hash.c

/*
 * Hash algorithms supported by the CESA: MD5, SHA1 and SHA256.
 *
 * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
 * Author: Arnaud Ebalard <arno@natisbad.org>
 *
 * This work is based on an initial version written by
 * Sebastian Andrzej Siewior < sebastian at breakpoint dot cc >
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 */

#include <crypto/sha.h>

#include "cesa.h"

static inline int mv_cesa_ahash_std_alloc_cache(struct mv_cesa_ahash_req *creq,
						gfp_t flags)
{
	creq->cache = kzalloc(CESA_MAX_HASH_BLOCK_SIZE, flags);
	if (!creq->cache)
		return -ENOMEM;

	return 0;
}

static int mv_cesa_ahash_alloc_cache(struct ahash_request *req)
{
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(req);
	gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
		      GFP_KERNEL : GFP_ATOMIC;

	if (creq->cache)
		return 0;

	return mv_cesa_ahash_std_alloc_cache(creq, flags);
}

static inline void mv_cesa_ahash_std_free_cache(struct mv_cesa_ahash_req *creq)
{
	kfree(creq->cache);
}

static void mv_cesa_ahash_free_cache(struct mv_cesa_ahash_req *creq)
{
	if (!creq->cache)
		return;

	mv_cesa_ahash_std_free_cache(creq);

	creq->cache = NULL;
}

static void mv_cesa_ahash_last_cleanup(struct ahash_request *req)
{
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(req);

	mv_cesa_ahash_free_cache(creq);
}

static int mv_cesa_ahash_pad_len(struct mv_cesa_ahash_req *creq)
{
	unsigned int index, padlen;

	index = creq->len & CESA_HASH_BLOCK_SIZE_MSK;
	padlen = (index < 56) ? (56 - index) : (64 + 56 - index);

	return padlen;
}

static int mv_cesa_ahash_pad_req(struct mv_cesa_ahash_req *creq, u8 *buf)
{
	__be64 bits = cpu_to_be64(creq->len << 3);
	unsigned int index, padlen;

	buf[0] = 0x80;
	/* Pad out to 56 mod 64 */
	index = creq->len & CESA_HASH_BLOCK_SIZE_MSK;
	padlen = mv_cesa_ahash_pad_len(creq);
	memset(buf + 1, 0, padlen - 1);
	memcpy(buf + padlen, &bits, sizeof(bits));

	return padlen + 8;
}

static void mv_cesa_ahash_std_step(struct ahash_request *req)
{
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(req);
	struct mv_cesa_ahash_std_req *sreq = &creq->req.std;
	struct mv_cesa_engine *engine = sreq->base.engine;
	struct mv_cesa_op_ctx *op;
	unsigned int new_cache_ptr = 0;
	u32 frag_mode;
	size_t  len;

	if (creq->cache_ptr)
		memcpy(engine->sram + CESA_SA_DATA_SRAM_OFFSET, creq->cache,
		       creq->cache_ptr);

	len = min_t(size_t, req->nbytes + creq->cache_ptr - sreq->offset,
		    CESA_SA_SRAM_PAYLOAD_SIZE);

	if (!creq->last_req) {
		new_cache_ptr = len & CESA_HASH_BLOCK_SIZE_MSK;
		len &= ~CESA_HASH_BLOCK_SIZE_MSK;
	}

	if (len - creq->cache_ptr)
		sreq->offset += sg_pcopy_to_buffer(req->src, creq->src_nents,
						   engine->sram +
						   CESA_SA_DATA_SRAM_OFFSET +
						   creq->cache_ptr,
						   len - creq->cache_ptr,
						   sreq->offset);

	op = &creq->op_tmpl;

	frag_mode = mv_cesa_get_op_cfg(op) & CESA_SA_DESC_CFG_FRAG_MSK;

