[dpdk-dev] [PATCH 4/5] crypto/aesni_mb: support all truncated CMAC digest sizes

[Pablo de Lara <pablo.de.lara.guarch@intel.com>]

The full digest size of CMAC algorithm is 16 bytes.
However, it is sometimes truncated to a smaller size (such as in IPSec).
This commit allows a user to generate a digest of any size
up to the full size.

Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
---
 drivers/crypto/aesni_mb/rte_aesni_mb_pmd.c    | 26 ++++++++++++++++++-
 .../crypto/aesni_mb/rte_aesni_mb_pmd_ops.c    |  4 +--
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/drivers/crypto/aesni_mb/rte_aesni_mb_pmd.c b/drivers/crypto/aesni_mb/rte_aesni_mb_pmd.c
index 54dcf7787..007c3fb2b 100644
--- a/drivers/crypto/aesni_mb/rte_aesni_mb_pmd.c
+++ b/drivers/crypto/aesni_mb/rte_aesni_mb_pmd.c
@@ -141,7 +141,31 @@ aesni_mb_set_session_auth_parameters(const struct aesni_mb_op_fns *mb_ops,
 	if (xform->auth.algo == RTE_CRYPTO_AUTH_AES_CMAC) {
 		sess->auth.algo = AES_CMAC;
 
-		sess->auth.gen_digest_len = sess->auth.req_digest_len;
+		uint16_t cmac_digest_len = get_digest_byte_length(AES_CMAC);
+
+		if (sess->auth.req_digest_len > cmac_digest_len) {
+			AESNI_MB_LOG(ERR, "Invalid digest size\n");
+			return -EINVAL;
+		}
+		/*
+		 * Multi-buffer lib supports digest sizes from 4 to 16 bytes
+		 * in version 0.50 and sizes of 12 and 16 bytes,
+		 * in version 0.49.
+		 * If size requested is different, generate the full digest
+		 * (16 bytes) in a temporary location and then memcpy
+		 * the requested number of bytes.
+		 */
+#if IMB_VERSION_NUM >= IMB_VERSION(0, 50, 0)
+		if (sess->auth.req_digest_len < 4)
+#else
+		uint16_t cmac_trunc_digest_len =
+				get_truncated_digest_byte_length(AES_CMAC);
+		if (sess->auth.req_digest_len != cmac_digest_len &&
+				sess->auth.req_digest_len != cmac_trunc_digest_len)
+#endif
+			sess->auth.gen_digest_len = cmac_digest_len;
+		else
+			sess->auth.gen_digest_len = sess->auth.req_digest_len;
 		(*mb_ops->aux.keyexp.aes_cmac_expkey)(xform->auth.key.data,
 				sess->auth.cmac.expkey);
 
diff --git a/drivers/crypto/aesni_mb/rte_aesni_mb_pmd_ops.c b/drivers/crypto/aesni_mb/rte_aesni_mb_pmd_ops.c
index e8397803e..e41ba70fa 100644
--- a/drivers/crypto/aesni_mb/rte_aesni_mb_pmd_ops.c
+++ b/drivers/crypto/aesni_mb/rte_aesni_mb_pmd_ops.c
@@ -358,9 +358,9 @@ static const struct rte_cryptodev_capabilities aesni_mb_pmd_capabilities[] = {
 					.increment = 0
 				},
 				.digest_size = {
-					.min = 12,
+					.min = 1,
 					.max = 16,
-					.increment = 4
+					.increment = 1
 				},
 				.iv_size = { 0 }
 			}, }
-- 
2.17.1