linux/drivers/crypto/starfive/jh7110-rsa.c
Jia Jie Ho 445a4aaf58 crypto: starfive - Add RSA algo support
Adding RSA enc/dec and sign/verify feature for StarFive cryptographic
module. The module only supports mod sizes up to 2048, therefore
calculations more than that will use fallback algo.

Co-developed-by: Huan Feng <huan.feng@starfivetech.com>
Signed-off-by: Huan Feng <huan.feng@starfivetech.com>
Signed-off-by: Jia Jie Ho <jiajie.ho@starfivetech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-06-23 16:15:36 +08:00

618 lines
15 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* StarFive Public Key Algo acceleration driver
*
* Copyright (c) 2022 StarFive Technology
*/
#include <linux/crypto.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-direct.h>
#include <linux/interrupt.h>
#include <linux/iopoll.h>
#include <linux/io.h>
#include <linux/mod_devicetable.h>
#include <crypto/akcipher.h>
#include <crypto/algapi.h>
#include <crypto/internal/akcipher.h>
#include <crypto/internal/rsa.h>
#include <crypto/scatterwalk.h>
#include "jh7110-cryp.h"
#define STARFIVE_PKA_REGS_OFFSET 0x400
#define STARFIVE_PKA_CACR_OFFSET (STARFIVE_PKA_REGS_OFFSET + 0x0)
#define STARFIVE_PKA_CASR_OFFSET (STARFIVE_PKA_REGS_OFFSET + 0x4)
#define STARFIVE_PKA_CAAR_OFFSET (STARFIVE_PKA_REGS_OFFSET + 0x8)
#define STARFIVE_PKA_CAER_OFFSET (STARFIVE_PKA_REGS_OFFSET + 0x108)
#define STARFIVE_PKA_CANR_OFFSET (STARFIVE_PKA_REGS_OFFSET + 0x208)
// R^2 mod N and N0'
#define CRYPTO_CMD_PRE 0x0
// A * R mod N ==> A
#define CRYPTO_CMD_ARN 0x5
// A * E * R mod N ==> A
#define CRYPTO_CMD_AERN 0x6
// A * A * R mod N ==> A
#define CRYPTO_CMD_AARN 0x7
#define STARFIVE_RSA_MAX_KEYSZ 256
#define STARFIVE_RSA_RESET 0x2
static inline int starfive_pka_wait_done(struct starfive_cryp_ctx *ctx)
{
struct starfive_cryp_dev *cryp = ctx->cryp;
return wait_for_completion_timeout(&cryp->pka_done,
usecs_to_jiffies(100000));
}
static inline void starfive_pka_irq_mask_clear(struct starfive_cryp_ctx *ctx)
{
struct starfive_cryp_dev *cryp = ctx->cryp;
u32 stat;
stat = readl(cryp->base + STARFIVE_IE_MASK_OFFSET);
stat &= ~STARFIVE_IE_MASK_PKA_DONE;
writel(stat, cryp->base + STARFIVE_IE_MASK_OFFSET);
reinit_completion(&cryp->pka_done);
}
static void starfive_rsa_free_key(struct starfive_rsa_key *key)
{
if (key->d)
kfree_sensitive(key->d);
if (key->e)
kfree_sensitive(key->e);
if (key->n)
kfree_sensitive(key->n);
memset(key, 0, sizeof(*key));
}
static unsigned int starfive_rsa_get_nbit(u8 *pa, u32 snum, int key_sz)
{
u32 i;
u8 value;
i = snum >> 3;
value = pa[key_sz - i - 1];
value >>= snum & 0x7;
value &= 0x1;
return value;
}
static int starfive_rsa_montgomery_form(struct starfive_cryp_ctx *ctx,
u32 *out, u32 *in, u8 mont,
u32 *mod, int bit_len)
{
struct starfive_cryp_dev *cryp = ctx->cryp;
struct starfive_cryp_request_ctx *rctx = ctx->rctx;
int count = rctx->total / sizeof(u32) - 1;
int loop;
u32 temp;
u8 opsize;
opsize = (bit_len - 1) >> 5;