	if (creq->last_req && sreq->offset == req->nbytes &&
	    creq->len <= CESA_SA_DESC_MAC_SRC_TOTAL_LEN_MAX) {
		if (frag_mode == CESA_SA_DESC_CFG_FIRST_FRAG)
			frag_mode = CESA_SA_DESC_CFG_NOT_FRAG;
		else if (frag_mode == CESA_SA_DESC_CFG_MID_FRAG)
			frag_mode = CESA_SA_DESC_CFG_LAST_FRAG;
	}

	if (frag_mode == CESA_SA_DESC_CFG_NOT_FRAG ||
	    frag_mode == CESA_SA_DESC_CFG_LAST_FRAG) {
		if (len &&
		    creq->len <= CESA_SA_DESC_MAC_SRC_TOTAL_LEN_MAX) {
			mv_cesa_set_mac_op_total_len(op, creq->len);
		} else {
			int trailerlen = mv_cesa_ahash_pad_len(creq) + 8;

			if (len + trailerlen > CESA_SA_SRAM_PAYLOAD_SIZE) {
				len &= CESA_HASH_BLOCK_SIZE_MSK;
				new_cache_ptr = 64 - trailerlen;
				memcpy(creq->cache,
				       engine->sram +
				       CESA_SA_DATA_SRAM_OFFSET + len,
				       new_cache_ptr);
			} else {
				len += mv_cesa_ahash_pad_req(creq,
						engine->sram + len +
						CESA_SA_DATA_SRAM_OFFSET);
			}

			if (frag_mode == CESA_SA_DESC_CFG_LAST_FRAG)
				frag_mode = CESA_SA_DESC_CFG_MID_FRAG;
			else
				frag_mode = CESA_SA_DESC_CFG_FIRST_FRAG;
		}
	}

	mv_cesa_set_mac_op_frag_len(op, len);
	mv_cesa_update_op_cfg(op, frag_mode, CESA_SA_DESC_CFG_FRAG_MSK);

	/* FIXME: only update enc_len field */
	memcpy(engine->sram, op, sizeof(*op));

	if (frag_mode == CESA_SA_DESC_CFG_FIRST_FRAG)
		mv_cesa_update_op_cfg(op, CESA_SA_DESC_CFG_MID_FRAG,
				      CESA_SA_DESC_CFG_FRAG_MSK);

	creq->cache_ptr = new_cache_ptr;

	mv_cesa_set_int_mask(engine, CESA_SA_INT_ACCEL0_DONE);
	writel(CESA_SA_CFG_PARA_DIS, engine->regs + CESA_SA_CFG);
	writel(CESA_SA_CMD_EN_CESA_SA_ACCL0, engine->regs + CESA_SA_CMD);
}

static int mv_cesa_ahash_std_process(struct ahash_request *req, u32 status)
{
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(req);
	struct mv_cesa_ahash_std_req *sreq = &creq->req.std;

	if (sreq->offset < (req->nbytes - creq->cache_ptr))
		return -EINPROGRESS;

	return 0;
}

static void mv_cesa_ahash_std_prepare(struct ahash_request *req)
{
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(req);
	struct mv_cesa_ahash_std_req *sreq = &creq->req.std;
	struct mv_cesa_engine *engine = sreq->base.engine;

	sreq->offset = 0;
	mv_cesa_adjust_op(engine, &creq->op_tmpl);
	memcpy(engine->sram, &creq->op_tmpl, sizeof(creq->op_tmpl));
}

static void mv_cesa_ahash_step(struct crypto_async_request *req)
{
	struct ahash_request *ahashreq = ahash_request_cast(req);

	mv_cesa_ahash_std_step(ahashreq);
}

static int mv_cesa_ahash_process(struct crypto_async_request *req, u32 status)
{
	struct ahash_request *ahashreq = ahash_request_cast(req);
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(ahashreq);
	struct mv_cesa_engine *engine = creq->req.base.engine;
	unsigned int digsize;
	int ret, i;

	ret = mv_cesa_ahash_std_process(ahashreq, status);
	if (ret == -EINPROGRESS)
		return ret;

