1 /* $OpenBSD: tasn_utl.c,v 1.17 2022/05/12 19:55:58 jsing Exp $ */ 2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL 3 * project 2000. 4 */ 5 /* ==================================================================== 6 * Copyright (c) 2000-2004 The OpenSSL Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * licensing@OpenSSL.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 * 53 * This product includes cryptographic software written by Eric Young 54 * (eay@cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh@cryptsoft.com). 56 * 57 */ 58 59 #include <limits.h> 60 #include <stddef.h> 61 #include <string.h> 62 63 #include <openssl/asn1.h> 64 #include <openssl/asn1t.h> 65 #include <openssl/objects.h> 66 #include <openssl/err.h> 67 68 #include "bytestring.h" 69 70 /* Utility functions for manipulating fields and offsets */ 71 72 /* Add 'offset' to 'addr' */ 73 #define offset2ptr(addr, offset) (void *)(((char *) addr) + offset) 74 75 /* Given an ASN1_ITEM CHOICE type return 76 * the selector value 77 */ 78 79 int 80 asn1_get_choice_selector(ASN1_VALUE **pval, const ASN1_ITEM *it) 81 { 82 int *sel = offset2ptr(*pval, it->utype); 83 return *sel; 84 } 85 86 /* Given an ASN1_ITEM CHOICE type set 87 * the selector value, return old value. 88 */ 89 90 int 91 asn1_set_choice_selector(ASN1_VALUE **pval, int value, const ASN1_ITEM *it) 92 { 93 int *sel, ret; 94 sel = offset2ptr(*pval, it->utype); 95 ret = *sel; 96 *sel = value; 97 return ret; 98 } 99 100 /* Do reference counting. The value 'op' decides what to do. 101 * if it is +1 then the count is incremented. If op is 0 count is 102 * set to 1. If op is -1 count is decremented and the return value 103 * is the current refrence count or 0 if no reference count exists. 104 */ 105 106 int 107 asn1_do_lock(ASN1_VALUE **pval, int op, const ASN1_ITEM *it) 108 { 109 const ASN1_AUX *aux; 110 int *lck, ret; 111 112 if ((it->itype != ASN1_ITYPE_SEQUENCE) && 113 (it->itype != ASN1_ITYPE_NDEF_SEQUENCE)) 114 return 0; 115 aux = it->funcs; 116 if (!aux || !(aux->flags & ASN1_AFLG_REFCOUNT)) 117 return 0; 118 lck = offset2ptr(*pval, aux->ref_offset); 119 if (op == 0) { 120 *lck = 1; 121 return 1; 122 } 123 ret = CRYPTO_add(lck, op, aux->ref_lock); 124 return ret; 125 } 126 127 static ASN1_ENCODING * 128 asn1_get_enc_ptr(ASN1_VALUE **pval, const ASN1_ITEM *it) 129 { 130 const ASN1_AUX *aux = it->funcs; 131 132 if (pval == NULL || *pval == NULL) 133 return NULL; 134 135 if (aux == NULL || (aux->flags & ASN1_AFLG_ENCODING) == 0) 136 return NULL; 137 138 return offset2ptr(*pval, aux->enc_offset); 139 } 140 141 void 142 asn1_enc_init(ASN1_VALUE **pval, const ASN1_ITEM *it) 143 { 144 ASN1_ENCODING *aenc; 145 146 if ((aenc = asn1_get_enc_ptr(pval, it)) == NULL) 147 return; 148 149 aenc->enc = NULL; 150 aenc->len = 0; 151 aenc->modified = 1; 152 } 153 154 static void 155 asn1_enc_clear(ASN1_ENCODING *aenc) 156 { 157 freezero(aenc->enc, aenc->len); 158 aenc->enc = NULL; 159 aenc->len = 0; 160 aenc->modified = 1; 161 } 162 163 void 164 asn1_enc_cleanup(ASN1_VALUE **pval, const ASN1_ITEM *it) 165 { 166 ASN1_ENCODING *aenc; 167 168 if ((aenc = asn1_get_enc_ptr(pval, it)) == NULL) 169 