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/** @file
OpenSSL_1_1_1b doesn't implement rand_pool_* functions for UEFI.
The file implement these functions.
Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "crypto/rand.h"
#include <openssl/aes.h>
#include <Uefi.h>
#include <Library/RngLib.h>
/**
Calls RandomNumber64 to fill
a buffer of arbitrary size with random bytes.
This is a shim layer to RngLib.
@param[in] Length Size of the buffer, in bytes, to fill with.
@param[out] RandBuffer Pointer to the buffer to store the random result.
@retval TRUE Random bytes generation succeeded.
@retval FALSE Failed to request random bytes.
**/
STATIC
BOOLEAN
EFIAPI
RandGetBytes (
IN UINTN Length,
OUT UINT8 *RandBuffer
)
{
BOOLEAN Ret;
UINT64 TempRand;
Ret = FALSE;
if (RandBuffer == NULL) {
DEBUG ((DEBUG_ERROR, "[OPENSSL_RAND_POOL] NULL RandBuffer. No random numbers are generated and your system is not secure\n"));
ASSERT (RandBuffer != NULL); // Since we can't generate random numbers, we should assert. Otherwise we will just blow up later.
return Ret;
}
while (Length > 0) {
// Use RngLib to get random number
Ret = GetRandomNumber64 (&TempRand);
if (!Ret) {
return Ret;
}
if (Length >= sizeof (TempRand)) {
*((UINT64 *)RandBuffer) = TempRand;
RandBuffer += sizeof (UINT64);
Length -= sizeof (TempRand);
} else {
CopyMem (RandBuffer, &TempRand, Length);
Length = 0;
}
}
return Ret;
}
/*
* Add random bytes to the pool to acquire requested amount of entropy
*
* This function is platform specific and tries to acquire the requested
* amount of entropy by polling platform specific entropy sources.
*
* This is OpenSSL required interface.
*/
size_t
ossl_pool_acquire_entropy (
RAND_POOL *pool
)
{
BOOLEAN Ret;
size_t Bytes_needed;
unsigned char *Buffer;
Bytes_needed = ossl_rand_pool_bytes_needed (pool, 1 /*entropy_factor*/);
if (Bytes_needed > 0) {
Buffer = ossl_rand_pool_add_begin (pool, Bytes_needed);
if (Buffer != NULL) {
Ret = RandGetBytes (Bytes_needed, Buffer);
if (FALSE == Ret) {
ossl_rand_pool_add_end (pool, 0, 0);
} else {
ossl_rand_pool_add_end (pool, Bytes_needed, 8 * Bytes_needed);
}
}
}
return ossl_rand_pool_entropy_available (pool);
}
/*
* Implementation for UEFI
*
* This is OpenSSL required interface.
*/
int
ossl_pool_add_nonce_data (
RAND_POOL *pool
)
{
UINT8 data[16];
RandGetBytes (sizeof (data), data);
return ossl_rand_pool_add (pool, (unsigned char *)&data, sizeof (data), 0);
}
/*
* Implementation for UEFI
*
* This is OpenSSL required interface.
*/
int
rand_pool_add_additional_data (
RAND_POOL *pool
)
{
UINT8 data[16];
RandGetBytes (sizeof (data), data);
return ossl_rand_pool_add (pool, (unsigned char *)&data, sizeof (data), 0);
}
/*
* Dummy Implementation for UEFI
*
* This is OpenSSL required interface.
*/
int
ossl_rand_pool_init (
VOID
)
{
return 1;
}
/*
* Dummy Implementation for UEFI
*
* This is OpenSSL required interface.
*/
VOID
ossl_rand_pool_cleanup (
VOID
)
{
}
/*
* Dummy Implementation for UEFI
*
* This is OpenSSL required interface.
*/
VOID
ossl_rand_pool_keep_random_devices_open (
int keep
)
{
}
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