1 /* $OpenBSD: sk-api.h,v 1.8 2020/01/25 23:13:09 djm Exp $ */ 2 /* 3 * Copyright (c) 2019 Google LLC 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #ifndef _SK_API_H 19 #define _SK_API_H 1 20 21 #include <stddef.h> 22 #include <stdint.h> 23 24 /* Flags */ 25 #define SSH_SK_USER_PRESENCE_REQD 0x01 26 #define SSH_SK_USER_VERIFICATION_REQD 0x04 27 #define SSH_SK_RESIDENT_KEY 0x20 28 29 /* Algs */ 30 #define SSH_SK_ECDSA 0x00 31 #define SSH_SK_ED25519 0x01 32 33 /* Error codes */ 34 #define SSH_SK_ERR_GENERAL -1 35 #define SSH_SK_ERR_UNSUPPORTED -2 36 #define SSH_SK_ERR_PIN_REQUIRED -3 37 #define SSH_SK_ERR_DEVICE_NOT_FOUND -4 38 39 struct sk_enroll_response { 40 uint8_t *public_key; 41 size_t public_key_len; 42 uint8_t *key_handle; 43 size_t key_handle_len; 44 uint8_t *signature; 45 size_t signature_len; 46 uint8_t *attestation_cert; 47 size_t attestation_cert_len; 48 }; 49 50 struct sk_sign_response { 51 uint8_t flags; 52 uint32_t counter; 53 uint8_t *sig_r; 54 size_t sig_r_len; 55 uint8_t *sig_s; 56 size_t sig_s_len; 57 }; 58 59 struct sk_resident_key { 60 uint32_t alg; 61 size_t slot; 62 char *application; 63 struct sk_enroll_response key; 64 }; 65 66 struct sk_option { 67 char *name; 68 char *value; 69 uint8_t required; 70 }; 71 72 #define SSH_SK_VERSION_MAJOR 0x00040000 /* current API version */ 73 #define SSH_SK_VERSION_MAJOR_MASK 0xffff0000 74 75 /* Return the version of the middleware API */ 76 uint32_t sk_api_version(void); 77 78 /* Enroll a U2F key (private key generation) */ 79 int sk_enroll(uint32_t alg, const uint8_t *challenge, size_t challenge_len, 80 const char *application, uint8_t flags, const char *pin, 81 struct sk_option **options, struct sk_enroll_response **enroll_response); 82 83 /* Sign a challenge */ 84 int sk_sign(uint32_t alg, const uint8_t *message, size_t message_len, 85 const char *application, const uint8_t *key_handle, size_t key_handle_len, 86 uint8_t flags, const char *pin, struct sk_option **options, 87 struct sk_sign_response **sign_response); 88 89 /* Enumerate all resident keys */ 90 int sk_load_resident_keys(const char *pin, struct sk_option **options, 91 struct sk_resident_key ***rks, size_t *nrks); 92 93 #endif /* _SK_API_H */ 94