/src/openssl/include/internal/quic_vlint.h

Source
/*
* Copyright 2022-2025 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License").  You may not use
* this file except in compliance with the License.  You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/

#ifndef OSSL_INTERNAL_QUIC_VLINT_H
# define OSSL_INTERNAL_QUIC_VLINT_H
# pragma once

# include "internal/e_os.h"

# ifndef OPENSSL_NO_QUIC

/* The smallest value requiring a 1, 2, 4, or 8-byte representation. */
#define OSSL_QUIC_VLINT_1B_MIN 0
#define OSSL_QUIC_VLINT_2B_MIN 64
#define OSSL_QUIC_VLINT_4B_MIN 16384
#define OSSL_QUIC_VLINT_8B_MIN 1073741824

/* The largest value representable in a given number of bytes. */
#define OSSL_QUIC_VLINT_1B_MAX (OSSL_QUIC_VLINT_2B_MIN - 1)
#define OSSL_QUIC_VLINT_2B_MAX (OSSL_QUIC_VLINT_4B_MIN - 1)
#define OSSL_QUIC_VLINT_4B_MAX (OSSL_QUIC_VLINT_8B_MIN - 1)
#define OSSL_QUIC_VLINT_8B_MAX (((uint64_t)1 << 62) - 1)

/* The largest value representable as a variable-length integer. */
#define OSSL_QUIC_VLINT_MAX    OSSL_QUIC_VLINT_8B_MAX

/*
 * Returns the number of bytes needed to encode v in the QUIC variable-length
 * integer encoding.
 *
 * Returns 0 if v exceeds OSSL_QUIC_VLINT_MAX.
 */
static ossl_unused ossl_inline size_t ossl_quic_vlint_encode_len(uint64_t v)
{
    if (v < OSSL_QUIC_VLINT_2B_MIN)
        return 1;

    if (v < OSSL_QUIC_VLINT_4B_MIN)
        return 2;

    if (v < OSSL_QUIC_VLINT_8B_MIN)
        return 4;

    if (v <= OSSL_QUIC_VLINT_MAX)
        return 8;

    return 0;
}

/*
 * This function writes a QUIC varable-length encoded integer to buf.
 * The smallest usable representation is used.
 *
 * It is the caller's responsibility to ensure that the buffer is big enough by
 * calling ossl_quic_vlint_encode_len(v) before calling this function.
 *
 * Precondition: buf is at least ossl_quic_vlint_enc_len(v) bytes in size
 *   (unchecked)
 * Precondition: v does not exceed OSSL_QUIC_VLINT_MAX
 *   (unchecked)
 */
void ossl_quic_vlint_encode(unsigned char *buf, uint64_t v);

/*
 * This function writes a QUIC variable-length encoded integer to buf. The
 * specified number of bytes n are used for the encoding, which means that the
 * encoded value may take up more space than necessary.
 *
 * It is the caller's responsibility to ensure that the buffer is of at least n
 * bytes, and that v is representable by a n-byte QUIC variable-length integer.
 * The representable ranges are:
 *
 *   1-byte encoding: [0, 2** 6-1]
 *   2-byte encoding: [0, 2**14-1]
 *   4-byte encoding: [0, 2**30-1]
 *   8-byte encoding: [0, 2**62-1]
 *
 * Precondition: buf is at least n bytes in size (unchecked)
 * Precondition: v does not exceed the representable range
 *   (ossl_quic_vlint_encode_len(v) <= n) (unchecked)
 * Precondition: v does not exceed OSSL_QUIC_VLINT_MAX
 *   (unchecked)
 */
void ossl_quic_vlint_encode_n(unsigned char *buf, uint64_t v, int n);

/*
 * Given the first byte of an encoded QUIC variable-length integer, returns
 * the number of bytes comprising the encoded integer, including the first
 * byte.
 */
static ossl_unused ossl_inline size_t ossl_quic_vlint_decode_len(uint8_t first_byte)
{
    return (size_t)(1U << ((first_byte & 0xC0) >> 6));
}

