Head

GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	lib/libssl/bs_cbs.c	Lines:	197	219	90.0 %
Date:	2017-11-13	Branches:	99	130	76.2 %


/*	$OpenBSD: bs_cbs.c,v 1.17 2015/06/24 09:44:18 jsing Exp $	*/
/*
 * Copyright (c) 2014, Google Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */

#include <assert.h>
#include <stdlib.h>
#include <string.h>

#include <openssl/opensslconf.h>
#include <openssl/buffer.h>
#include <openssl/crypto.h>

#include "bytestring.h"

void
CBS_init(CBS *cbs, const uint8_t *data, size_t len)
{
	cbs->data = data;
	cbs->initial_len = len;
	cbs->len = len;
}

void
CBS_dup(const CBS *cbs, CBS *out)
{
	CBS_init(out, CBS_data(cbs), CBS_len(cbs));
	out->initial_len = cbs->initial_len;
}

static int
cbs_get(CBS *cbs, const uint8_t **p, size_t n)
{
	if (cbs->len < n)
		return 0;

	*p = cbs->data;
	cbs->data += n;
	cbs->len -= n;
	return 1;
}

size_t
CBS_offset(const CBS *cbs)
{
	return cbs->initial_len - cbs->len;
}

int
CBS_skip(CBS *cbs, size_t len)
{
	const uint8_t *dummy;
	return cbs_get(cbs, &dummy, len);
}

const uint8_t *
CBS_data(const CBS *cbs)
{
	return cbs->data;
}

size_t
CBS_len(const CBS *cbs)
{
	return cbs->len;
}

int
CBS_stow(const CBS *cbs, uint8_t **out_ptr, size_t *out_len)
{
	free(*out_ptr);
	*out_ptr = NULL;
	*out_len = 0;

	if (cbs->len == 0)
		return 1;

	if ((*out_ptr = malloc(cbs->len)) == NULL)
		return 0;

	memcpy(*out_ptr, cbs->data, cbs->len);

	*out_len = cbs->len;
	return 1;
}

int
CBS_strdup(const CBS *cbs, char **out_ptr)
{
	free(*out_ptr);
	*out_ptr = strndup((const char *)cbs->data, cbs->len);
	return (*out_ptr != NULL);
}

int
CBS_write_bytes(const CBS *cbs, uint8_t *dst, size_t dst_len, size_t *copied)
{
	if (dst_len < cbs->len)
		return 0;

	memmove(dst, cbs->data, cbs->len);

	if (copied != NULL)
		*copied = cbs->len;

	return 1;
}

int
CBS_contains_zero_byte(const CBS *cbs)
{
	return memchr(cbs->data, 0, cbs->len) != NULL;
}

int
CBS_mem_equal(const CBS *cbs, const uint8_t *data, size_t len)
{
	if (len != cbs->len)
		return 0;

	return timingsafe_memcmp(cbs->data, data, len) == 0;
}

static int
cbs_get_u(CBS *cbs, uint32_t *out, size_t len)
{
	uint32_t result = 0;
	size_t i;
	const uint8_t *data;

	if (len < 1 || len > 4)
		return 0;

	if (!cbs_get(cbs, &data, len))
		return 0;

	for (i = 0; i < len; i++) {
		result <<= 8;
		result |= data[i];
	}
	*out = result;
	return 1;
}

int
CBS_get_u8(CBS *cbs, uint8_t *out)
{
	const uint8_t *v;

	if (!cbs_get(cbs, &v, 1))
		return 0;

	*out = *v;
	return 1;
}

int
CBS_get_u16(CBS *cbs, uint16_t *out)
{
	uint32_t v;

	if (!cbs_get_u(cbs, &v, 2))
		return 0;

	*out = v;
	return 1;
}

int
CBS_get_u24(CBS *cbs, uint32_t *out)
{
	return cbs_get_u(cbs, out, 3);
}

int
CBS_get_u32(CBS *cbs, uint32_t *out)
{
	return cbs_get_u(cbs, out, 4);
}

int
CBS_get_bytes(CBS *cbs, CBS *out, size_t len)
{
	const uint8_t *v;

	if (!cbs_get(cbs, &v, len))
		return 0;

