crypto: sun4i-ss - support the Security System PRNG

The Security System has a PRNG, this patch adds support for it via
crypto_rng.

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Corentin LABBE 2017-07-03 20:48:48 +02:00 committed by Herbert Xu
parent 3822c331c5
commit b8ae5c7387
5 changed files with 106 additions and 0 deletions

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@ -616,6 +616,14 @@ config CRYPTO_DEV_SUN4I_SS
To compile this driver as a module, choose M here: the module
will be called sun4i-ss.
config CRYPTO_DEV_SUN4I_SS_PRNG
bool "Support for Allwinner Security System PRNG"
depends on CRYPTO_DEV_SUN4I_SS
select CRYPTO_RNG
help
Select this option if you want to provide kernel-side support for
the Pseudo-Random Number Generator found in the Security System.
config CRYPTO_DEV_ROCKCHIP
tristate "Rockchip's Cryptographic Engine driver"
depends on OF && ARCH_ROCKCHIP

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@ -1,2 +1,3 @@
obj-$(CONFIG_CRYPTO_DEV_SUN4I_SS) += sun4i-ss.o
sun4i-ss-y += sun4i-ss-core.o sun4i-ss-hash.o sun4i-ss-cipher.o
sun4i-ss-$(CONFIG_CRYPTO_DEV_SUN4I_SS_PRNG) += sun4i-ss-prng.o

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@ -213,6 +213,23 @@ static struct sun4i_ss_alg_template ss_algs[] = {
}
}
},
#ifdef CONFIG_CRYPTO_DEV_SUN4I_SS_PRNG
{
.type = CRYPTO_ALG_TYPE_RNG,
.alg.rng = {
.base = {
.cra_name = "stdrng",
.cra_driver_name = "sun4i_ss_rng",
.cra_priority = 300,
.cra_ctxsize = 0,
.cra_module = THIS_MODULE,
},
.generate = sun4i_ss_prng_generate,
.seed = sun4i_ss_prng_seed,
.seedsize = SS_SEED_LEN / BITS_PER_BYTE,
}
},
#endif
};
static int sun4i_ss_probe(struct platform_device *pdev)
@ -355,6 +372,13 @@ static int sun4i_ss_probe(struct platform_device *pdev)
goto error_alg;
}
break;
case CRYPTO_ALG_TYPE_RNG:
err = crypto_register_rng(&ss_algs[i].alg.rng);
if (err) {
dev_err(ss->dev, "Fail to register %s\n",
ss_algs[i].alg.rng.base.cra_name);
}
break;
}
}
platform_set_drvdata(pdev, ss);
@ -369,6 +393,9 @@ error_alg:
case CRYPTO_ALG_TYPE_AHASH:
crypto_unregister_ahash(&ss_algs[i].alg.hash);
break;
case CRYPTO_ALG_TYPE_RNG:
crypto_unregister_rng(&ss_algs[i].alg.rng);
break;
}
}
if (ss->reset)
@ -393,6 +420,9 @@ static int sun4i_ss_remove(struct platform_device *pdev)
case CRYPTO_ALG_TYPE_AHASH:
crypto_unregister_ahash(&ss_algs[i].alg.hash);
break;
case CRYPTO_ALG_TYPE_RNG:
crypto_unregister_rng(&ss_algs[i].alg.rng);
break;
}
}

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@ -0,0 +1,56 @@
#include "sun4i-ss.h"
int sun4i_ss_prng_seed(struct crypto_rng *tfm, const u8 *seed,
unsigned int slen)
{
struct sun4i_ss_alg_template *algt;
struct rng_alg *alg = crypto_rng_alg(tfm);
algt = container_of(alg, struct sun4i_ss_alg_template, alg.rng);
memcpy(algt->ss->seed, seed, slen);
return 0;
}
int sun4i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int dlen)
{
struct sun4i_ss_alg_template *algt;
struct rng_alg *alg = crypto_rng_alg(tfm);
int i;
u32 v;
u32 *data = (u32 *)dst;
const u32 mode = SS_OP_PRNG | SS_PRNG_CONTINUE | SS_ENABLED;
size_t len;
struct sun4i_ss_ctx *ss;
unsigned int todo = (dlen / 4) * 4;
algt = container_of(alg, struct sun4i_ss_alg_template, alg.rng);
ss = algt->ss;
spin_lock(&ss->slock);
writel(mode, ss->base + SS_CTL);
while (todo > 0) {
/* write the seed */
for (i = 0; i < SS_SEED_LEN / BITS_PER_LONG; i++)
writel(ss->seed[i], ss->base + SS_KEY0 + i * 4);
/* Read the random data */
len = min_t(size_t, SS_DATA_LEN / BITS_PER_BYTE, todo);
readsl(ss->base + SS_TXFIFO, data, len / 4);
data += len / 4;
todo -= len;
/* Update the seed */
for (i = 0; i < SS_SEED_LEN / BITS_PER_LONG; i++) {
v = readl(ss->base + SS_KEY0 + i * 4);
ss->seed[i] = v;
}
}
writel(0, ss->base + SS_CTL);
spin_unlock(&ss->slock);
return dlen;
}

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@ -32,6 +32,7 @@
#include <crypto/aes.h>
#include <crypto/des.h>
#include <crypto/internal/rng.h>
#include <crypto/rng.h>
#define SS_CTL 0x00
#define SS_KEY0 0x04
@ -127,6 +128,9 @@
#define SS_RXFIFO_EMP_INT_ENABLE (1 << 2)
#define SS_TXFIFO_AVA_INT_ENABLE (1 << 0)
#define SS_SEED_LEN 192
#define SS_DATA_LEN 160
struct sun4i_ss_ctx {
void __iomem *base;
int irq;
@ -136,6 +140,9 @@ struct sun4i_ss_ctx {
struct device *dev;
struct resource *res;
spinlock_t slock; /* control the use of the device */
#ifdef CONFIG_CRYPTO_DEV_SUN4I_SS_PRNG
u32 seed[SS_SEED_LEN / BITS_PER_LONG];
#endif
};
struct sun4i_ss_alg_template {
@ -144,6 +151,7 @@ struct sun4i_ss_alg_template {
union {
struct skcipher_alg crypto;
struct ahash_alg hash;
struct rng_alg rng;
} alg;
struct sun4i_ss_ctx *ss;
};
@ -201,3 +209,6 @@ int sun4i_ss_des_setkey(struct crypto_skcipher *tfm, const u8 *key,
unsigned int keylen);
int sun4i_ss_des3_setkey(struct crypto_skcipher *tfm, const u8 *key,
unsigned int keylen);
int sun4i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int dlen);
int sun4i_ss_prng_seed(struct crypto_rng *tfm, const u8 *seed, unsigned int slen);