/*
 * Given a buffer containing an encoded QUIC variable-length integer, returns
 * the decoded value. The buffer must be of at least
 * ossl_quic_vlint_decode_len(buf[0]) bytes in size, and the caller is responsible
 * for checking this.
 *
 * Precondition: buf is at least ossl_quic_vlint_decode_len(buf[0]) bytes in size
 *   (unchecked)
 */
uint64_t ossl_quic_vlint_decode_unchecked(const unsigned char *buf);

/*
 * Given a buffer buf of buf_len bytes in length, attempts to decode an encoded
 * QUIC variable-length integer at the start of the buffer and writes the result
 * to *v. If buf_len is inadequate, suggesting a truncated encoded integer, the
 * function fails and 0 is returned. Otherwise, returns the number of bytes
 * consumed.
 *
 * Precondition: buf is at least buf_len bytes in size
 * Precondition: v (unchecked)
 */
int ossl_quic_vlint_decode(const unsigned char *buf, size_t buf_len, uint64_t *v);

# endif

#endif

Coverage Report

Created: 2025-10-28 06:56

Line	Count	Source
1		/*
2		* Copyright 2022-2025 The OpenSSL Project Authors. All Rights Reserved.
3		*
4		* Licensed under the Apache License 2.0 (the "License"). You may not use
5		* this file except in compliance with the License. You can obtain a copy
6		* in the file LICENSE in the source distribution or at
7		* https://www.openssl.org/source/license.html
8		*/
9
10		#ifndef OSSL_INTERNAL_QUIC_VLINT_H
11		# define OSSL_INTERNAL_QUIC_VLINT_H
12		# pragma once
13
14		# include "internal/e_os.h"
15
16		# ifndef OPENSSL_NO_QUIC
17
18		/* The smallest value requiring a 1, 2, 4, or 8-byte representation. */
19		#define OSSL_QUIC_VLINT_1B_MIN 0
20	0	#define OSSL_QUIC_VLINT_2B_MIN 64
21	0	#define OSSL_QUIC_VLINT_4B_MIN 16384
22	0	#define OSSL_QUIC_VLINT_8B_MIN 1073741824
23
24		/* The largest value representable in a given number of bytes. */
25	0	#define OSSL_QUIC_VLINT_1B_MAX (OSSL_QUIC_VLINT_2B_MIN - 1)
26	0	#define OSSL_QUIC_VLINT_2B_MAX (OSSL_QUIC_VLINT_4B_MIN - 1)
27	0	#define OSSL_QUIC_VLINT_4B_MAX (OSSL_QUIC_VLINT_8B_MIN - 1)
28	0	#define OSSL_QUIC_VLINT_8B_MAX (((uint64_t)1 << 62) - 1)
29
30		/* The largest value representable as a variable-length integer. */
31	0	#define OSSL_QUIC_VLINT_MAX OSSL_QUIC_VLINT_8B_MAX
32
33		/*
34		* Returns the number of bytes needed to encode v in the QUIC variable-length
35		* integer encoding.
36		*
37		* Returns 0 if v exceeds OSSL_QUIC_VLINT_MAX.
38		*/
39		static ossl_unused ossl_inline size_t ossl_quic_vlint_encode_len(uint64_t v)
40	0	{
41	0	if (v < OSSL_QUIC_VLINT_2B_MIN)
42	0	return 1;
43
44	0	if (v < OSSL_QUIC_VLINT_4B_MIN)
45	0	return 2;
46
47	0	if (v < OSSL_QUIC_VLINT_8B_MIN)
48	0	return 4;
49
50	0	if (v <= OSSL_QUIC_VLINT_MAX)
51	0	return 8;
52
53	0	return 0;
54	0	} Unexecuted instantiation: ssl_lib.c:ossl_quic_vlint_encode_len Unexecuted instantiation: t1_lib.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_impl.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_method.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_obj.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_port.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_record_rx.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_record_shared.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_record_tx.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_record_util.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_rstream.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_sf_list.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_srtm.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_sstream.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_stream_map.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_thread_assist.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_txp.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_txpim.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_wire.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_wire_pkt.c:ossl_quic_vlint_encode_len Unexecuted instantiation: rec_layer_s3.c:ossl_quic_vlint_encode_len Unexecuted instantiation: qlog_event_helpers.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_ackm.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_channel.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_demux.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_fifd.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_lcidm.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_rx_depack.c:ossl_quic_vlint_encode_len Unexecuted instantiation: packet.c:ossl_quic_vlint_encode_len Unexecuted instantiation: quic_vlint.c:ossl_quic_vlint_encode_len
55
56		/*
57		* This function writes a QUIC varable-length encoded integer to buf.
