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Diffstat (limited to 'drivers/crypto/keembay/keembay-ocs-ecc.c')
-rw-r--r--drivers/crypto/keembay/keembay-ocs-ecc.c1016
1 files changed, 1016 insertions, 0 deletions
diff --git a/drivers/crypto/keembay/keembay-ocs-ecc.c b/drivers/crypto/keembay/keembay-ocs-ecc.c
new file mode 100644
index 000000000..2269df175
--- /dev/null
+++ b/drivers/crypto/keembay/keembay-ocs-ecc.c
@@ -0,0 +1,1016 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel Keem Bay OCS ECC Crypto Driver.
+ *
+ * Copyright (C) 2019-2021 Intel Corporation
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/crypto.h>
+#include <linux/delay.h>
+#include <linux/fips.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <crypto/ecc_curve.h>
+#include <crypto/ecdh.h>
+#include <crypto/engine.h>
+#include <crypto/kpp.h>
+#include <crypto/rng.h>
+
+#include <crypto/internal/ecc.h>
+#include <crypto/internal/kpp.h>
+
+#define DRV_NAME "keembay-ocs-ecc"
+
+#define KMB_OCS_ECC_PRIORITY 350
+
+#define HW_OFFS_OCS_ECC_COMMAND 0x00000000
+#define HW_OFFS_OCS_ECC_STATUS 0x00000004
+#define HW_OFFS_OCS_ECC_DATA_IN 0x00000080
+#define HW_OFFS_OCS_ECC_CX_DATA_OUT 0x00000100
+#define HW_OFFS_OCS_ECC_CY_DATA_OUT 0x00000180
+#define HW_OFFS_OCS_ECC_ISR 0x00000400
+#define HW_OFFS_OCS_ECC_IER 0x00000404
+
+#define HW_OCS_ECC_ISR_INT_STATUS_DONE BIT(0)
+#define HW_OCS_ECC_COMMAND_INS_BP BIT(0)
+
+#define HW_OCS_ECC_COMMAND_START_VAL BIT(0)
+
+#define OCS_ECC_OP_SIZE_384 BIT(8)
+#define OCS_ECC_OP_SIZE_256 0
+
+/* ECC Instruction : for ECC_COMMAND */
+#define OCS_ECC_INST_WRITE_AX (0x1 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_WRITE_AY (0x2 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_WRITE_BX_D (0x3 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_WRITE_BY_L (0x4 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_WRITE_P (0x5 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_WRITE_A (0x6 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_CALC_D_IDX_A (0x8 << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_CALC_A_POW_B_MODP (0xB << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_CALC_A_MUL_B_MODP (0xC << HW_OCS_ECC_COMMAND_INS_BP)
+#define OCS_ECC_INST_CALC_A_ADD_B_MODP (0xD << HW_OCS_ECC_COMMAND_INS_BP)
+
+#define ECC_ENABLE_INTR 1
+
+#define POLL_USEC 100
+#define TIMEOUT_USEC 10000
+
+#define KMB_ECC_VLI_MAX_DIGITS ECC_CURVE_NIST_P384_DIGITS
+#define KMB_ECC_VLI_MAX_BYTES (KMB_ECC_VLI_MAX_DIGITS \
+ << ECC_DIGITS_TO_BYTES_SHIFT)
+
+#define POW_CUBE 3
+
+/**
+ * struct ocs_ecc_dev - ECC device context
+ * @list: List of device contexts
+ * @dev: OCS ECC device
+ * @base_reg: IO base address of OCS ECC
+ * @engine: Crypto engine for the device
+ * @irq_done: IRQ done completion.
+ * @irq: IRQ number
+ */
+struct ocs_ecc_dev {
+ struct list_head list;
+ struct device *dev;
+ void __iomem *base_reg;
+ struct crypto_engine *engine;
+ struct completion irq_done;
+ int irq;
+};
+
+/**
+ * struct ocs_ecc_ctx - Transformation context.
+ * @engine_ctx: Crypto engine ctx.
+ * @ecc_dev: The ECC driver associated with this context.
+ * @curve: The elliptic curve used by this transformation.
+ * @private_key: The private key.
+ */
+struct ocs_ecc_ctx {
+ struct crypto_engine_ctx engine_ctx;
+ struct ocs_ecc_dev *ecc_dev;
+ const struct ecc_curve *curve;
+ u64 private_key[KMB_ECC_VLI_MAX_DIGITS];
+};
+
+/* Driver data. */
+struct ocs_ecc_drv {
+ struct list_head dev_list;
+ spinlock_t lock; /* Protects dev_list. */
+};
+
+/* Global variable holding the list of OCS ECC devices (only one expected). */
+static struct ocs_ecc_drv ocs_ecc = {
+ .dev_list = LIST_HEAD_INIT(ocs_ecc.dev_list),
+ .lock = __SPIN_LOCK_UNLOCKED(ocs_ecc.lock),
+};
+
+/* Get OCS ECC tfm context from kpp_request. */
+static inline struct ocs_ecc_ctx *kmb_ocs_ecc_tctx(struct kpp_request *req)
+{
+ return kpp_tfm_ctx(crypto_kpp_reqtfm(req));
+}
+
+/* Converts number of digits to number of bytes. */
+static inline unsigned int digits_to_bytes(unsigned int n)
+{
+ return n << ECC_DIGITS_TO_BYTES_SHIFT;
+}
+
+/*
+ * Wait for ECC idle i.e when an operation (other than write operations)
+ * is done.
