1/* $OpenBSD: tls_content.c,v 1.2 2022/11/11 17:15:27 jsing Exp $ */ 2/* 3 * Copyright (c) 2020 Joel Sing <jsing@openbsd.org> 4 * 5 * Permission to use, copy, modify, and 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 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18#include <stdlib.h> 19#include <string.h> 20 21#include "tls_content.h" 22 23/* Content from a TLS record. */ 24struct tls_content { 25 uint8_t type; 26 uint16_t epoch; 27 28 const uint8_t *data; 29 size_t data_len; 30 CBS cbs; 31}; 32 33struct tls_content * 34tls_content_new(void) 35{ 36 return calloc(1, sizeof(struct tls_content)); 37} 38 39void 40tls_content_clear(struct tls_content *content) 41{ 42 freezero((void *)content->data, content->data_len); 43 memset(content, 0, sizeof(*content)); 44} 45 46void 47tls_content_free(struct tls_content *content) 48{ 49 if (content == NULL) 50 return; 51 52 tls_content_clear(content); 53 54 freezero(content, sizeof(struct tls_content)); 55} 56 57CBS * 58tls_content_cbs(struct tls_content *content) 59{ 60 return &content->cbs; 61} 62 63int 64tls_content_equal(struct tls_content *content, const uint8_t *buf, size_t n) 65{ 66 return CBS_mem_equal(&content->cbs, buf, n); 67} 68 69size_t 70tls_content_remaining(struct tls_content *content) 71{ 72 return CBS_len(&content->cbs); 73} 74 75uint8_t 76tls_content_type(struct tls_content *content) 77{ 78 return content->type; 79} 80 81int 82tls_content_dup_data(struct tls_content *content, uint8_t type, 83 const uint8_t *data, size_t data_len) 84{ 85 uint8_t *dup; 86 87 if ((dup = calloc(1, data_len)) == NULL) 88 return 0; 89 memcpy(dup, data, data_len); 90 91 tls_content_set_data(content, type, dup, data_len); 92 93 return 1; 94} 95 96uint16_t 97tls_content_epoch(struct tls_content *content) 98{ 99 return content->epoch; 100} 101 102void 103tls_content_set_epoch(struct tls_content *content, uint16_t epoch) 104{ 105 content->epoch = epoch; 106} 107 108void 109tls_content_set_data(struct tls_content *content, uint8_t type, 110 const uint8_t *data, size_t data_len) 111{ 112 tls_content_clear(content); 113 114 content->type = type; 115 content->data = data; 116 content->data_len = data_len; 117 118 CBS_init(&content->cbs, content->data, content->data_len); 119} 120 121int 122tls_content_set_bounds(struct tls_content *content, size_t offset, size_t len) 123{ 124 size_t content_len; 125 126 content_len = offset + len; 127 if (content_len < len) 128 return 0; 129 if (content_len > content->data_len) 130 return 0; 131 132 CBS_init(&content->cbs, content->data, content_len); 133 return CBS_skip(&content->cbs, offset); 134} 135 136static ssize_t 137tls_content_read_internal(struct tls_content *content, uint8_t *buf, size_t n, 138 int peek) 139{ 140 if (n > CBS_len(&content->cbs)) 141 n = CBS_len(&content->cbs); 142 143 /* XXX - CBS_memcpy? CBS_copy_bytes? */ 144 memcpy(buf, CBS_data(&content->cbs), n); 145 146 if (!peek) { 147 if (!CBS_skip(&content->cbs, n)) 148 return -1; 149 } 150 151 return n; 152} 153 154ssize_t 155tls_content_peek(struct tls_content *content, uint8_t *buf, size_t n) 156{ 157 return tls_content_read_internal(content, buf, n, 1); 158} 159 160ssize_t 161tls_content_read(struct tls_content *content, uint8_t *buf, size_t n) 162{ 163 return tls_content_read_internal(content, buf, n, 0); 164} 165