]>
Commit | Line | Data |
---|---|---|
4e5ecdba RC |
1 | /** @file\r |
2 | RNG Driver to produce the UEFI Random Number Generator protocol.\r | |
3 | \r | |
4 | The driver will use the new RDRAND instruction to produce high-quality, high-performance\r | |
5 | entropy and random number.\r | |
6 | \r | |
7 | RNG Algorithms defined in UEFI 2.4:\r | |
8 | - EFI_RNG_ALGORITHM_SP800_90_CTR_256_GUID - Supported\r | |
9 | (RDRAND implements a hardware NIST SP800-90 AES-CTR-256 based DRBG)\r | |
10 | - EFI_RNG_ALGORITHM_RAW - Supported\r | |
11 | (Structuring RDRAND invocation can be guaranteed as high-quality entropy source)\r | |
12 | - EFI_RNG_ALGORITHM_SP800_90_HMAC_256_GUID - Unsupported\r | |
13 | - EFI_RNG_ALGORITHM_SP800_90_HASH_256_GUID - Unsupported\r | |
14 | - EFI_RNG_ALGORITHM_X9_31_3DES_GUID - Unsupported\r | |
15 | - EFI_RNG_ALGORITHM_X9_31_AES_GUID - Unsupported\r | |
16 | \r | |
17 | Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>\r | |
18 | (C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>\r | |
19 | SPDX-License-Identifier: BSD-2-Clause-Patent\r | |
20 | \r | |
21 | **/\r | |
22 | \r | |
23 | #include "RdRand.h"\r | |
24 | #include "RngDxeInternals.h"\r | |
25 | \r | |
26 | /**\r | |
27 | Produces and returns an RNG value using either the default or specified RNG algorithm.\r | |
28 | \r | |
29 | @param[in] This A pointer to the EFI_RNG_PROTOCOL instance.\r | |
30 | @param[in] RNGAlgorithm A pointer to the EFI_RNG_ALGORITHM that identifies the RNG\r | |
31 | algorithm to use. May be NULL in which case the function will\r | |
32 | use its default RNG algorithm.\r | |
33 | @param[in] RNGValueLength The length in bytes of the memory buffer pointed to by\r | |
34 | RNGValue. The driver shall return exactly this numbers of bytes.\r | |
35 | @param[out] RNGValue A caller-allocated memory buffer filled by the driver with the\r | |
36 | resulting RNG value.\r | |
37 | \r | |
38 | @retval EFI_SUCCESS The RNG value was returned successfully.\r | |
39 | @retval EFI_UNSUPPORTED The algorithm specified by RNGAlgorithm is not supported by\r | |
40 | this driver.\r | |
41 | @retval EFI_DEVICE_ERROR An RNG value could not be retrieved due to a hardware or\r | |
42 | firmware error.\r | |
43 | @retval EFI_NOT_READY There is not enough random data available to satisfy the length\r | |
44 | requested by RNGValueLength.\r | |
45 | @retval EFI_INVALID_PARAMETER RNGValue is NULL or RNGValueLength is zero.\r | |
46 | \r | |
47 | **/\r | |
48 | EFI_STATUS\r | |
49 | EFIAPI\r | |
50 | RngGetRNG (\r | |
c411b485 MK |
51 | IN EFI_RNG_PROTOCOL *This,\r |
52 | IN EFI_RNG_ALGORITHM *RNGAlgorithm OPTIONAL,\r | |
53 | IN UINTN RNGValueLength,\r | |
54 | OUT UINT8 *RNGValue\r | |
4e5ecdba RC |
55 | )\r |
56 | {\r | |
c411b485 | 57 | EFI_STATUS Status;\r |
4e5ecdba RC |
58 | \r |
59 | if ((RNGValueLength == 0) || (RNGValue == NULL)) {\r | |
60 | return EFI_INVALID_PARAMETER;\r | |
61 | }\r | |
62 | \r | |
63 | Status = EFI_UNSUPPORTED;\r | |
64 | if (RNGAlgorithm == NULL) {\r | |
65 | //\r | |
66 | // Use the default RNG algorithm if RNGAlgorithm is NULL.\r | |
67 | //\r | |
68 | RNGAlgorithm = &gEfiRngAlgorithmSp80090Ctr256Guid;\r | |
69 | }\r | |
