2010-05-26 00:43:39

by David Miller

[permalink] [raw]
Subject: [PATCH 7/7] n2_crypto: Add HMAC support.


One note is that, unlike with non-HMAC hashes, we can't support
hmac(sha224) using the HMAC_SHA256 opcode.

Signed-off-by: David S. Miller <[email protected]>
---
drivers/crypto/n2_core.c | 210 +++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 206 insertions(+), 4 deletions(-)

diff --git a/drivers/crypto/n2_core.c b/drivers/crypto/n2_core.c
index d01a2af..b99c38f 100644
--- a/drivers/crypto/n2_core.c
+++ b/drivers/crypto/n2_core.c
@@ -246,6 +246,7 @@ struct n2_ahash_alg {
u8 hw_op_hashsz;
u8 digest_size;
u8 auth_type;
+ u8 hmac_type;
struct ahash_alg alg;
};

@@ -259,10 +260,36 @@ static inline struct n2_ahash_alg *n2_ahash_alg(struct crypto_tfm *tfm)
return container_of(ahash_alg, struct n2_ahash_alg, alg);
}

+struct n2_hmac_alg {
+ const char *child_alg;
+ struct n2_ahash_alg derived;
+};
+
+static inline struct n2_hmac_alg *n2_hmac_alg(struct crypto_tfm *tfm)
+{
+ struct crypto_alg *alg = tfm->__crt_alg;
+ struct ahash_alg *ahash_alg;
+
+ ahash_alg = container_of(alg, struct ahash_alg, halg.base);
+
+ return container_of(ahash_alg, struct n2_hmac_alg, derived.alg);
+}
+
struct n2_hash_ctx {
struct crypto_ahash *fallback_tfm;
};

+#define N2_HASH_KEY_MAX 32 /* HW limit for all HMAC requests */
+
+struct n2_hmac_ctx {
+ struct n2_hash_ctx base;
+
+ struct crypto_shash *child_shash;
+
+ int hash_key_len;
+ unsigned char hash_key[N2_HASH_KEY_MAX];
+};
+
struct n2_hash_req_ctx {
union {
struct md5_state md5;
@@ -362,6 +389,94 @@ static void n2_hash_cra_exit(struct crypto_tfm *tfm)
crypto_free_ahash(ctx->fallback_tfm);
}

+static int n2_hmac_cra_init(struct crypto_tfm *tfm)
+{
+ const char *fallback_driver_name = tfm->__crt_alg->cra_name;
+ struct crypto_ahash *ahash = __crypto_ahash_cast(tfm);
+ struct n2_hmac_ctx *ctx = crypto_ahash_ctx(ahash);
+ struct n2_hmac_alg *n2alg = n2_hmac_alg(tfm);
+ struct crypto_ahash *fallback_tfm;
+ struct crypto_shash *child_shash;
+ int err;
+
+ fallback_tfm = crypto_alloc_ahash(fallback_driver_name, 0,
+ CRYPTO_ALG_NEED_FALLBACK);
+ if (IS_ERR(fallback_tfm)) {
+ pr_warning("Fallback driver '%s' could not be loaded!\n",
+ fallback_driver_name);
+ err = PTR_ERR(fallback_tfm);
+ goto out;
+ }
+
+ child_shash = crypto_alloc_shash(n2alg->child_alg, 0, 0);
+ if (IS_ERR(child_shash)) {
+ pr_warning("Child shash '%s' could not be loaded!\n",
+ n2alg->child_alg);
+ err = PTR_ERR(child_shash);
+ goto out_free_fallback;
+ }
+
+ crypto_ahash_set_reqsize(ahash, (sizeof(struct n2_hash_req_ctx) +
+ crypto_ahash_reqsize(fallback_tfm)));
+
+ ctx->child_shash = child_shash;
+ ctx->base.fallback_tfm = fallback_tfm;
+ return 0;
+
+out_free_fallback:
+ crypto_free_ahash(fallback_tfm);
+
+out:
+ return err;
+}
+
+static void n2_hmac_cra_exit(struct crypto_tfm *tfm)
+{
+ struct crypto_ahash *ahash = __crypto_ahash_cast(tfm);
+ struct n2_hmac_ctx *ctx = crypto_ahash_ctx(ahash);
+
+ crypto_free_ahash(ctx->base.fallback_tfm);
+ crypto_free_shash(ctx->child_shash);
+}
+
+static int n2_hmac_async_setkey(struct crypto_ahash *tfm, const u8 *key,
+ unsigned int keylen)
+{
+ struct n2_hmac_ctx *ctx = crypto_ahash_ctx(tfm);
+ struct crypto_shash *child_shash = ctx->child_shash;
+ struct crypto_ahash *fallback_tfm;
+ struct {
+ struct shash_desc shash;
+ char ctx[crypto_shash_descsize(child_shash)];
+ } desc;
+ int err, bs, ds;
+
+ fallback_tfm = ctx->base.fallback_tfm;
+ err = crypto_ahash_setkey(fallback_tfm, key, keylen);
+ if (err)
+ return err;
+
+ desc.shash.tfm = child_shash;
+ desc.shash.flags = crypto_ahash_get_flags(tfm) &
+ CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ bs = crypto_shash_blocksize(child_shash);
+ ds = crypto_shash_digestsize(child_shash);
+ BUG_ON(ds > N2_HASH_KEY_MAX);
+ if (keylen > bs) {
+ err = crypto_shash_digest(&desc.shash, key, keylen,
+ ctx->hash_key);
+ if (err)
+ return err;
+ keylen = ds;
+ } else if (keylen <= N2_HASH_KEY_MAX)
+ memcpy(ctx->hash_key, key, keylen);
+
+ ctx->hash_key_len = keylen;
+
+ return err;
+}
+
static unsigned long wait_for_tail(struct spu_queue *qp)
{
unsigned long head, hv_ret;
@@ -393,7 +508,8 @@ static unsigned long submit_and_wait_for_tail(struct spu_queue *qp,