+ */
+static inline int ocs_ecc_wait_idle(struct ocs_ecc_dev *dev)
+{
+ u32 value;
+
+ return readl_poll_timeout((dev->base_reg + HW_OFFS_OCS_ECC_STATUS),
+ value,
+ !(value & HW_OCS_ECC_ISR_INT_STATUS_DONE),
+ POLL_USEC, TIMEOUT_USEC);
+}
+
+static void ocs_ecc_cmd_start(struct ocs_ecc_dev *ecc_dev, u32 op_size)
+{
+ iowrite32(op_size | HW_OCS_ECC_COMMAND_START_VAL,
+ ecc_dev->base_reg + HW_OFFS_OCS_ECC_COMMAND);
+}
+
+/* Direct write of u32 buffer to ECC engine with associated instruction. */
+static void ocs_ecc_write_cmd_and_data(struct ocs_ecc_dev *dev,
+ u32 op_size,
+ u32 inst,
+ const void *data_in,
+ size_t data_size)
+{
+ iowrite32(op_size | inst, dev->base_reg + HW_OFFS_OCS_ECC_COMMAND);
+
+ /* MMIO Write src uint32 to dst. */
+ memcpy_toio(dev->base_reg + HW_OFFS_OCS_ECC_DATA_IN, data_in,
+ data_size);
+}
+
+/* Start OCS ECC operation and wait for its completion. */
+static int ocs_ecc_trigger_op(struct ocs_ecc_dev *ecc_dev, u32 op_size,
+ u32 inst)
+{
+ reinit_completion(&ecc_dev->irq_done);
+
+ iowrite32(ECC_ENABLE_INTR, ecc_dev->base_reg + HW_OFFS_OCS_ECC_IER);
+ iowrite32(op_size | inst, ecc_dev->base_reg + HW_OFFS_OCS_ECC_COMMAND);
+
+ return wait_for_completion_interruptible(&ecc_dev->irq_done);
+}
+
+/**
+ * ocs_ecc_read_cx_out() - Read the CX data output buffer.
+ * @dev: The OCS ECC device to read from.
+ * @cx_out: The buffer where to store the CX value. Must be at least
+ * @byte_count byte long.
+ * @byte_count: The amount of data to read.
+ */
+static inline void ocs_ecc_read_cx_out(struct ocs_ecc_dev *dev, void *cx_out,
+ size_t byte_count)
+{
+ memcpy_fromio(cx_out, dev->base_reg + HW_OFFS_OCS_ECC_CX_DATA_OUT,
+ byte_count);
+}
+
+/**
+ * ocs_ecc_read_cy_out() - Read the CX data output buffer.
+ * @dev: The OCS ECC device to read from.
+ * @cy_out: The buffer where to store the CY value. Must be at least
+ * @byte_count byte long.
+ * @byte_count: The amount of data to read.
+ */
+static inline void ocs_ecc_read_cy_out(struct ocs_ecc_dev *dev, void *cy_out,
+ size_t byte_count)
+{
+ memcpy_fromio(cy_out, dev->base_reg + HW_OFFS_OCS_ECC_CY_DATA_OUT,
+ byte_count);
+}
+
+static struct ocs_ecc_dev *kmb_ocs_ecc_find_dev(struct ocs_ecc_ctx *tctx)
+{
+ if (tctx->ecc_dev)
+ return tctx->ecc_dev;
+
+ spin_lock(&ocs_ecc.lock);
+
+ /* Only a single OCS device available. */
+ tctx->ecc_dev = list_first_entry(&ocs_ecc.dev_list, struct ocs_ecc_dev,
+ list);
+
+ spin_unlock(&ocs_ecc.lock);
+
+ return tctx->ecc_dev;
+}
+
+/* Do point multiplication using OCS ECC HW. */
+static int kmb_ecc_point_mult(struct ocs_ecc_dev *ecc_dev,
+ struct ecc_point *result,
+ const struct ecc_point *point,
+ u64 *scalar,
+ const struct ecc_curve *curve)
+{
+ u8 sca[KMB_ECC_VLI_MAX_BYTES]; /* Use the maximum data size. */
+ u32 op_size = (curve->g.ndigits > ECC_CURVE_NIST_P256_DIGITS) ?