	digsize = crypto_ahash_digestsize(crypto_ahash_reqtfm(ahashreq));
	for (i = 0; i < digsize / 4; i++)
		creq->state[i] = readl(engine->regs + CESA_IVDIG(i));

	if (creq->cache_ptr)
		sg_pcopy_to_buffer(ahashreq->src, creq->src_nents,
				   creq->cache,
				   creq->cache_ptr,
				   ahashreq->nbytes - creq->cache_ptr);

	if (creq->last_req) {
		for (i = 0; i < digsize / 4; i++)
			creq->state[i] = cpu_to_be32(creq->state[i]);

		memcpy(ahashreq->result, creq->state, digsize);
	}

	return ret;
}

static void mv_cesa_ahash_prepare(struct crypto_async_request *req,
				  struct mv_cesa_engine *engine)
{
	struct ahash_request *ahashreq = ahash_request_cast(req);
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(ahashreq);
	unsigned int digsize;
	int i;

	creq->req.base.engine = engine;

	mv_cesa_ahash_std_prepare(ahashreq);

	digsize = crypto_ahash_digestsize(crypto_ahash_reqtfm(ahashreq));
	for (i = 0; i < digsize / 4; i++)
		writel(creq->state[i],
		       engine->regs + CESA_IVDIG(i));
}

static void mv_cesa_ahash_req_cleanup(struct crypto_async_request *req)
{
	struct ahash_request *ahashreq = ahash_request_cast(req);
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(ahashreq);

	if (creq->last_req)
		mv_cesa_ahash_last_cleanup(ahashreq);
}

static const struct mv_cesa_req_ops mv_cesa_ahash_req_ops = {
	.step = mv_cesa_ahash_step,
	.process = mv_cesa_ahash_process,
	.prepare = mv_cesa_ahash_prepare,
	.cleanup = mv_cesa_ahash_req_cleanup,
};

static int mv_cesa_ahash_init(struct ahash_request *req,
			      struct mv_cesa_op_ctx *tmpl)
{
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(req);

	memset(creq, 0, sizeof(*creq));
	mv_cesa_update_op_cfg(tmpl,
			      CESA_SA_DESC_CFG_OP_MAC_ONLY |
			      CESA_SA_DESC_CFG_FIRST_FRAG,
			      CESA_SA_DESC_CFG_OP_MSK |
			      CESA_SA_DESC_CFG_FRAG_MSK);
	mv_cesa_set_mac_op_total_len(tmpl, 0);
	mv_cesa_set_mac_op_frag_len(tmpl, 0);
	creq->op_tmpl = *tmpl;
	creq->len = 0;

	return 0;
}

static inline int mv_cesa_ahash_cra_init(struct crypto_tfm *tfm)
{
	struct mv_cesa_hash_ctx *ctx = crypto_tfm_ctx(tfm);

	ctx->base.ops = &mv_cesa_ahash_req_ops;

	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
				 sizeof(struct mv_cesa_ahash_req));
	return 0;
}

static int mv_cesa_ahash_cache_req(struct ahash_request *req, bool *cached)
{
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(req);
	int ret;

	if (((creq->cache_ptr + req->nbytes) & CESA_HASH_BLOCK_SIZE_MSK) &&
	    !creq->last_req) {
		ret = mv_cesa_ahash_alloc_cache(req);
		if (ret)
			return ret;
	}

	if (creq->cache_ptr + req->nbytes < 64 && !creq->last_req) {
		*cached = true;

		if (!req->nbytes)
			return 0;

		sg_pcopy_to_buffer(req->src, creq->src_nents,
				   creq->cache + creq->cache_ptr,
				   req->nbytes, 0);

		creq->cache_ptr += req->nbytes;
	}

	return 0;
}

static int mv_cesa_ahash_req_init(struct ahash_request *req, bool *cached)
{
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(req);