static int n2_do_async_digest(struct ahash_request *req,
unsigned int auth_type, unsigned int digest_size,
- unsigned int result_size, void *hash_loc)
+ unsigned int result_size, void *hash_loc,
+ unsigned long auth_key, unsigned int auth_key_len)
{
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
struct cwq_initial_entry *ent;
@@ -434,13 +550,13 @@ static int n2_do_async_digest(struct ahash_request *req,
*/
ent = qp->q + qp->tail;

- ent->control = control_word_base(nbytes, 0, 0,
+ ent->control = control_word_base(nbytes, auth_key_len, 0,
auth_type, digest_size,
false, true, false, false,
OPCODE_INPLACE_BIT |
OPCODE_AUTH_MAC);
ent->src_addr = __pa(walk.data);
- ent->auth_key_addr = 0UL;
+ ent->auth_key_addr = auth_key;
ent->auth_iv_addr = __pa(hash_loc);
ent->final_auth_state_addr = 0UL;
ent->enc_key_addr = 0UL;
@@ -494,7 +610,40 @@ static int n2_hash_async_digest(struct ahash_request *req)

return n2_do_async_digest(req, n2alg->auth_type,
n2alg->hw_op_hashsz, ds,
- &rctx->u);
+ &rctx->u, 0UL, 0);
+}
+
+static int n2_hmac_async_digest(struct ahash_request *req)
+{
+ struct n2_hmac_alg *n2alg = n2_hmac_alg(req->base.tfm);
+ struct n2_hash_req_ctx *rctx = ahash_request_ctx(req);
+ struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+ struct n2_hmac_ctx *ctx = crypto_ahash_ctx(tfm);
+ int ds;
+
+ ds = n2alg->derived.digest_size;
+ if (unlikely(req->nbytes == 0) ||
+ unlikely(ctx->hash_key_len > N2_HASH_KEY_MAX)) {
+ struct n2_hash_req_ctx *rctx = ahash_request_ctx(req);
+ struct n2_hash_ctx *ctx = crypto_ahash_ctx(tfm);
+
+ ahash_request_set_tfm(&rctx->fallback_req, ctx->fallback_tfm);
+ rctx->fallback_req.base.flags =
+ req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP;
+ rctx->fallback_req.nbytes = req->nbytes;
+ rctx->fallback_req.src = req->src;
+ rctx->fallback_req.result = req->result;
+
+ return crypto_ahash_digest(&rctx->fallback_req);
+ }
+ memcpy(&rctx->u, n2alg->derived.hash_init,
+ n2alg->derived.hw_op_hashsz);
+
+ return n2_do_async_digest(req, n2alg->derived.hmac_type,
+ n2alg->derived.hw_op_hashsz, ds,
+ &rctx->u,
+ __pa(&ctx->hash_key),
+ ctx->hash_key_len);
}

struct n2_cipher_context {
@@ -1127,6 +1276,7 @@ struct n2_hash_tmpl {
u8 digest_size;
u8 block_size;
u8 auth_type;
+ u8 hmac_type;
};

