crypto: drbg - Convert to new rng interface

This patch converts the DRBG implementation to the new low-level
rng interface.

This allows us to get rid of struct drbg_gen by using the new RNG
API instead.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Stephan Mueller <smueller@chronox.de>
This commit is contained in:
Herbert Xu 2015-04-21 10:46:41 +08:00
parent 881cd6c570
commit 8fded5925d
2 changed files with 65 additions and 106 deletions

View File

@ -235,7 +235,7 @@ static bool drbg_fips_continuous_test(struct drbg_state *drbg,
#ifdef CONFIG_CRYPTO_FIPS #ifdef CONFIG_CRYPTO_FIPS
int ret = 0; int ret = 0;
/* skip test if we test the overall system */ /* skip test if we test the overall system */
if (drbg->test_data) if (list_empty(&drbg->test_data.list))
return true; return true;
/* only perform test in FIPS mode */ /* only perform test in FIPS mode */
if (0 == fips_enabled) if (0 == fips_enabled)
@ -1068,9 +1068,9 @@ static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers,
return -EINVAL; return -EINVAL;
} }
if (drbg->test_data && drbg->test_data->testentropy) { if (list_empty(&drbg->test_data.list)) {
drbg_string_fill(&data1, drbg->test_data->testentropy->buf, drbg_string_fill(&data1, drbg->test_data.buf,
drbg->test_data->testentropy->len); drbg->test_data.len);
pr_devel("DRBG: using test entropy\n"); pr_devel("DRBG: using test entropy\n");
} else { } else {
/* /*
@ -1471,15 +1471,16 @@ static int drbg_uninstantiate(struct drbg_state *drbg)
* Helper function for setting the test data in the DRBG * Helper function for setting the test data in the DRBG
* *
* @drbg DRBG state handle * @drbg DRBG state handle
* @test_data test data to sets * @data test data
* @len test data length
*/ */
static inline void drbg_set_testdata(struct drbg_state *drbg, static void drbg_kcapi_set_entropy(struct crypto_rng *tfm,
struct drbg_test_data *test_data) const u8 *data, unsigned int len)
{ {
if (!test_data || !test_data->testentropy) struct drbg_state *drbg = crypto_rng_ctx(tfm);
return;
mutex_lock(&drbg->drbg_mutex);; mutex_lock(&drbg->drbg_mutex);
drbg->test_data = test_data; drbg_string_fill(&drbg->test_data, data, len);
mutex_unlock(&drbg->drbg_mutex); mutex_unlock(&drbg->drbg_mutex);
} }
@ -1645,63 +1646,49 @@ static void drbg_kcapi_cleanup(struct crypto_tfm *tfm)
* Generate random numbers invoked by the kernel crypto API: * Generate random numbers invoked by the kernel crypto API:
* The API of the kernel crypto API is extended as follows: * The API of the kernel crypto API is extended as follows:
* *
* If dlen is larger than zero, rdata is interpreted as the output buffer * src is additional input supplied to the RNG.
* where random data is to be stored. * slen is the length of src.
* * dst is the output buffer where random data is to be stored.
* If dlen is zero, rdata is interpreted as a pointer to a struct drbg_gen * dlen is the length of dst.
* which holds the additional information string that is used for the
* DRBG generation process. The output buffer that is to be used to store
* data is also pointed to by struct drbg_gen.
*/ */
static int drbg_kcapi_random(struct crypto_rng *tfm, u8 *rdata, static int drbg_kcapi_random(struct crypto_rng *tfm,
unsigned int dlen) const u8 *src, unsigned int slen,
u8 *dst, unsigned int dlen)
{ {
struct drbg_state *drbg = crypto_rng_ctx(tfm); struct drbg_state *drbg = crypto_rng_ctx(tfm);
if (0 < dlen) { struct drbg_string *addtl = NULL;
return drbg_generate_long(drbg, rdata, dlen, NULL); struct drbg_string string;
} else {
struct drbg_gen *data = (struct drbg_gen *)rdata; if (slen) {
struct drbg_string addtl;
/* catch NULL pointer */
if (!data)
return 0;
drbg_set_testdata(drbg, data->test_data);
/* linked list variable is now local to allow modification */ /* linked list variable is now local to allow modification */
drbg_string_fill(&addtl, data->addtl->buf, data->addtl->len); drbg_string_fill(&string, src, slen);
return drbg_generate_long(drbg, data->outbuf, data->outlen, addtl = &string;
&addtl);
} }
return drbg_generate_long(drbg, dst, dlen, addtl);
} }
/* /*
* Seed the DRBG invoked by the kernel crypto API * Seed the DRBG invoked by the kernel crypto API
* Similar to the generate function of drbg_kcapi_random, this
* function extends the kernel crypto API interface with struct drbg_gen
*/ */
static int drbg_kcapi_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen) static int drbg_kcapi_seed(struct crypto_rng *tfm,
const u8 *seed, unsigned int slen)
{ {
struct drbg_state *drbg = crypto_rng_ctx(tfm); struct drbg_state *drbg = crypto_rng_ctx(tfm);
