| Tamas Ban | 6dfa6eb | 2018-08-17 12:02:51 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (c) 2018, Arm Limited. All rights reserved. |
| 3 | * |
| 4 | * SPDX-License-Identifier: BSD-3-Clause |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | /***************************************************************************/ |
| 9 | /* DRAFT UNDER REVIEW */ |
| 10 | /* These APIs are still evolving and are meant as a prototype for review.*/ |
| 11 | /* The APIs will change depending on feedback and will be firmed up */ |
| 12 | /* to a stable set of APIs once all the feedback has been considered. */ |
| 13 | /***************************************************************************/ |
| 14 | |
| 15 | #ifndef __PSA_INITIAL_ATTESTATION_API_H__ |
| 16 | #define __PSA_INITIAL_ATTESTATION_API_H__ |
| 17 | |
| 18 | #include "tfm_api.h" |
| 19 | #include <limits.h> |
| 20 | |
| 21 | #ifdef __cplusplus |
| 22 | extern "C" { |
| 23 | #endif |
| 24 | |
| 25 | /** |
| 26 | * \brief PSA INITIAL ATTESTATION API version |
| 27 | */ |
| 28 | #define PSA_INITIAL_ATTEST_API_VERSION_MAJOR (0) |
| 29 | #define PSA_INITIAL_ATTEST_API_VERSION_MINOR (1) |
| 30 | |
| 31 | /* The return value is shared with the TFM partition status value. The ATTEST |
| 32 | * return codes shouldn't overlap with predefined TFM status values. |
| 33 | */ |
| 34 | #define PSA_ATTEST_ERR_OFFSET (TFM_PARTITION_SPECIFIC_ERROR_MIN) |
| 35 | |
| 36 | /** |
| 37 | * \enum psa_attest_err_t |
| 38 | * |
| 39 | * \brief Initial attestation service error types |
| 40 | * |
| 41 | */ |
| 42 | enum psa_attest_err_t { |
| 43 | PSA_ATTEST_ERR_SUCCESS = 0, |
| 44 | PSA_ATTEST_ERR_INIT_FAILED = PSA_ATTEST_ERR_OFFSET, |
| 45 | PSA_ATTEST_ERR_TOKEN_BUFFER_OVERFLOW, |
| 46 | PSA_ATTEST_ERR_CLAIM_UNAVAILABLE, |
| 47 | PSA_ATTEST_ERR_INVALID_INPUT, |
| 48 | PSA_ATTEST_ERR_GENERAL, |
| 49 | /* Following entry is only to ensure the error code of int size */ |
| 50 | PSA_ATTEST_ERR_FORCE_INT_SIZE = INT_MAX |
| 51 | }; |
| 52 | |
| 53 | /** |
| 54 | * Maximum size of input challenge in bytes. This can be a nonce from server or |
| 55 | * the hash of any data which must be attested to the server. |
| 56 | */ |
| 57 | #define PSA_INITIAL_ATTEST_MAX_CHALLENGE_SIZE (64u) |
| 58 | |
| 59 | /** |
| 60 | * The list of fixed claims in the initial attestation token is still evolving, |
| 61 | * you can expect slight changes in the future. |
| 62 | * |
| 63 | * The initial attestation token is planned to be aligned with later version of |
| 64 | * Entity Attestation Token format: |
| 65 | * https://tools.ietf.org/html/draft-mandyam-eat-00 |
| 66 | * |
| 67 | * Current list of claims: |
| 68 | * - Challenge: Input object from caller. Can be nonce from server or hash of |
| 69 | * attested data. |
| 70 | * - Client ID: The ID of that secure partition or non-secure thread who |
| 71 | * called the initial attestation API. |
| 72 | * - Boot status: Measurements(hash) of firmware components by secure |
| 73 | * bootloader. |
| 74 | * - Boot seed: Random number, which is constant during the same boot cycle. |
| 75 | * - Device ID: Universally and globally unique ID of the device. |
| 76 | * - HW version: Uniquely identifies the GDSII that went to fabrication, HW |
| 77 | * and ROM. |
| 78 | */ |
| 79 | |
| 80 | /** |
| 81 | * Calculated based on: |
| 82 | * - COSE header |
| 83 | * - Algorithm identifier |
| 84 | * - Key ID |
| 85 | * - Claims in initial attestation token: |
| 86 | * - COSE Signature |
| 87 | * |
| 88 | * This size (in bytes) is a maximum value, actual token size can be smaller. |
| 89 | */ |
| 90 | /* FixMe: Just initial value it must be updated if claims are fixed */ |
| 91 | #define PSA_INITIAL_ATTEST_TOKEN_SIZE (512u) |
| 92 | |
| 93 | /** |
| 94 | * \brief Get initial attestation token |
| 95 | * |
| 96 | * \param[in] challenge_obj Pointer to buffer where challenge input is |
| 97 | * stored. Nonce and / or hash of attested data. |
| 98 | * Must be always |
| 99 | * \ref PSA_INITIAL_ATTEST_CHALLENGE_SIZE bytes |
| 100 | * long. |
| 101 | * \param[in] challenge_size Size of challenge object in bytes. |
| 102 | * \param[out] token Pointer to the buffer where attestation token |
| 103 | * must be stored. |
| 104 | * \param[in/out] token_size Size of allocated buffer for token, which |
| 105 | * updated by initial attestation service with |
| 106 | * final token size. |
| 107 | * |
| 108 | * \return Returns error code as specified in \ref psa_attest_err_t |
| 109 | */ |
| 110 | enum psa_attest_err_t |
| 111 | psa_initial_attest_get_token(const uint8_t *challenge_obj, |
| 112 | uint32_t challenge_size, |
| 113 | uint8_t *token, |
| 114 | uint32_t *token_size); |
| 115 | |
| 116 | #ifdef __cplusplus |
| 117 | } |
| 118 | #endif |
| 119 | |
| 120 | #endif /* __PSA_INITIAL_ATTESTATION_API_H__ */ |