	CBS_init(out, v, len);
	return 1;
}

static int
cbs_get_length_prefixed(CBS *cbs, CBS *out, size_t len_len)
{
	uint32_t len;

	if (!cbs_get_u(cbs, &len, len_len))
		return 0;

	return CBS_get_bytes(cbs, out, len);
}

int
CBS_get_u8_length_prefixed(CBS *cbs, CBS *out)
{
	return cbs_get_length_prefixed(cbs, out, 1);
}

int
CBS_get_u16_length_prefixed(CBS *cbs, CBS *out)
{
	return cbs_get_length_prefixed(cbs, out, 2);
}

int
CBS_get_u24_length_prefixed(CBS *cbs, CBS *out)
{
	return cbs_get_length_prefixed(cbs, out, 3);
}

int
CBS_get_any_asn1_element(CBS *cbs, CBS *out, unsigned int *out_tag,
    size_t *out_header_len)
{
	return cbs_get_any_asn1_element_internal(cbs, out, out_tag,
	    out_header_len, 1);
}

/*
 * Review X.690 for details on ASN.1 DER encoding.
 *
 * If non-strict mode is enabled, then DER rules are relaxed
 * for indefinite constructs (violates DER but a little closer to BER).
 * Non-strict mode should only be used by bs_ber.c
 *
 * Sections 8, 10 and 11 for DER encoding
 */
int
cbs_get_any_asn1_element_internal(CBS *cbs, CBS *out, unsigned int *out_tag,
    size_t *out_header_len, int strict)
{
	uint8_t tag, length_byte;
	CBS header = *cbs;
	CBS throwaway;
	size_t len;

	if (out == NULL)
		out = &throwaway;

	/*
	 * Get identifier octet and length octet.  Only 1 octet for each
	 * is a CBS limitation.
	 */
	if (!CBS_get_u8(&header, &tag) || !CBS_get_u8(&header, &length_byte))
		return 0;

	/* CBS limitation: long form tags are not supported. */
	if ((tag & 0x1f) == 0x1f)
		return 0;

	if (out_tag != NULL)
		*out_tag = tag;

	if ((length_byte & 0x80) == 0) {
		/* Short form length. */
		len = ((size_t) length_byte) + 2;
		if (out_header_len != NULL)
			*out_header_len = 2;

	} else {
		/* Long form length. */
		const size_t num_bytes = length_byte & 0x7f;
		uint32_t len32;

		/* ASN.1 reserved value for future extensions */
		if (num_bytes == 0x7f)
			return 0;

		/* Handle indefinite form length */
		if (num_bytes == 0) {
			/* DER encoding doesn't allow for indefinite form. */
			if (strict)
				return 0;

			/* Primitive cannot use indefinite in BER or DER. */
			if ((tag & CBS_ASN1_CONSTRUCTED) == 0)
				return 0;

			/* Constructed, indefinite length allowed in BER. */
			if (out_header_len != NULL)
				*out_header_len = 2;
			return CBS_get_bytes(cbs, out, 2);
		}

		/* CBS limitation. */
		if (num_bytes > 4)
			return 0;

		if (!cbs_get_u(&header, &len32, num_bytes))
			return 0;

		/* DER has a minimum length octet requirement. */
		if (len32 < 128)
			/* Should have used short form instead */
			return 0;

		if ((len32 >> ((num_bytes - 1) * 8)) == 0)
			/* Length should have been at least one byte shorter. */
			return 0;

		len = len32;
		if (len + 2 + num_bytes < len)
			/* Overflow. */
			return 0;

		len += 2 + num_bytes;
		if (out_header_len != NULL)
			*out_header_len = 2 + num_bytes;
	}

	return CBS_get_bytes(cbs, out, len);
}

static int
cbs_get_asn1(CBS *cbs, CBS *out, unsigned int tag_value, int skip_header)
{
	size_t header_len;
	unsigned int tag;
	CBS throwaway;

