gcry_md_close (gcry_md_hd_t hd)
{
/* Note: We allow this even in fips non operational mode. */
md_close (hd);
}
static void
md_write (gcry_md_hd_t a, const void *inbuf, size_t inlen)
{
GcryDigestEntry *r;
if (a->ctx->debug)
{
if (a->bufpos && fwrite (a->buf, a->bufpos, 1, a->ctx->debug) != 1)
BUG();
if (inlen && fwrite (inbuf, inlen, 1, a->ctx->debug) != 1)
BUG();
}
for (r = a->ctx->list; r; r = r->next)
{
if (a->bufpos)
(*r->spec->write) (&r->context.c, a->buf, a->bufpos);
(*r->spec->write) (&r->context.c, inbuf, inlen);
}
a->bufpos = 0;
}
/* Note that this function may be used after finalize and read to keep
on writing to the transform function so to mitigate timing
attacks. */
void
_gcry_md_write (gcry_md_hd_t hd, const void *inbuf, size_t inlen)
{
md_write (hd, inbuf, inlen);
}
static void
md_final (gcry_md_hd_t a)
{
GcryDigestEntry *r;
if (a->ctx->flags.finalized)
return;
if (a->bufpos)
md_write (a, NULL, 0);
for (r = a->ctx->list; r; r = r->next)
(*r->spec->final) (&r->context.c);
a->ctx->flags.finalized = 1;
if (!a->ctx->flags.hmac)
return;
for (r = a->ctx->list; r; r = r->next)
{
byte *p;
size_t dlen = r->spec->mdlen;
byte *hash;
gcry_err_code_t err;
if (r->spec->read == NULL)
continue;
p = r->spec->read (&r->context.c);
if (a->ctx->flags.secure)
hash = xtrymalloc_secure (dlen);
else
hash = xtrymalloc (dlen);
if (!hash)
{
err = gpg_err_code_from_errno (errno);
_gcry_fatal_error (err, NULL);
}
memcpy (hash, p, dlen);
memcpy (r->context.c, r->context.c + r->spec->contextsize * 2,
r->spec->contextsize);
(*r->spec->write) (&r->context.c, hash, dlen);
(*r->spec->final) (&r->context.c);
xfree (hash);
}
}
static gcry_err_code_t
md_setkey (gcry_md_hd_t h, const unsigned char *key, size_t keylen)
{
gcry_err_code_t rc = 0;
GcryDigestEntry *r;
int algo_had_setkey = 0;
if (!h->ctx->list)
return GPG_ERR_DIGEST_ALGO; /* Might happen if no algo is enabled. */
if (h->ctx->flags.hmac)
return GPG_ERR_DIGEST_ALGO; /* Tried md_setkey for HMAC md. */
for (r = h->ctx->list; r; r = r->next)
{
switch (r->spec->algo)
{
/* TODO? add spec->init_with_key? */
case GCRY_MD_BLAKE2B_512:
case GCRY_MD_BLAKE2B_384:
case GCRY_MD_BLAKE2B_256:
case GCRY_MD_BLAKE2B_160:
case GCRY_MD_BLAKE2S_256:
case GCRY_MD_BLAKE2S_224:
case GCRY_MD_BLAKE2S_160:
case GCRY_MD_BLAKE2S_128:
algo_had_setkey = 1;
memset (r->context.c, 0, r->spec->contextsize);
rc = _gcry_blake2_init_with_key (r->context.c,
h->ctx->flags.bugemu1
? GCRY_MD_FLAG_BUGEMU1:0,
key, keylen, r->spec->algo);
break;
default:
rc = GPG_ERR_DIGEST_ALGO;
break;
}
if (rc)
break;
}
if (rc && !algo_had_setkey)
{
/* None of algorithms had setkey implementation, so contexts were not
* modified. Just return error. */
return rc;
}
else if (rc && algo_had_setkey)
{
/* Some of the contexts have been modified, but got error. Reset
* all contexts. */
_gcry_md_reset (h);
return rc;
}
/* Successful md_setkey implies reset. */
h->bufpos = h->ctx->flags.finalized = 0;
return 0;
}
static gcry_err_code_t
prepare_macpads (gcry_md_hd_t a, const unsigned char *key, size_t keylen)
{
GcryDigestEntry *r;
if (!a->ctx->list)
return GPG_ERR_DIGEST_ALGO; /* Might happen if no algo is enabled. */
if (!a->ctx->flags.hmac)
return GPG_ERR_DIGEST_ALGO; /* Tried prepare_macpads for non-HMAC md. */
for (r = a->ctx->list; r; r = r->next)
{
const unsigned char *k;
size_t k_len;
unsigned char *key_allocated = NULL;
