diff options
Diffstat (limited to 'drivers/crypto/starfive/jh7110-rsa.c')
| -rw-r--r-- | drivers/crypto/starfive/jh7110-rsa.c | 617 |
1 files changed, 617 insertions, 0 deletions
diff --git a/drivers/crypto/starfive/jh7110-rsa.c b/drivers/crypto/starfive/jh7110-rsa.c new file mode 100644 index 0000000000..f31bbd825f --- /dev/null +++ b/drivers/crypto/starfive/jh7110-rsa.c @@ -0,0 +1,617 @@ +// 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); +} |