1 /* $OpenBSD: sk-api.h,v 1.12 2021/02/18 02:15:07 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 #ifdef HAVE_STDINT_H 23 #include <stdint.h> 24 #endif 25 26 /* Flags */ 27 #define SSH_SK_USER_PRESENCE_REQD 0x01 28 #define SSH_SK_USER_VERIFICATION_REQD 0x04 29 #define SSH_SK_RESIDENT_KEY 0x20 30 31 /* Algs */ 32 #define SSH_SK_ECDSA 0x00 33 #define SSH_SK_ED25519 0x01 34 35 /* Error codes */ 36 #define SSH_SK_ERR_GENERAL -1 37 #define SSH_SK_ERR_UNSUPPORTED -2 38 #define SSH_SK_ERR_PIN_REQUIRED -3 39 #define SSH_SK_ERR_DEVICE_NOT_FOUND -4 40 41 struct sk_enroll_response { 42 uint8_t *public_key; 43 size_t public_key_len; 44 uint8_t *key_handle; 45 size_t key_handle_len; 46 uint8_t *signature; 47 size_t signature_len; 48 uint8_t *attestation_cert; 49 size_t attestation_cert_len; 50 uint8_t *authdata; 51 size_t authdata_len; 52 }; 53 54 struct sk_sign_response { 55 uint8_t flags; 56 uint32_t counter; 57 uint8_t *sig_r; 58 size_t sig_r_len; 59 uint8_t *sig_s; 60 size_t sig_s_len; 61 }; 62 63 struct sk_resident_key { 64 uint32_t alg; 65 size_t slot; 66 char *application; 67 struct sk_enroll_response key; 68 uint8_t flags; 69 }; 70 71 struct sk_option { 72 char *name; 73 char *value; 74 uint8_t required; 75 }; 76 77 #define SSH_SK_VERSION_MAJOR 0x00070000 /* current API version */ 78 #define SSH_SK_VERSION_MAJOR_MASK 0xffff0000 79 80 /* Return the version of the middleware API */ 81 uint32_t sk_api_version(void); 82 83 /* Enroll a U2F key (private key generation) */ 84 int sk_enroll(uint32_t alg, const uint8_t *challenge, size_t challenge_len, 85 const char *application, uint8_t flags, const char *pin, 86 struct sk_option **options, struct sk_enroll_response **enroll_response); 87 88 /* Sign a challenge */ 89 int sk_sign(uint32_t alg, const uint8_t *data, size_t data_len, 90 const char *application, const uint8_t *key_handle, size_t key_handle_len, 91 uint8_t flags, const char *pin, struct sk_option **options, 92 struct sk_sign_response **sign_response); 93 94 /* Enumerate all resident keys */ 95 int sk_load_resident_keys(const char *pin, struct sk_option **options, 96 struct sk_resident_key ***rks, size_t *nrks); 97 98 #endif /* _SK_API_H */ 99