+ OCS_ECC_OP_SIZE_384 : OCS_ECC_OP_SIZE_256;
+ size_t nbytes = digits_to_bytes(curve->g.ndigits);
+ int rc = 0;
+
+ /* Generate random nbytes for Simple and Differential SCA protection. */
+ rc = crypto_get_default_rng();
+ if (rc)
+ return rc;
+
+ rc = crypto_rng_get_bytes(crypto_default_rng, sca, nbytes);
+ crypto_put_default_rng();
+ if (rc)
+ return rc;
+
+ /* Wait engine to be idle before starting new operation. */
+ rc = ocs_ecc_wait_idle(ecc_dev);
+ if (rc)
+ return rc;
+
+ /* Send ecc_start pulse as well as indicating operation size. */
+ ocs_ecc_cmd_start(ecc_dev, op_size);
+
+ /* Write ax param; Base point (Gx). */
+ ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_AX,
+ point->x, nbytes);
+
+ /* Write ay param; Base point (Gy). */
+ ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_AY,
+ point->y, nbytes);
+
+ /*
+ * Write the private key into DATA_IN reg.
+ *
+ * Since DATA_IN register is used to write different values during the
+ * computation private Key value is overwritten with
+ * side-channel-resistance value.
+ */
+ ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_BX_D,
+ scalar, nbytes);
+
+ /* Write operand by/l. */
+ ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_BY_L,
+ sca, nbytes);
+ memzero_explicit(sca, sizeof(sca));
+
+ /* Write p = curve prime(GF modulus). */
+ ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_P,
+ curve->p, nbytes);
+
+ /* Write a = curve coefficient. */
+ ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_A,
+ curve->a, nbytes);
+
+ /* Make hardware perform the multiplication. */
+ rc = ocs_ecc_trigger_op(ecc_dev, op_size, OCS_ECC_INST_CALC_D_IDX_A);
+ if (rc)
+ return rc;
+
+ /* Read result. */
+ ocs_ecc_read_cx_out(ecc_dev, result->x, nbytes);
+ ocs_ecc_read_cy_out(ecc_dev, result->y, nbytes);
+
+ return 0;
+}
+
+/**
+ * kmb_ecc_do_scalar_op() - Perform Scalar operation using OCS ECC HW.
+ * @ecc_dev: The OCS ECC device to use.
+ * @scalar_out: Where to store the output scalar.
+ * @scalar_a: Input scalar operand 'a'.
+ * @scalar_b: Input scalar operand 'b'
+ * @curve: The curve on which the operation is performed.
+ * @ndigits: The size of the operands (in digits).
+ * @inst: The operation to perform (as an OCS ECC instruction).
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+static int kmb_ecc_do_scalar_op(struct ocs_ecc_dev *ecc_dev, u64 *scalar_out,
+ const u64 *scalar_a, const u64 *scalar_b,
+ const struct ecc_curve *curve,
+ unsigned int ndigits, const u32 inst)
+{
+ u32 op_size = (ndigits > ECC_CURVE_NIST_P256_DIGITS) ?
+ OCS_ECC_OP_SIZE_384 : OCS_ECC_OP_SIZE_256;
+ size_t nbytes = digits_to_bytes(ndigits);
+ int rc;
+
+ /* Wait engine to be idle before starting new operation. */
+ rc = ocs_ecc_wait_idle(ecc_dev);
+ if (rc)
+ return rc;
+
+ /* Send ecc_start pulse as well as indicating operation size. */
+ ocs_ecc_cmd_start(ecc_dev, op_size);
+
+ /* Write ax param (Base point (Gx).*/
+ ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_AX,
+ scalar_a, nbytes);
+
+ /* Write ay param Base point (Gy).*/
+ ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_AY,
+ scalar_b, nbytes);
+
+ /* Write p = curve prime(GF modulus).*/
+ ocs_ecc_write_cmd_and_data(ecc_dev, op_size, OCS_ECC_INST_WRITE_P,
+ curve->p, nbytes);
+
+ /* Give instruction A.B or A+B to ECC engine. */
+ rc = ocs_ecc_trigger_op(ecc_dev, op_size, inst);
+ if (rc)
+ return rc;
+
+ ocs_ecc_read_cx_out(ecc_dev, scalar_out, nbytes);
+
+ if (vli_is_zero(scalar_out, ndigits))
+ return -EINVAL;
+
+ return 0;
+}
+
+/* SP800-56A section 5.6.2.3.4 partial verification: ephemeral keys only */