struct crypto_tfm *tfm_base = crypto_rng_tfm(tfm); struct crypto_tfm *tfm_base = crypto_rng_tfm(tfm);
bool pr = false; bool pr = false;
struct drbg_string seed_string; struct drbg_string string;
struct drbg_string *seed_string = NULL;
int coreref = 0; int coreref = 0;
drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm_base), &coreref, drbg_convert_tfm_core(crypto_tfm_alg_driver_name(tfm_base), &coreref,
&pr); &pr);
if (0 < slen) { if (0 < slen) {
drbg_string_fill(&seed_string, seed, slen); drbg_string_fill(&string, seed, slen);
return drbg_instantiate(drbg, &seed_string, coreref, pr); seed_string = &string;
} else {
struct drbg_gen *data = (struct drbg_gen *)seed;
/* allow invocation of API call with NULL, 0 */
if (!data)
return drbg_instantiate(drbg, NULL, coreref, pr);
drbg_set_testdata(drbg, data->test_data);
/* linked list variable is now local to allow modification */
drbg_string_fill(&seed_string, data->addtl->buf,
data->addtl->len);
return drbg_instantiate(drbg, &seed_string, coreref, pr);
} }
return drbg_instantiate(drbg, seed_string, coreref, pr);
} }
/*************************************************************** /***************************************************************
@ -1793,32 +1780,31 @@ outbuf:
#endif /* CONFIG_CRYPTO_FIPS */ #endif /* CONFIG_CRYPTO_FIPS */
} }
static struct crypto_alg drbg_algs[22]; static struct rng_alg drbg_algs[22];
/* /*
* Fill the array drbg_algs used to register the different DRBGs * Fill the array drbg_algs used to register the different DRBGs
* with the kernel crypto API. To fill the array, the information * with the kernel crypto API. To fill the array, the information
* from drbg_cores[] is used. * from drbg_cores[] is used.
*/ */
static inline void __init drbg_fill_array(struct crypto_alg *alg, static inline void __init drbg_fill_array(struct rng_alg *alg,
const struct drbg_core *core, int pr) const struct drbg_core *core, int pr)
{ {
int pos = 0; int pos = 0;
static int priority = 100; static int priority = 100;
memset(alg, 0, sizeof(struct crypto_alg)); memcpy(alg->base.cra_name, "stdrng", 6);
memcpy(alg->cra_name, "stdrng", 6);
if (pr) { if (pr) {
memcpy(alg->cra_driver_name, "drbg_pr_", 8); memcpy(alg->base.cra_driver_name, "drbg_pr_", 8);
pos = 8; pos = 8;
} else { } else {
memcpy(alg->cra_driver_name, "drbg_nopr_", 10); memcpy(alg->base.cra_driver_name, "drbg_nopr_", 10);
pos = 10; pos = 10;
} }
memcpy(alg->cra_driver_name + pos, core->cra_name, memcpy(alg->base.cra_driver_name + pos, core->cra_name,
strlen(core->cra_name)); strlen(core->cra_name));
alg->cra_priority = priority; alg->base.cra_priority = priority;
priority++; priority++;
/* /*
* If FIPS mode enabled, the selected DRBG shall have the * If FIPS mode enabled, the selected DRBG shall have the
@ -1826,17 +1812,16 @@ static inline void __init drbg_fill_array(struct crypto_alg *alg,
* it is selected. * it is selected.
*/ */
if (fips_enabled) if (fips_enabled)
alg->cra_priority += 200; alg->base.cra_priority += 200;
alg->cra_flags = CRYPTO_ALG_TYPE_RNG; alg->base.cra_ctxsize = sizeof(struct drbg_state);
alg->cra_ctxsize = sizeof(struct drbg_state); alg->base.cra_module = THIS_MODULE;
alg->cra_type = &crypto_rng_type; alg->base.cra_init = drbg_kcapi_init;
alg->cra_module = THIS_MODULE; alg->base.cra_exit = drbg_kcapi_cleanup;
alg->cra_init = drbg_kcapi_init; alg->generate = drbg_kcapi_random;
alg->cra_exit = drbg_kcapi_cleanup; alg->seed = drbg_kcapi_seed;
alg->cra_u.rng.rng_make_random = drbg_kcapi_random; alg->set_ent = drbg_kcapi_set_entropy;
alg->cra_u.rng.rng_reset = drbg_kcapi_reset; alg->seedsize = 0;
alg->cra_u.rng.seedsize = 0;
} }
static int __init drbg_init(void) static int __init drbg_init(void)
@ -1869,12 +1854,12 @@ static int __init drbg_init(void)
drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 1); drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 1);
for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++) for (j = 0; ARRAY_SIZE(drbg_cores) > j; j++, i++)
drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 0); drbg_fill_array(&drbg_algs[i], &drbg_cores[j], 0);
return crypto_register_algs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2)); return crypto_register_rngs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2));
} }
static void __exit drbg_exit(void) static void __exit drbg_exit(void)
{ {
crypto_unregister_algs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2)); crypto_unregister_rngs(drbg_algs, (ARRAY_SIZE(drbg_cores) * 2));
} }
module_init(drbg_init); module_init(drbg_init);

