Add int return values to SHA-256 function calls

The following function calls are being deprecated to introduce int
return values.
    * mbedtls_sha256()
    * mbedtls_sha256_starts()
    * mbedtls_sha256_update()
    * mbedtls_sha256_finish()
    * mbedtls_sha256_process()
The return codes can be used to return error values. This is important
when using hardware accelerators.

include/mbedtls/sha256.h

@@ -32,6 +32,11 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
+    !defined(inline) && !defined(__cplusplus)
+#define inline __inline
+#endif
+
 #if !defined(MBEDTLS_SHA256_ALT)
 // Regular implementation
 //
@@ -80,8 +85,10 @@ void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
  *
  * \param ctx      context to be initialized
  * \param is224    0 = use SHA256, 1 = use SHA224
+ *
+ * \return         0 if successful
  */
-void mbedtls_sha256_starts( mbedtls_sha256_context *ctx, int is224 );
+int mbedtls_sha256_starts_ext( mbedtls_sha256_context *ctx, int is224 );
 
 /**
  * \brief          SHA-256 process buffer
@@ -89,8 +96,11 @@ void mbedtls_sha256_starts( mbedtls_sha256_context *ctx, int is224 );
  * \param ctx      SHA-256 context
  * \param input    buffer holding the  data
  * \param ilen     length of the input data
+ *
+ * \return         0 if successful
  */
-void mbedtls_sha256_update( mbedtls_sha256_context *ctx, const unsigned char *input,
+int mbedtls_sha256_update_ext( mbedtls_sha256_context *ctx,
+                               const unsigned char *input,
                                size_t ilen );
 
 /**
@@ -98,11 +108,93 @@ void mbedtls_sha256_update( mbedtls_sha256_context *ctx, const unsigned char *in
  *
  * \param ctx      SHA-256 context
  * \param output   SHA-224/256 checksum result
+ *
+ * \return         0 if successful
  */
-void mbedtls_sha256_finish( mbedtls_sha256_context *ctx, unsigned char output[32] );
+int mbedtls_sha256_finish_ext( mbedtls_sha256_context *ctx,
+                               unsigned char output[32] );
 
-/* Internal use */
+/**
-void mbedtls_sha256_process( mbedtls_sha256_context *ctx, const unsigned char data[64] );
+ * \brief          SHA-256 process data block (internal use only)
+ *
+ * \param ctx      SHA-256 context
+ * \param data     buffer holding one block of data
+ *
+ * \return         0 if successful
+ */
+int mbedtls_sha256_process_ext( mbedtls_sha256_context *ctx,
+                                const unsigned char data[64] );
+
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+#if defined(MBEDTLS_DEPRECATED_WARNING)
+#define MBEDTLS_DEPRECATED      __attribute__((deprecated))
+#else
+#define MBEDTLS_DEPRECATED
+#endif
+/**
+ * \brief          SHA-256 context setup
+ *
+ * \deprecated     Superseded by mbedtls_sha256_starts_ext() in 2.5.0
+ *
+ * \param ctx      context to be initialized
+ * \param is224    0 = use SHA256, 1 = use SHA224
+ */
+MBEDTLS_DEPRECATED static inline void mbedtls_sha256_starts(
+                                                mbedtls_sha256_context *ctx,
+                                                int is224 )
+{
+    mbedtls_sha256_starts_ext( ctx, is224 );
+}
+
+/**
+ * \brief          SHA-256 process buffer
+ *
+ * \deprecated     Superseded by mbedtls_sha256_update_ext() in 2.5.0
+ *
+ * \param ctx      SHA-256 context
+ * \param input    buffer holding the  data
+ * \param ilen     length of the input data
+ */
+MBEDTLS_DEPRECATED static inline void mbedtls_sha256_update(
+                                                mbedtls_sha256_context *ctx,
+                                                const unsigned char *input,
+                                                size_t ilen )
+{
+    mbedtls_sha256_update_ext( ctx, input, ilen );
+}
+
+/**
+ * \brief          SHA-256 final digest
+ *
+ * \deprecated     Superseded by mbedtls_sha256_finish_ext() in 2.5.0
+ *
+ * \param ctx      SHA-256 context
+ * \param output   SHA-224/256 checksum result
+ */
+MBEDTLS_DEPRECATED static inline void mbedtls_sha256_finish(
+                                                mbedtls_sha256_context *ctx,
+                                                unsigned char output[32] )
+{
+    mbedtls_sha256_finish_ext( ctx, output );
+}
+
+/**
+ * \brief          SHA-256 process data block (internal use only)
+ *
+ * \deprecated     Superseded by mbedtls_sha256_process_ext() in 2.5.0
+ *
+ * \param ctx      SHA-256 context
+ * \param data     buffer holding one block of data
+ */
+MBEDTLS_DEPRECATED static inline void mbedtls_sha256_process(
+                                                mbedtls_sha256_context *ctx,
+                                                const unsigned char data[64] )
+{
+    mbedtls_sha256_process_ext( ctx, data );
+}
+
+#undef MBEDTLS_DEPRECATED
+#endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
 #ifdef __cplusplus
 }
@@ -123,9 +215,41 @@ extern "C" {
  * \param ilen     length of the input data
  * \param output   SHA-224/256 checksum result
  * \param is224    0 = use SHA256, 1 = use SHA224
+ *
+ * \return         0 if successful
  */
-void mbedtls_sha256( const unsigned char *input, size_t ilen,
+int mbedtls_sha256_ext( const unsigned char *input,
-           unsigned char output[32], int is224 );
+                        size_t ilen,
+                        unsigned char output[32],
+                        int is224 );
+
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+#if defined(MBEDTLS_DEPRECATED_WARNING)
+#define MBEDTLS_DEPRECATED      __attribute__((deprecated))
+#else
+#define MBEDTLS_DEPRECATED
+#endif
+/**
+ * \brief          Output = SHA-256( input buffer )
+ *
+ * \deprecated     Superseded by mbedtls_sha256_ext() in 2.5.0
+ *
+ * \param input    buffer holding the  data
+ * \param ilen     length of the input data
+ * \param output   SHA-224/256 checksum result
+ * \param is224    0 = use SHA256, 1 = use SHA224
+ */
+MBEDTLS_DEPRECATED static inline void mbedtls_sha256(
+                                                    const unsigned char *input,
+                                                    size_t ilen,
+                                                    unsigned char output[32],
+                                                    int is224 )
+{
+    mbedtls_sha256_ext( input, ilen, output, is224 );
+}
+
+#undef MBEDTLS_DEPRECATED
+#endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
 /**
  * \brief          Checkup routine