+static int kmb_ocs_ecc_is_pubkey_valid_partial(struct ocs_ecc_dev *ecc_dev,
+ const struct ecc_curve *curve,
+ struct ecc_point *pk)
+{
+ u64 xxx[KMB_ECC_VLI_MAX_DIGITS] = { 0 };
+ u64 yy[KMB_ECC_VLI_MAX_DIGITS] = { 0 };
+ u64 w[KMB_ECC_VLI_MAX_DIGITS] = { 0 };
+ int rc;
+
+ if (WARN_ON(pk->ndigits != curve->g.ndigits))
+ return -EINVAL;
+
+ /* Check 1: Verify key is not the zero point. */
+ if (ecc_point_is_zero(pk))
+ return -EINVAL;
+
+ /* Check 2: Verify key is in the range [0, p-1]. */
+ if (vli_cmp(curve->p, pk->x, pk->ndigits) != 1)
+ return -EINVAL;
+
+ if (vli_cmp(curve->p, pk->y, pk->ndigits) != 1)
+ return -EINVAL;
+
+ /* Check 3: Verify that y^2 == (x^3 + a·x + b) mod p */
+
+ /* y^2 */
+ /* Compute y^2 -> store in yy */
+ rc = kmb_ecc_do_scalar_op(ecc_dev, yy, pk->y, pk->y, curve, pk->ndigits,
+ OCS_ECC_INST_CALC_A_MUL_B_MODP);
+ if (rc)
+ goto exit;
+
+ /* x^3 */
+ /* Assigning w = 3, used for calculating x^3. */
+ w[0] = POW_CUBE;
+ /* Load the next stage.*/
+ rc = kmb_ecc_do_scalar_op(ecc_dev, xxx, pk->x, w, curve, pk->ndigits,
+ OCS_ECC_INST_CALC_A_POW_B_MODP);
+ if (rc)
+ goto exit;
+
+ /* Do a*x -> store in w. */
+ rc = kmb_ecc_do_scalar_op(ecc_dev, w, curve->a, pk->x, curve,
+ pk->ndigits,
+ OCS_ECC_INST_CALC_A_MUL_B_MODP);
+ if (rc)
+ goto exit;
+
+ /* Do ax + b == w + b; store in w. */
+ rc = kmb_ecc_do_scalar_op(ecc_dev, w, w, curve->b, curve,
+ pk->ndigits,
+ OCS_ECC_INST_CALC_A_ADD_B_MODP);
+ if (rc)
+ goto exit;
+
+ /* x^3 + ax + b == x^3 + w -> store in w. */
+ rc = kmb_ecc_do_scalar_op(ecc_dev, w, xxx, w, curve, pk->ndigits,
+ OCS_ECC_INST_CALC_A_ADD_B_MODP);
+ if (rc)
+ goto exit;
+
+ /* Compare y^2 == x^3 + a·x + b. */
+ rc = vli_cmp(yy, w, pk->ndigits);
+ if (rc)
+ rc = -EINVAL;
+
+exit:
+ memzero_explicit(xxx, sizeof(xxx));
+ memzero_explicit(yy, sizeof(yy));
+ memzero_explicit(w, sizeof(w));
+
+ return rc;
+}
+
+/* SP800-56A section 5.6.2.3.3 full verification */
+static int kmb_ocs_ecc_is_pubkey_valid_full(struct ocs_ecc_dev *ecc_dev,
+ const struct ecc_curve *curve,
+ struct ecc_point *pk)
+{
+ struct ecc_point *nQ;
+ int rc;
+
+ /* Checks 1 through 3 */
+ rc = kmb_ocs_ecc_is_pubkey_valid_partial(ecc_dev, curve, pk);
+ if (rc)
+ return rc;
+
+ /* Check 4: Verify that nQ is the zero point. */
+ nQ = ecc_alloc_point(pk->ndigits);
+ if (!nQ)
+ return -ENOMEM;
+
+ rc = kmb_ecc_point_mult(ecc_dev, nQ, pk, curve->n, curve);
+ if (rc)
+ goto exit;
+
+ if (!ecc_point_is_zero(nQ))
+ rc = -EINVAL;
+
+exit:
+ ecc_free_point(nQ);
+
+ return rc;
+}
+
+static int kmb_ecc_is_key_valid(const struct ecc_curve *curve,
+ const u64 *private_key, size_t private_key_len)
+{
+ size_t ndigits = curve->g.ndigits;
+ u64 one[KMB_ECC_VLI_MAX_DIGITS] = {1};
+ u64 res[KMB_ECC_VLI_MAX_DIGITS];
+
+ if (private_key_len != digits_to_bytes(ndigits))
+ return -EINVAL;
+
+ if (!private_key)
+ return -EINVAL;
+
+ /* Make sure the private key is in the range [2, n-3]. */
+ if (vli_cmp(one, private_key, ndigits) != -1)
+ return -EINVAL;
+
+ vli_sub(res, curve->n, one, ndigits);
+ vli_sub(res, res, one, ndigits);
+ if (vli_cmp(res, private_key, ndigits) != 1)
+ return -EINVAL;
+
+ return 0;
+}
+
+/*
+ * ECC private keys are generated using the method of extra random bits,
+ * equivalent to that described in FIPS 186-4, Appendix B.4.1.
+ *
+ * d = (c mod(n–1)) + 1 where c is a string of random bits, 64 bits longer
+ * than requested
+ * 0 <= c mod(n-1) <= n-2 and implies that
+ * 1 <= d <= n-1
+ *
+ * This method generates a private key uniformly distributed in the range
+ * [1, n-1].
