[PATCH 2/4] crypto: ccp - Move HMAC calculation down to ccp ops file

From: Tom Lendacky
Date: Fri Jan 24 2014 - 17:18:16 EST


Move the support to perform an HMAC calculation into
the CCP operations file. This eliminates the need to
perform a synchronous SHA operation used to calculate
the HMAC.

Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
drivers/crypto/ccp/ccp-crypto-sha.c | 130 +++++++----------------------------
drivers/crypto/ccp/ccp-crypto.h | 8 +-
drivers/crypto/ccp/ccp-ops.c | 104 ++++++++++++++++++++++++++++
include/linux/ccp.h | 7 ++
4 files changed, 139 insertions(+), 110 deletions(-)

diff --git a/drivers/crypto/ccp/ccp-crypto-sha.c b/drivers/crypto/ccp/ccp-crypto-sha.c
index 3867290..873f234 100644
--- a/drivers/crypto/ccp/ccp-crypto-sha.c
+++ b/drivers/crypto/ccp/ccp-crypto-sha.c
@@ -24,75 +24,10 @@
#include "ccp-crypto.h"


-struct ccp_sha_result {
- struct completion completion;
- int err;
-};
-
-static void ccp_sync_hash_complete(struct crypto_async_request *req, int err)
-{
- struct ccp_sha_result *result = req->data;
-
- if (err == -EINPROGRESS)
- return;
-
- result->err = err;
- complete(&result->completion);
-}
-
-static int ccp_sync_hash(struct crypto_ahash *tfm, u8 *buf,
- struct scatterlist *sg, unsigned int len)
-{
- struct ccp_sha_result result;
- struct ahash_request *req;
- int ret;
-
- init_completion(&result.completion);
-
- req = ahash_request_alloc(tfm, GFP_KERNEL);
- if (!req)
- return -ENOMEM;
-
- ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
- ccp_sync_hash_complete, &result);
- ahash_request_set_crypt(req, sg, buf, len);
-
- ret = crypto_ahash_digest(req);
- if ((ret == -EINPROGRESS) || (ret == -EBUSY)) {
- ret = wait_for_completion_interruptible(&result.completion);
- if (!ret)
- ret = result.err;
- }
-
- ahash_request_free(req);
-
- return ret;
-}
-
-static int ccp_sha_finish_hmac(struct crypto_async_request *async_req)
-{
- struct ahash_request *req = ahash_request_cast(async_req);
- struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
- struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
- struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
- struct scatterlist sg[2];
- unsigned int block_size =
- crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
- unsigned int digest_size = crypto_ahash_digestsize(tfm);
-
- sg_init_table(sg, ARRAY_SIZE(sg));
- sg_set_buf(&sg[0], ctx->u.sha.opad, block_size);
- sg_set_buf(&sg[1], rctx->ctx, digest_size);
-
- return ccp_sync_hash(ctx->u.sha.hmac_tfm, req->result, sg,
- block_size + digest_size);
-}
-
static int ccp_sha_complete(struct crypto_async_request *async_req, int ret)
{
struct ahash_request *req = ahash_request_cast(async_req);
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
- struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
unsigned int digest_size = crypto_ahash_digestsize(tfm);

@@ -112,10 +47,6 @@ static int ccp_sha_complete(struct crypto_async_request *async_req, int ret)
if (req->result)
memcpy(req->result, rctx->ctx, digest_size);

- /* If we're doing an HMAC, we need to perform that on the final op */
- if (rctx->final && ctx->u.sha.key_len)
- ret = ccp_sha_finish_hmac(async_req);
-
e_free:
sg_free_table(&rctx->data_sg);

@@ -126,6 +57,7 @@ static int ccp_do_sha_update(struct ahash_request *req, unsigned int nbytes,
unsigned int final)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+ struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
struct scatterlist *sg;
unsigned int block_size =
@@ -196,6 +128,11 @@ static int ccp_do_sha_update(struct ahash_request *req, unsigned int nbytes,
rctx->cmd.u.sha.ctx_len = sizeof(rctx->ctx);
rctx->cmd.u.sha.src = sg;
rctx->cmd.u.sha.src_len = rctx->hash_cnt;
+ rctx->cmd.u.sha.opad = ctx->u.sha.key_len ?
+ &ctx->u.sha.opad_sg : NULL;
+ rctx->cmd.u.sha.opad_len = ctx->u.sha.key_len ?
+ ctx->u.sha.opad_count : 0;
+ rctx->cmd.u.sha.first = rctx->first;
rctx->cmd.u.sha.final = rctx->final;
rctx->cmd.u.sha.msg_bits = rctx->msg_bits;

@@ -218,7 +155,6 @@ static int ccp_sha_init(struct ahash_request *req)

memset(rctx, 0, sizeof(*rctx));

