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crypto: skcipher - Use RNG interface instead of get_random_bytes
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This patch makes the IV generators use the new RNG interface so
that the user can pick an RNG other than the default get_random_bytes.

Signed-off-by: Herbert Xu <[email protected]>
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@herbertx
herbertx committed Aug 29, 2008
1 parent 17f0f4a commit a0f000e
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Showing 4 changed files with 75 additions and 13 deletions.
2 changes: 2 additions & 0 deletions crypto/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,7 @@ config CRYPTO_AEAD
config CRYPTO_BLKCIPHER
tristate
select CRYPTO_ALGAPI
select CRYPTO_RNG

config CRYPTO_HASH
tristate
Expand Down Expand Up @@ -125,6 +126,7 @@ config CRYPTO_SEQIV
tristate "Sequence Number IV Generator"
select CRYPTO_AEAD
select CRYPTO_BLKCIPHER
select CRYPTO_RNG
help
This IV generator generates an IV based on a sequence number by
xoring it with a salt. This algorithm is mainly useful for CTR
Expand Down
34 changes: 29 additions & 5 deletions crypto/chainiv.c
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Original file line number Diff line number Diff line change
Expand Up @@ -14,11 +14,11 @@
*/

#include <crypto/internal/skcipher.h>
#include <crypto/rng.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/workqueue.h>
Expand Down Expand Up @@ -83,18 +83,23 @@ static int chainiv_givencrypt_first(struct skcipher_givcrypt_request *req)
{
struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);
struct chainiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
int err = 0;

spin_lock_bh(&ctx->lock);
if (crypto_ablkcipher_crt(geniv)->givencrypt !=
chainiv_givencrypt_first)
goto unlock;

crypto_ablkcipher_crt(geniv)->givencrypt = chainiv_givencrypt;
get_random_bytes(ctx->iv, crypto_ablkcipher_ivsize(geniv));
err = crypto_rng_get_bytes(crypto_default_rng, ctx->iv,
crypto_ablkcipher_ivsize(geniv));

unlock:
spin_unlock_bh(&ctx->lock);

if (err)
return err;

return chainiv_givencrypt(req);
}

Expand Down Expand Up @@ -203,6 +208,7 @@ static int async_chainiv_givencrypt_first(struct skcipher_givcrypt_request *req)
{
struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);
struct async_chainiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
int err = 0;

if (test_and_set_bit(CHAINIV_STATE_INUSE, &ctx->state))
goto out;
Expand All @@ -212,11 +218,15 @@ static int async_chainiv_givencrypt_first(struct skcipher_givcrypt_request *req)
goto unlock;

crypto_ablkcipher_crt(geniv)->givencrypt = async_chainiv_givencrypt;
get_random_bytes(ctx->iv, crypto_ablkcipher_ivsize(geniv));
err = crypto_rng_get_bytes(crypto_default_rng, ctx->iv,
crypto_ablkcipher_ivsize(geniv));

unlock:
clear_bit(CHAINIV_STATE_INUSE, &ctx->state);

if (err)
return err;

out:
return async_chainiv_givencrypt(req);
}
Expand Down Expand Up @@ -284,9 +294,13 @@ static struct crypto_instance *chainiv_alloc(struct rtattr **tb)
if (IS_ERR(algt))
return ERR_PTR(err);

err = crypto_get_default_rng();
if (err)
return ERR_PTR(err);

inst = skcipher_geniv_alloc(&chainiv_tmpl, tb, 0, 0);
if (IS_ERR(inst))
goto out;
goto put_rng;

inst->alg.cra_ablkcipher.givencrypt = chainiv_givencrypt_first;

Expand All @@ -311,12 +325,22 @@ static struct crypto_instance *chainiv_alloc(struct rtattr **tb)

out:
return inst;

put_rng:
crypto_put_default_rng();
goto out;
}

static void chainiv_free(struct crypto_instance *inst)
{
skcipher_geniv_free(inst);
crypto_put_default_rng();
}

static struct crypto_template chainiv_tmpl = {
.name = "chainiv",
.alloc = chainiv_alloc,
.free = skcipher_geniv_free,
.free = chainiv_free,
.module = THIS_MODULE,
};

Expand Down
25 changes: 21 additions & 4 deletions crypto/eseqiv.c
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Original file line number Diff line number Diff line change
Expand Up @@ -16,13 +16,13 @@
*/