static const char md5_zero[MD5_DIGEST_SIZE] = {
@@ -1173,6 +1323,7 @@ static const struct n2_hash_tmpl hash_tmpls[] = {
.hash_zero = md5_zero,
.hash_init = md5_init,
.auth_type = AUTH_TYPE_MD5,
+ .hmac_type = AUTH_TYPE_HMAC_MD5,
.hw_op_hashsz = MD5_DIGEST_SIZE,
.digest_size = MD5_DIGEST_SIZE,
.block_size = MD5_HMAC_BLOCK_SIZE },
@@ -1180,6 +1331,7 @@ static const struct n2_hash_tmpl hash_tmpls[] = {
.hash_zero = sha1_zero,
.hash_init = sha1_init,
.auth_type = AUTH_TYPE_SHA1,
+ .hmac_type = AUTH_TYPE_HMAC_SHA1,
.hw_op_hashsz = SHA1_DIGEST_SIZE,
.digest_size = SHA1_DIGEST_SIZE,
.block_size = SHA1_BLOCK_SIZE },
@@ -1187,6 +1339,7 @@ static const struct n2_hash_tmpl hash_tmpls[] = {
.hash_zero = sha256_zero,
.hash_init = sha256_init,
.auth_type = AUTH_TYPE_SHA256,
+ .hmac_type = AUTH_TYPE_HMAC_SHA256,
.hw_op_hashsz = SHA256_DIGEST_SIZE,
.digest_size = SHA256_DIGEST_SIZE,
.block_size = SHA256_BLOCK_SIZE },
@@ -1194,6 +1347,7 @@ static const struct n2_hash_tmpl hash_tmpls[] = {
.hash_zero = sha224_zero,
.hash_init = sha224_init,
.auth_type = AUTH_TYPE_SHA256,
+ .hmac_type = AUTH_TYPE_RESERVED,
.hw_op_hashsz = SHA256_DIGEST_SIZE,
.digest_size = SHA224_DIGEST_SIZE,
.block_size = SHA224_BLOCK_SIZE },
@@ -1201,6 +1355,7 @@ static const struct n2_hash_tmpl hash_tmpls[] = {
#define NUM_HASH_TMPLS ARRAY_SIZE(hash_tmpls)

static LIST_HEAD(ahash_algs);
+static LIST_HEAD(hmac_algs);

static int algs_registered;

@@ -1208,12 +1363,18 @@ static void __n2_unregister_algs(void)
{
struct n2_cipher_alg *cipher, *cipher_tmp;
struct n2_ahash_alg *alg, *alg_tmp;
+ struct n2_hmac_alg *hmac, *hmac_tmp;

list_for_each_entry_safe(cipher, cipher_tmp, &cipher_algs, entry) {
crypto_unregister_alg(&cipher->alg);
list_del(&cipher->entry);
kfree(cipher);
}
+ list_for_each_entry_safe(hmac, hmac_tmp, &hmac_algs, derived.entry) {
+ crypto_unregister_ahash(&hmac->derived.alg);
+ list_del(&hmac->derived.entry);
+ kfree(hmac);
+ }
list_for_each_entry_safe(alg, alg_tmp, &ahash_algs, entry) {
crypto_unregister_ahash(&alg->alg);
list_del(&alg->entry);
@@ -1262,6 +1423,44 @@ static int __devinit __n2_register_one_cipher(const struct n2_cipher_tmpl *tmpl)
return err;
}

+static int __devinit __n2_register_one_hmac(struct n2_ahash_alg *n2ahash)
+{
+ struct n2_hmac_alg *p = kzalloc(sizeof(*p), GFP_KERNEL);
+ struct ahash_alg *ahash;
+ struct crypto_alg *base;
+ int err;
+
+ if (!p)
+ return -ENOMEM;
+
+ p->child_alg = n2ahash->alg.halg.base.cra_name;
+ memcpy(&p->derived, n2ahash, sizeof(struct n2_ahash_alg));
+ INIT_LIST_HEAD(&p->derived.entry);
+
+ ahash = &p->derived.alg;
+ ahash->digest = n2_hmac_async_digest;
+ ahash->setkey = n2_hmac_async_setkey;
+
+ base = &ahash->halg.base;
+ snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)", p->child_alg);
+ snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "hmac-%s-n2", p->child_alg);
+
+ base->cra_ctxsize = sizeof(struct n2_hmac_ctx);
+ base->cra_init = n2_hmac_cra_init;
+ base->cra_exit = n2_hmac_cra_exit;
+
+ list_add(&p->derived.entry, &hmac_algs);
+ err = crypto_register_ahash(ahash);
+ if (err) {
+ pr_err("%s alg registration failed\n", base->cra_name);
+ list_del(&p->derived.entry);
+ kfree(p);
+ } else {
+ pr_info("%s alg registered\n", base->cra_name);
+ }
+ return err;
+}
+
static int __devinit __n2_register_one_ahash(const struct n2_hash_tmpl *tmpl)
{
struct n2_ahash_alg *p = kzalloc(sizeof(*p), GFP_KERNEL);
@@ -1276,6 +1475,7 @@ static int __devinit __n2_register_one_ahash(const struct n2_hash_tmpl *tmpl)
p->hash_zero = tmpl->hash_zero;
p->hash_init = tmpl->hash_init;
p->auth_type = tmpl->auth_type;
+ p->hmac_type = tmpl->hmac_type;
p->hw_op_hashsz = tmpl->hw_op_hashsz;
p->digest_size = tmpl->digest_size;

@@ -1309,6 +1509,8 @@ static int __devinit __n2_register_one_ahash(const struct n2_hash_tmpl *tmpl)
} else {
pr_info("%s alg registered\n", base->cra_name);
}
+ if (!err && p->hmac_type != AUTH_TYPE_RESERVED)
+ err = __n2_register_one_hmac(p);
return err;
}

--
1.7.0.4