int macpad_Bsize;
int i;
switch (r->spec->algo)
{
/* TODO: add spec->blocksize */
case GCRY_MD_SHA3_224:
macpad_Bsize = 1152 / 8;
break;
case GCRY_MD_SHA3_256:
macpad_Bsize = 1088 / 8;
break;
case GCRY_MD_SHA3_384:
macpad_Bsize = 832 / 8;
break;
case GCRY_MD_SHA3_512:
macpad_Bsize = 576 / 8;
break;
case GCRY_MD_SHA384:
case GCRY_MD_SHA512:
case GCRY_MD_BLAKE2B_512:
case GCRY_MD_BLAKE2B_384:
case GCRY_MD_BLAKE2B_256:
case GCRY_MD_BLAKE2B_160:
macpad_Bsize = 128;
break;
case GCRY_MD_GOSTR3411_94:
case GCRY_MD_GOSTR3411_CP:
macpad_Bsize = 32;
break;
default:
macpad_Bsize = 64;
break;
}
if ( keylen > macpad_Bsize )
{
k = key_allocated = xtrymalloc_secure (r->spec->mdlen);
if (!k)
return gpg_err_code_from_errno (errno);
_gcry_md_hash_buffer (r->spec->algo, key_allocated, key, keylen);
k_len = r->spec->mdlen;
gcry_assert ( k_len <= macpad_Bsize );
}
else
{
k = key;
k_len = keylen;
}
(*r->spec->init) (&r->context.c,
a->ctx->flags.bugemu1? GCRY_MD_FLAG_BUGEMU1:0);
a->bufpos = 0;
for (i=0; i < k_len; i++ )
_gcry_md_putc (a, k[i] ^ 0x36);
for (; i < macpad_Bsize; i++ )
_gcry_md_putc (a, 0x36);
(*r->spec->write) (&r->context.c, a->buf, a->bufpos);
memcpy (r->context.c + r->spec->contextsize, r->context.c,
r->spec->contextsize);
(*r->spec->init) (&r->context.c,
a->ctx->flags.bugemu1? GCRY_MD_FLAG_BUGEMU1:0);
a->bufpos = 0;
for (i=0; i < k_len; i++ )
_gcry_md_putc (a, k[i] ^ 0x5c);
for (; i < macpad_Bsize; i++ )
_gcry_md_putc (a, 0x5c);
(*r->spec->write) (&r->context.c, a->buf, a->bufpos);
memcpy (r->context.c + r->spec->contextsize*2, r->context.c,
r->spec->contextsize);
xfree (key_allocated);
}
a->bufpos = 0;
return 0;
}
gcry_err_code_t
_gcry_md_ctl (gcry_md_hd_t hd, int cmd, void *buffer, size_t buflen)
{
gcry_err_code_t rc = 0;
(void)buflen; /* Currently not used. */
switch (cmd)
{
case GCRYCTL_FINALIZE:
md_final (hd);
break;
case GCRYCTL_START_DUMP:
md_start_debug (hd, buffer);
break;
case GCRYCTL_STOP_DUMP:
md_stop_debug ( hd );
break;
default:
rc = GPG_ERR_INV_OP;
}
return rc;
}
gcry_err_code_t
_gcry_md_setkey (gcry_md_hd_t hd, const void *key, size_t keylen)
{
gcry_err_code_t rc;
if (hd->ctx->flags.hmac)
{
rc = prepare_macpads (hd, key, keylen);
if (!rc)
_gcry_md_reset (hd);
}
else
{
rc = md_setkey (hd, key, keylen);
}
return rc;
}
/* The new debug interface. If SUFFIX is a string it creates an debug
file for the context HD. IF suffix is NULL, the file is closed and
debugging is stopped. */
void
_gcry_md_debug (gcry_md_hd_t hd, const char *suffix)
{
if (suffix)
md_start_debug (hd, suffix);
else
md_stop_debug (hd);
}
/****************
* If ALGO is null get the digest for the used algo (which should be
* only one)
*/
static byte *
md_read( gcry_md_hd_t a, int algo )
{
GcryDigestEntry *r = a->ctx->list;
if (! algo)
{
/* Return the first algorithm */
if (r)
{
if (r->next)
log_debug ("more than one algorithm in md_read(0)\n");
if (r->spec->read)
return r->spec->read (&r->context.c);
}
}
else
{
for (r = a->ctx->list; r; r = r->next)
if (r->spec->algo == algo)
{
if (r->spec->read)
return r->spec->read (&r->context.c);
break;
}
}
if (r && !r->spec->read)
_gcry_fatal_error (GPG_ERR_DIGEST_ALGO,
"requested algo has no fixed digest length");
else
_gcry_fatal_error (GPG_ERR_DIGEST_ALGO, "requested algo not in md context");
return NULL;
}
/*
* Read out the complete digest, this function implictly finalizes
* the hash.