library/sha256.c

@@ -100,7 +100,7 @@ void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
 /*
  * SHA-256 context setup
  */
-void mbedtls_sha256_starts( mbedtls_sha256_context *ctx, int is224 )
+int mbedtls_sha256_starts_ext( mbedtls_sha256_context *ctx, int is224 )
 {
     ctx->total[0] = 0;
     ctx->total[1] = 0;
@@ -131,6 +131,8 @@ void mbedtls_sha256_starts( mbedtls_sha256_context *ctx, int is224 )
     }
 
     ctx->is224 = is224;
+
+    return( 0 );
 }
 
 #if !defined(MBEDTLS_SHA256_PROCESS_ALT)
@@ -179,7 +181,8 @@ static const uint32_t K[] =
     d += temp1; h = temp1 + temp2;              \
 }
 
-void mbedtls_sha256_process( mbedtls_sha256_context *ctx, const unsigned char data[64] )
+int mbedtls_sha256_process_ext( mbedtls_sha256_context *ctx,
+                                const unsigned char data[64] )
 {
     uint32_t temp1, temp2, W[64];
     uint32_t A[8];
@@ -232,20 +235,24 @@ void mbedtls_sha256_process( mbedtls_sha256_context *ctx, const unsigned char da
 
     for( i = 0; i < 8; i++ )
         ctx->state[i] += A[i];
+
+    return( 0 );
 }
 #endif /* !MBEDTLS_SHA256_PROCESS_ALT */
 
 /*
  * SHA-256 process buffer
  */
-void mbedtls_sha256_update( mbedtls_sha256_context *ctx, const unsigned char *input,
+int mbedtls_sha256_update_ext( mbedtls_sha256_context *ctx,
+                               const unsigned char *input,
                                size_t ilen )
 {
+    int ret;
     size_t fill;
     uint32_t left;
 
     if( ilen == 0 )
-        return;
+        return( 0 );
 
     left = ctx->total[0] & 0x3F;
     fill = 64 - left;
@@ -259,7 +266,10 @@ void mbedtls_sha256_update( mbedtls_sha256_context *ctx, const unsigned char *in
     if( left && ilen >= fill )
     {
         memcpy( (void *) (ctx->buffer + left), input, fill );
-        mbedtls_sha256_process( ctx, ctx->buffer );
+
+        if( ( ret = mbedtls_sha256_process_ext( ctx, ctx->buffer ) ) != 0 )
+            return( ret );
+
         input += fill;
         ilen  -= fill;
         left = 0;
@@ -267,13 +277,17 @@ void mbedtls_sha256_update( mbedtls_sha256_context *ctx, const unsigned char *in
 
     while( ilen >= 64 )
     {
-        mbedtls_sha256_process( ctx, input );
+        if( ( ret = mbedtls_sha256_process_ext( ctx, input ) ) != 0 )
+            return( ret );
+
         input += 64;
         ilen  -= 64;
     }
 
     if( ilen > 0 )
         memcpy( (void *) (ctx->buffer + left), input, ilen );
+
+    return( 0 );
 }
 
 static const unsigned char sha256_padding[64] =
@@ -287,8 +301,10 @@ static const unsigned char sha256_padding[64] =
 /*
  * SHA-256 final digest
  */
-void mbedtls_sha256_finish( mbedtls_sha256_context *ctx, unsigned char output[32] )
+int mbedtls_sha256_finish_ext( mbedtls_sha256_context *ctx,
+                               unsigned char output[32] )
 {
+    int ret;
     uint32_t last, padn;
     uint32_t high, low;
     unsigned char msglen[8];
@@ -303,8 +319,11 @@ void mbedtls_sha256_finish( mbedtls_sha256_context *ctx, unsigned char output[32
     last = ctx->total[0] & 0x3F;
     padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );
 
