1 /* 2 * X.509 base functions for creating certificates / CSRs 3 * 4 * Copyright The Mbed TLS Contributors 5 * SPDX-License-Identifier: Apache-2.0 6 * 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may 8 * not use this file except in compliance with the License. 9 * You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, software 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 * See the License for the specific language governing permissions and 17 * limitations under the License. 18 */ 19 20 #include "common.h" 21 22 #if defined(MBEDTLS_X509_CREATE_C) 23 24 #include "mbedtls/x509.h" 25 #include "mbedtls/asn1write.h" 26 #include "mbedtls/error.h" 27 #include "mbedtls/oid.h" 28 29 #include <string.h> 30 31 /* Structure linking OIDs for X.509 DN AttributeTypes to their 32 * string representations and default string encodings used by Mbed TLS. */ 33 typedef struct { 34 const char *name; /* String representation of AttributeType, e.g. 35 * "CN" or "emailAddress". */ 36 size_t name_len; /* Length of 'name', without trailing 0 byte. */ 37 const char *oid; /* String representation of OID of AttributeType, 38 * as per RFC 5280, Appendix A.1. */ 39 int default_tag; /* The default character encoding used for the 40 * given attribute type, e.g. 41 * MBEDTLS_ASN1_UTF8_STRING for UTF-8. */ 42 } x509_attr_descriptor_t; 43 44 #define ADD_STRLEN( s ) s, sizeof( s ) - 1 45 46 /* X.509 DN attributes from RFC 5280, Appendix A.1. */ 47 static const x509_attr_descriptor_t x509_attrs[] = 48 { 49 { ADD_STRLEN( "CN" ), 50 MBEDTLS_OID_AT_CN, MBEDTLS_ASN1_UTF8_STRING }, 51 { ADD_STRLEN( "commonName" ), 52 MBEDTLS_OID_AT_CN, MBEDTLS_ASN1_UTF8_STRING }, 53 { ADD_STRLEN( "C" ), 54 MBEDTLS_OID_AT_COUNTRY, MBEDTLS_ASN1_PRINTABLE_STRING }, 55 { ADD_STRLEN( "countryName" ), 56 MBEDTLS_OID_AT_COUNTRY, MBEDTLS_ASN1_PRINTABLE_STRING }, 57 { ADD_STRLEN( "O" ), 58 MBEDTLS_OID_AT_ORGANIZATION, MBEDTLS_ASN1_UTF8_STRING }, 59 { ADD_STRLEN( "organizationName" ), 60 MBEDTLS_OID_AT_ORGANIZATION, MBEDTLS_ASN1_UTF8_STRING }, 61 { ADD_STRLEN( "L" ), 62 MBEDTLS_OID_AT_LOCALITY, MBEDTLS_ASN1_UTF8_STRING }, 63 { ADD_STRLEN( "locality" ), 64 MBEDTLS_OID_AT_LOCALITY, MBEDTLS_ASN1_UTF8_STRING }, 65 { ADD_STRLEN( "R" ), 66 MBEDTLS_OID_PKCS9_EMAIL, MBEDTLS_ASN1_IA5_STRING }, 67 { ADD_STRLEN( "OU" ), 68 MBEDTLS_OID_AT_ORG_UNIT, MBEDTLS_ASN1_UTF8_STRING }, 69 { ADD_STRLEN( "organizationalUnitName" ), 70 MBEDTLS_OID_AT_ORG_UNIT, MBEDTLS_ASN1_UTF8_STRING }, 71 { ADD_STRLEN( "ST" ), 72 MBEDTLS_OID_AT_STATE, MBEDTLS_ASN1_UTF8_STRING }, 73 { ADD_STRLEN( "stateOrProvinceName" ), 74 MBEDTLS_OID_AT_STATE, MBEDTLS_ASN1_UTF8_STRING }, 75 { ADD_STRLEN( "emailAddress" ), 76 MBEDTLS_OID_PKCS9_EMAIL, MBEDTLS_ASN1_IA5_STRING }, 77 { ADD_STRLEN( "serialNumber" ), 78 MBEDTLS_OID_AT_SERIAL_NUMBER, MBEDTLS_ASN1_PRINTABLE_STRING }, 79 { ADD_STRLEN( "postalAddress" ), 80 MBEDTLS_OID_AT_POSTAL_ADDRESS, MBEDTLS_ASN1_PRINTABLE_STRING }, 81 { ADD_STRLEN( "postalCode" ), 82 MBEDTLS_OID_AT_POSTAL_CODE, MBEDTLS_ASN1_PRINTABLE_STRING }, 83 { ADD_STRLEN( "dnQualifier" ), 84 MBEDTLS_OID_AT_DN_QUALIFIER, MBEDTLS_ASN1_PRINTABLE_STRING }, 85 { ADD_STRLEN( "title" ), 86 MBEDTLS_OID_AT_TITLE, MBEDTLS_ASN1_UTF8_STRING }, 87 { ADD_STRLEN( "surName" ), 88 MBEDTLS_OID_AT_SUR_NAME, MBEDTLS_ASN1_UTF8_STRING }, 89 { ADD_STRLEN( "SN" ), 90 MBEDTLS_OID_AT_SUR_NAME, MBEDTLS_ASN1_UTF8_STRING }, 91 { ADD_STRLEN( "givenName" ), 92 MBEDTLS_OID_AT_GIVEN_NAME, MBEDTLS_ASN1_UTF8_STRING }, 93 { ADD_STRLEN( "GN" ), 94 MBEDTLS_OID_AT_GIVEN_NAME, MBEDTLS_ASN1_UTF8_STRING }, 95 { ADD_STRLEN( "initials" ), 96 MBEDTLS_OID_AT_INITIALS, MBEDTLS_ASN1_UTF8_STRING }, 97 { ADD_STRLEN( "pseudonym" ), 98 MBEDTLS_OID_AT_PSEUDONYM, MBEDTLS_ASN1_UTF8_STRING }, 99 { ADD_STRLEN( "generationQualifier" ), 100 