Add int return values to MD2 function calls

The following function calls are being deprecated to introduce int
return values.
    * mbedtls_md2()
    * mbedtls_md2_starts()
    * mbedtls_md2_update()
    * mbedtls_md2_finish()
    * mbedtls_md2_process()
The return codes can be used to return error values. This is important
when using hardware accelerators.
diff --git a/include/mbedtls/md2.h b/include/mbedtls/md2.h
index 0f93fbf..1f3b107 100644
--- a/include/mbedtls/md2.h
+++ b/include/mbedtls/md2.h
@@ -31,6 +31,11 @@
 
 #include <stddef.h>
 
+#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
+    !defined(inline) && !defined(__cplusplus)
+#define inline __inline
+#endif
+
 #if !defined(MBEDTLS_MD2_ALT)
 // Regular implementation
 //
@@ -78,8 +83,10 @@
  * \brief          MD2 context setup
  *
  * \param ctx      context to be initialized
+ *
+ * \return         0 if successful
  */
-void mbedtls_md2_starts( mbedtls_md2_context *ctx );
+int mbedtls_md2_starts_ext( mbedtls_md2_context *ctx );
 
 /**
  * \brief          MD2 process buffer
@@ -87,16 +94,99 @@
  * \param ctx      MD2 context
  * \param input    buffer holding the  data
  * \param ilen     length of the input data
+ *
+ * \return         0 if successful
  */
-void mbedtls_md2_update( mbedtls_md2_context *ctx, const unsigned char *input, size_t ilen );
+int mbedtls_md2_update_ext( mbedtls_md2_context *ctx,
+                            const unsigned char *input,
+                            size_t ilen );
 
 /**
  * \brief          MD2 final digest
  *
  * \param ctx      MD2 context
  * \param output   MD2 checksum result
+ *
+ * \return         0 if successful
  */
-void mbedtls_md2_finish( mbedtls_md2_context *ctx, unsigned char output[16] );
+int mbedtls_md2_finish_ext( mbedtls_md2_context *ctx,
+                            unsigned char output[16] );
+
+/**
+ * \brief          MD2 process data block (internal use only)
+ *
+ * \param ctx      MD2 context
+ *
+ * \return         0 if successful
+ */
+int mbedtls_md2_process_ext( mbedtls_md2_context *ctx );
+
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+#if defined(MBEDTLS_DEPRECATED_WARNING)
+#define MBEDTLS_DEPRECATED      __attribute__((deprecated))
+#else
+#define MBEDTLS_DEPRECATED
+#endif
+/**
+ * \brief          MD2 context setup
+ *
+ * \deprecated     Superseded by mbedtls_md2_starts_ext() in 2.5.0
+ *
+ * \param ctx      context to be initialized
+ */
+MBEDTLS_DEPRECATED static inline void mbedtls_md2_starts(
+                                                    mbedtls_md2_context *ctx )
+{
+    mbedtls_md2_starts_ext( ctx );
+}
+
+/**
+ * \brief          MD2 process buffer
+ *
+ * \deprecated     Superseded by mbedtls_md2_update_ext() in 2.5.0
+ *
+ * \param ctx      MD2 context
+ * \param input    buffer holding the  data
+ * \param ilen     length of the input data
+ */
+MBEDTLS_DEPRECATED static inline void mbedtls_md2_update(
+                                                mbedtls_md2_context *ctx,
+                                                const unsigned char *input,
+                                                size_t ilen )
+{
+    mbedtls_md2_update_ext( ctx, input, ilen );
+}
+
+/**
+ * \brief          MD2 final digest
+ *
+ * \deprecated     Superseded by mbedtls_md2_finish_ext() in 2.5.0
+ *
+ * \param ctx      MD2 context
+ * \param output   MD2 checksum result
+ */
+MBEDTLS_DEPRECATED static inline void mbedtls_md2_finish(
+                                                    mbedtls_md2_context *ctx,
+                                                    unsigned char output[16] )
+{
+    mbedtls_md2_finish_ext( ctx, output );
+}
+
+/**
+ * \brief          MD2 process data block (internal use only)
+ *
+ * \deprecated     Superseded by mbedtls_md2_process_ext() in 2.5.0
+ *
+ * \param ctx      MD2 context
+ */
+MBEDTLS_DEPRECATED static inline void mbedtls_md2_process(
+                                                    mbedtls_md2_context *ctx )
+{
+    mbedtls_md2_process_ext( ctx );
+}
+
+#undef MBEDTLS_DEPRECATED
+#endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
 #ifdef __cplusplus
 }
@@ -117,7 +207,36 @@
  * \param ilen     length of the input data
  * \param output   MD2 checksum result
  */
-void mbedtls_md2( const unsigned char *input, size_t ilen, unsigned char output[16] );
+int mbedtls_md2_ext( const unsigned char *input,
+                     size_t ilen,
+                     unsigned char output[16] );
+
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+#if defined(MBEDTLS_DEPRECATED_WARNING)
+#define MBEDTLS_DEPRECATED      __attribute__((deprecated))
+#else
+#define MBEDTLS_DEPRECATED
+#endif
+/**
+ * \brief          Output = MD2( input buffer )
+ *
+ * \deprecated     Superseded by mbedtls_md2() in 2.5.0
+ *
+ * \param input    buffer holding the  data
+ * \param ilen     length of the input data
+ * \param output   MD2 checksum result
+ *
+ * \return         0 if successful
+ */
+MBEDTLS_DEPRECATED static inline void mbedtls_md2( const unsigned char *input,
+                                                   size_t ilen,
+                                                   unsigned char output[16] )
+{
+    mbedtls_md2_ext( input, ilen, output );
+}
+
+#undef MBEDTLS_DEPRECATED
+#endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
 /**
  * \brief          Checkup routine
@@ -126,9 +245,6 @@
  */
 int mbedtls_md2_self_test( int verbose );
 
