~funderscore blog cgit wiki get in touch
aboutsummaryrefslogtreecommitdiff
blob: 7020fae18941fa22ab340b21847fd61630967ab8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2016
 * Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
 */

#include <common.h>
#include <command.h>
#include <env.h>
#include <tpm-v1.h>
#include <malloc.h>
#include <linux/ctype.h>
#include <asm/unaligned.h>

#include "hre.h"

int flush_keys(struct udevice *tpm)
{
	u16 key_count;
	u8 buf[288];
	u8 *ptr;
	u32 err;
	uint i;

	/* fetch list of already loaded keys in the TPM */
	err = tpm1_get_capability(tpm, TPM_CAP_HANDLE, TPM_RT_KEY, buf,
				  sizeof(buf));
	if (err)
		return -1;
	key_count = get_unaligned_be16(buf);
	ptr = buf + 2;
	for (i = 0; i < key_count; ++i, ptr += 4) {
		err = tpm1_flush_specific(tpm, get_unaligned_be32(ptr),
					  TPM_RT_KEY);
		if (err && err != TPM_KEY_OWNER_CONTROL)
			return err;
	}

	return 0;
}

int decode_hexstr(char *hexstr, u8 **result)
{
	int len = strlen(hexstr);
	int bytes = len / 2;
	int i;
	u8 acc = 0;

	if (len % 2 == 1)
		return 1;

	*result = (u8 *)malloc(bytes);

	for (i = 0; i < len; i++) {
		char cur = tolower(hexstr[i]);
		u8 val;

		if ((cur >= 'a' && cur <= 'f') || (cur >= '0' && cur <= '9')) {
			val = cur - (cur > '9' ? 87 : 48);

			if (i % 2 == 0)
				acc = 16 * val;
			else
				(*result)[i / 2] = acc + val;
		} else {
			free(*result);
			return 1;
		}
	}

	return 0;
}

int extract_subprogram(u8 **progdata, u32 expected_magic,
		       struct key_program **result)
{
	struct key_program *prog = *result;
	u32 magic, code_crc, code_size;

	magic = get_unaligned_be32(*progdata);
	code_crc = get_unaligned_be32(*progdata + 4);
	code_size = get_unaligned_be32(*progdata + 8);

	*progdata += 12;

	if (magic != expected_magic)
		return -1;

	*result = malloc(sizeof(struct key_program) + code_size);

	if (!*result)
		return -1;

	prog->magic = magic;
	prog->code_crc = code_crc;
	prog->code_size = code_size;
	memcpy(prog->code, *progdata, code_size);

	*progdata += code_size;

	if (hre_verify_program(prog)) {
		free(prog);
		return -1;
	}

	return 0;
}

struct key_program *parse_and_check_keyprog(u8 *progdata)
{
	struct key_program *result = NULL, *hmac = NULL;

	/* Part 1: Load key program */

	if (extract_subprogram(&progdata, MAGIC_KEY_PROGRAM, &result))
		return NULL;

	/* Part 2: Load hmac program */

	if (extract_subprogram(&progdata, MAGIC_HMAC, &hmac))
		return NULL;

	free(hmac);

	return result;
}

int load_and_run_keyprog(struct udevice *tpm)
{
	char *cmd = NULL;
	u8 *binprog = NULL;
	char *hexprog;
	struct key_program *prog;

	cmd = env_get("loadkeyprogram");

	if (!cmd || run_command(cmd, 0))
		return 1;

	hexprog = env_get("keyprogram");

	if (decode_hexstr(hexprog, &binprog))
		return 1;

	prog = parse_and_check_keyprog(binprog);
	free(binprog);

	if (!prog)
		return 1;

	if (hre_run_program(tpm, prog->code, prog->code_size)) {
		free(prog);
		return 1;
	}

	printf("\nSD code ran successfully\n");

	free(prog);

	return 0;
}