MBEDTLS_OID_AT_GENERATION_QUALIFIER, MBEDTLS_ASN1_UTF8_STRING }, 101 { ADD_STRLEN( "domainComponent" ), 102 MBEDTLS_OID_DOMAIN_COMPONENT, MBEDTLS_ASN1_IA5_STRING }, 103 { ADD_STRLEN( "DC" ), 104 MBEDTLS_OID_DOMAIN_COMPONENT, MBEDTLS_ASN1_IA5_STRING }, 105 { NULL, 0, NULL, MBEDTLS_ASN1_NULL } 106 }; 107 108 static const x509_attr_descriptor_t *x509_attr_descr_from_name( const char *name, size_t name_len ) 109 { 110 const x509_attr_descriptor_t *cur; 111 112 for( cur = x509_attrs; cur->name != NULL; cur++ ) 113 if( cur->name_len == name_len && 114 strncmp( cur->name, name, name_len ) == 0 ) 115 break; 116 117 if ( cur->name == NULL ) 118 return( NULL ); 119 120 return( cur ); 121 } 122 123 int mbedtls_x509_string_to_names( mbedtls_asn1_named_data **head, const char *name ) 124 { 125 int ret = 0; 126 const char *s = name, *c = s; 127 const char *end = s + strlen( s ); 128 const char *oid = NULL; 129 const x509_attr_descriptor_t* attr_descr = NULL; 130 int in_tag = 1; 131 char data[MBEDTLS_X509_MAX_DN_NAME_SIZE]; 132 char *d = data; 133 134 /* Clear existing chain if present */ 135 mbedtls_asn1_free_named_data_list( head ); 136 137 while( c <= end ) 138 { 139 if( in_tag && *c == '=' ) 140 { 141 if( ( attr_descr = x509_attr_descr_from_name( s, c - s ) ) == NULL ) 142 { 143 ret = MBEDTLS_ERR_X509_UNKNOWN_OID; 144 goto exit; 145 } 146 147 oid = attr_descr->oid; 148 s = c + 1; 149 in_tag = 0; 150 d = data; 151 } 152 153 if( !in_tag && *c == '\\' && c != end ) 154 { 155 c++; 156 157 /* Check for valid escaped characters */ 158 if( c == end || *c != ',' ) 159 { 160 ret = MBEDTLS_ERR_X509_INVALID_NAME; 161 goto exit; 162 } 163 } 164 else if( !in_tag && ( *c == ',' || c == end ) ) 165 { 166 mbedtls_asn1_named_data* cur = 167 mbedtls_asn1_store_named_data( head, oid, strlen( oid ), 168 (unsigned char *) data, 169 d - data ); 170 171 if(cur == NULL ) 172 { 173 return( MBEDTLS_ERR_X509_ALLOC_FAILED ); 174 } 175 176 // set tagType 177 cur->val.tag = attr_descr->default_tag; 178 179 while( c < end && *(c + 1) == ' ' ) 180 c++; 181 182 s = c + 1; 183 in_tag = 1; 184 } 185 186 if( !in_tag && s != c + 1 ) 187 { 188 *(d++) = *c; 189 190 if( d - data == MBEDTLS_X509_MAX_DN_NAME_SIZE ) 191 { 192 ret = MBEDTLS_ERR_X509_INVALID_NAME; 193 goto exit; 194 } 195 } 196 197 c++; 198 } 199 200 exit: 201 202 return( ret ); 203 } 204 205 /* The first byte of the value in the mbedtls_asn1_named_data structure is reserved 206 * to store the critical boolean for us 207 */ 208 int mbedtls_x509_set_extension( mbedtls_asn1_named_data **head, const char *oid, size_t oid_len, 209 int critical, const unsigned char *val, size_t val_len ) 210 { 211 mbedtls_asn1_named_data *cur; 212 213 if( ( cur = mbedtls_asn1_store_named_data( head, oid, oid_len, 214 NULL, val_len + 1 ) ) == NULL ) 215 { 216 return( MBEDTLS_ERR_X509_ALLOC_FAILED ); 217 } 218 219 cur->val.p[0] = critical; 220 memcpy( cur->val.p + 1, val, val_len ); 221 222 return( 0 ); 223 } 224 225 /* 226 * RelativeDistinguishedName ::= 227 * SET OF AttributeTypeAndValue 228 * 229 * AttributeTypeAndValue ::= SEQUENCE { 230 * type AttributeType, 231 * value AttributeValue } 232 * 233 * AttributeType ::= OBJECT IDENTIFIER 234 * 235 * AttributeValue ::= ANY DEFINED BY AttributeType 236 */ 237 static int x509_write_name( unsigned char **p, unsigned char *start, mbedtls_asn1_named_data* cur_name) 238 { 239 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 240 size_t len = 0; 241 const char *oid = (const char*)cur_name->oid.p; 242 size_t oid_len = cur_name->oid.len; 243 const unsigned char *name = cur_name->val.p; 244 size_t name_len = cur_name->val.len; 245 246 // Write correct string tag and value 247 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tagged_string( p, start, 248 cur_name->val.tag, 249 (const