17c478bd9Sstevel@tonic-gate /* 27c478bd9Sstevel@tonic-gate * src/lib/krb5/asn.1/asn1_decode.c 37c478bd9Sstevel@tonic-gate * 47c478bd9Sstevel@tonic-gate * Copyright 1994, 2003 by the Massachusetts Institute of Technology. 57c478bd9Sstevel@tonic-gate * All Rights Reserved. 67c478bd9Sstevel@tonic-gate * 77c478bd9Sstevel@tonic-gate * Export of this software from the United States of America may 87c478bd9Sstevel@tonic-gate * require a specific license from the United States Government. 97c478bd9Sstevel@tonic-gate * It is the responsibility of any person or organization contemplating 107c478bd9Sstevel@tonic-gate * export to obtain such a license before exporting. 117c478bd9Sstevel@tonic-gate * 127c478bd9Sstevel@tonic-gate * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and 137c478bd9Sstevel@tonic-gate * distribute this software and its documentation for any purpose and 147c478bd9Sstevel@tonic-gate * without fee is hereby granted, provided that the above copyright 157c478bd9Sstevel@tonic-gate * notice appear in all copies and that both that copyright notice and 167c478bd9Sstevel@tonic-gate * this permission notice appear in supporting documentation, and that 177c478bd9Sstevel@tonic-gate * the name of M.I.T. not be used in advertising or publicity pertaining 187c478bd9Sstevel@tonic-gate * to distribution of the software without specific, written prior 197c478bd9Sstevel@tonic-gate * permission. Furthermore if you modify this software you must label 207c478bd9Sstevel@tonic-gate * your software as modified software and not distribute it in such a 217c478bd9Sstevel@tonic-gate * fashion that it might be confused with the original M.I.T. software. 227c478bd9Sstevel@tonic-gate * M.I.T. makes no representations about the suitability of 237c478bd9Sstevel@tonic-gate * this software for any purpose. It is provided "as is" without express 247c478bd9Sstevel@tonic-gate * or implied warranty. 257c478bd9Sstevel@tonic-gate */ 267c478bd9Sstevel@tonic-gate 277c478bd9Sstevel@tonic-gate /* ASN.1 primitive decoders */ 287c478bd9Sstevel@tonic-gate #include "asn1_decode.h" 297c478bd9Sstevel@tonic-gate #include "asn1_get.h" 307c478bd9Sstevel@tonic-gate #include <stdio.h> 317c478bd9Sstevel@tonic-gate #ifdef HAVE_SYS_TIME_H 327c478bd9Sstevel@tonic-gate #include <sys/time.h> 337c478bd9Sstevel@tonic-gate #ifdef TIME_WITH_SYS_TIME 347c478bd9Sstevel@tonic-gate #include <time.h> 357c478bd9Sstevel@tonic-gate #endif 367c478bd9Sstevel@tonic-gate #else 377c478bd9Sstevel@tonic-gate #include <time.h> 387c478bd9Sstevel@tonic-gate #endif 397c478bd9Sstevel@tonic-gate 407c478bd9Sstevel@tonic-gate #define setup()\ 417c478bd9Sstevel@tonic-gate asn1_error_code retval;\ 427c478bd9Sstevel@tonic-gate taginfo tinfo 437c478bd9Sstevel@tonic-gate 447c478bd9Sstevel@tonic-gate #define asn1class (tinfo.asn1class) 457c478bd9Sstevel@tonic-gate #define construction (tinfo.construction) 467c478bd9Sstevel@tonic-gate #define tagnum (tinfo.tagnum) 477c478bd9Sstevel@tonic-gate #define length (tinfo.length) 487c478bd9Sstevel@tonic-gate 497c478bd9Sstevel@tonic-gate #define tag(type)\ 507c478bd9Sstevel@tonic-gate retval = asn1_get_tag_2(buf,&tinfo);\ 517c478bd9Sstevel@tonic-gate if(retval) return retval;\ 527c478bd9Sstevel@tonic-gate if(asn1class != UNIVERSAL || construction != PRIMITIVE || tagnum != type)\ 537c478bd9Sstevel@tonic-gate return ASN1_BAD_ID 547c478bd9Sstevel@tonic-gate 557c478bd9Sstevel@tonic-gate #define cleanup()\ 567c478bd9Sstevel@tonic-gate return 0 577c478bd9Sstevel@tonic-gate 58159d09a2SMark Phalan extern time_t krb5int_gmt_mktime (struct tm *); 597c478bd9Sstevel@tonic-gate 607c478bd9Sstevel@tonic-gate asn1_error_code asn1_decode_integer(asn1buf *buf, long int *val) 617c478bd9Sstevel@tonic-gate { 627c478bd9Sstevel@tonic-gate setup(); 637c478bd9Sstevel@tonic-gate asn1_octet o; 647c478bd9Sstevel@tonic-gate long n = 0; /* initialize to keep gcc happy */ 657c478bd9Sstevel@tonic-gate int i; 667c478bd9Sstevel@tonic-gate 677c478bd9Sstevel@tonic-gate tag(ASN1_INTEGER); 687c478bd9Sstevel@tonic-gate 697c478bd9Sstevel@tonic-gate for (i = 0; i < length; i++) { 707c478bd9Sstevel@tonic-gate retval = asn1buf_remove_octet(buf, &o); 717c478bd9Sstevel@tonic-gate if (retval) return retval; 727c478bd9Sstevel@tonic-gate if (!i) { 737c478bd9Sstevel@tonic-gate n = (0x80 & o) ? -1 : 0; /* grab sign bit */ 747c478bd9Sstevel@tonic-gate if (n < 0 && length > sizeof (long)) 757c478bd9Sstevel@tonic-gate return ASN1_OVERFLOW; 767c478bd9Sstevel@tonic-gate else if (length > sizeof (long) + 1) /* allow extra octet for positive */ 777c478bd9Sstevel@tonic-gate return ASN1_OVERFLOW; 787c478bd9Sstevel@tonic-gate } 797c478bd9Sstevel@tonic-gate n = (n << 8) | o; 807c478bd9Sstevel@tonic-gate } 817c478bd9Sstevel@tonic-gate *val = n; 827c478bd9Sstevel@tonic-gate cleanup(); 837c478bd9Sstevel@tonic-gate } 847c478bd9Sstevel@tonic-gate 857c478bd9Sstevel@tonic-gate asn1_error_code asn1_decode_unsigned_integer(asn1buf *buf, long unsigned int *val) 867c478bd9Sstevel@tonic-gate { 877c478bd9Sstevel@tonic-gate setup(); 887c478bd9Sstevel@tonic-gate asn1_octet o; 897c478bd9Sstevel@tonic-gate unsigned long n; 907c478bd9Sstevel@tonic-gate int i; 917c478bd9Sstevel@tonic-gate 927c478bd9Sstevel@tonic-gate tag(ASN1_INTEGER); 937c478bd9Sstevel@tonic-gate 947c478bd9Sstevel@tonic-gate for (i = 0, n = 0; i < length; i++) { 957c478bd9Sstevel@tonic-gate retval = asn1buf_remove_octet(buf, &o); 967c478bd9Sstevel@tonic-gate if(retval) return retval; 977c478bd9Sstevel@tonic-gate if (!i) { 987c478bd9Sstevel@tonic-gate if (0x80 & o) 997c478bd9Sstevel@tonic-gate return ASN1_OVERFLOW; 