The ESSIV support in ccree was added before the kernel
generic support and using a slightly different API.
This patch brings the ccree essiv interface into
compliance with kernel crypto api one.
Since CryptoCell only support 256 bit AES key for ESSIV,
also use a fallback if requested a smaller key size.
Signed-off-by: Gilad Ben-Yossef <gi...@benyossef.com>
Cc: Ard Biesheuvel <ard.biesheu...@linaro.org>
Cc: Libo Wang <libo.w...@arm.com>
---
drivers/crypto/ccree/cc_cipher.c | 124 +++++++++++++++++++++++--------
1 file changed, 93 insertions(+), 31 deletions(-)
diff --git a/drivers/crypto/ccree/cc_cipher.c b/drivers/crypto/ccree/cc_cipher.c
index e61f35ca9945..6575e216262b 100644
--- a/drivers/crypto/ccree/cc_cipher.c
+++ b/drivers/crypto/ccree/cc_cipher.c
@@ -60,6 +60,8 @@ struct cc_cipher_ctx {
struct cc_cpp_key_info cpp;
};
struct crypto_shash *shash_tfm;
+ struct crypto_skcipher *fallback_tfm;
+ bool fallback_on;
};
static void cc_cipher_complete(struct device *dev, void *cc_req, int err);
@@ -79,7 +81,6 @@ static int validate_keys_sizes(struct cc_cipher_ctx *ctx_p,
u32 size)
case CC_AES_128_BIT_KEY_SIZE:
case CC_AES_192_BIT_KEY_SIZE:
if (ctx_p->cipher_mode != DRV_CIPHER_XTS &&
- ctx_p->cipher_mode != DRV_CIPHER_ESSIV &&
ctx_p->cipher_mode != DRV_CIPHER_BITLOCKER)
return 0;
break;
@@ -163,30 +164,49 @@ static int cc_cipher_init(struct crypto_tfm *tfm)
skcipher_alg.base);
struct device *dev = drvdata_to_dev(cc_alg->drvdata);
unsigned int max_key_buf_size = cc_alg->skcipher_alg.max_keysize;
+ unsigned int fallback_req_size = 0;
dev_dbg(dev, "Initializing context @%p for %s\n", ctx_p,
crypto_tfm_alg_name(tfm));
- crypto_skcipher_set_reqsize(__crypto_skcipher_cast(tfm),
- sizeof(struct cipher_req_ctx));
-
ctx_p->cipher_mode = cc_alg->cipher_mode;
ctx_p->flow_mode = cc_alg->flow_mode;
ctx_p->drvdata = cc_alg->drvdata;
if (ctx_p->cipher_mode == DRV_CIPHER_ESSIV) {
+ const char *name = crypto_tfm_alg_name(tfm);
+
/* Alloc hash tfm for essiv */
- ctx_p->shash_tfm = crypto_alloc_shash("sha256-generic", 0, 0);
+ ctx_p->shash_tfm = crypto_alloc_shash("sha256", 0, 0);
if (IS_ERR(ctx_p->shash_tfm)) {
dev_err(dev, "Error allocating hash tfm for ESSIV.\n");
return PTR_ERR(ctx_p->shash_tfm);
}
+ max_key_buf_size <<= 1;
+
+ /* Alloc fallabck tfm or essiv when key size != 256 bit */
+ ctx_p->fallback_tfm =
+ crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK
| CRYPTO_ALG_ASYNC);
+
+ if (IS_ERR(ctx_p->fallback_tfm)) {
+ /* Note we're still allowing registration with no
fallback since it's
+ * better to have most modes supported than none at all.