char *) name, 250 name_len ) ); 251 // Write OID 252 // 253 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( p, start, oid, 254 oid_len ) ); 255 256 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); 257 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, 258 MBEDTLS_ASN1_CONSTRUCTED | 259 MBEDTLS_ASN1_SEQUENCE ) ); 260 261 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); 262 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, 263 MBEDTLS_ASN1_CONSTRUCTED | 264 MBEDTLS_ASN1_SET ) ); 265 266 return( (int) len ); 267 } 268 269 int mbedtls_x509_write_names( unsigned char **p, unsigned char *start, 270 mbedtls_asn1_named_data *first ) 271 { 272 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 273 size_t len = 0; 274 mbedtls_asn1_named_data *cur = first; 275 276 while( cur != NULL ) 277 { 278 MBEDTLS_ASN1_CHK_ADD( len, x509_write_name( p, start, cur ) ); 279 cur = cur->next; 280 } 281 282 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); 283 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_CONSTRUCTED | 284 MBEDTLS_ASN1_SEQUENCE ) ); 285 286 return( (int) len ); 287 } 288 289 int mbedtls_x509_write_sig( unsigned char **p, unsigned char *start, 290 const char *oid, size_t oid_len, 291 unsigned char *sig, size_t size ) 292 { 293 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 294 size_t len = 0; 295 296 if( *p < start || (size_t)( *p - start ) < size ) 297 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 298 299 len = size; 300 (*p) -= len; 301 memcpy( *p, sig, len ); 302 303 if( *p - start < 1 ) 304 return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); 305 306 *--(*p) = 0; 307 len += 1; 308 309 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); 310 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_BIT_STRING ) ); 311 312 // Write OID 313 // 314 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_algorithm_identifier( p, start, oid, 315 oid_len, 0 ) ); 316 317 return( (int) len ); 318 } 319 320 static int x509_write_extension( unsigned char **p, unsigned char *start, 321 mbedtls_asn1_named_data *ext ) 322 { 323 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 324 size_t len = 0; 325 326 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, ext->val.p + 1, 327 ext->val.len - 1 ) ); 328 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, ext->val.len - 1 ) ); 329 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OCTET_STRING ) ); 330 331 if( ext->val.p[0] != 0 ) 332 { 333 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_bool( p, start, 1 ) ); 334 } 335 336 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, ext->oid.p, 337 ext->oid.len ) ); 338 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, ext->oid.len ) ); 339 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OID ) ); 340 341 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); 342 MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_CONSTRUCTED | 343 MBEDTLS_ASN1_SEQUENCE ) ); 344 345 return( (int) len ); 346 } 347 348 /* 349 * Extension ::= SEQUENCE { 350 * extnID OBJECT IDENTIFIER, 351 * critical BOOLEAN DEFAULT FALSE, 352 * extnValue OCTET STRING 353 * -- contains the DER encoding of an ASN.1 value 354 * -- corresponding to the extension type identified 355 * -- by extnID 356 * } 357 */ 358 int mbedtls_x509_write_extensions( unsigned char **p, unsigned char *start, 359 mbedtls_asn1_named_data *first ) 360 { 361 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; 362 size_t len = 0; 363 mbedtls_asn1_named_data *cur_ext = first; 364 365 while( cur_ext != NULL ) 366 { 367 MBEDTLS_ASN1_CHK_ADD( len, x509_write_extension( p, start, cur_ext ) ); 368 cur_ext = cur_ext->next; 369 } 370 371 return( (int) len ); 372 } 373 374 #endif /* MBEDTLS_X509_CREATE_C */ 375