summaryrefslogtreecommitdiffstats
path: root/src/VBox/Devices/EFI/Firmware/CryptoPkg/Library/BaseCryptLib/Rand/CryptRand.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/VBox/Devices/EFI/Firmware/CryptoPkg/Library/BaseCryptLib/Rand/CryptRand.c')
-rw-r--r--src/VBox/Devices/EFI/Firmware/CryptoPkg/Library/BaseCryptLib/Rand/CryptRand.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/src/VBox/Devices/EFI/Firmware/CryptoPkg/Library/BaseCryptLib/Rand/CryptRand.c b/src/VBox/Devices/EFI/Firmware/CryptoPkg/Library/BaseCryptLib/Rand/CryptRand.c
new file mode 100644
index 00000000..31b08b7a
--- /dev/null
+++ b/src/VBox/Devices/EFI/Firmware/CryptoPkg/Library/BaseCryptLib/Rand/CryptRand.c
@@ -0,0 +1,104 @@
+/** @file
+ Pseudorandom Number Generator Wrapper Implementation over OpenSSL.
+
+Copyright (c) 2010 - 2013, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalCryptLib.h"
+#include <openssl/rand.h>
+#include <openssl/evp.h>
+
+//
+// Default seed for UEFI Crypto Library
+//
+CONST UINT8 DefaultSeed[] = "UEFI Crypto Library default seed";
+
+/**
+ Sets up the seed value for the pseudorandom number generator.
+
+ This function sets up the seed value for the pseudorandom number generator.
+ If Seed is not NULL, then the seed passed in is used.
+ If Seed is NULL, then default seed is used.
+
+ @param[in] Seed Pointer to seed value.
+ If NULL, default seed is used.
+ @param[in] SeedSize Size of seed value.
+ If Seed is NULL, this parameter is ignored.
+
+ @retval TRUE Pseudorandom number generator has enough entropy for random generation.
+ @retval FALSE Pseudorandom number generator does not have enough entropy for random generation.
+
+**/
+BOOLEAN
+EFIAPI
+RandomSeed (
+ IN CONST UINT8 *Seed OPTIONAL,
+ IN UINTN SeedSize
+ )
+{
+ if (SeedSize > INT_MAX) {
+ return FALSE;
+ }
+
+ //
+ // The software PRNG implementation built in OpenSSL depends on message digest algorithm.
+ // Make sure SHA-1 digest algorithm is available here.
+ //
+ if (EVP_add_digest (EVP_sha1 ()) == 0) {
+ return FALSE;
+ }
+
+ //
+ // Seed the pseudorandom number generator with user-supplied value.
+ // NOTE: A cryptographic PRNG must be seeded with unpredictable data.
+ //
+ if (Seed != NULL) {
+ RAND_seed (Seed, (UINT32) SeedSize);
+ } else {
+ RAND_seed (DefaultSeed, sizeof (DefaultSeed));
+ }
+
+ if (RAND_status () == 1) {
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+/**
+ Generates a pseudorandom byte stream of the specified size.
+
+ If Output is NULL, then return FALSE.
+
+ @param[out] Output Pointer to buffer to receive random value.
+ @param[in] Size Size of random bytes to generate.
+
+ @retval TRUE Pseudorandom byte stream generated successfully.
+ @retval FALSE Pseudorandom number generator fails to generate due to lack of entropy.
+
+**/
+BOOLEAN
+EFIAPI
+RandomBytes (
+ OUT UINT8 *Output,
+ IN UINTN Size
+ )
+{
+ //
+ // Check input parameters.
+ //
+ if (Output == NULL || Size > INT_MAX) {
+ return FALSE;
+ }
+
+ //
+ // Generate random data.
+ //
+ if (RAND_bytes (Output, (UINT32) Size) != 1) {
+ return FALSE;
+ }
+
+ return TRUE;
+}