rctx->csr.pka.v = 0;
writel(rctx->csr.pka.v, cryp->base + STARFIVE_PKA_CACR_OFFSET);
for (loop = 0; loop <= opsize; loop++)
writel(mod[opsize - loop], cryp->base + STARFIVE_PKA_CANR_OFFSET + loop * 4);
if (mont) {
rctx->csr.pka.v = 0;
rctx->csr.pka.cln_done = 1;
rctx->csr.pka.opsize = opsize;
rctx->csr.pka.exposize = opsize;
rctx->csr.pka.cmd = CRYPTO_CMD_PRE;
rctx->csr.pka.start = 1;
rctx->csr.pka.not_r2 = 1;
rctx->csr.pka.ie = 1;
starfive_pka_irq_mask_clear(ctx);
writel(rctx->csr.pka.v, cryp->base + STARFIVE_PKA_CACR_OFFSET);
if (!starfive_pka_wait_done(ctx))
return -ETIMEDOUT;
for (loop = 0; loop <= opsize; loop++)
writel(in[opsize - loop], cryp->base + STARFIVE_PKA_CAAR_OFFSET + loop * 4);
writel(0x1000000, cryp->base + STARFIVE_PKA_CAER_OFFSET);
for (loop = 1; loop <= opsize; loop++)
writel(0, cryp->base + STARFIVE_PKA_CAER_OFFSET + loop * 4);
rctx->csr.pka.v = 0;
rctx->csr.pka.cln_done = 1;
rctx->csr.pka.opsize = opsize;
rctx->csr.pka.exposize = opsize;
rctx->csr.pka.cmd = CRYPTO_CMD_AERN;
rctx->csr.pka.start = 1;
rctx->csr.pka.ie = 1;
starfive_pka_irq_mask_clear(ctx);
writel(rctx->csr.pka.v, cryp->base + STARFIVE_PKA_CACR_OFFSET);
if (!starfive_pka_wait_done(ctx))
return -ETIMEDOUT;
} else {
rctx->csr.pka.v = 0;
rctx->csr.pka.cln_done = 1;
rctx->csr.pka.opsize = opsize;
rctx->csr.pka.exposize = opsize;
rctx->csr.pka.cmd = CRYPTO_CMD_PRE;
rctx->csr.pka.start = 1;
rctx->csr.pka.pre_expf = 1;
rctx->csr.pka.ie = 1;
starfive_pka_irq_mask_clear(ctx);
writel(rctx->csr.pka.v, cryp->base + STARFIVE_PKA_CACR_OFFSET);
if (!starfive_pka_wait_done(ctx))
return -ETIMEDOUT;
for (loop = 0; loop <= count; loop++)
writel(in[count - loop], cryp->base + STARFIVE_PKA_CAER_OFFSET + loop * 4);
/*pad with 0 up to opsize*/
for (loop = count + 1; loop <= opsize; loop++)
writel(0, cryp->base + STARFIVE_PKA_CAER_OFFSET + loop * 4);
rctx->csr.pka.v = 0;
rctx->csr.pka.cln_done = 1;
rctx->csr.pka.opsize = opsize;
rctx->csr.pka.exposize = opsize;
rctx->csr.pka.cmd = CRYPTO_CMD_ARN;
rctx->csr.pka.start = 1;
rctx->csr.pka.ie = 1;
starfive_pka_irq_mask_clear(ctx);
writel(rctx->csr.pka.v, cryp->base + STARFIVE_PKA_CACR_OFFSET);
if (!starfive_pka_wait_done(ctx))
return -ETIMEDOUT;
}
for (loop = 0; loop <= opsize; loop++) {
temp = readl(cryp->base + STARFIVE_PKA_CAAR_OFFSET + 0x4 * loop);
out[opsize - loop] = temp;
}
return 0;
}
static int starfive_rsa_cpu_start(struct starfive_cryp_ctx *ctx, u32 *result,
u8 *de, u32 *n, int key_sz)
{
struct starfive_cryp_dev *cryp = ctx->cryp;
struct starfive_cryp_request_ctx *rctx = ctx->rctx;
struct starfive_rsa_key *key = &ctx->rsa_key;
u32 temp;
int ret = 0;
int opsize, mlen, loop;
unsigned int *mta;
opsize = (key_sz - 1) >> 2;
mta = kmalloc(key_sz, GFP_KERNEL);
if (!mta)
return -ENOMEM;
ret = starfive_rsa_montgomery_form(ctx, mta, (u32 *)rctx->rsa_data,
0, n, key_sz << 3);
if (ret) {
dev_err_probe(cryp->dev, ret, "Conversion to Montgomery failed");