#include <crypto/internal/skcipher.h>
#include <crypto/rng.h>
#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/scatterlist.h>
#include <linux/spinlock.h>
#include <linux/string.h>
Expand Down Expand Up @@ -163,17 +163,22 @@ static int eseqiv_givencrypt_first(struct skcipher_givcrypt_request *req)
{
struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);
struct eseqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
int err = 0;

spin_lock_bh(&ctx->lock);
if (crypto_ablkcipher_crt(geniv)->givencrypt != eseqiv_givencrypt_first)
goto unlock;

crypto_ablkcipher_crt(geniv)->givencrypt = eseqiv_givencrypt;
get_random_bytes(ctx->salt, crypto_ablkcipher_ivsize(geniv));
err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
crypto_ablkcipher_ivsize(geniv));

unlock:
spin_unlock_bh(&ctx->lock);

if (err)
return err;

return eseqiv_givencrypt(req);
}

Expand Down Expand Up @@ -216,9 +221,13 @@ static struct crypto_instance *eseqiv_alloc(struct rtattr **tb)
struct crypto_instance *inst;
int err;

err = crypto_get_default_rng();
if (err)
return ERR_PTR(err);

inst = skcipher_geniv_alloc(&eseqiv_tmpl, tb, 0, 0);
if (IS_ERR(inst))
goto out;
goto put_rng;

err = -EINVAL;
if (inst->alg.cra_ablkcipher.ivsize != inst->alg.cra_blocksize)
Expand All @@ -238,13 +247,21 @@ static struct crypto_instance *eseqiv_alloc(struct rtattr **tb)
free_inst:
skcipher_geniv_free(inst);
inst = ERR_PTR(err);
put_rng:
crypto_put_default_rng();
goto out;
}

static void eseqiv_free(struct crypto_instance *inst)
{
skcipher_geniv_free(inst);
crypto_put_default_rng();
}

static struct crypto_template eseqiv_tmpl = {
.name = "eseqiv",
.alloc = eseqiv_alloc,
.free = skcipher_geniv_free,
.free = eseqiv_free,
.module = THIS_MODULE,
};

Expand Down
27 changes: 23 additions & 4 deletions crypto/seqiv.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -15,11 +15,11 @@

#include <crypto/internal/aead.h>
#include <crypto/internal/skcipher.h>
#include <crypto/rng.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/spinlock.h>
#include <linux/string.h>

Expand Down Expand Up @@ -189,35 +189,45 @@ static int seqiv_givencrypt_first(struct skcipher_givcrypt_request *req)
{
struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);
struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
int err = 0;

spin_lock_bh(&ctx->lock);
if (crypto_ablkcipher_crt(geniv)->givencrypt != seqiv_givencrypt_first)
goto unlock;

crypto_ablkcipher_crt(geniv)->givencrypt = seqiv_givencrypt;
get_random_bytes(ctx->salt, crypto_ablkcipher_ivsize(geniv));
err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
crypto_ablkcipher_ivsize(geniv));

unlock:
spin_unlock_bh(&ctx->lock);

if (err)
return err;

return seqiv_givencrypt(req);
}

static int seqiv_aead_givencrypt_first(struct aead_givcrypt_request *req)
{
struct crypto_aead *geniv = aead_givcrypt_reqtfm(req);
struct seqiv_ctx *ctx = crypto_aead_ctx(geniv);
int err = 0;

spin_lock_bh(&ctx->lock);
if (crypto_aead_crt(geniv)->givencrypt != seqiv_aead_givencrypt_first)
goto unlock;

crypto_aead_crt(geniv)->givencrypt = seqiv_aead_givencrypt;
get_random_bytes(ctx->salt, crypto_aead_ivsize(geniv));
err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
crypto_aead_ivsize(geniv));

unlock:
spin_unlock_bh(&ctx->lock);

if (err)
return err;

return seqiv_aead_givencrypt(req);
}

Expand Down Expand Up @@ -298,19 +308,27 @@ static struct crypto_instance *seqiv_alloc(struct rtattr **tb)
if (IS_ERR(algt))
return ERR_PTR(err);

err = crypto_get_default_rng();
if (err)
return ERR_PTR(err);

if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK)
inst = seqiv_ablkcipher_alloc(tb);
else
inst = seqiv_aead_alloc(tb);

if (IS_ERR(inst))
goto out;
goto put_rng;

inst->alg.cra_alignmask |= __alignof__(u32) - 1;
inst->alg.cra_ctxsize += sizeof(struct seqiv_ctx);

out:
return inst;

put_rng:
crypto_put_default_rng();
goto out;
}

static void seqiv_free(struct crypto_instance *inst)
Expand All @@ -319,6 +337,7 @@ static void seqiv_free(struct crypto_instance *inst)
skcipher_geniv_free(inst);
else
aead_geniv_free(inst);
crypto_put_default_rng();
}

static struct crypto_template seqiv_tmpl = {
Expand Down

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