1                 : /*
       2                 :  * Copyright (c) 2008 The Native Client Authors. All rights reserved.
       3                 :  * Use of this source code is governed by a BSD-style license that can be
       4                 :  * found in the LICENSE file.
       5                 :  */
       6                 : 
       7                 : /*
       8                 :  * NaCl Service Runtime.  Secure RNG implementation.
       9                 :  */
      10                 : #include <windows.h>
      11                 : 
      12                 : /*
      13                 :  * #define needed to link in RtlGenRandom(), a.k.a. SystemFunction036. See
      14                 :  * the "Community Additions" comment on MSDN here:
      15                 :  *   http://msdn.microsoft.com/en-us/library/windows/desktop/aa387694.aspx
      16                 :  */
      17                 : #define SystemFunction036 NTAPI SystemFunction036
      18                 : #include <NTSecAPI.h>
      19                 : #undef SystemFunction036
      20                 : 
      21                 : #include "native_client/src/shared/platform/nacl_log.h"
      22                 : #include "native_client/src/shared/platform/nacl_secure_random.h"
      23                 : 
      24                 : 
      25                 : static void NaClSecureRngDtor(struct NaClSecureRngIf *vself);
      26                 : static uint8_t NaClSecureRngGenByte(struct NaClSecureRngIf *vself);
      27                 : 
      28                 : static struct NaClSecureRngIfVtbl const kNaClSecureRngVtbl = {
      29                 :   NaClSecureRngDtor,
      30                 :   NaClSecureRngGenByte,
      31                 :   NaClSecureRngDefaultGenUint32,
      32                 :   NaClSecureRngDefaultGenBytes,
      33                 :   NaClSecureRngDefaultUniform,
      34                 : };
      35                 : 
      36              16 : void NaClSecureRngModuleInit(void) {
      37                 :   return;
      38              16 : }
      39                 : 
      40              11 : void NaClSecureRngModuleFini(void) {
      41                 :   return;
      42              11 : }
      43                 : 
      44              16 : int NaClSecureRngCtor(struct NaClSecureRng *self) {
      45              16 :   self->base.vtbl = &kNaClSecureRngVtbl;
      46              16 :   self->nvalid = 0;
      47              16 :   return 1;
      48              16 : }
      49                 : 
      50                 : int NaClSecureRngTestingCtor(struct NaClSecureRng *self,
      51                 :                              uint8_t              *seed_material,
      52               0 :                              size_t               seed_bytes) {
      53                 :   UNREFERENCED_PARAMETER(seed_material);
      54                 :   UNREFERENCED_PARAMETER(seed_bytes);
      55               0 :   self->base.vtbl = NULL;
      56               0 :   self->nvalid = 0;
      57               0 :   return 0;
      58               0 : }
      59                 : 
      60              11 : static void NaClSecureRngDtor(struct NaClSecureRngIf *vself) {
      61              11 :   struct NaClSecureRng *self = (struct NaClSecureRng *) vself;
      62              11 :   SecureZeroMemory(self->buf, sizeof self->buf);
      63              11 :   vself->vtbl = NULL;
      64                 :   return;
      65              11 : }
      66                 : 
      67               3 : static void NaClSecureRngFilbuf(struct NaClSecureRng *self) {
      68               3 :   if (!RtlGenRandom(self->buf, sizeof self->buf)) {
      69               0 :     NaClLog(LOG_FATAL, "RtlGenRandom failed: error 0x%x\n", GetLastError());
      70                 :   }
      71               3 :   self->nvalid = sizeof self->buf;
      72               3 : }
      73                 : 
      74               3 : static uint8_t NaClSecureRngGenByte(struct NaClSecureRngIf *vself) {
      75               3 :   struct NaClSecureRng *self = (struct NaClSecureRng *) vself;
      76               3 :   if (0 > self->nvalid) {
      77                 :     NaClLog(LOG_FATAL,
      78                 :             "NaClSecureRngGenByte: illegal buffer state, nvalid = %d\n",
      79               0 :             self->nvalid);
      80                 :   }
      81               3 :   if (0 == self->nvalid) {
      82               3 :     NaClSecureRngFilbuf(self);
      83                 :   }
      84               3 :   return self->buf[--self->nvalid];
      85               3 : }