goto rsa_err;
}
for (loop = 0; loop <= opsize; loop++)
writel(mta[opsize - loop],
cryp->base + STARFIVE_PKA_CAER_OFFSET + loop * 4);
for (loop = key->bitlen - 1; loop > 0; loop--) {
mlen = starfive_rsa_get_nbit(de, loop - 1, key_sz);
rctx->csr.pka.v = 0;
rctx->csr.pka.cln_done = 1;
rctx->csr.pka.opsize = opsize;
rctx->csr.pka.exposize = opsize;
rctx->csr.pka.cmd = CRYPTO_CMD_AARN;
rctx->csr.pka.start = 1;
rctx->csr.pka.ie = 1;
starfive_pka_irq_mask_clear(ctx);
writel(rctx->csr.pka.v, cryp->base + STARFIVE_PKA_CACR_OFFSET);
ret = -ETIMEDOUT;
if (!starfive_pka_wait_done(ctx))
goto rsa_err;
if (mlen) {
rctx->csr.pka.v = 0;
rctx->csr.pka.cln_done = 1;
rctx->csr.pka.opsize = opsize;
rctx->csr.pka.exposize = opsize;
rctx->csr.pka.cmd = CRYPTO_CMD_AERN;
rctx->csr.pka.start = 1;
rctx->csr.pka.ie = 1;
starfive_pka_irq_mask_clear(ctx);
writel(rctx->csr.pka.v, cryp->base + STARFIVE_PKA_CACR_OFFSET);
if (!starfive_pka_wait_done(ctx))
goto rsa_err;
}
}
for (loop = 0; loop <= opsize; loop++) {
temp = readl(cryp->base + STARFIVE_PKA_CAAR_OFFSET + 0x4 * loop);
result[opsize - loop] = temp;
}
ret = starfive_rsa_montgomery_form(ctx, result, result, 1, n, key_sz << 3);
if (ret)
dev_err_probe(cryp->dev, ret, "Conversion from Montgomery failed");
rsa_err:
kfree(mta);
return ret;
}
static int starfive_rsa_start(struct starfive_cryp_ctx *ctx, u8 *result,
u8 *de, u8 *n, int key_sz)
{
return starfive_rsa_cpu_start(ctx, (u32 *)result, de, (u32 *)n, key_sz);
}
static int starfive_rsa_enc_core(struct starfive_cryp_ctx *ctx, int enc)
{
struct starfive_cryp_dev *cryp = ctx->cryp;
struct starfive_cryp_request_ctx *rctx = ctx->rctx;
struct starfive_rsa_key *key = &ctx->rsa_key;
int ret = 0;
writel(STARFIVE_RSA_RESET, cryp->base + STARFIVE_PKA_CACR_OFFSET);
rctx->total = sg_copy_to_buffer(rctx->in_sg, rctx->nents,
rctx->rsa_data, rctx->total);
if (enc) {
key->bitlen = key->e_bitlen;
ret = starfive_rsa_start(ctx, rctx->rsa_data, key->e,
key->n, key->key_sz);
} else {
key->bitlen = key->d_bitlen;
ret = starfive_rsa_start(ctx, rctx->rsa_data, key->d,
key->n, key->key_sz);
}
if (ret)
goto err_rsa_crypt;
sg_copy_buffer(rctx->out_sg, sg_nents(rctx->out_sg),
rctx->rsa_data, key->key_sz, 0, 0);
err_rsa_crypt:
writel(STARFIVE_RSA_RESET, cryp->base + STARFIVE_PKA_CACR_OFFSET);
kfree(rctx->rsa_data);
return ret;
}
static int starfive_rsa_enc(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
struct starfive_cryp_dev *cryp = ctx->cryp;
struct starfive_rsa_key *key = &ctx->rsa_key;
struct starfive_cryp_request_ctx *rctx = akcipher_request_ctx(req);
int ret;
if (!key->key_sz) {
akcipher_request_set_tfm(req, ctx->akcipher_fbk);
ret = crypto_akcipher_encrypt(req);
akcipher_request_set_tfm(req, tfm);
return ret;
}
if (unlikely(!key->n || !key->e))
return -EINVAL;
if (req->dst_len < key->key_sz)
return dev_err_probe(cryp->dev, -EOVERFLOW,
"Output buffer length less than parameter n\n");
rctx->in_sg = req->src;
rctx->out_sg = req->dst;