- memcpy(rctx->ctx, alg->init, sizeof(rctx->ctx));
rctx->type = alg->type;
rctx->first = 1;

@@ -261,10 +197,13 @@ static int ccp_sha_setkey(struct crypto_ahash *tfm, const u8 *key,
unsigned int key_len)
{
struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm));
- struct scatterlist sg;
- unsigned int block_size =
- crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
- unsigned int digest_size = crypto_ahash_digestsize(tfm);
+ struct crypto_shash *shash = ctx->u.sha.hmac_tfm;
+ struct {
+ struct shash_desc sdesc;
+ char ctx[crypto_shash_descsize(shash)];
+ } desc;
+ unsigned int block_size = crypto_shash_blocksize(shash);
+ unsigned int digest_size = crypto_shash_digestsize(shash);
int i, ret;

/* Set to zero until complete */
@@ -277,8 +216,12 @@ static int ccp_sha_setkey(struct crypto_ahash *tfm, const u8 *key,

if (key_len > block_size) {
/* Must hash the input key */
- sg_init_one(&sg, key, key_len);
- ret = ccp_sync_hash(tfm, ctx->u.sha.key, &sg, key_len);
+ desc.sdesc.tfm = shash;
+ desc.sdesc.flags = crypto_ahash_get_flags(tfm) &
+ CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ ret = crypto_shash_digest(&desc.sdesc, key, key_len,
+ ctx->u.sha.key);
if (ret) {
crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
return -EINVAL;
@@ -293,6 +236,9 @@ static int ccp_sha_setkey(struct crypto_ahash *tfm, const u8 *key,
ctx->u.sha.opad[i] = ctx->u.sha.key[i] ^ 0x5c;
}

+ sg_init_one(&ctx->u.sha.opad_sg, ctx->u.sha.opad, block_size);
+ ctx->u.sha.opad_count = block_size;
+
ctx->u.sha.key_len = key_len;

return 0;
@@ -319,10 +265,9 @@ static int ccp_hmac_sha_cra_init(struct crypto_tfm *tfm)
{
struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
struct ccp_crypto_ahash_alg *alg = ccp_crypto_ahash_alg(tfm);
- struct crypto_ahash *hmac_tfm;
+ struct crypto_shash *hmac_tfm;

- hmac_tfm = crypto_alloc_ahash(alg->child_alg,
- CRYPTO_ALG_TYPE_AHASH, 0);
+ hmac_tfm = crypto_alloc_shash(alg->child_alg, 0, 0);
if (IS_ERR(hmac_tfm)) {
pr_warn("could not load driver %s need for HMAC support\n",
alg->child_alg);
@@ -339,35 +284,14 @@ static void ccp_hmac_sha_cra_exit(struct crypto_tfm *tfm)
struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);

if (ctx->u.sha.hmac_tfm)
- crypto_free_ahash(ctx->u.sha.hmac_tfm);
+ crypto_free_shash(ctx->u.sha.hmac_tfm);

ccp_sha_cra_exit(tfm);
}

-static const __be32 sha1_init[CCP_SHA_CTXSIZE / sizeof(__be32)] = {
- cpu_to_be32(SHA1_H0), cpu_to_be32(SHA1_H1),
- cpu_to_be32(SHA1_H2), cpu_to_be32(SHA1_H3),
- cpu_to_be32(SHA1_H4), 0, 0, 0,
-};
-
-static const __be32 sha224_init[CCP_SHA_CTXSIZE / sizeof(__be32)] = {
- cpu_to_be32(SHA224_H0), cpu_to_be32(SHA224_H1),
- cpu_to_be32(SHA224_H2), cpu_to_be32(SHA224_H3),
- cpu_to_be32(SHA224_H4), cpu_to_be32(SHA224_H5),
- cpu_to_be32(SHA224_H6), cpu_to_be32(SHA224_H7),
-};
-
-static const __be32 sha256_init[CCP_SHA_CTXSIZE / sizeof(__be32)] = {
- cpu_to_be32(SHA256_H0), cpu_to_be32(SHA256_H1),
- cpu_to_be32(SHA256_H2), cpu_to_be32(SHA256_H3),
- cpu_to_be32(SHA256_H4), cpu_to_be32(SHA256_H5),
- cpu_to_be32(SHA256_H6), cpu_to_be32(SHA256_H7),
-};
-
struct ccp_sha_def {
const char *name;
const char *drv_name;
- const __be32 *init;
enum ccp_sha_type type;
u32 digest_size;
u32 block_size;
@@ -377,7 +301,6 @@ static struct ccp_sha_def sha_algs[] = {
{
.name = "sha1",
.drv_name = "sha1-ccp",
- .init = sha1_init,
.type = CCP_SHA_TYPE_1,
.digest_size = SHA1_DIGEST_SIZE,
.block_size = SHA1_BLOCK_SIZE,
@@ -385,7 +308,6 @@ static struct ccp_sha_def sha_algs[] = {
{
.name = "sha224",
.drv_name = "sha224-ccp",
- .init = sha224_init,
.type = CCP_SHA_TYPE_224,
.digest_size = SHA224_DIGEST_SIZE,
.block_size = SHA224_BLOCK_SIZE,
@@ -393,7 +315,6 @@ static struct ccp_sha_def sha_algs[] = {
{
.name = "sha256",
.drv_name = "sha256-ccp",
- .init = sha256_init,
.type = CCP_SHA_TYPE_256,
.digest_size = SHA256_DIGEST_SIZE,
.block_size = SHA256_BLOCK_SIZE,
@@ -460,7 +381,6 @@ static int ccp_register_sha_alg(struct list_head *head,

