drivers: crypto: Add authenticated decryption framework

Add framework for autheticated decryption of data. Currently this
patch optionally imports mbedtls library as a backend if build option
"DECRYPTION_SUPPORT = aes_gcm" is set to perform authenticated decryption
using AES-GCM algorithm.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Change-Id: I2966f0e79033151012bf4ffc66f484cd949e7271
diff --git a/drivers/auth/mbedtls/mbedtls_common.mk b/drivers/auth/mbedtls/mbedtls_common.mk
index 4b83015..044b368 100644
--- a/drivers/auth/mbedtls/mbedtls_common.mk
+++ b/drivers/auth/mbedtls/mbedtls_common.mk
@@ -23,13 +23,17 @@
 
 
 LIBMBEDTLS_SRCS		:= $(addprefix ${MBEDTLS_DIR}/library/,	\
+					aes.c 					\
 					asn1parse.c 				\
 					asn1write.c 				\
+					cipher.c 				\
+					cipher_wrap.c 				\
 					memory_buffer_alloc.c			\
 					oid.c 					\
 					platform.c 				\
 					platform_util.c				\
 					bignum.c				\
+					gcm.c 					\
 					md.c					\
 					md_wrap.c				\
 					pk.c 					\
@@ -87,11 +91,17 @@
     $(error "TF_MBEDTLS_KEY_ALG=${TF_MBEDTLS_KEY_ALG} not supported on mbed TLS")
 endif
 
+ifeq (${DECRYPTION_SUPPORT}, aes_gcm)
+    TF_MBEDTLS_USE_AES_GCM	:=	1
+else
+    TF_MBEDTLS_USE_AES_GCM	:=	0
+endif
+
 # Needs to be set to drive mbed TLS configuration correctly
 $(eval $(call add_define,TF_MBEDTLS_KEY_ALG_ID))
 $(eval $(call add_define,TF_MBEDTLS_KEY_SIZE))
 $(eval $(call add_define,TF_MBEDTLS_HASH_ALG_ID))
-
+$(eval $(call add_define,TF_MBEDTLS_USE_AES_GCM))
 
 $(eval $(call MAKE_LIB,mbedtls))