rctx->total = req->src_len;
rctx->nents = sg_nents(rctx->in_sg);
ctx->rctx = rctx;
return starfive_rsa_enc_core(ctx, 1);
}
static int starfive_rsa_dec(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
struct starfive_cryp_dev *cryp = ctx->cryp;
struct starfive_rsa_key *key = &ctx->rsa_key;
struct starfive_cryp_request_ctx *rctx = akcipher_request_ctx(req);
int ret;
if (!key->key_sz) {
akcipher_request_set_tfm(req, ctx->akcipher_fbk);
ret = crypto_akcipher_decrypt(req);
akcipher_request_set_tfm(req, tfm);
return ret;
}
if (unlikely(!key->n || !key->d))
return -EINVAL;
if (req->dst_len < key->key_sz)
return dev_err_probe(cryp->dev, -EOVERFLOW,
"Output buffer length less than parameter n\n");
rctx->in_sg = req->src;
rctx->out_sg = req->dst;
ctx->rctx = rctx;
rctx->total = req->src_len;
return starfive_rsa_enc_core(ctx, 0);
}
static int starfive_rsa_set_n(struct starfive_rsa_key *rsa_key,
const char *value, size_t vlen)
{
const char *ptr = value;
unsigned int bitslen;
int ret;
while (!*ptr && vlen) {
ptr++;
vlen--;
}
rsa_key->key_sz = vlen;
bitslen = rsa_key->key_sz << 3;
/* check valid key size */
if (bitslen & 0x1f)
return -EINVAL;
ret = -ENOMEM;
rsa_key->n = kmemdup(ptr, rsa_key->key_sz, GFP_KERNEL);
if (!rsa_key->n)
goto err;
return 0;
err:
rsa_key->key_sz = 0;
rsa_key->n = NULL;
starfive_rsa_free_key(rsa_key);
return ret;
}
static int starfive_rsa_set_e(struct starfive_rsa_key *rsa_key,
const char *value, size_t vlen)
{
const char *ptr = value;
unsigned char pt;
int loop;
while (!*ptr && vlen) {
ptr++;
vlen--;
}
pt = *ptr;
if (!rsa_key->key_sz || !vlen || vlen > rsa_key->key_sz) {
rsa_key->e = NULL;
return -EINVAL;
}
rsa_key->e = kzalloc(rsa_key->key_sz, GFP_KERNEL);
if (!rsa_key->e)
return -ENOMEM;
for (loop = 8; loop > 0; loop--) {
if (pt >> (loop - 1))
break;
}
rsa_key->e_bitlen = (vlen - 1) * 8 + loop;
memcpy(rsa_key->e + (rsa_key->key_sz - vlen), ptr, vlen);
return 0;
}
static int starfive_rsa_set_d(struct starfive_rsa_key *rsa_key,
const char *value, size_t vlen)
{
const char *ptr = value;
unsigned char pt;
int loop;
int ret;
while (!*ptr && vlen) {
ptr++;
vlen--;
}
pt = *ptr;
ret = -EINVAL;
if (!rsa_key->key_sz || !vlen || vlen > rsa_key->key_sz)
goto err;
ret = -ENOMEM;
rsa_key->d = kzalloc(rsa_key->key_sz, GFP_KERNEL);
if (!rsa_key->d)
goto err;
for (loop = 8; loop > 0; loop--) {
if (pt >> (loop - 1))
break;
}
rsa_key->d_bitlen = (vlen - 1) * 8 + loop;
memcpy(rsa_key->d + (rsa_key->key_sz - vlen), ptr, vlen);
return 0;
err:
rsa_key->d = NULL;
return ret;
}
static int starfive_rsa_setkey(struct crypto_akcipher *tfm, const void *key,
unsigned int keylen, bool private)
{
struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
struct rsa_key raw_key = {NULL};
struct starfive_rsa_key *rsa_key = &ctx->rsa_key;
int ret;
if (private)
ret = rsa_parse_priv_key(&raw_key, key, keylen);
else
ret = rsa_parse_pub_key(&raw_key, key, keylen);
if (ret < 0)
goto err;