1007c478bd9Sstevel@tonic-gate else if (length > sizeof (long) + 1) 1017c478bd9Sstevel@tonic-gate return ASN1_OVERFLOW; 1027c478bd9Sstevel@tonic-gate } 1037c478bd9Sstevel@tonic-gate n = (n << 8) | o; 1047c478bd9Sstevel@tonic-gate } 1057c478bd9Sstevel@tonic-gate *val = n; 1067c478bd9Sstevel@tonic-gate cleanup(); 1077c478bd9Sstevel@tonic-gate } 1087c478bd9Sstevel@tonic-gate 1097c478bd9Sstevel@tonic-gate /* 1107c478bd9Sstevel@tonic-gate * asn1_decode_maybe_unsigned 1117c478bd9Sstevel@tonic-gate * 1127c478bd9Sstevel@tonic-gate * This is needed because older releases of MIT krb5 have signed 1137c478bd9Sstevel@tonic-gate * sequence numbers. We want to accept both signed and unsigned 1147c478bd9Sstevel@tonic-gate * sequence numbers, in the range -2^31..2^32-1, mapping negative 1157c478bd9Sstevel@tonic-gate * numbers into their positive equivalents in the same way that C's 1167c478bd9Sstevel@tonic-gate * normal integer conversions do, i.e., would preserve bits on a 1177c478bd9Sstevel@tonic-gate * two's-complement architecture. 1187c478bd9Sstevel@tonic-gate */ 1197c478bd9Sstevel@tonic-gate asn1_error_code asn1_decode_maybe_unsigned(asn1buf *buf, unsigned long *val) 1207c478bd9Sstevel@tonic-gate { 1217c478bd9Sstevel@tonic-gate setup(); 1227c478bd9Sstevel@tonic-gate asn1_octet o; 1237c478bd9Sstevel@tonic-gate unsigned long n, bitsremain; 1247c478bd9Sstevel@tonic-gate unsigned int i; 1257c478bd9Sstevel@tonic-gate 1267c478bd9Sstevel@tonic-gate tag(ASN1_INTEGER); 1277c478bd9Sstevel@tonic-gate o = 0; 1287c478bd9Sstevel@tonic-gate n = 0; 1297c478bd9Sstevel@tonic-gate bitsremain = ~0UL; 1307c478bd9Sstevel@tonic-gate for (i = 0; i < length; i++) { 1317c478bd9Sstevel@tonic-gate /* Accounts for u_long width not being a multiple of 8. */ 1327c478bd9Sstevel@tonic-gate if (bitsremain < 0xff) return ASN1_OVERFLOW; 1337c478bd9Sstevel@tonic-gate retval = asn1buf_remove_octet(buf, &o); 1347c478bd9Sstevel@tonic-gate if (retval) return retval; 1357c478bd9Sstevel@tonic-gate if (bitsremain == ~0UL) { 1367c478bd9Sstevel@tonic-gate if (i == 0) 1377c478bd9Sstevel@tonic-gate n = (o & 0x80) ? ~0UL : 0UL; /* grab sign bit */ 1387c478bd9Sstevel@tonic-gate /* 1397c478bd9Sstevel@tonic-gate * Skip leading zero or 0xFF octets to humor non-compliant encoders. 1407c478bd9Sstevel@tonic-gate */ 1417c478bd9Sstevel@tonic-gate if (n == 0 && o == 0) 1427c478bd9Sstevel@tonic-gate continue; 1437c478bd9Sstevel@tonic-gate if (n == ~0UL && o == 0xff) 1447c478bd9Sstevel@tonic-gate continue; 1457c478bd9Sstevel@tonic-gate } 1467c478bd9Sstevel@tonic-gate n = (n << 8) | o; 1477c478bd9Sstevel@tonic-gate bitsremain >>= 8; 1487c478bd9Sstevel@tonic-gate } 1497c478bd9Sstevel@tonic-gate *val = n; 1507c478bd9Sstevel@tonic-gate cleanup(); 1517c478bd9Sstevel@tonic-gate } 1527c478bd9Sstevel@tonic-gate 