summaryrefslogtreecommitdiffstats
path: root/lib/ngtcp2_ppe.h
blob: bf220df37c14f2b8277861461cefe6af58bd35ca (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
/*
 * ngtcp2
 *
 * Copyright (c) 2017 ngtcp2 contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#ifndef NGTCP2_PPE_H
#define NGTCP2_PPE_H

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif /* HAVE_CONFIG_H */

#include <ngtcp2/ngtcp2.h>

#include "ngtcp2_pkt.h"
#include "ngtcp2_buf.h"
#include "ngtcp2_crypto.h"

/*
 * ngtcp2_ppe is the Protected Packet Encoder.
 */
typedef struct ngtcp2_ppe {
  ngtcp2_buf buf;
  ngtcp2_crypto_cc *cc;
  /* hdlen is the number of bytes for packet header written in buf. */
  size_t hdlen;
  /* len_offset is the offset to Length field. */
  size_t len_offset;
  /* pkt_num_offset is the offset to packet number field. */
  size_t pkt_num_offset;
  /* pkt_numlen is the number of bytes used to encode a packet
     number */
  size_t pkt_numlen;
  /* sample_offset is the offset to sample for packet number
     encryption. */
  size_t sample_offset;
  /* pkt_num is the packet number written in buf. */
  int64_t pkt_num;
  /* nonce is the buffer to store nonce.  It should be equal or longer
     than then length of IV. */
  uint8_t nonce[32];
} ngtcp2_ppe;

/*
 * ngtcp2_ppe_init initializes |ppe| with the given buffer.
 */
void ngtcp2_ppe_init(ngtcp2_ppe *ppe, uint8_t *out, size_t outlen,
                     ngtcp2_crypto_cc *cc);

/*
 * ngtcp2_ppe_encode_hd encodes |hd|.
 *
 * This function returns 0 if it succeeds, or one of the following
 * negative error codes:
 *
 * NGTCP2_ERR_NOBUF
 *     The buffer is too small.
 */
int ngtcp2_ppe_encode_hd(ngtcp2_ppe *ppe, const ngtcp2_pkt_hd *hd);

/*
 * ngtcp2_ppe_encode_frame encodes |fr|.
 *
 * This function returns 0 if it succeeds, or one of the following
 * negative error codes:
 *
 * NGTCP2_ERR_NOBUF
 *     The buffer is too small.
 */
int ngtcp2_ppe_encode_frame(ngtcp2_ppe *ppe, ngtcp2_frame *fr);

/*
 * ngtcp2_ppe_final encrypts QUIC packet payload.  If |**ppkt| is not
 * NULL, the pointer to the packet is assigned to it.
 *
 * This function returns the length of QUIC packet, including header,
 * and payload if it succeeds, or one of the following negative error
 * codes:
 *
 * NGTCP2_ERR_CALLBACK_FAILURE
 *     User-defined callback function failed.
 */
ngtcp2_ssize ngtcp2_ppe_final(ngtcp2_ppe *ppe, const uint8_t **ppkt);

/*
 * ngtcp2_ppe_left returns the number of bytes left to write
 * additional frames.  This does not count AEAD overhead.
 */
size_t ngtcp2_ppe_left(ngtcp2_ppe *ppe);

/*
 * ngtcp2_ppe_pktlen returns the provisional packet length.  It
 * includes AEAD overhead.
 */
size_t ngtcp2_ppe_pktlen(ngtcp2_ppe *ppe);

/**
 * @function
 *
 * `ngtcp2_ppe_padding` encodes PADDING frames to the end of the
 * buffer.  This function returns the number of bytes padded.
 */
size_t ngtcp2_ppe_padding(ngtcp2_ppe *ppe);

/*
 * ngtcp2_ppe_padding_hp_sample adds PADDING frame if the current
 * payload does not have enough space for header protection sample.
 * This function should be called just before calling
 * ngtcp2_ppe_final().
 *
 * This function returns the number of bytes added as padding.
 */
size_t ngtcp2_ppe_padding_hp_sample(ngtcp2_ppe *ppe);

/*
 * ngtcp2_ppe_padding_size adds PADDING frame so that the size of QUIC
 * packet is at least |n| bytes long.  If it is unable to add PADDING
 * in that way, this function still adds PADDING frame as much as
 * possible.  This function should be called just before calling
 * ngtcp2_ppe_final().  For Short packet, this function should be
 * called instead of ngtcp2_ppe_padding_hp_sample.
 *
 * This function returns the number of bytes added as padding.
 */
size_t ngtcp2_ppe_padding_size(ngtcp2_ppe *ppe, size_t n);

/*
 * ngtcp2_ppe_ensure_hp_sample returns nonzero if the buffer has
 * enough space for header protection sample.  This should be called
 * right after packet header is written.
 */
int ngtcp2_ppe_ensure_hp_sample(ngtcp2_ppe *ppe);

#endif /* NGTCP2_PPE_H */