*/
byte *
_gcry_md_read (gcry_md_hd_t hd, int algo)
{
/* This function is expected to always return a digest, thus we
can't return an error which we actually should do in
non-operational state. */
_gcry_md_ctl (hd, GCRYCTL_FINALIZE, NULL, 0);
return md_read (hd, algo);
}
/****************
* If ALGO is null get the digest for the used algo (which should be
* only one)
*/
static gcry_err_code_t
md_extract(gcry_md_hd_t a, int algo, void *out, size_t outlen)
{
GcryDigestEntry *r = a->ctx->list;
if (!algo)
{
/* Return the first algorithm */
if (r && r->spec->extract)
{
if (r->next)
log_debug ("more than one algorithm in md_extract(0)\n");
r->spec->extract (&r->context.c, out, outlen);
return 0;
}
}
else
{
for (r = a->ctx->list; r; r = r->next)
if (r->spec->algo == algo && r->spec->extract)
{
r->spec->extract (&r->context.c, out, outlen);
return 0;
}
}
return GPG_ERR_DIGEST_ALGO;
}
/*
* Expand the output from XOF class digest, this function implictly finalizes
* the hash.
*/
gcry_err_code_t
_gcry_md_extract (gcry_md_hd_t hd, int algo, void *out, size_t outlen)
{
_gcry_md_ctl (hd, GCRYCTL_FINALIZE, NULL, 0);
return md_extract (hd, algo, out, outlen);
}
/*
* Read out an intermediate digest. Not yet functional.
*/
gcry_err_code_t
_gcry_md_get (gcry_md_hd_t hd, int algo, byte *buffer, int buflen)
{
(void)hd;
(void)algo;
(void)buffer;
(void)buflen;
/*md_digest ... */
fips_signal_error ("unimplemented function called");
return GPG_ERR_INTERNAL;
}
/*
* Shortcut function to hash a buffer with a given algo. The only
* guaranteed supported algorithms are RIPE-MD160 and SHA-1. The
* supplied digest buffer must be large enough to store the resulting
* hash. No error is returned, the function will abort on an invalid
* algo. DISABLED_ALGOS are ignored here. */
void
_gcry_md_hash_buffer (int algo, void *digest,
const void *buffer, size_t length)
{
if (0)
;
#if USE_SHA256
else if (algo == GCRY_MD_SHA256)
_gcry_sha256_hash_buffer (digest, buffer, length);
#endif
#if USE_SHA512
else if (algo == GCRY_MD_SHA512)
_gcry_sha512_hash_buffer (digest, buffer, length);
#endif
#if USE_SHA1
else if (algo == GCRY_MD_SHA1)
_gcry_sha1_hash_buffer (digest, buffer, length);
#endif
#if USE_RMD160
else if (algo == GCRY_MD_RMD160 && !fips_mode () )
_gcry_rmd160_hash_buffer (digest, buffer, length);
#endif
else
{
/* For the others we do not have a fast function, so we use the
normal functions. */
gcry_md_hd_t h;
gpg_err_code_t err;
if (algo == GCRY_MD_MD5 && fips_mode ())
{
_gcry_inactivate_fips_mode ("MD5 used");
if (_gcry_enforced_fips_mode () )
{
/* We should never get to here because we do not register
MD5 in enforced fips mode. */
_gcry_fips_noreturn ();
}
}
err = md_open (&h, algo, 0);
if (err)
log_bug ("gcry_md_open failed for algo %d: %s",
algo, gpg_strerror (gcry_error(err)));
md_write (h, (byte *) buffer, length);
md_final (h);
memcpy (digest, md_read (h, algo), md_digest_length (algo));
md_close (h);
}
}
/* Shortcut function to hash multiple buffers with a given algo. In
contrast to gcry_md_hash_buffer, this function returns an error on
invalid arguments or on other problems; disabled algorithms are
_not_ ignored but flagged as an error.
The data to sign is taken from the array IOV which has IOVCNT items.
The only supported flag in FLAGS is GCRY_MD_FLAG_HMAC which turns
this function into a HMAC function; the first item in IOV is then
used as the key.
