/* $OpenBSD: efirng.c,v 1.2 2021/06/25 17:49:49 krw Exp $ */ /* * Copyright (c) 2018 Mark Kettenis * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include "libsa.h" extern EFI_BOOT_SERVICES *BS; /* Random Number Generator Protocol */ #define EFI_RNG_PROTOCOL_GUID \ { 0x3152bca5, 0xeade, 0x433d, {0x86, 0x2e, 0xc0, 0x1c, 0xdc, 0x29, 0x1f, 0x44} } INTERFACE_DECL(_EFI_RNG_PROTOCOL); typedef EFI_GUID EFI_RNG_ALGORITHM; typedef EFI_STATUS (EFIAPI *EFI_RNG_GET_INFO) ( IN struct _EFI_RNG_PROTOCOL *This, IN OUT UINTN *RNGAlgorithmListSize, OUT EFI_RNG_ALGORITHM *RNGAlgorithmList ); typedef EFI_STATUS (EFIAPI *EFI_RNG_GET_RNG) ( IN struct _EFI_RNG_PROTOCOL *This, IN EFI_RNG_ALGORITHM *RNGAlgorithm, OPTIONAL IN UINTN RNGValueLength, OUT UINT8 *RNGValue ); typedef struct _EFI_RNG_PROTOCOL { EFI_RNG_GET_INFO GetInfo; EFI_RNG_GET_RNG GetRNG; } EFI_RNG_PROTOCOL; static EFI_GUID rng_guid = EFI_RNG_PROTOCOL_GUID; int fwrandom(char *buf, size_t buflen) { EFI_STATUS status; EFI_RNG_PROTOCOL *rng = NULL; UINT8 *random; size_t i; int ret = 0; status = BS->LocateProtocol(&rng_guid, NULL, (void **)&rng); if (rng == NULL || EFI_ERROR(status)) return -1; random = alloc(buflen); status = rng->GetRNG(rng, NULL, buflen, random); if (EFI_ERROR(status)) { printf("RNG GetRNG() failed (%d)\n", status); ret = -1; goto out; } for (i = 0; i < buflen; i++) buf[i] ^= random[i]; out: free(random, buflen); return ret; }