+ */
+ dev_warn(dev, "Error allocating fallback algo %s. Some
modes may be available.\n",
+ name);
+ ctx_p->fallback_tfm = NULL;
+ } else {
+ fallback_req_size =
crypto_skcipher_reqsize(ctx_p->fallback_tfm);
+ }
}
+ crypto_skcipher_set_reqsize(__crypto_skcipher_cast(tfm),
+ sizeof(struct cipher_req_ctx) +
fallback_req_size);
+
/* Allocate key buffer, cache line aligned */
- ctx_p->user.key = kmalloc(max_key_buf_size, GFP_KERNEL);
+ ctx_p->user.key = kzalloc(max_key_buf_size, GFP_KERNEL);
if (!ctx_p->user.key)
- goto out_shash;
+ goto out_fallback;
dev_dbg(dev, "Allocated key buffer in context. key=@%p\n",
ctx_p->user.key);
@@ -207,7 +227,8 @@ static int cc_cipher_init(struct crypto_tfm *tfm)
out_key:
kfree(ctx_p->user.key);
-out_shash:
+out_fallback:
+ crypto_free_skcipher(ctx_p->fallback_tfm);
crypto_free_shash(ctx_p->shash_tfm);
return -ENOMEM;
@@ -230,6 +251,8 @@ static void cc_cipher_exit(struct crypto_tfm *tfm)
/* Free hash tfm for essiv */
crypto_free_shash(ctx_p->shash_tfm);
ctx_p->shash_tfm = NULL;
+ crypto_free_skcipher(ctx_p->fallback_tfm);
+ ctx_p->fallback_tfm = NULL;
}
/* Unmap key buffer */
@@ -313,6 +336,7 @@ static int cc_cipher_sethkey(struct crypto_skcipher *sktfm,
const u8 *key,
}
ctx_p->keylen = keylen;
+ ctx_p->fallback_on = false;
switch (cc_slot_to_key_type(hki.hw_key1)) {
case CC_HW_PROTECTED_KEY:
@@ -398,10 +422,33 @@ static int cc_cipher_setkey(struct crypto_skcipher
*sktfm, const u8 *key,
/* STAT_PHASE_0: Init and sanity checks */
if (validate_keys_sizes(ctx_p, keylen)) {
- dev_dbg(dev, "Unsupported key size %d.\n", keylen);
+ dev_dbg(dev, "Invalid key size %d.\n", keylen);
return -EINVAL;
}
+ if (ctx_p->cipher_mode == DRV_CIPHER_ESSIV) {
+
+ /* We only support 256 bit ESSIV-CBC-AES keys */
+ if (keylen != AES_KEYSIZE_256) {
+ unsigned int flags = crypto_tfm_get_flags(tfm) &
CRYPTO_TFM_REQ_MASK;
+
+ if (likely(ctx_p->fallback_tfm)) {
+ ctx_p->fallback_on = true;
+ crypto_skcipher_clear_flags(ctx_p->fallback_tfm,
+
CRYPTO_TFM_REQ_MASK);
+
crypto_skcipher_clear_flags(ctx_p->fallback_tfm, flags);
+ return
crypto_skcipher_setkey(ctx_p->fallback_tfm, key, keylen);
+ }
+
+ dev_dbg(dev, "Unsupported key size %d and no
fallback.\n", keylen);
+ return -EINVAL;
+ }
+
+ /* Internal ESSIV key buffer is double sized */
+ max_key_buf_size <<= 1;
+ }
+
+ ctx_p->fallback_on = false;
ctx_p->key_type = CC_UNPROTECTED_KEY;
/*
@@ -429,24 +476,23 @@ static int cc_cipher_setkey(struct crypto_skcipher
*sktfm, const u8 *key,
max_key_buf_size, DMA_TO_DEVICE);
memcpy(ctx_p->user.key, key, keylen);
- if (keylen == 24)
- memset(ctx_p->user.key + 24, 0, CC_AES_KEY_SIZE_MAX - 24);
if (ctx_p->cipher_mode == DRV_CIPHER_ESSIV) {
/* sha256 for key2 - use sw implementation */
- int key_len = keylen >> 1;
int err;
SHASH_DESC_ON_STACK(desc, ctx_p->shash_tfm);
desc->tfm = ctx_p->shash_tfm;
- err = crypto_shash_digest(desc, ctx_p->user.key, key_len,
- ctx_p->user.key + key_len);
+ err = crypto_shash_digest(desc, ctx_p->user.key, keylen,
+ ctx_p->user.key + keylen);
if (err) {
dev_err(dev, "Failed to hash ESSIV key.\n");
return err;
}
+
+ keylen <<= 1;
}
dma_sync_single_for_device(dev, ctx_p->user.key_dma_addr,
max_key_buf_size, DMA_TO_DEVICE);
@@ -584,9 +630,10 @@ static void cc_setup_xex_state_desc(struct crypto_tfm *tfm,
int flow_mode = ctx_p->flow_mode;
int direction = req_ctx->gen_ctx.op_type;
dma_addr_t key_dma_addr = ctx_p->user.key_dma_addr;
- unsigned int key_len = ctx_p->keylen;
+ unsigned int key_len = (ctx_p->keylen / 2);
dma_addr_t iv_dma_addr = req_ctx->gen_ctx.iv_dma_addr;
unsigned int du_size = nbytes;
+ unsigned int key_offset = key_len;
struct cc_crypto_alg *cc_alg =
container_of(tfm->__crt_alg, struct cc_crypto_alg,
@@ -606,6 +653,10 @@ static void cc_setup_xex_state_desc(struct crypto_tfm *tfm,
case DRV_CIPHER_XTS:
case DRV_CIPHER_ESSIV:
case DRV_CIPHER_BITLOCKER:
+
+ if (cipher_mode == DRV_CIPHER_ESSIV)
+ key_len = SHA256_DIGEST_SIZE;
+
/* load XEX key */