70 | \r | |
71 | //\r | |
72 | // NIST SP800-90-AES-CTR-256 supported by RDRAND\r | |
73 | //\r | |
74 | if (CompareGuid (RNGAlgorithm, &gEfiRngAlgorithmSp80090Ctr256Guid)) {\r | |
75 | Status = RngGetBytes (RNGValueLength, RNGValue);\r | |
76 | return Status;\r | |
77 | }\r | |
78 | \r | |
79 | //\r | |
80 | // The "raw" algorithm is intended to provide entropy directly\r | |
81 | //\r | |
82 | if (CompareGuid (RNGAlgorithm, &gEfiRngAlgorithmRaw)) {\r | |
83 | //\r | |
84 | // When a DRBG is used on the output of a entropy source,\r | |
85 | // its security level must be at least 256 bits according to UEFI Spec.\r | |
86 | //\r | |
87 | if (RNGValueLength < 32) {\r | |
88 | return EFI_INVALID_PARAMETER;\r | |
89 | }\r | |
90 | \r | |
91 | Status = RdRandGenerateEntropy (RNGValueLength, RNGValue);\r | |
92 | return Status;\r | |
93 | }\r | |
94 | \r | |
95 | //\r | |
96 | // Other algorithms were unsupported by this driver.\r | |
97 | //\r | |
98 | return Status;\r | |
99 | }\r | |
100 | \r | |
101 | /**\r | |
102 | Returns information about the random number generation implementation.\r | |
103 | \r | |
104 | @param[in,out] RNGAlgorithmListSize On input, the size in bytes of RNGAlgorithmList.\r | |
105 | On output with a return code of EFI_SUCCESS, the size\r | |
106 | in bytes of the data returned in RNGAlgorithmList. On output\r | |
107 | with a return code of EFI_BUFFER_TOO_SMALL,\r | |
108 | the size of RNGAlgorithmList required to obtain the list.\r | |
109 | @param[out] RNGAlgorithmList A caller-allocated memory buffer filled by the driver\r | |
110 | with one EFI_RNG_ALGORITHM element for each supported\r | |
111 | RNG algorithm. The list must not change across multiple\r | |
112 | calls to the same driver. The first algorithm in the list\r | |
113 | is the default algorithm for the driver.\r | |
114 | \r | |
115 | @retval EFI_SUCCESS The RNG algorithm list was returned successfully.\r | |
116 | @retval EFI_BUFFER_TOO_SMALL The buffer RNGAlgorithmList is too small to hold the result.\r | |
117 | \r | |
118 | **/\r | |
119 | UINTN\r | |
120 | EFIAPI\r | |
121 | ArchGetSupportedRngAlgorithms (\r | |
c411b485 MK |
122 | IN OUT UINTN *RNGAlgorithmListSize,\r |
123 | OUT EFI_RNG_ALGORITHM *RNGAlgorithmList\r | |
4e5ecdba RC |
124 | )\r |
125 | {\r | |
c411b485 MK |
126 | UINTN RequiredSize;\r |
127 | EFI_RNG_ALGORITHM *CpuRngSupportedAlgorithm;\r | |
4e5ecdba RC |
128 | \r |
129 | RequiredSize = 2 * sizeof (EFI_RNG_ALGORITHM);\r | |
130 | \r | |
131 | if (*RNGAlgorithmListSize < RequiredSize) {\r | |
132 | *RNGAlgorithmListSize = RequiredSize;\r | |
133 | return EFI_BUFFER_TOO_SMALL;\r | |
134 | }\r | |
135 | \r | |
136 | CpuRngSupportedAlgorithm = PcdGetPtr (PcdCpuRngSupportedAlgorithm);\r | |
137 | \r | |
c411b485 | 138 | CopyMem (&RNGAlgorithmList[0], CpuRngSupportedAlgorithm, sizeof (EFI_RNG_ALGORITHM));\r |
4e5ecdba RC |
139 | \r |
140 | // x86 platforms also support EFI_RNG_ALGORITHM_RAW via RDSEED\r | |
c411b485 | 141 | CopyMem (&RNGAlgorithmList[1], &gEfiRngAlgorithmRaw, sizeof (EFI_RNG_ALGORITHM));\r |
4e5ecdba RC |
142 | \r |
143 | *RNGAlgorithmListSize = RequiredSize;\r | |
144 | return EFI_SUCCESS;\r | |
145 | }\r |