[dpdk-dev] [PATCH] crypto/qat: fix out-of-bounds compiler error

[Tomasz Jozwiak]

This commit fixes
  - bpi_cipher_encrypt to prevent before 'array subscript is
    above array bounds' error
  - bpi_cipher_decrypt to prevent before 'array subscript is
    above array bounds' error
  - right cast from qat_cipher_get_block_size function.
    This function can return -EFAULT in case of any error,
    and that value must be cast to int instead of uint8_t
  - typo in error message

A performance improvement was added to bpi_cipher_encrypt and
bpi_cipher_decrypt as well.

Fixes: d18ab45f7654 ("crypto/qat: support DOCSIS BPI mode")

Signed-off-by: Tomasz Jozwiak <tomaszx.jozwiak at intel.com>
---
 drivers/crypto/qat/qat_crypto.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/crypto/qat/qat_crypto.c b/drivers/crypto/qat/qat_crypto.c
index a572967..c63697e 100644
--- a/drivers/crypto/qat/qat_crypto.c
+++ b/drivers/crypto/qat/qat_crypto.c
@@ -69,6 +69,10 @@
 #include "adf_transport_access_macros.h"
 
 #define BYTE_LENGTH    8
+/* bpi is only used for partial blocks of DES and AES
+ * so AES block len can be assumed as max len for iv, src and dst
+ */
+#define BPI_MAX_ENCR_IV_LEN ICP_QAT_HW_AES_BLK_SZ
 
 static int
 qat_is_cipher_alg_supported(enum rte_crypto_cipher_algorithm algo,
@@ -121,16 +125,17 @@ bpi_cipher_encrypt(uint8_t *src, uint8_t *dst,
 {
 	EVP_CIPHER_CTX *ctx = (EVP_CIPHER_CTX *)bpi_ctx;
 	int encrypted_ivlen;
-	uint8_t encrypted_iv[16];
-	int i;
+	uint8_t encrypted_iv[BPI_MAX_ENCR_IV_LEN];
+
+	register uint8_t *encr = encrypted_iv;
 
 	/* ECB method: encrypt the IV, then XOR this with plaintext */
 	if (EVP_EncryptUpdate(ctx, encrypted_iv, &encrypted_ivlen, iv, ivlen)
 								<= 0)
 		goto cipher_encrypt_err;
 
-	for (i = 0; i < srclen; i++)
-		*(dst+i) = *(src+i)^(encrypted_iv[i]);
+	for (; srclen != 0; --srclen, ++dst, ++src, ++encr)
+		*dst = *src ^ *encr;
 
 	return 0;
 
@@ -150,21 +155,22 @@ bpi_cipher_decrypt(uint8_t *src, uint8_t *dst,
 {
 	EVP_CIPHER_CTX *ctx = (EVP_CIPHER_CTX *)bpi_ctx;
 	int encrypted_ivlen;
-	uint8_t encrypted_iv[16];
-	int i;
+	uint8_t encrypted_iv[BPI_MAX_ENCR_IV_LEN];
+
+	register uint8_t *encr = encrypted_iv;
 
 	/* ECB method: encrypt (not decrypt!) the IV, then XOR with plaintext */
 	if (EVP_EncryptUpdate(ctx, encrypted_iv, &encrypted_ivlen, iv, ivlen)
 								<= 0)
 		goto cipher_decrypt_err;
 
-	for (i = 0; i < srclen; i++)
-		*(dst+i) = *(src+i)^(encrypted_iv[i]);
+	for (; srclen != 0; --srclen, ++dst, ++src, ++encr)
+		*dst = *src ^ *encr;
 
 	return 0;
 
 cipher_decrypt_err:
-	PMD_DRV_LOG(ERR, "libcrypto ECB cipher encrypt for BPI IV failed");
+	PMD_DRV_LOG(ERR, "libcrypto ECB cipher decrypt for BPI IV failed");
 	return -EINVAL;
 }
 
@@ -844,7 +850,7 @@ static inline uint32_t
 qat_bpicipher_preprocess(struct qat_session *ctx,
 				struct rte_crypto_op *op)
 {
-	uint8_t block_len = qat_cipher_get_block_size(ctx->qat_cipher_alg);
+	int block_len = qat_cipher_get_block_size(ctx->qat_cipher_alg);
 	struct rte_crypto_sym_op *sym_op = op->sym;
 	uint8_t last_block_len = block_len > 0 ?
 			sym_op->cipher.data.length % block_len : 0;
@@ -899,7 +905,7 @@ static inline uint32_t
 qat_bpicipher_postprocess(struct qat_session *ctx,
 				struct rte_crypto_op *op)
 {
-	uint8_t block_len = qat_cipher_get_block_size(ctx->qat_cipher_alg);
+	int block_len = qat_cipher_get_block_size(ctx->qat_cipher_alg);
 	struct rte_crypto_sym_op *sym_op = op->sym;
 	uint8_t last_block_len = block_len > 0 ?
 			sym_op->cipher.data.length % block_len : 0;
-- 
2.7.4