1 /*
2 * Copyright (c) 2024, NVIDIA Corporation. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 #include <errno.h>
8 #include <string.h>
9
10 #include <plat/common/platform.h>
11 #include <services/rmm_el3_token_sign.h>
12
13 static struct el3_token_sign_request el3_req = { 0 };
14 static bool el3_req_valid;
15
16 /*
17 * According to https://www.secg.org/sec1-v2.pdf 2.3.3
18 * the size of the ECDSA P384 public key is 97 bytes,
19 * with the first byte being 0x04.
20 */
21 static uint8_t sample_attest_pub_key[] = {
22 0x04, 0x76, 0xf9, 0x88, 0x09, 0x1b, 0xe5, 0x85, 0xed, 0x41,
23 0x80, 0x1a, 0xec, 0xfa, 0xb8, 0x58, 0x54, 0x8c, 0x63, 0x05,
24 0x7e, 0x16, 0xb0, 0xe6, 0x76, 0x12, 0x0b, 0xbd, 0x0d, 0x2f,
25 0x9c, 0x29, 0xe0, 0x56, 0xc5, 0xd4, 0x1a, 0x01, 0x30, 0xeb,
26 0x9c, 0x21, 0x51, 0x78, 0x99, 0xdc, 0x23, 0x14, 0x6b, 0x28,
27 0xe1, 0xb0, 0x62, 0xbd, 0x3e, 0xa4, 0xb3, 0x15, 0xfd, 0x21,
28 0x9f, 0x1c, 0xbb, 0x52, 0x8c, 0xb6, 0xe7, 0x4c, 0xa4, 0x9b,
29 0xe1, 0x67, 0x73, 0x73, 0x4f, 0x61, 0xa1, 0xca, 0x61, 0x03,
30 0x1b, 0x2b, 0xbf, 0x3d, 0x91, 0x8f, 0x2f, 0x94, 0xff, 0xc4,
31 0x22, 0x8e, 0x50, 0x91, 0x95, 0x44, 0xae
32 };
33
34 /*
35 * FVP does not support HES, so provide 0's as keys.
36 */
plat_rmmd_el3_token_sign_get_rak_pub(uintptr_t buf,size_t * len,unsigned int type)37 int plat_rmmd_el3_token_sign_get_rak_pub(uintptr_t buf, size_t *len,
38 unsigned int type)
39 {
40 (void)type;
41 if (*len < sizeof(sample_attest_pub_key)) {
42 return E_RMM_INVAL;
43 }
44
45 if (type != ATTEST_KEY_CURVE_ECC_SECP384R1) {
46 ERROR("Invalid ECC curve specified\n");
47 return E_RMM_INVAL;
48 }
49
50 *len = sizeof(sample_attest_pub_key);
51
52 (void)memcpy((void *)buf, sample_attest_pub_key,
53 sizeof(sample_attest_pub_key));
54
55 return 0;
56 }
57
plat_rmmd_el3_token_sign_push_req(const struct el3_token_sign_request * req)58 int plat_rmmd_el3_token_sign_push_req(const struct el3_token_sign_request *req)
59 {
60 /*
61 * TODO: Today this function is called with a lock held on the
62 * RMM<->EL3 shared buffer. In the future, we may move to a
63 * different design that may require handling multi-threaded
64 * calls to this function, for example, if we have a per CPU
65 * buffer between RMM and EL3.
66 */
67 if (el3_req_valid) {
68 return E_RMM_AGAIN;
69 }
70
71 el3_req = *req;
72
73 if ((el3_req.hash_alg_id != EL3_TOKEN_SIGN_HASH_ALG_SHA384) ||
74 (el3_req.sig_alg_id != ATTEST_KEY_CURVE_ECC_SECP384R1)) {
75 return E_RMM_INVAL;
76 }
77
78 el3_req_valid = true;
79
80 return 0;
81 }
82
plat_rmmd_el3_token_sign_pull_resp(struct el3_token_sign_response * resp)83 int plat_rmmd_el3_token_sign_pull_resp(struct el3_token_sign_response *resp)
84 {
85 if (!el3_req_valid) {
86 return E_RMM_AGAIN;
87 }
88
89 resp->rec_granule = el3_req.rec_granule;
90 resp->req_ticket = el3_req.req_ticket;
91 resp->sig_len = (uint16_t)sizeof(resp->signature_buf);
92 /* TODO: Provide real signature */
93 memset(resp->signature_buf, 0, sizeof(resp->signature_buf));
94
95 el3_req_valid = false;
96
97 return 0;
98 }
99