1 static const char rcsid[] = "$Header: /proj/cvs/prod/libbind/dst/support.c,v 1.6 2005/10/11 00:10:13 marka Exp $"; 2 3 4 /* 5 * Portions Copyright (c) 1995-1998 by Trusted Information Systems, Inc. 6 * 7 * Permission to use, copy modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND TRUSTED INFORMATION SYSTEMS 12 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL 13 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL 14 * TRUSTED INFORMATION SYSTEMS BE LIABLE FOR ANY SPECIAL, DIRECT, 15 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING 16 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, 17 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION 18 * WITH THE USE OR PERFORMANCE OF THE SOFTWARE. 19 */ 20 21 #include "port_before.h" 22 23 #include <stdio.h> 24 #include <unistd.h> 25 #include <memory.h> 26 #include <string.h> 27 #include <errno.h> 28 #include <sys/stat.h> 29 #include <netinet/in.h> 30 #include <arpa/nameser.h> 31 #include <resolv.h> 32 33 #include "dst_internal.h" 34 35 #include "port_after.h" 36 37 /*% 38 * dst_s_verify_str() 39 * Validate that the input string(*str) is at the head of the input 40 * buffer(**buf). If so, move the buffer head pointer (*buf) to 41 * the first byte of data following the string(*str). 42 * Parameters 43 * buf Input buffer. 44 * str Input string. 45 * Return 46 * 0 *str is not the head of **buff 47 * 1 *str is the head of **buff, *buf is is advanced to 48 * the tail of **buf. 49 */ 50 51 int 52 dst_s_verify_str(const char **buf, const char *str) 53 { 54 int b, s; 55 if (*buf == NULL) /*%< error checks */ 56 return (0); 57 if (str == NULL || *str == '\0') 58 return (1); 59 60 b = strlen(*buf); /*%< get length of strings */ 61 s = strlen(str); 62 if (s > b || strncmp(*buf, str, s)) /*%< check if same */ 63 return (0); /*%< not a match */ 64 (*buf) += s; /*%< advance pointer */ 65 return (1); 66 } 67 68 /*% 69 * dst_s_calculate_bits 70 * Given a binary number represented in a u_char[], determine 71 * the number of significant bits used. 72 * Parameters 73 * str An input character string containing a binary number. 74 * max_bits The maximum possible significant bits. 75 * Return 76 * N The number of significant bits in str. 77 */ 78 79 int 80 dst_s_calculate_bits(const u_char *str, const int max_bits) 81 { 82 const u_char *p = str; 83 u_char i, j = 0x80; 84 int bits; 85 for (bits = max_bits; *p == 0x00 && bits > 0; p++) 86 bits -= 8; 87 for (i = *p; (i & j) != j; j >>= 1) 88 bits--; 89 return (bits); 90 } 91 92 /*% 93 * calculates a checksum used in dst for an id. 94 * takes an array of bytes and a length. 95 * returns a 16 bit checksum. 96 */ 97 u_int16_t 98 dst_s_id_calc(const u_char *key, const int keysize) 99 { 100 u_int32_t ac; 101 const u_char *kp = key; 102 int size = keysize; 103 104 if (!key || (keysize <= 0)) 105 return (0xffffU); 106 107 for (ac = 0; size > 1; size -= 2, kp += 2) 108 ac += ((*kp) << 8) + *(kp + 1); 109 110 if (size > 0) 111 ac += ((*kp) << 8); 112 ac += (ac >> 16) & 0xffff; 113 114 return (ac & 0xffff); 115 } 116 117 /*% 118 * dst_s_dns_key_id() Function to calculate DNSSEC footprint from KEY record 119 * rdata 120 * Input: 121 * dns_key_rdata: the raw data in wire format 122 * rdata_len: the size of the input data 123 * Output: 124 * the key footprint/id calculated from the key data 125 */ 126 u_int16_t 127 dst_s_dns_key_id(const u_char *dns_key_rdata, const int rdata_len) 128 { 129 if (!dns_key_rdata) 130 return 0; 131 132 /* compute id */ 133 if (dns_key_rdata[3] == KEY_RSA) /*%< Algorithm RSA */ 134 return dst_s_get_int16((const u_char *) 135 &dns_key_rdata[rdata_len - 3]); 136 else if (dns_key_rdata[3] == KEY_HMAC_MD5) 137 /* compatibility */ 138 return 0; 139 else 140 /* compute a checksum on the key part of the key rr */ 141 return dst_s_id_calc(dns_key_rdata, rdata_len); 142 } 143 144 /*% 145 * dst_s_get_int16 146 * This routine extracts a 16 bit integer from a two byte character 147 * string. The character string is assumed to be in network byte 148 * order and may be unaligned. The number returned is in host order. 149 * Parameter 150 * buf A two byte character string. 151 * Return 152 * The converted integer value. 153 */ 154 155 u_int16_t 156 dst_s_get_int16(const u_char *buf) 157 { 158 register u_int16_t a = 0; 159 a = ((u_int16_t)(buf[0] << 8)) | ((u_int16_t)(buf[1])); 160 return (a); 161 } 162 163 /*% 164 * dst_s_get_int32 165 * This routine extracts a 32 bit integer from a four byte character 166 * string. The character string is assumed to be in network byte 167 * order and may be unaligned. The number returned is in host order. 