#include <errno.h>
#include <ipxe/entropy.h>
+#include <ipxe/crc32.h>
#include <ipxe/efi/efi.h>
+#include <ipxe/efi/Protocol/Rng.h>
/** @file
*
*
*/
+/** Random number generator protocol */
+static EFI_RNG_PROTOCOL *efirng;
+EFI_REQUEST_PROTOCOL ( EFI_RNG_PROTOCOL, &efirng );
+
+/** Minimum number of bytes to request from RNG
+ *
+ * The UEFI spec states (for no apparently good reason) that "When a
+ * Deterministic Random Bit Generator (DRBG) is used on the output of
+ * a (raw) entropy source, its security level must be at least 256
+ * bits." The EDK2 codebase (mis)interprets this to mean that the
+ * call to GetRNG() should fail if given a buffer less than 32 bytes.
+ *
+ * Incidentally, nothing in the EFI RNG protocol provides any way to
+ * report the actual amount of entropy returned by GetRNG().
+ */
+#define EFI_ENTROPY_RNG_LEN 32
+
/** Time (in 100ns units) to delay waiting for timer tick
*
* In theory, UEFI allows us to specify a trigger time of zero to
EFI_STATUS efirc;
int rc;
+ DBGC ( &tick, "ENTROPY %s RNG protocol\n",
+ ( efirng ? "has" : "has no" ) );
+
/* Create timer tick event */
if ( ( efirc = bs->CreateEvent ( EVT_TIMER, TPL_NOTIFY, NULL, NULL,
&tick ) ) != 0 ) {
}
/**
- * Wait for an RTC tick
+ * Wait for a timer tick
*
* @ret low TSC low-order bits, or negative error
*/
}
/**
- * Get noise sample
+ * Get noise sample from timer ticks
*
* @ret noise Noise sample
* @ret rc Return status code
*/
-static int efi_get_noise ( noise_sample_t *noise ) {
+static int efi_get_noise_ticks ( noise_sample_t *noise ) {
int before;
int after;
int rc;
return 0;
}
+/**
+ * Get noise sample from RNG protocol
+ *
+ * @ret noise Noise sample
+ * @ret rc Return status code
+ */
+static int efi_get_noise_rng ( noise_sample_t *noise ) {
+ uint8_t buf[EFI_ENTROPY_RNG_LEN];
+ EFI_STATUS efirc;
+ int rc;
+
+ /* Fail if we have no EFI RNG protocol */
+ if ( ! efirng )
+ return -ENOTSUP;
+
+ /* Get the minimum allowed number of random bytes */
+ if ( ( efirc = efirng->GetRNG ( efirng, NULL, EFI_ENTROPY_RNG_LEN,
+ buf ) ) != 0 ) {
+ rc = -EEFI ( efirc );
+ DBGC ( &tick, "ENTROPY could not read from RNG: %s\n",
+ strerror ( rc ) );
+ return rc;
+ }
+
+ /* Reduce random bytes to a single noise sample. This seems
+ * like overkill, but we have no way of knowing how much
+ * entropy is actually present in the bytes returned by the
+ * RNG protocol.
+ */
+ *noise = crc32_le ( 0, buf, sizeof ( buf ) );
+
+ return 0;
+}
+
+/**
+ * Get noise sample
+ *
+ * @ret noise Noise sample
+ * @ret rc Return status code
+ */
+static int efi_get_noise ( noise_sample_t *noise ) {
+ int rc;
+
+ /* Try RNG first, falling back to timer ticks */
+ if ( ( ( rc = efi_get_noise_rng ( noise ) ) != 0 ) &&
+ ( ( rc = efi_get_noise_ticks ( noise ) ) != 0 ) )
+ return rc;
+
+ return 0;
+}
+
PROVIDE_ENTROPY_INLINE ( efi, min_entropy_per_sample );
PROVIDE_ENTROPY ( efi, entropy_enable, efi_entropy_enable );
PROVIDE_ENTROPY ( efi, entropy_disable, efi_entropy_disable );
--- /dev/null
+/** @file
+ EFI_RNG_PROTOCOL as defined in UEFI 2.4.