	if (out == NULL)
		out = &throwaway;

	if (!CBS_get_any_asn1_element(cbs, out, &tag, &header_len) ||
	    tag != tag_value)
		return 0;

	if (skip_header && !CBS_skip(out, header_len)) {
		assert(0);
		return 0;
	}

	return 1;
}

int
CBS_get_asn1(CBS *cbs, CBS *out, unsigned int tag_value)
{
	return cbs_get_asn1(cbs, out, tag_value, 1 /* skip header */);
}

int
CBS_get_asn1_element(CBS *cbs, CBS *out, unsigned int tag_value)
{
	return cbs_get_asn1(cbs, out, tag_value, 0 /* include header */);
}

int
CBS_peek_asn1_tag(const CBS *cbs, unsigned int tag_value)
{
	if (CBS_len(cbs) < 1)
		return 0;

	/*
	 * Tag number 31 indicates the start of a long form number.
	 * This is valid in ASN.1, but CBS only supports short form.
	 */
	if ((tag_value & 0x1f) == 0x1f)
		return 0;

	return CBS_data(cbs)[0] == tag_value;
}

/* Encoding details are in ASN.1: X.690 section 8.3 */
int
CBS_get_asn1_uint64(CBS *cbs, uint64_t *out)
{
	CBS bytes;
	const uint8_t *data;
	size_t i, len;

	if (!CBS_get_asn1(cbs, &bytes, CBS_ASN1_INTEGER))
		return 0;

	*out = 0;
	data = CBS_data(&bytes);
	len = CBS_len(&bytes);

	if (len == 0)
		/* An INTEGER is encoded with at least one content octet. */
		return 0;

	if ((data[0] & 0x80) != 0)
		/* Negative number. */
		return 0;

	if (data[0] == 0 && len > 1 && (data[1] & 0x80) == 0)
		/* Violates smallest encoding rule: excessive leading zeros. */
		return 0;

	for (i = 0; i < len; i++) {
		if ((*out >> 56) != 0)
			/* Too large to represent as a uint64_t. */
			return 0;

		*out <<= 8;
		*out |= data[i];
	}

	return 1;
}

int
CBS_get_optional_asn1(CBS *cbs, CBS *out, int *out_present, unsigned int tag)
{
	if (CBS_peek_asn1_tag(cbs, tag)) {
		if (!CBS_get_asn1(cbs, out, tag))
			return 0;

		*out_present = 1;
	} else {
		*out_present = 0;
	}
	return 1;
}

int
CBS_get_optional_asn1_octet_string(CBS *cbs, CBS *out, int *out_present,
    unsigned int tag)
{
	CBS child;
	int present;

	if (!CBS_get_optional_asn1(cbs, &child, &present, tag))
		return 0;

	if (present) {
		if (!CBS_get_asn1(&child, out, CBS_ASN1_OCTETSTRING) ||
		    CBS_len(&child) != 0)
			return 0;
	} else {
		CBS_init(out, NULL, 0);
	}
	if (out_present)
		*out_present = present;

	return 1;
}

int
CBS_get_optional_asn1_uint64(CBS *cbs, uint64_t *out, unsigned int tag,
    uint64_t default_value)
{
	CBS child;
	int present;

	if (!CBS_get_optional_asn1(cbs, &child, &present, tag))
		return 0;

	if (present) {
		if (!CBS_get_asn1_uint64(&child, out) ||
		    CBS_len(&child) != 0)
			return 0;
	} else {
		*out = default_value;
	}
	return 1;
}

int
CBS_get_optional_asn1_bool(CBS *cbs, int *out, unsigned int tag,
    int default_value)
{
	CBS child, child2;
	int present;

	if (!CBS_get_optional_asn1(cbs, &child, &present, tag))
		return 0;

	if (present) {
		uint8_t boolean;

		if (!CBS_get_asn1(&child, &child2, CBS_ASN1_BOOLEAN) ||
		    CBS_len(&child2) != 1 || CBS_len(&child) != 0)
			return 0;

		boolean = CBS_data(&child2)[0];
		if (boolean == 0)
			*out = 0;
		else if (boolean == 0xff)
			*out = 1;
		else
			return 0;

