libmbedtls: implement AES encrypt api

These two implemented interfaces will be used by AES-GCM algo.

Acked-by: Etienne Carriere <etienne.carriere@linaro.org>
Signed-off-by: Summer Qin <summer.qin@arm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

3 files changed, 46 insertions, 16 deletions

diff --git a/lib/libmbedtls/core/aes.c b/lib/libmbedtls/core/aes.c
new file mode 100644
index 00000000..4d317f0f
--- /dev/null
+++ b/lib/libmbedtls/core/aes.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * Copyright (C) 2018, ARM Limited
+ * Copyright (C) 2019, Linaro Limited
+ */
+
+#include <crypto/crypto.h>
+#include <kernel/panic.h>
+#include <mbedtls/aes.h>
+#include <string.h>
+
+TEE_Result crypto_aes_expand_enc_key(const void *key, size_t key_len,
+				     void *enc_key, size_t enc_keylen,
+				     unsigned int *rounds)
+{
+	mbedtls_aes_context ctx;
+
+	memset(&ctx, 0, sizeof(ctx));
+	mbedtls_aes_init(&ctx);
+	if (mbedtls_aes_setkey_enc(&ctx, key, key_len * 8) != 0)
+		return TEE_ERROR_BAD_PARAMETERS;
+
+	if (enc_keylen > sizeof(ctx.buf))
+		return TEE_ERROR_BAD_PARAMETERS;
+	memcpy(enc_key, ctx.buf, enc_keylen);
+	*rounds = ctx.nr;
+	mbedtls_aes_free(&ctx);
+	return TEE_SUCCESS;
+}
+
+void crypto_aes_enc_block(const void *enc_key, size_t enc_keylen,
+			  unsigned int rounds, const void *src, void *dst)
+{
+	mbedtls_aes_context ctx;
+
+	memset(&ctx, 0, sizeof(ctx));
+	mbedtls_aes_init(&ctx);
+	if (enc_keylen > sizeof(ctx.buf))
+		panic();
+	memcpy(ctx.buf, enc_key, enc_keylen);
+	ctx.rk = ctx.buf;
+	ctx.nr = rounds;
+	mbedtls_aes_encrypt(&ctx, src, dst);
+	mbedtls_aes_free(&ctx);
+}
diff --git a/lib/libmbedtls/core/stubbed.c b/lib/libmbedtls/core/stubbed.c
index 2bbab959..58ddcf56 100644
--- a/lib/libmbedtls/core/stubbed.c
+++ b/lib/libmbedtls/core/stubbed.c
@@ -275,22 +275,6 @@ crypto_acipher_ecc_shared_secret(struct ecc_keypair *private_key __unused,
 #endif /* CFG_CRYPTO_ECC */
 
 
-TEE_Result crypto_aes_expand_enc_key(const void *key __unused,
-				     size_t key_len __unused,
-				     void *enc_key __unused,
-				     size_t enc_keylen __unused,
-				     unsigned int *rounds __unused)
-{
-	return TEE_ERROR_NOT_IMPLEMENTED;
-}
-
-void crypto_aes_enc_block(const void *enc_key __unused,
-			  size_t enc_keylen __unused,
-			  unsigned int rounds __unused,
-			  const void *src __unused, void *dst __unused)
-{
-}
-
 /* Stubs for the crypto alloc ctx functions matching crypto_impl.h */
 #undef CRYPTO_ALLOC_CTX_NOT_IMPLEMENTED
 
diff --git a/lib/libmbedtls/core/sub.mk b/lib/libmbedtls/core/sub.mk
index 42ff2037..0626574d 100644
--- a/lib/libmbedtls/core/sub.mk
+++ b/lib/libmbedtls/core/sub.mk
@@ -7,6 +7,7 @@ srcs-$(call cfg-one-enabled, CFG_CRYPTO_MD5 CFG_CRYPTO_SHA1 CFG_CRYPTO_SHA224 \
 			     CFG_CRYPTO_SHA512) += hash.c
 
 ifeq ($(CFG_CRYPTO_AES),y)
+srcs-y += aes.c
 srcs-$(CFG_CRYPTO_ECB) += aes_ecb.c
 srcs-$(CFG_CRYPTO_CBC) += aes_cbc.c
 srcs-$(CFG_CRYPTO_CTR) += aes_ctr.c