1 /*
2 * Copyright (c) 2018-2022 Yubico AB. All rights reserved.
3 * Use of this source code is governed by a BSD-style
4 * license that can be found in the LICENSE file.
5 * SPDX-License-Identifier: BSD-2-Clause
6 */
7
8 #include "fido.h"
9
10 static int
parse_authkey(const cbor_item_t * key,const cbor_item_t * val,void * arg)11 parse_authkey(const cbor_item_t *key, const cbor_item_t *val, void *arg)
12 {
13 es256_pk_t *authkey = arg;
14
15 if (cbor_isa_uint(key) == false ||
16 cbor_int_get_width(key) != CBOR_INT_8 ||
17 cbor_get_uint8(key) != 1) {
18 fido_log_debug("%s: cbor type", __func__);
19 return (0); /* ignore */
20 }
21
22 return (es256_pk_decode(val, authkey));
23 }
24
25 static int
fido_dev_authkey_tx(fido_dev_t * dev,int * ms)26 fido_dev_authkey_tx(fido_dev_t *dev, int *ms)
27 {
28 fido_blob_t f;
29 cbor_item_t *argv[2];
30 int r;
31
32 fido_log_debug("%s: dev=%p", __func__, (void *)dev);
33
34 memset(&f, 0, sizeof(f));
35 memset(argv, 0, sizeof(argv));
36
37 /* add command parameters */
38 if ((argv[0] = cbor_encode_pin_opt(dev)) == NULL ||
39 (argv[1] = cbor_build_uint8(2)) == NULL) {
40 fido_log_debug("%s: cbor_build", __func__);
41 r = FIDO_ERR_INTERNAL;
42 goto fail;
43 }
44
45 /* frame and transmit */
46 if (cbor_build_frame(CTAP_CBOR_CLIENT_PIN, argv, nitems(argv),
47 &f) < 0 || fido_tx(dev, CTAP_CMD_CBOR, f.ptr, f.len, ms) < 0) {
48 fido_log_debug("%s: fido_tx", __func__);
49 r = FIDO_ERR_TX;
50 goto fail;
51 }
52
53 r = FIDO_OK;
54 fail:
55 cbor_vector_free(argv, nitems(argv));
56 free(f.ptr);
57
58 return (r);
59 }
60
61 static int
fido_dev_authkey_rx(fido_dev_t * dev,es256_pk_t * authkey,int * ms)62 fido_dev_authkey_rx(fido_dev_t *dev, es256_pk_t *authkey, int *ms)
63 {
64 unsigned char *msg;
65 int msglen;
66 int r;
67
68 fido_log_debug("%s: dev=%p, authkey=%p, ms=%d", __func__, (void *)dev,
69 (void *)authkey, *ms);
70
71 memset(authkey, 0, sizeof(*authkey));
72
73 if ((msg = malloc(FIDO_MAXMSG)) == NULL) {
74 r = FIDO_ERR_INTERNAL;
75 goto out;
76 }
77
78 if ((msglen = fido_rx(dev, CTAP_CMD_CBOR, msg, FIDO_MAXMSG, ms)) < 0) {
79 fido_log_debug("%s: fido_rx", __func__);
80 r = FIDO_ERR_RX;
81 goto out;
82 }
83
84 r = cbor_parse_reply(msg, (size_t)msglen, authkey, parse_authkey);
85 out:
86 freezero(msg, FIDO_MAXMSG);
87
88 return (r);
89 }
90
91 static int
fido_dev_authkey_wait(fido_dev_t * dev,es256_pk_t * authkey,int * ms)92 fido_dev_authkey_wait(fido_dev_t *dev, es256_pk_t *authkey, int *ms)
93 {
94 int r;
95
96 if ((r = fido_dev_authkey_tx(dev, ms)) != FIDO_OK ||
97 (r = fido_dev_authkey_rx(dev, authkey, ms)) != FIDO_OK)
98 return (r);
99
100 return (FIDO_OK);
101 }
102
103 int
fido_dev_authkey(fido_dev_t * dev,es256_pk_t * authkey,int * ms)104 fido_dev_authkey(fido_dev_t *dev, es256_pk_t *authkey, int *ms)
105 {
106 return (fido_dev_authkey_wait(dev, authkey, ms));
107 }
108