hw_desc_init(&desc[*seq_size]);
set_cipher_mode(&desc[*seq_size], cipher_mode);
@@ -615,12 +666,12 @@ static void cc_setup_xex_state_desc(struct crypto_tfm
*tfm,
ctx_p->hw.key2_slot);
} else {
set_din_type(&desc[*seq_size], DMA_DLLI,
- (key_dma_addr + (key_len / 2)),
- (key_len / 2), NS_BIT);
+ (key_dma_addr + key_offset),
+ key_len, NS_BIT);
}
set_xex_data_unit_size(&desc[*seq_size], du_size);
set_flow_mode(&desc[*seq_size], S_DIN_to_AES2);
- set_key_size_aes(&desc[*seq_size], (key_len / 2));
+ set_key_size_aes(&desc[*seq_size], key_len);
set_setup_mode(&desc[*seq_size], SETUP_LOAD_XEX_KEY);
(*seq_size)++;
@@ -629,7 +680,7 @@ static void cc_setup_xex_state_desc(struct crypto_tfm *tfm,
set_setup_mode(&desc[*seq_size], SETUP_LOAD_STATE1);
set_cipher_mode(&desc[*seq_size], cipher_mode);
set_cipher_config0(&desc[*seq_size], direction);
- set_key_size_aes(&desc[*seq_size], (key_len / 2));
+ set_key_size_aes(&desc[*seq_size], key_len);
set_flow_mode(&desc[*seq_size], flow_mode);
set_din_type(&desc[*seq_size], DMA_DLLI, iv_dma_addr,
CC_AES_BLOCK_SIZE, NS_BIT);
@@ -880,6 +931,17 @@ static int cc_cipher_process(struct skcipher_request *req,
goto exit_process;
}
+ if (ctx_p->fallback_on) {
+ struct skcipher_request *subreq = skcipher_request_ctx(req);
+
+ *subreq = *req;
+ skcipher_request_set_tfm(subreq, ctx_p->fallback_tfm);
+ if (direction == DRV_CRYPTO_DIRECTION_ENCRYPT)
+ return crypto_skcipher_encrypt(subreq);
+ else
+ return crypto_skcipher_decrypt(subreq);
+ }
+
/* The IV we are handed may be allocted from the stack so
* we must copy it to a DMAable buffer before use.
*/
@@ -1023,7 +1085,7 @@ static const struct cc_alg_template skcipher_algs[] = {
.sec_func = true,
},
{
- .name = "essiv(paes)",
+ .name = "essiv(cbc(paes),sha256)",
.driver_name = "essiv-paes-ccree",
.blocksize = AES_BLOCK_SIZE,
.template_skcipher = {
@@ -1041,7 +1103,7 @@ static const struct cc_alg_template skcipher_algs[] = {
.sec_func = true,
},
{
- .name = "essiv512(paes)",
+ .name = "essiv512(cbc(paes),sha256)",
.driver_name = "essiv-paes-du512-ccree",
.blocksize = AES_BLOCK_SIZE,
.template_skcipher = {
@@ -1060,7 +1122,7 @@ static const struct cc_alg_template skcipher_algs[] = {
.sec_func = true,
},
{
- .name = "essiv4096(paes)",
+ .name = "essiv4096(cbc(paes),sha256)",
.driver_name = "essiv-paes-du4096-ccree",
.blocksize = AES_BLOCK_SIZE,
.template_skcipher = {
@@ -1282,15 +1344,15 @@ static const struct cc_alg_template skcipher_algs[] = {
.std_body = CC_STD_NIST,
},
{
- .name = "essiv(aes)",
+ .name = "essiv(cbc(aes),sha256)",
.driver_name = "essiv-aes-ccree",
.blocksize = AES_BLOCK_SIZE,
.template_skcipher = {
.setkey = cc_cipher_setkey,
.encrypt = cc_cipher_encrypt,
.decrypt = cc_cipher_decrypt,
- .min_keysize = AES_MIN_KEY_SIZE * 2,
- .max_keysize = AES_MAX_KEY_SIZE * 2,
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
},
.cipher_mode = DRV_CIPHER_ESSIV,
@@ -1299,15 +1361,15 @@ static const struct cc_alg_template skcipher_algs[] = {
.std_body = CC_STD_NIST,
},
{
- .name = "essiv512(aes)",
+ .name = "essiv512(cbc(aes),sha256)",
.driver_name = "essiv-aes-du512-ccree",
.blocksize = AES_BLOCK_SIZE,
.template_skcipher = {
.setkey = cc_cipher_setkey,
.encrypt = cc_cipher_encrypt,
.decrypt = cc_cipher_decrypt,
- .min_keysize = AES_MIN_KEY_SIZE * 2,
- .max_keysize = AES_MAX_KEY_SIZE * 2,
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
},
.cipher_mode = DRV_CIPHER_ESSIV,
@@ -1317,15 +1379,15 @@ static const struct cc_alg_template skcipher_algs[] = {
.std_body = CC_STD_NIST,
},
{
- .name = "essiv4096(aes)",
+ .name = "essiv4096(cbc(aes),sha256)",
.driver_name = "essiv-aes-du4096-ccree",
.blocksize = AES_BLOCK_SIZE,
.template_skcipher = {
.setkey = cc_cipher_setkey,
.encrypt = cc_cipher_encrypt,
.decrypt = cc_cipher_decrypt,
- .min_keysize = AES_MIN_KEY_SIZE * 2,
- .max_keysize = AES_MAX_KEY_SIZE * 2,
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
},
.cipher_mode = DRV_CIPHER_ESSIV,
--
2.27.0