1537c478bd9Sstevel@tonic-gate asn1_error_code asn1_decode_oid(asn1buf *buf, unsigned int *retlen, asn1_octet **val) 1547c478bd9Sstevel@tonic-gate { 1557c478bd9Sstevel@tonic-gate setup(); 1567c478bd9Sstevel@tonic-gate tag(ASN1_OBJECTIDENTIFIER); 1577c478bd9Sstevel@tonic-gate retval = asn1buf_remove_octetstring(buf, length, val); 1587c478bd9Sstevel@tonic-gate if (retval) return retval; 1597c478bd9Sstevel@tonic-gate *retlen = length; 1607c478bd9Sstevel@tonic-gate cleanup(); 1617c478bd9Sstevel@tonic-gate } 1627c478bd9Sstevel@tonic-gate 1637c478bd9Sstevel@tonic-gate asn1_error_code asn1_decode_octetstring(asn1buf *buf, unsigned int *retlen, asn1_octet **val) 1647c478bd9Sstevel@tonic-gate { 1657c478bd9Sstevel@tonic-gate setup(); 1667c478bd9Sstevel@tonic-gate tag(ASN1_OCTETSTRING); 1677c478bd9Sstevel@tonic-gate retval = asn1buf_remove_octetstring(buf,length,val); 1687c478bd9Sstevel@tonic-gate if(retval) return retval; 1697c478bd9Sstevel@tonic-gate *retlen = length; 1707c478bd9Sstevel@tonic-gate cleanup(); 1717c478bd9Sstevel@tonic-gate } 1727c478bd9Sstevel@tonic-gate 1737c478bd9Sstevel@tonic-gate asn1_error_code asn1_decode_charstring(asn1buf *buf, unsigned int *retlen, char **val) 1747c478bd9Sstevel@tonic-gate { 1757c478bd9Sstevel@tonic-gate setup(); 1767c478bd9Sstevel@tonic-gate tag(ASN1_OCTETSTRING); 1777c478bd9Sstevel@tonic-gate retval = asn1buf_remove_charstring(buf,length,val); 1787c478bd9Sstevel@tonic-gate if(retval) return retval; 1797c478bd9Sstevel@tonic-gate *retlen = length; 1807c478bd9Sstevel@tonic-gate cleanup(); 1817c478bd9Sstevel@tonic-gate } 1827c478bd9Sstevel@tonic-gate 1837c478bd9Sstevel@tonic-gate 1847c478bd9Sstevel@tonic-gate asn1_error_code asn1_decode_generalstring(asn1buf *buf, unsigned int *retlen, char **val) 1857c478bd9Sstevel@tonic-gate { 1867c478bd9Sstevel@tonic-gate setup(); 1877c478bd9Sstevel@tonic-gate tag(ASN1_GENERALSTRING); 1887c478bd9Sstevel@tonic-gate retval = asn1buf_remove_charstring(buf,length,val); 1897c478bd9Sstevel@tonic-gate if(retval) return retval; 1907c478bd9Sstevel@tonic-gate *retlen = length; 1917c478bd9Sstevel@tonic-gate cleanup(); 1927c478bd9Sstevel@tonic-gate } 1937c478bd9Sstevel@tonic-gate 1947c478bd9Sstevel@tonic-gate 1957c478bd9Sstevel@tonic-gate asn1_error_code asn1_decode_null(asn1buf *buf) 1967c478bd9Sstevel@tonic-gate { 1977c478bd9Sstevel@tonic-gate setup(); 1987c478bd9Sstevel@tonic-gate tag(ASN1_NULL); 1997c478bd9Sstevel@tonic-gate if(length != 0) return ASN1_BAD_LENGTH; 2007c478bd9Sstevel@tonic-gate cleanup(); 2017c478bd9Sstevel@tonic-gate } 2027c478bd9Sstevel@tonic-gate 2037c478bd9Sstevel@tonic-gate asn1_error_code asn1_decode_printablestring(asn1buf *buf, int *retlen, char **val) 2047c478bd9Sstevel@tonic-gate { 2057c478bd9Sstevel@tonic-gate setup(); 2067c478bd9Sstevel@tonic-gate