+ */
+static int kmb_ecc_gen_privkey(const struct ecc_curve *curve, u64 *privkey)
+{
+ size_t nbytes = digits_to_bytes(curve->g.ndigits);
+ u64 priv[KMB_ECC_VLI_MAX_DIGITS];
+ size_t nbits;
+ int rc;
+
+ nbits = vli_num_bits(curve->n, curve->g.ndigits);
+
+ /* Check that N is included in Table 1 of FIPS 186-4, section 6.1.1 */
+ if (nbits < 160 || curve->g.ndigits > ARRAY_SIZE(priv))
+ return -EINVAL;
+
+ /*
+ * FIPS 186-4 recommends that the private key should be obtained from a
+ * RBG with a security strength equal to or greater than the security
+ * strength associated with N.
+ *
+ * The maximum security strength identified by NIST SP800-57pt1r4 for
+ * ECC is 256 (N >= 512).
+ *
+ * This condition is met by the default RNG because it selects a favored
+ * DRBG with a security strength of 256.
+ */
+ if (crypto_get_default_rng())
+ return -EFAULT;
+
+ rc = crypto_rng_get_bytes(crypto_default_rng, (u8 *)priv, nbytes);
+ crypto_put_default_rng();
+ if (rc)
+ goto cleanup;
+
+ rc = kmb_ecc_is_key_valid(curve, priv, nbytes);
+ if (rc)
+ goto cleanup;
+
+ ecc_swap_digits(priv, privkey, curve->g.ndigits);
+
+cleanup:
+ memzero_explicit(&priv, sizeof(priv));
+
+ return rc;
+}
+
+static int kmb_ocs_ecdh_set_secret(struct crypto_kpp *tfm, const void *buf,
+ unsigned int len)
+{
+ struct ocs_ecc_ctx *tctx = kpp_tfm_ctx(tfm);
+ struct ecdh params;
+ int rc = 0;
+
+ rc = crypto_ecdh_decode_key(buf, len, &params);
+ if (rc)
+ goto cleanup;
+
+ /* Ensure key size is not bigger then expected. */
+ if (params.key_size > digits_to_bytes(tctx->curve->g.ndigits)) {
+ rc = -EINVAL;
+ goto cleanup;
+ }
+
+ /* Auto-generate private key is not provided. */
+ if (!params.key || !params.key_size) {
+ rc = kmb_ecc_gen_privkey(tctx->curve, tctx->private_key);
+ goto cleanup;
+ }
+
+ rc = kmb_ecc_is_key_valid(tctx->curve, (const u64 *)params.key,
+ params.key_size);
+ if (rc)
+ goto cleanup;
+
+ ecc_swap_digits((const u64 *)params.key, tctx->private_key,
+ tctx->curve->g.ndigits);
+cleanup:
+ memzero_explicit(&params, sizeof(params));
+
+ if (rc)
+ tctx->curve = NULL;
+
+ return rc;
+}
+
+/* Compute shared secret. */
+static int kmb_ecc_do_shared_secret(struct ocs_ecc_ctx *tctx,
+ struct kpp_request *req)
+{
+ struct ocs_ecc_dev *ecc_dev = tctx->ecc_dev;
+ const struct ecc_curve *curve = tctx->curve;
+ u64 shared_secret[KMB_ECC_VLI_MAX_DIGITS];
+ u64 pubk_buf[KMB_ECC_VLI_MAX_DIGITS * 2];
+ size_t copied, nbytes, pubk_len;
+ struct ecc_point *pk, *result;
+ int rc;
+
+ nbytes = digits_to_bytes(curve->g.ndigits);
+
+ /* Public key is a point, thus it has two coordinates */
+ pubk_len = 2 * nbytes;
+
+ /* Copy public key from SG list to pubk_buf. */
+ copied = sg_copy_to_buffer(req->src,
+ sg_nents_for_len(req->src, pubk_len),
+ pubk_buf, pubk_len);
+ if (copied != pubk_len)
+ return -EINVAL;
+
+ /* Allocate and initialize public key point. */
+ pk = ecc_alloc_point(curve->g.ndigits);
+ if (!pk)
+ return -ENOMEM;
+
+ ecc_swap_digits(pubk_buf, pk->x, curve->g.ndigits);
+ ecc_swap_digits(&pubk_buf[curve->g.ndigits], pk->y, curve->g.ndigits);
+
+ /*
+ * Check the public key for following
+ * Check 1: Verify key is not the zero point.
+ * Check 2: Verify key is in the range [1, p-1].