INIT_LIST_HEAD(&ccp_alg->entry);

- ccp_alg->init = def->init;
ccp_alg->type = def->type;

alg = &ccp_alg->alg;
diff --git a/drivers/crypto/ccp/ccp-crypto.h b/drivers/crypto/ccp/ccp-crypto.h
index b222231..9aa4ae1 100644
--- a/drivers/crypto/ccp/ccp-crypto.h
+++ b/drivers/crypto/ccp/ccp-crypto.h
@@ -137,11 +137,14 @@ struct ccp_aes_cmac_req_ctx {
#define MAX_SHA_BLOCK_SIZE SHA256_BLOCK_SIZE

struct ccp_sha_ctx {
+ struct scatterlist opad_sg;
+ unsigned int opad_count;
+
unsigned int key_len;
u8 key[MAX_SHA_BLOCK_SIZE];
u8 ipad[MAX_SHA_BLOCK_SIZE];
u8 opad[MAX_SHA_BLOCK_SIZE];
- struct crypto_ahash *hmac_tfm;
+ struct crypto_shash *hmac_tfm;
};

struct ccp_sha_req_ctx {
@@ -167,9 +170,6 @@ struct ccp_sha_req_ctx {
unsigned int buf_count;
u8 buf[MAX_SHA_BLOCK_SIZE];

- /* HMAC support field */
- struct scatterlist pad_sg;
-
/* CCP driver command */
struct ccp_cmd cmd;
};
diff --git a/drivers/crypto/ccp/ccp-ops.c b/drivers/crypto/ccp/ccp-ops.c
index 71ed3ad..c3462e5 100644
--- a/drivers/crypto/ccp/ccp-ops.c
+++ b/drivers/crypto/ccp/ccp-ops.c
@@ -23,6 +23,7 @@
#include <linux/ccp.h>
#include <linux/scatterlist.h>
#include <crypto/scatterwalk.h>
+#include <crypto/sha.h>

#include "ccp-dev.h"

@@ -132,6 +133,27 @@ struct ccp_op {
} u;
};

+/* SHA initial context values */
+static const __be32 ccp_sha1_init[CCP_SHA_CTXSIZE / sizeof(__be32)] = {
+ cpu_to_be32(SHA1_H0), cpu_to_be32(SHA1_H1),
+ cpu_to_be32(SHA1_H2), cpu_to_be32(SHA1_H3),
+ cpu_to_be32(SHA1_H4), 0, 0, 0,
+};
+
+static const __be32 ccp_sha224_init[CCP_SHA_CTXSIZE / sizeof(__be32)] = {
+ cpu_to_be32(SHA224_H0), cpu_to_be32(SHA224_H1),
+ cpu_to_be32(SHA224_H2), cpu_to_be32(SHA224_H3),
+ cpu_to_be32(SHA224_H4), cpu_to_be32(SHA224_H5),
+ cpu_to_be32(SHA224_H6), cpu_to_be32(SHA224_H7),
+};
+
+static const __be32 ccp_sha256_init[CCP_SHA_CTXSIZE / sizeof(__be32)] = {
+ cpu_to_be32(SHA256_H0), cpu_to_be32(SHA256_H1),
+ cpu_to_be32(SHA256_H2), cpu_to_be32(SHA256_H3),
+ cpu_to_be32(SHA256_H4), cpu_to_be32(SHA256_H5),
+ cpu_to_be32(SHA256_H6), cpu_to_be32(SHA256_H7),
+};
+
/* The CCP cannot perform zero-length sha operations so the caller
* is required to buffer data for the final operation. However, a
* sha operation for a message with a total length of zero is valid
@@ -1411,7 +1433,27 @@ static int ccp_run_sha_cmd(struct ccp_cmd_queue *cmd_q, struct ccp_cmd *cmd)
if (ret)
return ret;