	} else {
		*out = default_value;
	}
	return 1;
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: bs_cbs.c,v 1.17 2015/06/24 09:44:18 jsing Exp $ */
2			/*
3			* Copyright (c) 2014, Google Inc.
4			*
5			* Permission to use, copy, modify, and/or 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 ANY
12			* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13			* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
14			* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
15			* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
16
17			#include <assert.h>
18			#include <stdlib.h>
19			#include <string.h>
20
21			#include <openssl/opensslconf.h>
22			#include <openssl/buffer.h>
23			#include <openssl/crypto.h>
24
25			#include "bytestring.h"
26
27			void
28			CBS_init(CBS cbs, const uint8_t data, size_t len)
29			{
30		485812	cbs->data = data;
31		242906	cbs->initial_len = len;
32		242906	cbs->len = len;
33		242906	}
34
35			void
36			CBS_dup(const CBS cbs, CBS out)
37			{
38		444	CBS_init(out, CBS_data(cbs), CBS_len(cbs));
39		222	out->initial_len = cbs->initial_len;
40		222	}
41
42			static int
43			cbs_get(CBS cbs, const uint8_t *p, size_t n)
44			{
45	✓✓	886074	if (cbs->len < n)
46		63	return 0;
47
48		442974	*p = cbs->data;
49		442974	cbs->data += n;
50		442974	cbs->len -= n;
51		442974	return 1;
52		443037	}
53
54			size_t
55			CBS_offset(const CBS *cbs)
56			{
57		66	return cbs->initial_len - cbs->len;
58			}
59
60			int
61			CBS_skip(CBS *cbs, size_t len)
62			{
63		5716	const uint8_t *dummy;
64		5716	return cbs_get(cbs, &dummy, len);
65		2858	}
66
67			const uint8_t *
68			CBS_data(const CBS *cbs)
69			{
70		87712	return cbs->data;
71			}
72
73			size_t
74			CBS_len(const CBS *cbs)
75			{
76		362928	return cbs->len;
77			}
78
79			int
80			CBS_stow(const CBS cbs, uint8_t out_ptr, size_t out_len)
81			{
82		5238	free(*out_ptr);
83		2619	*out_ptr = NULL;
84		2619	*out_len = 0;
85
86	✗✓	2619	if (cbs->len == 0)
87			return 1;
88
89	✗✓	2619	if ((*out_ptr = malloc(cbs->len)) == NULL)
90			return 0;
91
92		2619	memcpy(*out_ptr, cbs->data, cbs->len);
93
94		2619	*out_len = cbs->len;
95		2619	return 1;
96		2619	}
97
98			int
99			CBS_strdup(const CBS cbs, char *out_ptr)
100			{
101		36	free(*out_ptr);
102		18	out_ptr = strndup((const char )cbs->data, cbs->len);
103		18	return (*out_ptr != NULL);
104			}
105
106			int
107			CBS_write_bytes(const CBS cbs, uint8_t dst, size_t dst_len, size_t *copied)
108			{
109	✗✓	36922	if (dst_len < cbs->len)
110			return 0;
111
112		18461	memmove(dst, cbs->data, cbs->len);
113
114	✓✓	18461	if (copied != NULL)
115		1876	*copied = cbs->len;
116
117		18461	return 1;
118		18461	}
119
120			int
121			CBS_contains_zero_byte(const CBS *cbs)
122			{
123		2618	return memchr(cbs->data, 0, cbs->len) != NULL;
124			}
125
126			int
127			CBS_mem_equal(const CBS cbs, const uint8_t data, size_t len)
128			{
129	✓✓	124866	if (len != cbs->len)
130		3	return 0;
131
132		62430	return timingsafe_memcmp(cbs->data, data, len) == 0;
133		62433	}
134
135			static int