	creq->req.base.type = CESA_STD_REQ;
	creq->src_nents = sg_nents_for_len(req->src, req->nbytes);

	return mv_cesa_ahash_cache_req(req, cached);
}

static int mv_cesa_ahash_update(struct ahash_request *req)
{
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(req);
	bool cached = false;
	int ret;

	creq->len += req->nbytes;
	ret = mv_cesa_ahash_req_init(req, &cached);
	if (ret)
		return ret;

	if (cached)
		return 0;

	return mv_cesa_queue_req(&req->base);
}

static int mv_cesa_ahash_final(struct ahash_request *req)
{
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(req);
	struct mv_cesa_op_ctx *tmpl = &creq->op_tmpl;
	bool cached = false;
	int ret;

	mv_cesa_set_mac_op_total_len(tmpl, creq->len);
	creq->last_req = true;
	req->nbytes = 0;

	ret = mv_cesa_ahash_req_init(req, &cached);
	if (ret)
		return ret;

	if (cached)
		return 0;

	return mv_cesa_queue_req(&req->base);
}

static int mv_cesa_ahash_finup(struct ahash_request *req)
{
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(req);
	struct mv_cesa_op_ctx *tmpl = &creq->op_tmpl;
	bool cached = false;
	int ret;

	creq->len += req->nbytes;
	mv_cesa_set_mac_op_total_len(tmpl, creq->len);
	creq->last_req = true;

	ret = mv_cesa_ahash_req_init(req, &cached);
	if (ret)
		return ret;

	if (cached)
		return 0;

	return mv_cesa_queue_req(&req->base);
}

static int mv_cesa_sha1_init(struct ahash_request *req)
{
	struct mv_cesa_op_ctx tmpl;

	mv_cesa_set_op_cfg(&tmpl, CESA_SA_DESC_CFG_MACM_SHA1);

	mv_cesa_ahash_init(req, &tmpl);

	return 0;
}

static int mv_cesa_sha1_export(struct ahash_request *req, void *out)
{
	struct sha1_state *out_state = out;
	struct crypto_ahash *ahash = crypto_ahash_reqtfm(req);
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(req);
	unsigned int digsize = crypto_ahash_digestsize(ahash);

	out_state->count = creq->len;
	memcpy(out_state->state, creq->state, digsize);
	memset(out_state->buffer, 0, sizeof(out_state->buffer));
	if (creq->cache)
		memcpy(out_state->buffer, creq->cache, creq->cache_ptr);

	return 0;
}

static int mv_cesa_sha1_import(struct ahash_request *req, const void *in)
{
	const struct sha1_state *in_state = in;
	struct crypto_ahash *ahash = crypto_ahash_reqtfm(req);
	struct mv_cesa_ahash_req *creq = ahash_request_ctx(req);
	unsigned int digsize = crypto_ahash_digestsize(ahash);
	unsigned int cache_ptr;
	int ret;

	creq->len = in_state->count;
	memcpy(creq->state, in_state->state, digsize);
	creq->cache_ptr = 0;

	cache_ptr = creq->len % SHA1_BLOCK_SIZE;
	if (!cache_ptr)
		return 0;

	ret = mv_cesa_ahash_alloc_cache(req);
	if (ret)
		return ret;

	memcpy(creq->cache, in_state->buffer, cache_ptr);
	creq->cache_ptr = cache_ptr;

	return 0;
}

static int mv_cesa_sha1_digest(struct ahash_request *req)
{
	int ret;

	ret = mv_cesa_sha1_init(req);
	if (ret)
		return ret;