58		* The smallest usable representation is used.
59		*
60		* It is the caller's responsibility to ensure that the buffer is big enough by
61		* calling ossl_quic_vlint_encode_len(v) before calling this function.
62		*
63		* Precondition: buf is at least ossl_quic_vlint_enc_len(v) bytes in size
64		* (unchecked)
65		* Precondition: v does not exceed OSSL_QUIC_VLINT_MAX
66		* (unchecked)
67		*/
68		void ossl_quic_vlint_encode(unsigned char *buf, uint64_t v);
69
70		/*
71		* This function writes a QUIC variable-length encoded integer to buf. The
72		* specified number of bytes n are used for the encoding, which means that the
73		* encoded value may take up more space than necessary.
74		*
75		* It is the caller's responsibility to ensure that the buffer is of at least n
76		* bytes, and that v is representable by a n-byte QUIC variable-length integer.
77		* The representable ranges are:
78		*
79		* 1-byte encoding: [0, 2** 6-1]
80		* 2-byte encoding: [0, 2**14-1]
81		* 4-byte encoding: [0, 2**30-1]
82		* 8-byte encoding: [0, 2**62-1]
83		*
84		* Precondition: buf is at least n bytes in size (unchecked)
85		* Precondition: v does not exceed the representable range
86		* (ossl_quic_vlint_encode_len(v) <= n) (unchecked)
87		* Precondition: v does not exceed OSSL_QUIC_VLINT_MAX
88		* (unchecked)
89		*/
90		void ossl_quic_vlint_encode_n(unsigned char *buf, uint64_t v, int n);
91
92		/*
93		* Given the first byte of an encoded QUIC variable-length integer, returns
94		* the number of bytes comprising the encoded integer, including the first
95		* byte.
96		*/
97		static ossl_unused ossl_inline size_t ossl_quic_vlint_decode_len(uint8_t first_byte)
98	0	{
99	0	return (size_t)(1U << ((first_byte & 0xC0) >> 6));
100	0	} Unexecuted instantiation: ssl_lib.c:ossl_quic_vlint_decode_len Unexecuted instantiation: t1_lib.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_impl.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_method.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_obj.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_port.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_record_rx.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_record_shared.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_record_tx.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_record_util.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_rstream.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_sf_list.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_srtm.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_sstream.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_stream_map.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_thread_assist.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_txp.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_txpim.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_wire.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_wire_pkt.c:ossl_quic_vlint_decode_len Unexecuted instantiation: rec_layer_s3.c:ossl_quic_vlint_decode_len Unexecuted instantiation: qlog_event_helpers.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_ackm.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_channel.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_demux.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_fifd.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_lcidm.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_rx_depack.c:ossl_quic_vlint_decode_len Unexecuted instantiation: packet.c:ossl_quic_vlint_decode_len Unexecuted instantiation: quic_vlint.c:ossl_quic_vlint_decode_len
101
102		/*
103		* Given a buffer containing an encoded QUIC variable-length integer, returns
104		* the decoded value. The buffer must be of at least
105		* ossl_quic_vlint_decode_len(buf[0]) bytes in size, and the caller is responsible
106		* for checking this.
107		*
108		* Precondition: buf is at least ossl_quic_vlint_decode_len(buf[0]) bytes in size
109		* (unchecked)
110		*/
111		uint64_t ossl_quic_vlint_decode_unchecked(const unsigned char *buf);
112
113		/*
114		* Given a buffer buf of buf_len bytes in length, attempts to decode an encoded
115		* QUIC variable-length integer at the start of the buffer and writes the result
116		* to *v. If buf_len is inadequate, suggesting a truncated encoded integer, the
117		* function fails and 0 is returned. Otherwise, returns the number of bytes
118		* consumed.
119		*
120		* Precondition: buf is at least buf_len bytes in size
121		* Precondition: v (unchecked)
122		*/
123		int ossl_quic_vlint_decode(const unsigned char buf, size_t buf_len, uint64_t v);
124
125		# endif
126
127		#endif