136			cbs_get_u(CBS cbs, uint32_t out, size_t len)
137			{
138			uint32_t result = 0;
139			size_t i;
140		460034	const uint8_t *data;
141
142	✗✓	230017	if (len < 1 \|\| len > 4)
143			return 0;
144
145	✓✓	230017	if (!cbs_get(cbs, &data, len))
146		6	return 0;
147
148	✓✓	1399652	for (i = 0; i < len; i++) {
149		469815	result <<= 8;
150		469815	result \|= data[i];
151			}
152		230011	*out = result;
153		230011	return 1;
154		230017	}
155
156			int
157			CBS_get_u8(CBS cbs, uint8_t out)
158			{
159		235118	const uint8_t *v;
160
161	✓✓	117559	if (!cbs_get(cbs, &v, 1))
162		6	return 0;
163
164		117553	out = v;
165		117553	return 1;
166		117559	}
167
168			int
169			CBS_get_u16(CBS cbs, uint16_t out)
170			{
171		296894	uint32_t v;
172
173	✓✓	148447	if (!cbs_get_u(cbs, &v, 2))
174		6	return 0;
175
176		148441	*out = v;
177		148441	return 1;
178		148447	}
179
180			int
181			CBS_get_u24(CBS cbs, uint32_t out)
182			{
183		76968	return cbs_get_u(cbs, out, 3);
184			}
185
186			int
187			CBS_get_u32(CBS cbs, uint32_t out)
188			{
189		2582	return cbs_get_u(cbs, out, 4);
190			}
191
192			int
193			CBS_get_bytes(CBS cbs, CBS out, size_t len)
194			{
195		185206	const uint8_t *v;
196
197	✓✓	92603	if (!cbs_get(cbs, &v, len))
198		42	return 0;
199
200		92561	CBS_init(out, v, len);
201		92561	return 1;
202		92603	}
203
204			static int
205			cbs_get_length_prefixed(CBS cbs, CBS out, size_t len_len)
206			{
207		83454	uint32_t len;
208
209	✗✓	41727	if (!cbs_get_u(cbs, &len, len_len))
210			return 0;
211
212		41727	return CBS_get_bytes(cbs, out, len);
213		41727	}
214
215			int
216			CBS_get_u8_length_prefixed(CBS cbs, CBS out)
217			{
218		70116	return cbs_get_length_prefixed(cbs, out, 1);
219			}
220
221			int
222			CBS_get_u16_length_prefixed(CBS cbs, CBS out)
223			{
224		5742	return cbs_get_length_prefixed(cbs, out, 2);
225			}
226
227			int
228			CBS_get_u24_length_prefixed(CBS cbs, CBS out)
229			{
230		7596	return cbs_get_length_prefixed(cbs, out, 3);
231			}
232
233			int
234			CBS_get_any_asn1_element(CBS cbs, CBS out, unsigned int *out_tag,
235			size_t *out_header_len)
236			{
237		4870	return cbs_get_any_asn1_element_internal(cbs, out, out_tag,
238			out_header_len, 1);
239			}
240
241			/*
242			* Review X.690 for details on ASN.1 DER encoding.
243			*
244			* If non-strict mode is enabled, then DER rules are relaxed
245			* for indefinite constructs (violates DER but a little closer to BER).
246			* Non-strict mode should only be used by bs_ber.c
247			*
248			* Sections 8, 10 and 11 for DER encoding
249			*/
250			int
251			cbs_get_any_asn1_element_internal(CBS cbs, CBS out, unsigned int *out_tag,
252			size_t *out_header_len, int strict)
253			{
254		5056	uint8_t tag, length_byte;
255		2528	CBS header = *cbs;
256		2528	CBS throwaway;
257			size_t len;
258
259	✗✓	2528	if (out == NULL)
260			out = &throwaway;
261
262			/*
263			* Get identifier octet and length octet. Only 1 octet for each
264			* is a CBS limitation.
265			*/
266	✓✗✗✓	5056	if (!CBS_get_u8(&header, &tag) \|\| !CBS_get_u8(&header, &length_byte))
267			return 0;
268