+ The UEFI Random Number Generator Protocol is used to provide random bits for use
+ in applications, or entropy for seeding other random number generators.
+
+Copyright (c) 2013, Intel Corporation. All rights reserved.<BR>
+This program and the accompanying materials are licensed and made available under
+the terms and conditions of the BSD License that accompanies this distribution.
+The full text of the license may be found at
+http://opensource.org/licenses/bsd-license.php.
+
+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#ifndef __EFI_RNG_PROTOCOL_H__
+#define __EFI_RNG_PROTOCOL_H__
+
+FILE_LICENCE ( BSD3 );
+
+///
+/// Global ID for the Random Number Generator Protocol
+///
+#define EFI_RNG_PROTOCOL_GUID \
+ { \
+ 0x3152bca5, 0xeade, 0x433d, {0x86, 0x2e, 0xc0, 0x1c, 0xdc, 0x29, 0x1f, 0x44 } \
+ }
+
+typedef struct _EFI_RNG_PROTOCOL EFI_RNG_PROTOCOL;
+
+///
+/// A selection of EFI_RNG_PROTOCOL algorithms.
+/// The algorithms listed are optional, not meant to be exhaustive and be argmented by
+/// vendors or other industry standards.
+///
+
+typedef EFI_GUID EFI_RNG_ALGORITHM;
+
+///
+/// The algorithms corresponds to SP800-90 as defined in
+/// NIST SP 800-90, "Recommendation for Random Number Generation Using Deterministic Random
+/// Bit Generators", March 2007.
+///
+#define EFI_RNG_ALGORITHM_SP800_90_HASH_256_GUID \
+ { \
+ 0xa7af67cb, 0x603b, 0x4d42, {0xba, 0x21, 0x70, 0xbf, 0xb6, 0x29, 0x3f, 0x96 } \
+ }
+#define EFI_RNG_ALGORITHM_SP800_90_HMAC_256_GUID \
+ { \
+ 0xc5149b43, 0xae85, 0x4f53, {0x99, 0x82, 0xb9, 0x43, 0x35, 0xd3, 0xa9, 0xe7 } \
+ }
+#define EFI_RNG_ALGORITHM_SP800_90_CTR_256_GUID \
+ { \
+ 0x44f0de6e, 0x4d8c, 0x4045, {0xa8, 0xc7, 0x4d, 0xd1, 0x68, 0x85, 0x6b, 0x9e } \
+ }
+///
+/// The algorithms correspond to X9.31 as defined in
+/// NIST, "Recommended Random Number Generator Based on ANSI X9.31 Appendix A.2.4 Using
+/// the 3-Key Triple DES and AES Algorithm", January 2005.
+///
+#define EFI_RNG_ALGORITHM_X9_31_3DES_GUID \
+ { \
+ 0x63c4785a, 0xca34, 0x4012, {0xa3, 0xc8, 0x0b, 0x6a, 0x32, 0x4f, 0x55, 0x46 } \
+ }
+#define EFI_RNG_ALGORITHM_X9_31_AES_GUID \
+ { \
+ 0xacd03321, 0x777e, 0x4d3d, {0xb1, 0xc8, 0x20, 0xcf, 0xd8, 0x88, 0x20, 0xc9 } \
+ }
+///
+/// The "raw" algorithm, when supported, is intended to provide entropy directly from
+/// the source, without it going through some deterministic random bit generator.
+///
+#define EFI_RNG_ALGORITHM_RAW \
+ { \
+ 0xe43176d7, 0xb6e8, 0x4827, {0xb7, 0x84, 0x7f, 0xfd, 0xc4, 0xb6, 0x85, 0x61 } \
+ }
+
+/**
+ Returns information about the random number generation implementation.