tag(ASN1_PRINTABLESTRING); 2077c478bd9Sstevel@tonic-gate retval = asn1buf_remove_charstring(buf,length,val); 2087c478bd9Sstevel@tonic-gate if(retval) return retval; 2097c478bd9Sstevel@tonic-gate *retlen = length; 2107c478bd9Sstevel@tonic-gate cleanup(); 2117c478bd9Sstevel@tonic-gate } 2127c478bd9Sstevel@tonic-gate 2137c478bd9Sstevel@tonic-gate asn1_error_code asn1_decode_ia5string(asn1buf *buf, int *retlen, char **val) 2147c478bd9Sstevel@tonic-gate { 2157c478bd9Sstevel@tonic-gate setup(); 2167c478bd9Sstevel@tonic-gate tag(ASN1_IA5STRING); 2177c478bd9Sstevel@tonic-gate retval = asn1buf_remove_charstring(buf,length,val); 2187c478bd9Sstevel@tonic-gate if(retval) return retval; 2197c478bd9Sstevel@tonic-gate *retlen = length; 2207c478bd9Sstevel@tonic-gate cleanup(); 2217c478bd9Sstevel@tonic-gate } 2227c478bd9Sstevel@tonic-gate 2237c478bd9Sstevel@tonic-gate asn1_error_code asn1_decode_generaltime(asn1buf *buf, time_t *val) 2247c478bd9Sstevel@tonic-gate { 2257c478bd9Sstevel@tonic-gate setup(); 2267c478bd9Sstevel@tonic-gate char *s; 2277c478bd9Sstevel@tonic-gate struct tm ts; 2287c478bd9Sstevel@tonic-gate time_t t; 2297c478bd9Sstevel@tonic-gate 2307c478bd9Sstevel@tonic-gate tag(ASN1_GENERALTIME); 2317c478bd9Sstevel@tonic-gate 2327c478bd9Sstevel@tonic-gate if(length != 15) return ASN1_BAD_LENGTH; 2337c478bd9Sstevel@tonic-gate retval = asn1buf_remove_charstring(buf,15,&s); 234*5caf4451SPeter Shoults if (retval) return retval; 2357c478bd9Sstevel@tonic-gate /* Time encoding: YYYYMMDDhhmmssZ */ 2367c478bd9Sstevel@tonic-gate if(s[14] != 'Z') { 2377c478bd9Sstevel@tonic-gate free(s); 2387c478bd9Sstevel@tonic-gate return ASN1_BAD_FORMAT; 2397c478bd9Sstevel@tonic-gate } 240505d05c7Sgtb if(s[0] == '1' && !memcmp("19700101000000Z", s, 15)) { 241505d05c7Sgtb t = 0; 242505d05c7Sgtb free(s); 243505d05c7Sgtb goto done; 244505d05c7Sgtb } 2457c478bd9Sstevel@tonic-gate #define c2i(c) ((c)-'0') 2467c478bd9Sstevel@tonic-gate ts.tm_year = 1000*c2i(s[0]) + 100*c2i(s[1]) + 10*c2i(s[2]) + c2i(s[3]) 2477c478bd9Sstevel@tonic-gate - 1900; 2487c478bd9Sstevel@tonic-gate ts.tm_mon = 10*c2i(s[4]) + c2i(s[5]) - 1; 2497c478bd9Sstevel@tonic-gate ts.tm_mday = 10*c2i(s[6]) + c2i(s[7]); 2507c478bd9Sstevel@tonic-gate ts.tm_hour = 10*c2i(s[8]) + c2i(s[9]); 2517c478bd9Sstevel@tonic-gate ts.tm_min = 10*c2i(s[10]) + c2i(s[11]); 2527c478bd9Sstevel@tonic-gate ts.tm_sec = 10*c2i(s[12]) + c2i(s[13]); 2537c478bd9Sstevel@tonic-gate ts.tm_isdst = -1; 254159d09a2SMark Phalan t = krb5int_gmt_mktime(&ts); 2557c478bd9Sstevel@tonic-gate free(s); 2567c478bd9Sstevel@tonic-gate 2577c478bd9Sstevel@tonic-gate if(t == -1) return ASN1_BAD_TIMEFORMAT; 2587c478bd9Sstevel@tonic-gate 259505d05c7Sgtb done: 2607c478bd9Sstevel@tonic-gate *val = t; 2617c478bd9Sstevel@tonic-gate cleanup(); 2627c478bd9Sstevel@tonic-gate } 263