269			/* CBS limitation: long form tags are not supported. */
270	✗✓	2528	if ((tag & 0x1f) == 0x1f)
271			return 0;
272
273	✓✗	2528	if (out_tag != NULL)
274		2528	*out_tag = tag;
275
276	✓✓	2528	if ((length_byte & 0x80) == 0) {
277			/* Short form length. */
278		2427	len = ((size_t) length_byte) + 2;
279	✓✗	2427	if (out_header_len != NULL)
280		2427	*out_header_len = 2;
281
282			} else {
283			/* Long form length. */
284		101	const size_t num_bytes = length_byte & 0x7f;
285		101	uint32_t len32;
286
287			/* ASN.1 reserved value for future extensions */
288	✗✓	101	if (num_bytes == 0x7f)
289			return 0;
290
291			/* Handle indefinite form length */
292	✓✓	101	if (num_bytes == 0) {
293			/* DER encoding doesn't allow for indefinite form. */
294	✓✓	33	if (strict)
295		3	return 0;
296
297			/* Primitive cannot use indefinite in BER or DER. */
298	✗✓	30	if ((tag & CBS_ASN1_CONSTRUCTED) == 0)
299			return 0;
300
301			/* Constructed, indefinite length allowed in BER. */
302	✓✗	30	if (out_header_len != NULL)
303		30	*out_header_len = 2;
304		30	return CBS_get_bytes(cbs, out, 2);
305			}
306
307			/* CBS limitation. */
308	✗✓	68	if (num_bytes > 4)
309			return 0;
310
311	✗✓	68	if (!cbs_get_u(&header, &len32, num_bytes))
312			return 0;
313
314			/* DER has a minimum length octet requirement. */
315	✓✓	68	if (len32 < 128)
316			/* Should have used short form instead */
317		3	return 0;
318
319	✓✓	65	if ((len32 >> ((num_bytes - 1) * 8)) == 0)
320			/* Length should have been at least one byte shorter. */
321		3	return 0;
322
323		62	len = len32;
324	✗✓	62	if (len + 2 + num_bytes < len)
325			/* Overflow. */
326			return 0;
327
328		62	len += 2 + num_bytes;
329	✓✗	62	if (out_header_len != NULL)
330		62	*out_header_len = 2 + num_bytes;
331	✓✓	163	}
332
333		2489	return CBS_get_bytes(cbs, out, len);
334		2528	}
335
336			static int
337			cbs_get_asn1(CBS cbs, CBS out, unsigned int tag_value, int skip_header)
338			{
339		4870	size_t header_len;
340		2435	unsigned int tag;
341		2435	CBS throwaway;
342
343	✗✓	2435	if (out == NULL)
344			out = &throwaway;
345
346	✓✓✓✓	4855	if (!CBS_get_any_asn1_element(cbs, out, &tag, &header_len) \|\|
347		2420	tag != tag_value)
348		21	return 0;
349
350	✓✗✗✓	4828	if (skip_header && !CBS_skip(out, header_len)) {
351			assert(0);
352			return 0;
353			}
354
355		2414	return 1;
356		2435	}
357
358			int
359			CBS_get_asn1(CBS cbs, CBS out, unsigned int tag_value)
360			{
361		4870	return cbs_get_asn1(cbs, out, tag_value, 1 /* skip header */);
362			}
363
364			int
365			CBS_get_asn1_element(CBS cbs, CBS out, unsigned int tag_value)
366			{
367			return cbs_get_asn1(cbs, out, tag_value, 0 /* include header */);
368			}
369
370			int
371			CBS_peek_asn1_tag(const CBS *cbs, unsigned int tag_value)
372			{
373	✓✓	3170	if (CBS_len(cbs) < 1)
374		759	return 0;
375
376			/*
377			* Tag number 31 indicates the start of a long form number.
378			* This is valid in ASN.1, but CBS only supports short form.
379			*/
380	✗✓	826	if ((tag_value & 0x1f) == 0x1f)
381			return 0;
382
383		826	return CBS_data(cbs)[0] == tag_value;