On success 0 is returned and resulting hash or HMAC is stored at
DIGEST which must have been provided by the caller with an
appropriate length. */
gpg_err_code_t
_gcry_md_hash_buffers (int algo, unsigned int flags, void *digest,
const gcry_buffer_t *iov, int iovcnt)
{
int hmac;
if (!iov || iovcnt < 0)
return GPG_ERR_INV_ARG;
if (flags & ~(GCRY_MD_FLAG_HMAC))
return GPG_ERR_INV_ARG;
hmac = !!(flags & GCRY_MD_FLAG_HMAC);
if (hmac && iovcnt < 1)
return GPG_ERR_INV_ARG;
if (0)
;
#if USE_SHA256
else if (algo == GCRY_MD_SHA256 && !hmac)
_gcry_sha256_hash_buffers (digest, iov, iovcnt);
#endif
#if USE_SHA512
else if (algo == GCRY_MD_SHA512 && !hmac)
_gcry_sha512_hash_buffers (digest, iov, iovcnt);
#endif
#if USE_SHA1
else if (algo == GCRY_MD_SHA1 && !hmac)
_gcry_sha1_hash_buffers (digest, iov, iovcnt);
#endif
else
{
/* For the others we do not have a fast function, so we use the
normal functions. */
gcry_md_hd_t h;
gpg_err_code_t rc;
int dlen;
if (algo == GCRY_MD_MD5 && fips_mode ())
{
_gcry_inactivate_fips_mode ("MD5 used");
if (_gcry_enforced_fips_mode () )
{
/* We should never get to here because we do not register
MD5 in enforced fips mode. */
_gcry_fips_noreturn ();
}
}
/* Detect SHAKE128 like algorithms which we can't use because
* our API does not allow for a variable length digest. */
dlen = md_digest_length (algo);
if (!dlen)
return GPG_ERR_DIGEST_ALGO;
rc = md_open (&h, algo, (hmac? GCRY_MD_FLAG_HMAC:0));
if (rc)
return rc;
if (hmac)
{
rc = _gcry_md_setkey (h,
(const char*)iov[0].data + iov[0].off,
iov[0].len);
if (rc)
{
md_close (h);
return rc;
}
iov++; iovcnt--;
}
for (;iovcnt; iov++, iovcnt--)
md_write (h, (const char*)iov[0].data + iov[0].off, iov[0].len);
md_final (h);
memcpy (digest, md_read (h, algo), dlen);
md_close (h);
}
return 0;
}
static int
md_get_algo (gcry_md_hd_t a)
{
GcryDigestEntry *r = a->ctx->list;
if (r && r->next)
{
fips_signal_error ("possible usage error");
log_error ("WARNING: more than one algorithm in md_get_algo()\n");
}
return r ? r->spec->algo : 0;
}
int
_gcry_md_get_algo (gcry_md_hd_t hd)
{
return md_get_algo (hd);
}
/****************
* Return the length of the digest
*/
static int
md_digest_length (int algorithm)
{
gcry_md_spec_t *spec;
spec = spec_from_algo (algorithm);
return spec? spec->mdlen : 0;
}
/****************
* Return the length of the digest in bytes.
* This function will return 0 in case of errors.
*/
unsigned int
_gcry_md_get_algo_dlen (int algorithm)
{
return md_digest_length (algorithm);
}
/* Hmmm: add a mode to enumerate the OIDs
* to make g10/sig-check.c more portable */
static const byte *
md_asn_oid (int algorithm, size_t *asnlen, size_t *mdlen)
{
gcry_md_spec_t *spec;
const byte *asnoid = NULL;
spec = spec_from_algo (algorithm);
if (spec)
{
if (asnlen)
*asnlen = spec->asnlen;
if (mdlen)
*mdlen = spec->mdlen;
asnoid = spec->asnoid;
}
else
log_bug ("no ASN.1 OID for md algo %d\n", algorithm);
return asnoid;
}
/****************
* Return information about the given cipher algorithm
* WHAT select the kind of information returned:
* GCRYCTL_TEST_ALGO:
* Returns 0 when the specified algorithm is available for use.
* buffer and nbytes must be zero.
* GCRYCTL_GET_ASNOID:
* Return the ASNOID of the algorithm in buffer. if buffer is NULL, only
* the required length is returned.
* GCRYCTL_SELFTEST
* Helper for the regression tests - shall not be used by applications.