starfive_rsa_free_key(rsa_key);
/* Use fallback for mod > 256 + 1 byte prefix */
if (raw_key.n_sz > STARFIVE_RSA_MAX_KEYSZ + 1)
return 0;
ret = starfive_rsa_set_n(rsa_key, raw_key.n, raw_key.n_sz);
if (ret)
return ret;
ret = starfive_rsa_set_e(rsa_key, raw_key.e, raw_key.e_sz);
if (ret)
goto err;
if (private) {
ret = starfive_rsa_set_d(rsa_key, raw_key.d, raw_key.d_sz);
if (ret)
goto err;
}
if (!rsa_key->n || !rsa_key->e) {
ret = -EINVAL;
goto err;
}
if (private && !rsa_key->d) {
ret = -EINVAL;
goto err;
}
return 0;
err:
starfive_rsa_free_key(rsa_key);
return ret;
}
static int starfive_rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
unsigned int keylen)
{
struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
int ret;
ret = crypto_akcipher_set_pub_key(ctx->akcipher_fbk, key, keylen);
if (ret)
return ret;
return starfive_rsa_setkey(tfm, key, keylen, false);
}
static int starfive_rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,
unsigned int keylen)
{
struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
int ret;
ret = crypto_akcipher_set_priv_key(ctx->akcipher_fbk, key, keylen);
if (ret)
return ret;
return starfive_rsa_setkey(tfm, key, keylen, true);
}
static unsigned int starfive_rsa_max_size(struct crypto_akcipher *tfm)
{
struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
if (ctx->rsa_key.key_sz)
return ctx->rsa_key.key_sz;
return crypto_akcipher_maxsize(ctx->akcipher_fbk);
}
static int starfive_rsa_init_tfm(struct crypto_akcipher *tfm)
{
struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
ctx->akcipher_fbk = crypto_alloc_akcipher("rsa-generic", 0, 0);
if (IS_ERR(ctx->akcipher_fbk))
return PTR_ERR(ctx->akcipher_fbk);
ctx->cryp = starfive_cryp_find_dev(ctx);
if (!ctx->cryp) {
crypto_free_akcipher(ctx->akcipher_fbk);
return -ENODEV;
}
akcipher_set_reqsize(tfm, sizeof(struct starfive_cryp_request_ctx) +
sizeof(struct crypto_akcipher) + 32);
return 0;
}
static void starfive_rsa_exit_tfm(struct crypto_akcipher *tfm)
{
struct starfive_cryp_ctx *ctx = akcipher_tfm_ctx(tfm);
struct starfive_rsa_key *key = (struct starfive_rsa_key *)&ctx->rsa_key;
crypto_free_akcipher(ctx->akcipher_fbk);
starfive_rsa_free_key(key);
}
static struct akcipher_alg starfive_rsa = {
.encrypt = starfive_rsa_enc,
.decrypt = starfive_rsa_dec,
.sign = starfive_rsa_dec,
.verify = starfive_rsa_enc,
.set_pub_key = starfive_rsa_set_pub_key,
.set_priv_key = starfive_rsa_set_priv_key,
.max_size = starfive_rsa_max_size,
.init = starfive_rsa_init_tfm,
.exit = starfive_rsa_exit_tfm,
.base = {
.cra_name = "rsa",
.cra_driver_name = "starfive-rsa",
.cra_flags = CRYPTO_ALG_TYPE_AKCIPHER |
CRYPTO_ALG_NEED_FALLBACK,
.cra_priority = 3000,
.cra_module = THIS_MODULE,
.cra_ctxsize = sizeof(struct starfive_cryp_ctx),
},
};
int starfive_rsa_register_algs(void)
{
return crypto_register_akcipher(&starfive_rsa);
}
void starfive_rsa_unregister_algs(void)
{
crypto_unregister_akcipher(&starfive_rsa);
}