384		1585	}
385
386			/* Encoding details are in ASN.1: X.690 section 8.3 */
387			int
388			CBS_get_asn1_uint64(CBS cbs, uint64_t out)
389			{
390		1614	CBS bytes;
391			const uint8_t *data;
392			size_t i, len;
393
394	✓✓	807	if (!CBS_get_asn1(cbs, &bytes, CBS_ASN1_INTEGER))
395		3	return 0;
396
397		804	*out = 0;
398		804	data = CBS_data(&bytes);
399		804	len = CBS_len(&bytes);
400
401	✓✓	804	if (len == 0)
402			/* An INTEGER is encoded with at least one content octet. */
403		3	return 0;
404
405	✓✓	801	if ((data[0] & 0x80) != 0)
406			/* Negative number. */
407		6	return 0;
408
409	✓✓✓✓	843	if (data[0] == 0 && len > 1 && (data[1] & 0x80) == 0)
410			/* Violates smallest encoding rule: excessive leading zeros. */
411		3	return 0;
412
413	✓✓	5280	for (i = 0; i < len; i++) {
414	✓✓	1851	if ((*out >> 56) != 0)
415			/* Too large to represent as a uint64_t. */
416		3	return 0;
417
418		1848	*out <<= 8;
419		1848	*out \|= data[i];
420			}
421
422		789	return 1;
423		807	}
424
425			int
426			CBS_get_optional_asn1(CBS cbs, CBS out, int *out_present, unsigned int tag)
427			{
428	✓✓	3152	if (CBS_peek_asn1_tag(cbs, tag)) {
429	✗✓	632	if (!CBS_get_asn1(cbs, out, tag))
430			return 0;
431
432		632	*out_present = 1;
433		632	} else {
434		944	*out_present = 0;
435			}
436		1576	return 1;
437		1576	}
438
439			int
440			CBS_get_optional_asn1_octet_string(CBS cbs, CBS out, int *out_present,
441			unsigned int tag)
442			{
443		1176	CBS child;
444		588	int present;
445
446	✗✓	588	if (!CBS_get_optional_asn1(cbs, &child, &present, tag))
447			return 0;
448
449	✓✓	588	if (present) {
450	✓✓✗✓	407	if (!CBS_get_asn1(&child, out, CBS_ASN1_OCTETSTRING) \|\|
451		202	CBS_len(&child) != 0)
452		3	return 0;
453			} else {
454		383	CBS_init(out, NULL, 0);
455			}
456	✓✓	585	if (out_present)
457		582	*out_present = present;
458
459		585	return 1;
460		588	}
461
462			int
463			CBS_get_optional_asn1_uint64(CBS cbs, uint64_t out, unsigned int tag,
464			uint64_t default_value)
465			{
466		1552	CBS child;
467		776	int present;
468
469	✗✓	776	if (!CBS_get_optional_asn1(cbs, &child, &present, tag))
470			return 0;
471
472	✓✓	776	if (present) {
473	✓✓✗✓	775	if (!CBS_get_asn1_uint64(&child, out) \|\|
474		386	CBS_len(&child) != 0)
475		3	return 0;
476			} else {
477		387	*out = default_value;
478			}
479		773	return 1;
480		776	}
481
482			int
483			CBS_get_optional_asn1_bool(CBS cbs, int out, unsigned int tag,
484			int default_value)
485			{
486		24	CBS child, child2;
487		12	int present;
488
489	✗✓	12	if (!CBS_get_optional_asn1(cbs, &child, &present, tag))
490			return 0;
491
492	✓✓	12	if (present) {
493			uint8_t boolean;
494
495	✓✗✗✓	18	if (!CBS_get_asn1(&child, &child2, CBS_ASN1_BOOLEAN) \|\|
496	✓✗	18	CBS_len(&child2) != 1 \|\| CBS_len(&child) != 0)
497			return 0;
498
499		9	boolean = CBS_data(&child2)[0];
500	✓✓	9	if (boolean == 0)
501		3	*out = 0;
502	✓✓	6	else if (boolean == 0xff)
503		3	*out = 1;
504			else
505		3	return 0;
506
507	✓✓	6	} else {
508		3	*out = default_value;
509			}
510		9	return 1;
511		12	}