return; 170 171 asn1_enc_clear(aenc); 172 } 173 174 int 175 asn1_enc_save(ASN1_VALUE **pval, CBS *cbs, const ASN1_ITEM *it) 176 { 177 ASN1_ENCODING *aenc; 178 uint8_t *data = NULL; 179 size_t data_len = 0; 180 181 if ((aenc = asn1_get_enc_ptr(pval, it)) == NULL) 182 return 1; 183 184 asn1_enc_clear(aenc); 185 186 if (!CBS_stow(cbs, &data, &data_len)) 187 return 0; 188 if (data_len > LONG_MAX) { 189 freezero(data, data_len); 190 return 0; 191 } 192 193 aenc->enc = data; 194 aenc->len = (long)data_len; 195 aenc->modified = 0; 196 197 return 1; 198 } 199 200 int 201 asn1_enc_restore(int *out_len, unsigned char **out, ASN1_VALUE **pval, 202 const ASN1_ITEM *it) 203 { 204 ASN1_ENCODING *aenc; 205 206 if ((aenc = asn1_get_enc_ptr(pval, it)) == NULL) 207 return 0; 208 209 if (aenc->modified) 210 return 0; 211 212 if (out != NULL) { 213 memcpy(*out, aenc->enc, aenc->len); 214 *out += aenc->len; 215 } 216 217 if (out_len != NULL) 218 *out_len = aenc->len; 219 220 return 1; 221 } 222 223 /* Given an ASN1_TEMPLATE get a pointer to a field */ 224 ASN1_VALUE ** 225 asn1_get_field_ptr(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt) 226 { 227 ASN1_VALUE **pvaltmp; 228 229 pvaltmp = offset2ptr(*pval, tt->offset); 230 /* NOTE for BOOLEAN types the field is just a plain 231 * int so we can't return int **, so settle for 232 * (int *). 233 */ 234 return pvaltmp; 235 } 236 237 /* Handle ANY DEFINED BY template, find the selector, look up 238 * the relevant ASN1_TEMPLATE in the table and return it. 239 */ 240 241 const ASN1_TEMPLATE * 242 asn1_do_adb(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt, int nullerr) 243 { 244 const ASN1_ADB *adb; 245 const ASN1_ADB_TABLE *atbl; 246 long selector; 247 ASN1_VALUE **sfld; 248 int i; 249 250 if (!(tt->flags & ASN1_TFLG_ADB_MASK)) 251 return tt; 252 253 /* Else ANY DEFINED BY ... get the table */ 254 adb = (const ASN1_ADB *)tt->item; 255 256 /* Get the selector field */ 257 sfld = offset2ptr(*pval, adb->offset); 258 259 /* Check if NULL */ 260 if (!sfld) { 261 if (!adb->null_tt) 262 goto err; 263 return adb->null_tt; 264 } 265 266 /* Convert type to a long: 267 * NB: don't check for NID_undef here because it 268 * might be a legitimate value in the table 269 */ 270 if (tt->flags & ASN1_TFLG_ADB_OID) 271 selector = OBJ_obj2nid((ASN1_OBJECT *)*sfld); 272 else 273 selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld); 274 275 /* Try to find matching entry in table 276 * Maybe should check application types first to 277 * allow application override? Might also be useful 278 * to have a flag which indicates table is sorted and 279 * we can do a binary search. For now stick to a 280 * linear search. 281 */ 282 283 for (atbl = adb->tbl, i = 0; i < adb->tblcount; i++, atbl++) 284 if (atbl->value == selector) 285 return &atbl->tt; 286 287 /* FIXME: need to search application table too */ 288 289 /* No match, return default type */ 290 if (!adb->default_tt) 291 goto err; 292 return adb->default_tt; 293 294 err: 295 /* FIXME: should log the value or OID of unsupported type */ 296 if (nullerr) 297 ASN1error(ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE); 298 return NULL; 299 } 300