-    mbedtls_sha256_update( ctx, sha256_padding, padn );
+    if( ( ret = mbedtls_sha256_update_ext( ctx, sha256_padding, padn ) ) != 0 )
-    mbedtls_sha256_update( ctx, msglen, 8 );
+            return( ret );
+
+    if( ( ret = mbedtls_sha256_update_ext( ctx, msglen, 8 ) ) != 0 )
+            return( ret );
 
     PUT_UINT32_BE( ctx->state[0], output,  0 );
     PUT_UINT32_BE( ctx->state[1], output,  4 );
@@ -316,6 +335,8 @@ void mbedtls_sha256_finish( mbedtls_sha256_context *ctx, unsigned char output[32
 
     if( ctx->is224 == 0 )
         PUT_UINT32_BE( ctx->state[7], output, 28 );
+
+    return( 0 );
 }
 
 #endif /* !MBEDTLS_SHA256_ALT */
@@ -323,16 +344,28 @@ void mbedtls_sha256_finish( mbedtls_sha256_context *ctx, unsigned char output[32
 /*
  * output = SHA-256( input buffer )
  */
-void mbedtls_sha256( const unsigned char *input, size_t ilen,
+int mbedtls_sha256_ext( const unsigned char *input,
-             unsigned char output[32], int is224 )
+                        size_t ilen,
+                        unsigned char output[32],
+                        int is224 )
 {
+    int ret;
     mbedtls_sha256_context ctx;
 
     mbedtls_sha256_init( &ctx );
-    mbedtls_sha256_starts( &ctx, is224 );
+
-    mbedtls_sha256_update( &ctx, input, ilen );
+    if( ( ret = mbedtls_sha256_starts_ext( &ctx, is224 ) ) != 0 )
-    mbedtls_sha256_finish( &ctx, output );
+            return( ret );
+
+    if( ( ret = mbedtls_sha256_update_ext( &ctx, input, ilen ) ) != 0 )
+            return( ret );
+
+    if( ( ret = mbedtls_sha256_finish_ext( &ctx, output ) ) != 0 )
+            return( ret );
+
     mbedtls_sha256_free( &ctx );
+
+    return( 0 );
 }
 
 #if defined(MBEDTLS_SELF_TEST)
@@ -415,29 +448,31 @@ int mbedtls_sha256_self_test( int verbose )
         if( verbose != 0 )
             mbedtls_printf( "  SHA-%d test #%d: ", 256 - k * 32, j + 1 );
 
-        mbedtls_sha256_starts( &ctx, k );
+        if( mbedtls_sha256_starts_ext( &ctx, k ) != 0 )
+            goto fail;
 
         if( j == 2 )
         {
             memset( buf, 'a', buflen = 1000 );
 
             for( j = 0; j < 1000; j++ )
-                mbedtls_sha256_update( &ctx, buf, buflen );
+                if( mbedtls_sha256_update_ext( &ctx, buf, buflen ) != 0 )
+                    goto fail;
+
         }
         else
-            mbedtls_sha256_update( &ctx, sha256_test_buf[j],
+        {
-                                 sha256_test_buflen[j] );
+           if(  mbedtls_sha256_update_ext( &ctx, sha256_test_buf[j],
+                                           sha256_test_buflen[j] ) != 0 )
+                goto fail;
+        }
+
+        if( mbedtls_sha256_finish_ext( &ctx, sha256sum ) != 0 )
+            goto fail;
 
-        mbedtls_sha256_finish( &ctx, sha256sum );
 
         if( memcmp( sha256sum, sha256_test_sum[i], 32 - k * 4 ) != 0 )
-        {
+            goto fail;
-            if( verbose != 0 )
-                mbedtls_printf( "failed\n" );
-
-            ret = 1;
-            goto exit;
-        }
 
         if( verbose != 0 )
             mbedtls_printf( "passed\n" );
@@ -446,6 +481,14 @@ int mbedtls_sha256_self_test( int verbose )
     if( verbose != 0 )
         mbedtls_printf( "\n" );
 
+    goto exit;
+
+fail:
+    if( verbose != 0 )
+        mbedtls_printf( "failed\n" );
+
+    ret = 1;
+
 exit:
     mbedtls_sha256_free( &ctx );
     mbedtls_free( buf );