168 * Parameter 169 * buf A four byte character string. 170 * Return 171 * The converted integer value. 172 */ 173 174 u_int32_t 175 dst_s_get_int32(const u_char *buf) 176 { 177 register u_int32_t a = 0; 178 a = ((u_int32_t)(buf[0] << 24)) | ((u_int32_t)(buf[1] << 16)) | 179 ((u_int32_t)(buf[2] << 8)) | ((u_int32_t)(buf[3])); 180 return (a); 181 } 182 183 /*% 184 * dst_s_put_int16 185 * Take a 16 bit integer and store the value in a two byte 186 * character string. The integer is assumed to be in network 187 * order and the string is returned in host order. 188 * 189 * Parameters 190 * buf Storage for a two byte character string. 191 * val 16 bit integer. 192 */ 193 194 void 195 dst_s_put_int16(u_int8_t *buf, const u_int16_t val) 196 { 197 buf[0] = (u_int8_t)(val >> 8); 198 buf[1] = (u_int8_t)(val); 199 } 200 201 /*% 202 * dst_s_put_int32 203 * Take a 32 bit integer and store the value in a four byte 204 * character string. The integer is assumed to be in network 205 * order and the string is returned in host order. 206 * 207 * Parameters 208 * buf Storage for a four byte character string. 209 * val 32 bit integer. 210 */ 211 212 void 213 dst_s_put_int32(u_int8_t *buf, const u_int32_t val) 214 { 215 buf[0] = (u_int8_t)(val >> 24); 216 buf[1] = (u_int8_t)(val >> 16); 217 buf[2] = (u_int8_t)(val >> 8); 218 buf[3] = (u_int8_t)(val); 219 } 220 221 /*% 222 * dst_s_filename_length 223 * 224 * This function returns the number of bytes needed to hold the 225 * filename for a key file. '/', '\' and ':' are not allowed. 226 * form: K<keyname>+<alg>+<id>.<suffix> 227 * 228 * Returns 0 if the filename would contain either '\', '/' or ':' 229 */ 230 size_t 231 dst_s_filename_length(const char *name, const char *suffix) 232 { 233 if (name == NULL) 234 return (0); 235 if (strrchr(name, '\\')) 236 return (0); 237 if (strrchr(name, '/')) 238 return (0); 239 if (strrchr(name, ':')) 240 return (0); 241 if (suffix == NULL) 242 return (0); 243 if (strrchr(suffix, '\\')) 244 return (0); 245 if (strrchr(suffix, '/')) 246 return (0); 247 if (strrchr(suffix, ':')) 248 return (0); 249 return (1 + strlen(name) + 6 + strlen(suffix)); 250 } 251 252 /*% 253 * dst_s_build_filename () 254 * Builds a key filename from the key name, it's id, and a 255 * suffix. '\', '/' and ':' are not allowed. fA filename is of the 256 * form: K<keyname><id>.<suffix> 257 * form: K<keyname>+<alg>+<id>.<suffix> 258 * 259 * Returns -1 if the conversion fails: 260 * if the filename would be too long for space allotted 261 * if the filename would contain a '\', '/' or ':' 262 * Returns 0 on success 263 */ 264 265 int 266 dst_s_build_filename(char *filename, const char *name, u_int16_t id, 267 int alg, const char *suffix, size_t filename_length) 268 { 269 u_int32_t my_id; 270 if (filename == NULL) 271 return (-1); 272 memset(filename, 0, filename_length); 273 if (name == NULL) 274 return (-1); 275 if (suffix == NULL) 276 return (-1); 277 if (filename_length < 1 + strlen(name) + 4 + 6 + 1 + strlen(suffix)) 278 return (-1); 279 my_id = id; 280 sprintf(filename, "K%s+%03d+%05d.%s", name, alg, my_id, 281 (const char *) suffix); 282 if (strrchr(filename, '/')) 283 return (-1); 284 if (strrchr(filename, '\\')) 285 return (-1); 286 if (strrchr(filename, ':')) 287 return (-1); 288 return (0); 289 } 290 291 /*% 292 * dst_s_fopen () 293 * Open a file in the dst_path directory. If perm is specified, the 294 * file is checked for existence first, and not opened if it exists. 295 * Parameters 296 * filename File to open 297 * mode Mode to open the file (passed directly to fopen) 298 * perm File permission, if creating a new file. 299 * Returns 300 * NULL Failure 301 * NON-NULL (FILE *) of opened file. 302 */ 303 FILE * 304 dst_s_fopen(const char *filename, const char *mode, int perm) 305 { 306 FILE *fp; 307 char pathname[PATH_MAX]; 308 309 if (strlen(filename) + strlen(dst_path) >= sizeof(pathname)) 310 return (NULL); 311 312 if (*dst_path != '\0') { 313 strcpy(pathname, dst_path); 314 strcat(pathname, filename); 315 } else 316 strcpy(pathname, filename); 317 318 fp = fopen(pathname, mode); 319 if (perm) 320 chmod(pathname, perm); 321 return (fp); 322 } 323 324 void 325 dst_s_dump(const int mode, const u_char *data, const int size, 326 const char *msg) 327 { 328 UNUSED(data); 329 330 if (size > 0) { 331 #ifdef LONG_TEST 332 static u_char scratch[1000]; 333 int n ; 334 n = b64_ntop(data, scratch, size, sizeof(scratch)); 335 printf("%s: %x %d %s\n", msg, mode, n, scratch); 336 #else 337 printf("%s,%x %d\n", msg, mode, size); 338 #endif 339 } 340 } 341 342 /*! \file */ 343