- ccp_set_dm_area(&ctx, 0, sha->ctx, 0, sha->ctx_len);
+ if (sha->first) {
+ const __be32 *init;
+
+ switch (sha->type) {
+ case CCP_SHA_TYPE_1:
+ init = ccp_sha1_init;
+ break;
+ case CCP_SHA_TYPE_224:
+ init = ccp_sha224_init;
+ break;
+ case CCP_SHA_TYPE_256:
+ init = ccp_sha256_init;
+ break;
+ default:
+ ret = -EINVAL;
+ goto e_ctx;
+ }
+ memcpy(ctx.address, init, CCP_SHA_CTXSIZE);
+ } else
+ ccp_set_dm_area(&ctx, 0, sha->ctx, 0, sha->ctx_len);
+
ret = ccp_copy_to_ksb(cmd_q, &ctx, op.jobid, op.ksb_ctx,
CCP_PASSTHRU_BYTESWAP_256BIT);
if (ret) {
@@ -1451,6 +1493,66 @@ static int ccp_run_sha_cmd(struct ccp_cmd_queue *cmd_q, struct ccp_cmd *cmd)

ccp_get_dm_area(&ctx, 0, sha->ctx, 0, sha->ctx_len);

+ if (sha->final && sha->opad) {
+ /* HMAC operation, recursively perform final SHA */
+ struct ccp_cmd hmac_cmd;
+ struct scatterlist sg;
+ u64 block_size, digest_size;
+ u8 *hmac_buf;
+
+ switch (sha->type) {
+ case CCP_SHA_TYPE_1:
+ block_size = SHA1_BLOCK_SIZE;
+ digest_size = SHA1_DIGEST_SIZE;
+ break;
+ case CCP_SHA_TYPE_224:
+ block_size = SHA224_BLOCK_SIZE;
+ digest_size = SHA224_DIGEST_SIZE;
+ break;
+ case CCP_SHA_TYPE_256:
+ block_size = SHA256_BLOCK_SIZE;
+ digest_size = SHA256_DIGEST_SIZE;
+ break;
+ default:
+ ret = -EINVAL;
+ goto e_data;
+ }
+
+ if (sha->opad_len != block_size) {
+ ret = -EINVAL;
+ goto e_data;
+ }
+
+ hmac_buf = kmalloc(block_size + digest_size, GFP_KERNEL);
+ if (!hmac_buf) {
+ ret = -ENOMEM;
+ goto e_data;
+ }
+ sg_init_one(&sg, hmac_buf, block_size + digest_size);
+
+ scatterwalk_map_and_copy(hmac_buf, sha->opad, 0, block_size, 0);
+ memcpy(hmac_buf + block_size, ctx.address, digest_size);
+
+ memset(&hmac_cmd, 0, sizeof(hmac_cmd));
+ hmac_cmd.engine = CCP_ENGINE_SHA;
+ hmac_cmd.u.sha.type = sha->type;
+ hmac_cmd.u.sha.ctx = sha->ctx;
+ hmac_cmd.u.sha.ctx_len = sha->ctx_len;
+ hmac_cmd.u.sha.src = &sg;
+ hmac_cmd.u.sha.src_len = block_size + digest_size;
+ hmac_cmd.u.sha.opad = NULL;
+ hmac_cmd.u.sha.opad_len = 0;
+ hmac_cmd.u.sha.first = 1;
+ hmac_cmd.u.sha.final = 1;
+ hmac_cmd.u.sha.msg_bits = (block_size + digest_size) << 3;
+
+ ret = ccp_run_sha_cmd(cmd_q, &hmac_cmd);
+ if (ret)
+ cmd->engine_error = hmac_cmd.engine_error;
+
+ kfree(hmac_buf);
+ }
+
e_data:
ccp_free_data(&src, cmd_q);

diff --git a/include/linux/ccp.h b/include/linux/ccp.h
index b941ab9..ebcc9d1 100644
--- a/include/linux/ccp.h
+++ b/include/linux/ccp.h
@@ -232,6 +232,9 @@ enum ccp_sha_type {
* @ctx_len: length in bytes of hash value
* @src: data to be used for this operation
* @src_len: length in bytes of data used for this operation
+ * @opad: data to be used for final HMAC operation
+ * @opad_len: length in bytes of data used for final HMAC operation
+ * @first: indicates first SHA operation
* @final: indicates final SHA operation
* @msg_bits: total length of the message in bits used in final SHA operation
*
@@ -251,6 +254,10 @@ struct ccp_sha_engine {
struct scatterlist *src;
u64 src_len; /* In bytes */

+ struct scatterlist *opad;
+ u32 opad_len; /* In bytes */
+
+ u32 first; /* Indicates first sha cmd */
u32 final; /* Indicates final sha cmd */
u64 msg_bits; /* Message length in bits required for
* final sha cmd */


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