	return mv_cesa_ahash_finup(req);
}

struct ahash_alg mv_sha1_alg = {
	.init = mv_cesa_sha1_init,
	.update = mv_cesa_ahash_update,
	.final = mv_cesa_ahash_final,
	.finup = mv_cesa_ahash_finup,
	.digest = mv_cesa_sha1_digest,
	.export = mv_cesa_sha1_export,
	.import = mv_cesa_sha1_import,
	.halg = {
		.digestsize = SHA1_DIGEST_SIZE,
		.base = {
			.cra_name = "sha1",
			.cra_driver_name = "mv-sha1",
			.cra_priority = 300,
			.cra_flags = CRYPTO_ALG_ASYNC |
				     CRYPTO_ALG_KERN_DRIVER_ONLY,
			.cra_blocksize = SHA1_BLOCK_SIZE,
			.cra_ctxsize = sizeof(struct mv_cesa_hash_ctx),
			.cra_init = mv_cesa_ahash_cra_init,
			.cra_module = THIS_MODULE,
		 }
	}
};

struct mv_cesa_ahash_result {
	struct completion completion;
	int error;
};

static void mv_cesa_hmac_ahash_complete(struct crypto_async_request *req,
					int error)
{
	struct mv_cesa_ahash_result *result = req->data;

	if (error == -EINPROGRESS)
		return;

	result->error = error;
	complete(&result->completion);
}

static int mv_cesa_ahmac_iv_state_init(struct ahash_request *req, u8 *pad,
				       void *state, unsigned int blocksize)
{
	struct mv_cesa_ahash_result result;
	struct scatterlist sg;
	int ret;

	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
				   mv_cesa_hmac_ahash_complete, &result);
	sg_init_one(&sg, pad, blocksize);
	ahash_request_set_crypt(req, &sg, pad, blocksize);
	init_completion(&result.completion);

	ret = crypto_ahash_init(req);
	if (ret)
		return ret;

	ret = crypto_ahash_update(req);
	if (ret && ret != -EINPROGRESS)
		return ret;

	wait_for_completion_interruptible(&result.completion);
	if (result.error)
		return result.error;

	ret = crypto_ahash_export(req, state);
	if (ret)
		return ret;

	return 0;
}

static int mv_cesa_ahmac_pad_init(struct ahash_request *req,
				  const u8 *key, unsigned int keylen,
				  u8 *ipad, u8 *opad,
				  unsigned int blocksize)
{
	struct mv_cesa_ahash_result result;
	struct scatterlist sg;
	int ret;
	int i;

	if (keylen <= blocksize) {
		memcpy(ipad, key, keylen);
	} else {
		u8 *keydup = kmemdup(key, keylen, GFP_KERNEL);

		if (!keydup)
			return -ENOMEM;

		ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
					   mv_cesa_hmac_ahash_complete,
					   &result);
		sg_init_one(&sg, keydup, keylen);
		ahash_request_set_crypt(req, &sg, ipad, keylen);
		init_completion(&result.completion);

		ret = crypto_ahash_digest(req);
		if (ret == -EINPROGRESS) {
			wait_for_completion_interruptible(&result.completion);
			ret = result.error;
		}

		/* Set the memory region to 0 to avoid any leak. */
		memset(keydup, 0, keylen);
		kfree(keydup);

		if (ret)
			return ret;

		keylen = crypto_ahash_digestsize(crypto_ahash_reqtfm(req));
	}

	memset(ipad + keylen, 0, blocksize - keylen);
	memcpy(opad, ipad, blocksize);

	for (i = 0; i < blocksize; i++) {
		ipad[i] ^= 0x36;
		opad[i] ^= 0x5c;
	}

	return 0;
}

static int mv_cesa_ahmac_setkey(const char *hash_alg_name,
				const u8 *key, unsigned int keylen,
				void *istate, void *ostate)
{
	struct ahash_request *req;
	struct crypto_ahash *tfm;
	unsigned int blocksize;
	u8 *ipad = NULL;
	u8 *opad;
	int ret;

	tfm = crypto_alloc_ahash(hash_alg_name, CRYPTO_ALG_TYPE_AHASH,
				 CRYPTO_ALG_TYPE_AHASH_MASK);
	if (IS_ERR(tfm))
		return PTR_ERR(tfm);