+ * Check 3: Verify that y^2 == (x^3 + a·x + b) mod p
+ */
+ rc = kmb_ocs_ecc_is_pubkey_valid_partial(ecc_dev, curve, pk);
+ if (rc)
+ goto exit_free_pk;
+
+ /* Allocate point for storing computed shared secret. */
+ result = ecc_alloc_point(pk->ndigits);
+ if (!result) {
+ rc = -ENOMEM;
+ goto exit_free_pk;
+ }
+
+ /* Calculate the shared secret.*/
+ rc = kmb_ecc_point_mult(ecc_dev, result, pk, tctx->private_key, curve);
+ if (rc)
+ goto exit_free_result;
+
+ if (ecc_point_is_zero(result)) {
+ rc = -EFAULT;
+ goto exit_free_result;
+ }
+
+ /* Copy shared secret from point to buffer. */
+ ecc_swap_digits(result->x, shared_secret, result->ndigits);
+
+ /* Request might ask for less bytes than what we have. */
+ nbytes = min_t(size_t, nbytes, req->dst_len);
+
+ copied = sg_copy_from_buffer(req->dst,
+ sg_nents_for_len(req->dst, nbytes),
+ shared_secret, nbytes);
+
+ if (copied != nbytes)
+ rc = -EINVAL;
+
+ memzero_explicit(shared_secret, sizeof(shared_secret));
+
+exit_free_result:
+ ecc_free_point(result);
+
+exit_free_pk:
+ ecc_free_point(pk);
+
+ return rc;
+}
+
+/* Compute public key. */
+static int kmb_ecc_do_public_key(struct ocs_ecc_ctx *tctx,
+ struct kpp_request *req)
+{
+ const struct ecc_curve *curve = tctx->curve;
+ u64 pubk_buf[KMB_ECC_VLI_MAX_DIGITS * 2];
+ struct ecc_point *pk;
+ size_t pubk_len;
+ size_t copied;
+ int rc;
+
+ /* Public key is a point, so it has double the digits. */
+ pubk_len = 2 * digits_to_bytes(curve->g.ndigits);
+
+ pk = ecc_alloc_point(curve->g.ndigits);
+ if (!pk)
+ return -ENOMEM;
+
+ /* Public Key(pk) = priv * G. */
+ rc = kmb_ecc_point_mult(tctx->ecc_dev, pk, &curve->g, tctx->private_key,
+ curve);
+ if (rc)
+ goto exit;
+
+ /* SP800-56A rev 3 5.6.2.1.3 key check */
+ if (kmb_ocs_ecc_is_pubkey_valid_full(tctx->ecc_dev, curve, pk)) {
+ rc = -EAGAIN;
+ goto exit;
+ }
+
+ /* Copy public key from point to buffer. */
+ ecc_swap_digits(pk->x, pubk_buf, pk->ndigits);
+ ecc_swap_digits(pk->y, &pubk_buf[pk->ndigits], pk->ndigits);
+
+ /* Copy public key to req->dst. */
+ copied = sg_copy_from_buffer(req->dst,
+ sg_nents_for_len(req->dst, pubk_len),
+ pubk_buf, pubk_len);
+
+ if (copied != pubk_len)
+ rc = -EINVAL;
+
+exit:
+ ecc_free_point(pk);
+
+ return rc;
+}
+
+static int kmb_ocs_ecc_do_one_request(struct crypto_engine *engine,
+ void *areq)
+{
+ struct kpp_request *req = container_of(areq, struct kpp_request, base);
+ struct ocs_ecc_ctx *tctx = kmb_ocs_ecc_tctx(req);
+ struct ocs_ecc_dev *ecc_dev = tctx->ecc_dev;
+ int rc;
+
+ if (req->src)
+ rc = kmb_ecc_do_shared_secret(tctx, req);
+ else
+ rc = kmb_ecc_do_public_key(tctx, req);
+
+ crypto_finalize_kpp_request(ecc_dev->engine, req, rc);
+
+ return 0;
+}
+
+static int kmb_ocs_ecdh_generate_public_key(struct kpp_request *req)
+{
+ struct ocs_ecc_ctx *tctx = kmb_ocs_ecc_tctx(req);
+ const struct ecc_curve *curve = tctx->curve;
+
+ /* Ensure kmb_ocs_ecdh_set_secret() has been successfully called. */
+ if (!tctx->curve)
+ return -EINVAL;
+
+ /* Ensure dst is present. */
+ if (!req->dst)
+ return -EINVAL;
+
+ /* Check the request dst is big enough to hold the public key. */
+ if (req->dst_len < (2 * digits_to_bytes(curve->g.ndigits)))
+ return -EINVAL;
+
+ /* 'src' is not supposed to be present when generate pubk is called. */
+ if (req->src)
+ return -EINVAL;
+
+ return crypto_transfer_kpp_request_to_engine(tctx->ecc_dev->engine,
+ req);
+}
+
+static int kmb_ocs_ecdh_compute_shared_secret(struct kpp_request *req)
+{
+ struct ocs_ecc_ctx *tctx = kmb_ocs_ecc_tctx(req);
+ const struct ecc_curve *curve = tctx->curve;
+
+ /* Ensure kmb_ocs_ecdh_set_secret() has been successfully called. */
+ if (!tctx->curve)
+ return -EINVAL;
+
+ /* Ensure dst is present. */
+ if (!req->dst)
+ return -EINVAL;
+
+ /* Ensure src is present. */
+ if (!req->src)
+ return -EINVAL;
+
+ /*
+ * req->src is expected to the (other-side) public key, so its length
+ * must be 2 * coordinate size (in bytes).