*
* 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_md_algo_info (int algo, int what, void *buffer, size_t *nbytes)
{
gcry_err_code_t rc;
switch (what)
{
case GCRYCTL_TEST_ALGO:
if (buffer || nbytes)
rc = GPG_ERR_INV_ARG;
else
rc = check_digest_algo (algo);
break;
case GCRYCTL_GET_ASNOID:
/* We need to check that the algo is available because
md_asn_oid would otherwise raise an assertion. */
rc = check_digest_algo (algo);
if (!rc)
{
const char unsigned *asn;
size_t asnlen;
asn = md_asn_oid (algo, &asnlen, NULL);
if (buffer && (*nbytes >= asnlen))
{
memcpy (buffer, asn, asnlen);
*nbytes = asnlen;
}
else if (!buffer && nbytes)
*nbytes = asnlen;
else
{
if (buffer)
rc = GPG_ERR_TOO_SHORT;
else
rc = GPG_ERR_INV_ARG;
}
}
break;
case GCRYCTL_SELFTEST:
/* Helper function for the regression tests. */
rc = gpg_err_code (_gcry_md_selftest (algo, nbytes? (int)*nbytes : 0,
NULL));
break;
default:
rc = GPG_ERR_INV_OP;
break;
}
return rc;
}
static void
md_start_debug ( gcry_md_hd_t md, const char *suffix )
{
static int idx=0;
char buf[50];
if (fips_mode ())
return;
if ( md->ctx->debug )
{
log_debug("Oops: md debug already started\n");
return;
}
idx++;
snprintf (buf, DIM(buf)-1, "dbgmd-%05d.%.10s", idx, suffix );
md->ctx->debug = fopen(buf, "w");
if ( !md->ctx->debug )
log_debug("md debug: can't open %s\n", buf );
}
static void
md_stop_debug( gcry_md_hd_t md )
{
if ( md->ctx->debug )
{
if ( md->bufpos )
md_write ( md, NULL, 0 );
fclose (md->ctx->debug);
md->ctx->debug = NULL;
}
{ /* a kludge to pull in the __muldi3 for Solaris */
volatile u32 a = (u32)(uintptr_t)md;
volatile u64 b = 42;
volatile u64 c;
c = a * b;
(void)c;
}
}
/*
* Return information about the digest handle.
* GCRYCTL_IS_SECURE:
* Returns 1 when the handle works on secured memory
* otherwise 0 is returned. There is no error return.
* GCRYCTL_IS_ALGO_ENABLED:
* Returns 1 if the algo is enabled for that handle.
* The algo must be passed as the address of an int.
*/
gcry_err_code_t
_gcry_md_info (gcry_md_hd_t h, int cmd, void *buffer, size_t *nbytes)
{
gcry_err_code_t rc = 0;
switch (cmd)
{
case GCRYCTL_IS_SECURE:
*nbytes = h->ctx->flags.secure;
break;
case GCRYCTL_IS_ALGO_ENABLED:
{
GcryDigestEntry *r;
int algo;
if ( !buffer || !nbytes || *nbytes != sizeof (int))
rc = GPG_ERR_INV_ARG;
else
{
algo = *(int*)buffer;
*nbytes = 0;
for(r=h->ctx->list; r; r = r->next ) {
if (r->spec->algo == algo)
{
*nbytes = 1;
break;
}
}
}
break;
}
default:
rc = GPG_ERR_INV_OP;
}
return rc;
}
/* Explicitly initialize this module. */
gcry_err_code_t
_gcry_md_init (void)
{
if (fips_mode())
{
/* disable algorithms that are disallowed in fips */
int idx;
gcry_md_spec_t *spec;
for (idx = 0; (spec = digest_list[idx]); idx++)
if (!spec->flags.fips)
spec->flags.disabled = 1;
}
return 0;
}
int
_gcry_md_is_secure (gcry_md_hd_t a)
{
size_t value;
if (_gcry_md_info (a, GCRYCTL_IS_SECURE, NULL, &value))
value = 1; /* It seems to be better to assume secure memory on
error. */
return value;
}
int
_gcry_md_is_enabled (gcry_md_hd_t a, int algo)
{
size_t value;
value = sizeof algo;
if (_gcry_md_info (a, GCRYCTL_IS_ALGO_ENABLED, &algo, &value))
value = 0;
return value;
}
/* Run the selftests for digest algorithm ALGO with optional reporting
function REPORT. */
gpg_error_t
_gcry_md_selftest (int algo, int extended, selftest_report_func_t report)
{
gcry_err_code_t ec = 0;
gcry_md_spec_t *spec;
spec = spec_from_algo (algo);
if (spec && !spec->flags.disabled && spec->selftest)
ec = spec->selftest (algo, extended, report);
else
{
ec = (spec && spec->selftest) ? GPG_ERR_DIGEST_ALGO
/* */ : GPG_ERR_NOT_IMPLEMENTED;
if (report)
report ("digest", algo, "module",
(spec && !spec->flags.disabled)?
"no selftest available" :
spec? "algorithm disabled" : "algorithm not found");
}
return gpg_error (ec);
}