View File

@ -121,7 +121,7 @@ struct drbg_state {
#endif #endif
const struct drbg_state_ops *d_ops; const struct drbg_state_ops *d_ops;
const struct drbg_core *core; const struct drbg_core *core;
struct drbg_test_data *test_data; struct drbg_string test_data;
}; };
static inline __u8 drbg_statelen(struct drbg_state *drbg) static inline __u8 drbg_statelen(struct drbg_state *drbg)
@ -176,20 +176,9 @@ static inline size_t drbg_max_requests(struct drbg_state *drbg)
#endif #endif
} }
/*
* kernel crypto API input data structure for DRBG generate in case dlen
* is set to 0
*/
struct drbg_gen {
unsigned char *outbuf; /* output buffer for random numbers */
unsigned int outlen; /* size of output buffer */
struct drbg_string *addtl; /* additional information string */
struct drbg_test_data *test_data; /* test data */
};
/* /*
* This is a wrapper to the kernel crypto API function of * This is a wrapper to the kernel crypto API function of
* crypto_rng_get_bytes() to allow the caller to provide additional data. * crypto_rng_generate() to allow the caller to provide additional data.
* *
* @drng DRBG handle -- see crypto_rng_get_bytes * @drng DRBG handle -- see crypto_rng_get_bytes
* @outbuf output buffer -- see crypto_rng_get_bytes * @outbuf output buffer -- see crypto_rng_get_bytes
@ -204,21 +193,15 @@ static inline int crypto_drbg_get_bytes_addtl(struct crypto_rng *drng,
unsigned char *outbuf, unsigned int outlen, unsigned char *outbuf, unsigned int outlen,
struct drbg_string *addtl) struct drbg_string *addtl)
{ {
int ret; return crypto_rng_generate(drng, addtl->buf, addtl->len,
struct drbg_gen genbuf; outbuf, outlen);
genbuf.outbuf = outbuf;
genbuf.outlen = outlen;
genbuf.addtl = addtl;
genbuf.test_data = NULL;
ret = crypto_rng_get_bytes(drng, (u8 *)&genbuf, 0);
return ret;
} }
/* /*
* TEST code * TEST code
* *
* This is a wrapper to the kernel crypto API function of * This is a wrapper to the kernel crypto API function of
* crypto_rng_get_bytes() to allow the caller to provide additional data and * crypto_rng_generate() to allow the caller to provide additional data and
* allow furnishing of test_data * allow furnishing of test_data
* *
* @drng DRBG handle -- see crypto_rng_get_bytes * @drng DRBG handle -- see crypto_rng_get_bytes
@ -236,14 +219,10 @@ static inline int crypto_drbg_get_bytes_addtl_test(struct crypto_rng *drng,
struct drbg_string *addtl, struct drbg_string *addtl,
struct drbg_test_data *test_data) struct drbg_test_data *test_data)
{ {
int ret; crypto_rng_set_entropy(drng, test_data->testentropy->buf,
struct drbg_gen genbuf; test_data->testentropy->len);
genbuf.outbuf = outbuf; return crypto_rng_generate(drng, addtl->buf, addtl->len,
genbuf.outlen = outlen; outbuf, outlen);
genbuf.addtl = addtl;
genbuf.test_data = test_data;
ret = crypto_rng_get_bytes(drng, (u8 *)&genbuf, 0);
return ret;
} }
/* /*
@ -264,14 +243,9 @@ static inline int crypto_drbg_reset_test(struct crypto_rng *drng,
struct drbg_string *pers, struct drbg_string *pers,
struct drbg_test_data *test_data) struct drbg_test_data *test_data)
{ {
int ret; crypto_rng_set_entropy(drng, test_data->testentropy->buf,
struct drbg_gen genbuf; test_data->testentropy->len);
genbuf.outbuf = NULL; return crypto_rng_reset(drng, pers->buf, pers->len);
genbuf.outlen = 0;
genbuf.addtl = pers;
genbuf.test_data = test_data;
ret = crypto_rng_reset(drng, (u8 *)&genbuf, 0);
return ret;
} }
/* DRBG type flags */ /* DRBG type flags */