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. */ 24 struct 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 33 struct tls_content * 34 tls_content_new(void) 35 { 36 return calloc(1, sizeof(struct tls_content)); 37 } 38 39 void 40 tls_content_clear(struct tls_content *content) 41 { 42 freezero((void *)content->data, content->data_len); 43 memset(content, 0, sizeof(*content)); 44 } 45 46 void 47 tls_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 57 CBS * 58 tls_content_cbs(struct tls_content *content) 59 { 60 return &content->cbs; 61 } 62 63 int 64 tls_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 69 size_t 70 tls_content_remaining(struct tls_content *content) 71 { 72 return CBS_len(&content->cbs); 73 } 74 75 uint8_t 76 tls_content_type(struct tls_content *content) 77 { 78 return content->type; 79 } 80 81 int 82 tls_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 96 uint16_t 97 tls_content_epoch(struct tls_content *content) 98 { 99 return content->epoch; 100 } 101 102 void 103 tls_content_set_epoch(struct tls_content *content, uint16_t epoch) 104 { 105 content->epoch = epoch; 106 } 107 108 void 109 tls_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 } 120 121 int 122 tls_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 } 135 136 static ssize_t 137 tls_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 } 153 154 ssize_t 155 tls_content_peek(struct tls_content *content, uint8_t *buf, size_t n) 156 { 157 return tls_content_read_internal(content, buf, n, 1); 158 } 159 160 ssize_t 161 tls_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