+ */
+ if (req->src_len != 2 * digits_to_bytes(curve->g.ndigits))
+ return -EINVAL;
+
+ return crypto_transfer_kpp_request_to_engine(tctx->ecc_dev->engine,
+ req);
+}
+
+static int kmb_ecc_tctx_init(struct ocs_ecc_ctx *tctx, unsigned int curve_id)
+{
+ memset(tctx, 0, sizeof(*tctx));
+
+ tctx->ecc_dev = kmb_ocs_ecc_find_dev(tctx);
+
+ if (IS_ERR(tctx->ecc_dev)) {
+ pr_err("Failed to find the device : %ld\n",
+ PTR_ERR(tctx->ecc_dev));
+ return PTR_ERR(tctx->ecc_dev);
+ }
+
+ tctx->curve = ecc_get_curve(curve_id);
+ if (!tctx->curve)
+ return -EOPNOTSUPP;
+
+ tctx->engine_ctx.op.prepare_request = NULL;
+ tctx->engine_ctx.op.do_one_request = kmb_ocs_ecc_do_one_request;
+ tctx->engine_ctx.op.unprepare_request = NULL;
+
+ return 0;
+}
+
+static int kmb_ocs_ecdh_nist_p256_init_tfm(struct crypto_kpp *tfm)
+{
+ struct ocs_ecc_ctx *tctx = kpp_tfm_ctx(tfm);
+
+ return kmb_ecc_tctx_init(tctx, ECC_CURVE_NIST_P256);
+}
+
+static int kmb_ocs_ecdh_nist_p384_init_tfm(struct crypto_kpp *tfm)
+{
+ struct ocs_ecc_ctx *tctx = kpp_tfm_ctx(tfm);
+
+ return kmb_ecc_tctx_init(tctx, ECC_CURVE_NIST_P384);
+}
+
+static void kmb_ocs_ecdh_exit_tfm(struct crypto_kpp *tfm)
+{
+ struct ocs_ecc_ctx *tctx = kpp_tfm_ctx(tfm);
+
+ memzero_explicit(tctx->private_key, sizeof(*tctx->private_key));
+}
+
+static unsigned int kmb_ocs_ecdh_max_size(struct crypto_kpp *tfm)
+{
+ struct ocs_ecc_ctx *tctx = kpp_tfm_ctx(tfm);
+
+ /* Public key is made of two coordinates, so double the digits. */
+ return digits_to_bytes(tctx->curve->g.ndigits) * 2;
+}
+
+static struct kpp_alg ocs_ecdh_p256 = {
+ .set_secret = kmb_ocs_ecdh_set_secret,
+ .generate_public_key = kmb_ocs_ecdh_generate_public_key,
+ .compute_shared_secret = kmb_ocs_ecdh_compute_shared_secret,
+ .init = kmb_ocs_ecdh_nist_p256_init_tfm,
+ .exit = kmb_ocs_ecdh_exit_tfm,
+ .max_size = kmb_ocs_ecdh_max_size,
+ .base = {
+ .cra_name = "ecdh-nist-p256",
+ .cra_driver_name = "ecdh-nist-p256-keembay-ocs",
+ .cra_priority = KMB_OCS_ECC_PRIORITY,
+ .cra_module = THIS_MODULE,
+ .cra_ctxsize = sizeof(struct ocs_ecc_ctx),
+ },
+};
+
+static struct kpp_alg ocs_ecdh_p384 = {
+ .set_secret = kmb_ocs_ecdh_set_secret,
+ .generate_public_key = kmb_ocs_ecdh_generate_public_key,
+ .compute_shared_secret = kmb_ocs_ecdh_compute_shared_secret,
+ .init = kmb_ocs_ecdh_nist_p384_init_tfm,
+ .exit = kmb_ocs_ecdh_exit_tfm,
+ .max_size = kmb_ocs_ecdh_max_size,
+ .base = {
+ .cra_name = "ecdh-nist-p384",
+ .cra_driver_name = "ecdh-nist-p384-keembay-ocs",
+ .cra_priority = KMB_OCS_ECC_PRIORITY,
+ .cra_module = THIS_MODULE,
+ .cra_ctxsize = sizeof(struct ocs_ecc_ctx),
+ },
+};
+
+static irqreturn_t ocs_ecc_irq_handler(int irq, void *dev_id)
+{
+ struct ocs_ecc_dev *ecc_dev = dev_id;
+ u32 status;
+
+ /*
+ * Read the status register and write it back to clear the
+ * DONE_INT_STATUS bit.