-/* Internal use */
-void mbedtls_md2_process( mbedtls_md2_context *ctx );
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/library/md2.c b/library/md2.c
index 95cbcce..7dd2b6b 100644
--- a/library/md2.c
+++ b/library/md2.c
@@ -105,16 +105,18 @@
 /*
  * MD2 context setup
  */
-void mbedtls_md2_starts( mbedtls_md2_context *ctx )
+int mbedtls_md2_starts_ext( mbedtls_md2_context *ctx )
 {
     memset( ctx->cksum, 0, 16 );
     memset( ctx->state, 0, 46 );
     memset( ctx->buffer, 0, 16 );
     ctx->left = 0;
+
+    return( 0 );
 }
 
 #if !defined(MBEDTLS_MD2_PROCESS_ALT)
-void mbedtls_md2_process( mbedtls_md2_context *ctx )
+int mbedtls_md2_process_ext( mbedtls_md2_context *ctx )
 {
     int i, j;
     unsigned char t = 0;
@@ -146,14 +148,19 @@
            ( ctx->cksum[i] ^ PI_SUBST[ctx->buffer[i] ^ t] );
         t  = ctx->cksum[i];
     }
+
+    return( 0 );
 }
 #endif /* !MBEDTLS_MD2_PROCESS_ALT */
 
 /*
  * MD2 process buffer
  */
-void mbedtls_md2_update( mbedtls_md2_context *ctx, const unsigned char *input, size_t ilen )
+int mbedtls_md2_update_ext( mbedtls_md2_context *ctx,
+                            const unsigned char *input,
+                            size_t ilen )
 {
+    int ret;
     size_t fill;
 
     while( ilen > 0 )
@@ -172,16 +179,21 @@
         if( ctx->left == 16 )
         {
             ctx->left = 0;
-            mbedtls_md2_process( ctx );
+            if( ( ret = mbedtls_md2_process_ext( ctx ) ) != 0 )
+                return( ret );
         }
     }
+
+    return( 0 );
 }
 
 /*
  * MD2 final digest
  */
-void mbedtls_md2_finish( mbedtls_md2_context *ctx, unsigned char output[16] )
+int mbedtls_md2_finish_ext( mbedtls_md2_context *ctx,
+                            unsigned char output[16] )
 {
+    int ret;
     size_t i;
     unsigned char x;
 
@@ -190,12 +202,16 @@
     for( i = ctx->left; i < 16; i++ )
         ctx->buffer[i] = x;
 
-    mbedtls_md2_process( ctx );
+    if( ( ret = mbedtls_md2_process_ext( ctx ) ) != 0 )
+        return( ret );
 
     memcpy( ctx->buffer, ctx->cksum, 16 );
-    mbedtls_md2_process( ctx );
+    if( ( ret = mbedtls_md2_process_ext( ctx ) ) != 0 )
+        return( ret );
 
     memcpy( output, ctx->state, 16 );
+
+    return( 0 );
 }
 
 #endif /* !MBEDTLS_MD2_ALT */
@@ -203,15 +219,28 @@
 /*
  * output = MD2( input buffer )
  */
-void mbedtls_md2( const unsigned char *input, size_t ilen, unsigned char output[16] )
+int mbedtls_md2_ext( const unsigned char *input,
+                     size_t ilen,
+                     unsigned char output[16] )
 {
+    int ret;
     mbedtls_md2_context ctx;
 
     mbedtls_md2_init( &ctx );
-    mbedtls_md2_starts( &ctx );
-    mbedtls_md2_update( &ctx, input, ilen );
-    mbedtls_md2_finish( &ctx, output );
+
+    if( ( ret = mbedtls_md2_starts_ext( &ctx ) ) != 0 )
+        return( ret );
+
+    if( ( ret = mbedtls_md2_update_ext( &ctx, input, ilen ) ) != 0 )
+        return( ret );
+
+    if( ( ret = mbedtls_md2_finish_ext( &ctx, output ) ) != 0 )
+        return( ret );
+
+
     mbedtls_md2_free( &ctx );
+
+    return( 0 );
 }
 
 #if defined(MBEDTLS_SELF_TEST)
@@ -262,16 +291,12 @@
         if( verbose != 0 )
             mbedtls_printf( "  MD2 test #%d: ", i + 1 );
 
-        mbedtls_md2( (unsigned char *) md2_test_str[i],
-             strlen( md2_test_str[i] ), md2sum );
+        if( mbedtls_md2_ext( (unsigned char *)md2_test_str[i],
+                             strlen( md2_test_str[i] ), md2sum ) != 0 )
+            goto fail;
 
         if( memcmp( md2sum, md2_test_sum[i], 16 ) != 0 )
-        {
-            if( verbose != 0 )
-                mbedtls_printf( "failed\n" );
-
-            return( 1 );
-        }
+            goto fail;
 
         if( verbose != 0 )
             mbedtls_printf( "passed\n" );
@@ -281,6 +306,12 @@
         mbedtls_printf( "\n" );
 
     return( 0 );
+
+fail:
+    if( verbose != 0 )
+        mbedtls_printf( "failed\n" );
+
+    return( 1 );
 }
 
 #endif /* MBEDTLS_SELF_TEST */