commit e4daf77c2e050617ecba19351a2284c3b70547ca
author Jaeden Amero <jaeden.amero@arm.com> Mon Apr 30 17:17:41 2018 +0100
committer Jaeden Amero <jaeden.amero@arm.com> Thu May 10 09:17:25 2018 +0100
tree cfa113a293abaa01ce767040512f44a00470b6a9
parent 184d06942e8dfc3754f2e6af02880c64f9518a2b

cipher: Add wrappers for AES-XTS

AES-XTS does not support multipart use as it can only operate on an entire
sector at a time.

library/cipher.c

diff --git a/library/cipher.c b/library/cipher.c
index a5cd61c..4f12b72 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -440,6 +440,27 @@
     }
 #endif /* MBEDTLS_CIPHER_MODE_CTR */
 
+#if defined(MBEDTLS_CIPHER_MODE_XTS)
+    if( ctx->cipher_info->mode == MBEDTLS_MODE_XTS )
+    {
+        if ( ctx->unprocessed_len ) {
+            /* We can only process an entire sector at a time. */
+            return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE );
+        }
+
+        ret = ctx->cipher_info->base->xts_func( ctx->cipher_ctx,
+                ctx->operation, ilen, ctx->iv, input, output );
+        if( ret != 0 )
+        {
+            return( ret );
+        }
+
+        *olen = ilen;
+
+        return( 0 );
+    }
+#endif /* MBEDTLS_CIPHER_MODE_XTS */
+
 #if defined(MBEDTLS_CIPHER_MODE_STREAM)
     if( ctx->cipher_info->mode == MBEDTLS_MODE_STREAM )
     {
@@ -641,6 +662,7 @@
     if( MBEDTLS_MODE_CFB == ctx->cipher_info->mode ||
         MBEDTLS_MODE_CTR == ctx->cipher_info->mode ||
         MBEDTLS_MODE_GCM == ctx->cipher_info->mode ||
+        MBEDTLS_MODE_XTS == ctx->cipher_info->mode ||
         MBEDTLS_MODE_STREAM == ctx->cipher_info->mode )
     {
         return( 0 );