+ */
+ status = ioread32(ecc_dev->base_reg + HW_OFFS_OCS_ECC_ISR);
+ iowrite32(status, ecc_dev->base_reg + HW_OFFS_OCS_ECC_ISR);
+
+ if (!(status & HW_OCS_ECC_ISR_INT_STATUS_DONE))
+ return IRQ_NONE;
+
+ complete(&ecc_dev->irq_done);
+
+ return IRQ_HANDLED;
+}
+
+static int kmb_ocs_ecc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ocs_ecc_dev *ecc_dev;
+ int rc;
+
+ ecc_dev = devm_kzalloc(dev, sizeof(*ecc_dev), GFP_KERNEL);
+ if (!ecc_dev)
+ return -ENOMEM;
+
+ ecc_dev->dev = dev;
+
+ platform_set_drvdata(pdev, ecc_dev);
+
+ INIT_LIST_HEAD(&ecc_dev->list);
+ init_completion(&ecc_dev->irq_done);
+
+ /* Get base register address. */
+ ecc_dev->base_reg = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(ecc_dev->base_reg)) {
+ dev_err(dev, "Failed to get base address\n");
+ rc = PTR_ERR(ecc_dev->base_reg);
+ goto list_del;
+ }
+
+ /* Get and request IRQ */
+ ecc_dev->irq = platform_get_irq(pdev, 0);
+ if (ecc_dev->irq < 0) {
+ rc = ecc_dev->irq;
+ goto list_del;
+ }
+
+ rc = devm_request_threaded_irq(dev, ecc_dev->irq, ocs_ecc_irq_handler,
+ NULL, 0, "keembay-ocs-ecc", ecc_dev);
+ if (rc < 0) {
+ dev_err(dev, "Could not request IRQ\n");
+ goto list_del;
+ }
+
+ /* Add device to the list of OCS ECC devices. */
+ spin_lock(&ocs_ecc.lock);
+ list_add_tail(&ecc_dev->list, &ocs_ecc.dev_list);
+ spin_unlock(&ocs_ecc.lock);
+
+ /* Initialize crypto engine. */
+ ecc_dev->engine = crypto_engine_alloc_init(dev, 1);
+ if (!ecc_dev->engine) {
+ dev_err(dev, "Could not allocate crypto engine\n");
+ rc = -ENOMEM;
+ goto list_del;
+ }
+
+ rc = crypto_engine_start(ecc_dev->engine);
+ if (rc) {
+ dev_err(dev, "Could not start crypto engine\n");
+ goto cleanup;
+ }
+
+ /* Register the KPP algo. */
+ rc = crypto_register_kpp(&ocs_ecdh_p256);
+ if (rc) {
+ dev_err(dev,
+ "Could not register OCS algorithms with Crypto API\n");
+ goto cleanup;
+ }
+
+ rc = crypto_register_kpp(&ocs_ecdh_p384);
+ if (rc) {
+ dev_err(dev,
+ "Could not register OCS algorithms with Crypto API\n");
+ goto ocs_ecdh_p384_error;
+ }
+
+ return 0;
+
+ocs_ecdh_p384_error:
+ crypto_unregister_kpp(&ocs_ecdh_p256);
+
+cleanup:
+ crypto_engine_exit(ecc_dev->engine);
+
+list_del:
+ spin_lock(&ocs_ecc.lock);
+ list_del(&ecc_dev->list);
+ spin_unlock(&ocs_ecc.lock);
+
+ return rc;
+}
+
+static int kmb_ocs_ecc_remove(struct platform_device *pdev)
+{
+ struct ocs_ecc_dev *ecc_dev;
+
+ ecc_dev = platform_get_drvdata(pdev);
+
+ crypto_unregister_kpp(&ocs_ecdh_p384);
+ crypto_unregister_kpp(&ocs_ecdh_p256);
+
+ spin_lock(&ocs_ecc.lock);
+ list_del(&ecc_dev->list);
+ spin_unlock(&ocs_ecc.lock);
+
+ crypto_engine_exit(ecc_dev->engine);
+
+ return 0;
+}
+
+/* Device tree driver match. */
+static const struct of_device_id kmb_ocs_ecc_of_match[] = {
+ {
+ .compatible = "intel,keembay-ocs-ecc",
+ },
+ {}
+};
+
+/* The OCS driver is a platform device. */
+static struct platform_driver kmb_ocs_ecc_driver = {
+ .probe = kmb_ocs_ecc_probe,
+ .remove = kmb_ocs_ecc_remove,
+ .driver = {
+ .name = DRV_NAME,
+ .of_match_table = kmb_ocs_ecc_of_match,
+ },
+};
+module_platform_driver(kmb_ocs_ecc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Intel Keem Bay OCS ECC Driver");
+MODULE_ALIAS_CRYPTO("ecdh-nist-p256");
+MODULE_ALIAS_CRYPTO("ecdh-nist-p384");
+MODULE_ALIAS_CRYPTO("ecdh-nist-p256-keembay-ocs");
+MODULE_ALIAS_CRYPTO("ecdh-nist-p384-keembay-ocs");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-16 03:55:59 +0000