+
+ @param[in] This A pointer to the EFI_RNG_PROTOCOL instance.
+ @param[in,out] RNGAlgorithmListSize On input, the size in bytes of RNGAlgorithmList.
+ On output with a return code of EFI_SUCCESS, the size
+ in bytes of the data returned in RNGAlgorithmList. On output
+ with a return code of EFI_BUFFER_TOO_SMALL,
+ the size of RNGAlgorithmList required to obtain the list.
+ @param[out] RNGAlgorithmList A caller-allocated memory buffer filled by the driver
+ with one EFI_RNG_ALGORITHM element for each supported
+ RNG algorithm. The list must not change across multiple
+ calls to the same driver. The first algorithm in the list
+ is the default algorithm for the driver.
+
+ @retval EFI_SUCCESS The RNG algorithm list was returned successfully.
+ @retval EFI_UNSUPPORTED The services is not supported by this driver.
+ @retval EFI_DEVICE_ERROR The list of algorithms could not be retrieved due to a
+ hardware or firmware error.
+ @retval EFI_INVALID_PARAMETER One or more of the parameters are incorrect.
+ @retval EFI_BUFFER_TOO_SMALL The buffer RNGAlgorithmList is too small to hold the result.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EFI_RNG_GET_INFO) (
+ IN EFI_RNG_PROTOCOL *This,
+ IN OUT UINTN *RNGAlgorithmListSize,
+ OUT EFI_RNG_ALGORITHM *RNGAlgorithmList
+ );
+
+/**
+ Produces and returns an RNG value using either the default or specified RNG algorithm.
+
+ @param[in] This A pointer to the EFI_RNG_PROTOCOL instance.
+ @param[in] RNGAlgorithm A pointer to the EFI_RNG_ALGORITHM that identifies the RNG
+ algorithm to use. May be NULL in which case the function will
+ use its default RNG algorithm.
+ @param[in] RNGValueLength The length in bytes of the memory buffer pointed to by
+ RNGValue. The driver shall return exactly this numbers of bytes.
+ @param[out] RNGValue A caller-allocated memory buffer filled by the driver with the
+ resulting RNG value.
+
+ @retval EFI_SUCCESS The RNG value was returned successfully.
+ @retval EFI_UNSUPPORTED The algorithm specified by RNGAlgorithm is not supported by
+ this driver.
+ @retval EFI_DEVICE_ERROR An RNG value could not be retrieved due to a hardware or
+ firmware error.
+ @retval EFI_NOT_READY There is not enough random data available to satisfy the length
+ requested by RNGValueLength.
+ @retval EFI_INVALID_PARAMETER RNGValue is NULL or RNGValueLength is zero.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EFI_RNG_GET_RNG) (
+ IN EFI_RNG_PROTOCOL *This,
+ IN EFI_RNG_ALGORITHM *RNGAlgorithm, OPTIONAL
+ IN UINTN RNGValueLength,
+ OUT UINT8 *RNGValue
+ );
+
+///
+/// The Random Number Generator (RNG) protocol provides random bits for use in
+/// applications, or entropy for seeding other random number generators.
+///
+struct _EFI_RNG_PROTOCOL {
+ EFI_RNG_GET_INFO GetInfo;
+ EFI_RNG_GET_RNG GetRNG;
+};
+
+extern EFI_GUID gEfiRngProtocolGuid;
+extern EFI_GUID gEfiRngAlgorithmSp80090Hash256Guid;
+extern EFI_GUID gEfiRngAlgorithmSp80090Hmac256Guid;
+extern EFI_GUID gEfiRngAlgorithmSp80090Ctr256Guid;
+extern EFI_GUID gEfiRngAlgorithmX9313DesGuid;
+extern EFI_GUID gEfiRngAlgorithmX931AesGuid;
+extern EFI_GUID gEfiRngAlgorithmRaw;
+
+#endif
projects / thirdparty / ipxe.git / commitdiff
