commit f5bf7189d303e602992c750c09e429e23c7b2abf
author Andres AG <andres.amayagarcia@arm.com> Fri Mar 03 14:09:56 2017 +0000
committer Simon Butcher <simon.butcher@arm.com> Tue May 16 10:22:37 2017 +0100
tree 7c801a2343346388e706e2f16e9b8d64b80a08fc
parent 2850cdaed992ca38d1765e465fc1b9830d098a51

Change return type of AES decrypt and encrypt

This patch modifies the following 2 functions in the AES module to
change the return type from void to int:
    * mbedtls_aes_encrypt() -> mbedtls_internal_aes_encrypt()
    * mbedtls_aes_decrypt() -> mbedtls_internal_aes_decrypt()
This change is necessary to allow users of MBEDTLS_AES_ALT,
MBEDTLS_AES_DECRYPT_ALT and MBEDTLS_AES_ENCRYPT_ALT to return an error
code when replacing the default with their own implementation, e.g.
a hardware crypto accelerator.

library/aes.c

diff --git a/library/aes.c b/library/aes.c
index a186dee..5e01c4f 100644
--- a/library/aes.c
+++ b/library/aes.c
@@ -710,9 +710,9 @@
  * AES-ECB block encryption
  */
 #if !defined(MBEDTLS_AES_ENCRYPT_ALT)
-void mbedtls_aes_encrypt( mbedtls_aes_context *ctx,
-                          const unsigned char input[16],
-                          unsigned char output[16] )
+int mbedtls_internal_aes_encrypt( mbedtls_aes_context *ctx,
+                                  const unsigned char input[16],
+                                  unsigned char output[16] )
 {
     int i;
     uint32_t *RK, X0, X1, X2, X3, Y0, Y1, Y2, Y3;
@@ -760,6 +760,8 @@
     PUT_UINT32_LE( X1, output,  4 );
     PUT_UINT32_LE( X2, output,  8 );
     PUT_UINT32_LE( X3, output, 12 );
+
+    return( 0 );
 }
 #endif /* !MBEDTLS_AES_ENCRYPT_ALT */
 
@@ -767,9 +769,9 @@
  * AES-ECB block decryption
  */
 #if !defined(MBEDTLS_AES_DECRYPT_ALT)
-void mbedtls_aes_decrypt( mbedtls_aes_context *ctx,
-                          const unsigned char input[16],
-                          unsigned char output[16] )
+int mbedtls_internal_aes_decrypt( mbedtls_aes_context *ctx,
+                                  const unsigned char input[16],
+                                  unsigned char output[16] )
 {
     int i;
     uint32_t *RK, X0, X1, X2, X3, Y0, Y1, Y2, Y3;
@@ -817,6 +819,8 @@
     PUT_UINT32_LE( X1, output,  4 );
     PUT_UINT32_LE( X2, output,  8 );
     PUT_UINT32_LE( X3, output, 12 );
+
+    return( 0 );
 }
 #endif /* !MBEDTLS_AES_DECRYPT_ALT */
 
@@ -846,11 +850,9 @@
 #endif
 
     if( mode == MBEDTLS_AES_ENCRYPT )
-        mbedtls_aes_encrypt( ctx, input, output );
+        return( mbedtls_internal_aes_encrypt( ctx, input, output ) );
     else
-        mbedtls_aes_decrypt( ctx, input, output );
-
-    return( 0 );
+        return( mbedtls_internal_aes_decrypt( ctx, input, output ) );
 }
 
 #if defined(MBEDTLS_CIPHER_MODE_CBC)