	req = ahash_request_alloc(tfm, GFP_KERNEL);
	if (!req) {
		ret = -ENOMEM;
		goto free_ahash;
	}

	crypto_ahash_clear_flags(tfm, ~0);

	blocksize = crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));

	ipad = kzalloc(2 * blocksize, GFP_KERNEL);
	if (!ipad) {
		ret = -ENOMEM;
		goto free_req;
	}

	opad = ipad + blocksize;

	ret = mv_cesa_ahmac_pad_init(req, key, keylen, ipad, opad, blocksize);
	if (ret)
		goto free_ipad;

	ret = mv_cesa_ahmac_iv_state_init(req, ipad, istate, blocksize);
	if (ret)
		goto free_ipad;

	ret = mv_cesa_ahmac_iv_state_init(req, opad, ostate, blocksize);

free_ipad:
	kfree(ipad);
free_req:
	ahash_request_free(req);
free_ahash:
	crypto_free_ahash(tfm);

	return ret;
}

static int mv_cesa_ahmac_cra_init(struct crypto_tfm *tfm)
{
	struct mv_cesa_hmac_ctx *ctx = crypto_tfm_ctx(tfm);

	ctx->base.ops = &mv_cesa_ahash_req_ops;

	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
				 sizeof(struct mv_cesa_ahash_req));
	return 0;
}

static int mv_cesa_ahmac_sha1_init(struct ahash_request *req)
{
	struct mv_cesa_hmac_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
	struct mv_cesa_op_ctx tmpl;

	mv_cesa_set_op_cfg(&tmpl, CESA_SA_DESC_CFG_MACM_HMAC_SHA1);
	memcpy(tmpl.ctx.hash.iv, ctx->iv, sizeof(ctx->iv));

	mv_cesa_ahash_init(req, &tmpl);

	return 0;
}

static int mv_cesa_ahmac_sha1_setkey(struct crypto_ahash *tfm, const u8 *key,
				     unsigned int keylen)
{
	struct mv_cesa_hmac_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm));
	struct sha1_state istate, ostate;
	int ret, i;

	ret = mv_cesa_ahmac_setkey("mv-sha1", key, keylen, &istate, &ostate);
	if (ret)
		return ret;

	for (i = 0; i < ARRAY_SIZE(istate.state); i++)
		ctx->iv[i] = be32_to_cpu(istate.state[i]);

	for (i = 0; i < ARRAY_SIZE(ostate.state); i++)
		ctx->iv[i + 8] = be32_to_cpu(ostate.state[i]);

	return 0;
}

static int mv_cesa_ahmac_sha1_digest(struct ahash_request *req)
{
	int ret;

	ret = mv_cesa_ahmac_sha1_init(req);
	if (ret)
		return ret;

	return mv_cesa_ahash_finup(req);
}

struct ahash_alg mv_ahmac_sha1_alg = {
	.init = mv_cesa_ahmac_sha1_init,
	.update = mv_cesa_ahash_update,
	.final = mv_cesa_ahash_final,
	.finup = mv_cesa_ahash_finup,
	.digest = mv_cesa_ahmac_sha1_digest,
	.setkey = mv_cesa_ahmac_sha1_setkey,
	.export = mv_cesa_sha1_export,
	.import = mv_cesa_sha1_import,
	.halg = {
		.digestsize = SHA1_DIGEST_SIZE,
		.statesize = sizeof(struct sha1_state),
		.base = {
			.cra_name = "hmac(sha1)",
			.cra_driver_name = "mv-hmac-sha1",
			.cra_priority = 300,
			.cra_flags = CRYPTO_ALG_ASYNC |
				     CRYPTO_ALG_KERN_DRIVER_ONLY,
			.cra_blocksize = SHA1_BLOCK_SIZE,
			.cra_ctxsize = sizeof(struct mv_cesa_hmac_ctx),
			.cra_init = mv_cesa_ahmac_cra_init,
			.cra_module = THIS_MODULE,
		 }
	}
};