/* * Abstract Syntax Notation One, ASN.1 * As defined in ISO/IS 8824 and ISO/IS 8825 * This implements a subset of the above International Standards that * is sufficient to implement SNMP. * * Encodes abstract data types into a machine independent stream of bytes. * */ /********************************************************************** Copyright 1988, 1989, 1991, 1992 by Carnegie Mellon University All Rights Reserved Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of CMU not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. CMU DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL CMU BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. ******************************************************************/ #include #ifdef KINETICS #include "gw.h" #endif #if HAVE_STRING_H #include #else #include #endif #include #if HAVE_NETINET_IN_H #include #endif #if HAVE_WINSOCK_H #include #endif #ifdef vms #include #endif #include "asn1.h" #ifndef NULL #define NULL 0 #endif #include "snmp_api.h" #include "snmp_impl.h" /* to define ERROR_MSG */ /* * asn_parse_int - pulls a long out of an ASN int type. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the end of this object. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_parse_int( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char *type OUT - asn type of object long *intp IN/OUT - pointer to start of output buffer int intsize IN - size of output buffer */ u_char * asn_parse_int(u_char *data, int *datalength, u_char *type, long *intp, int intsize) { /* * ASN.1 integer ::= 0x02 asnlength byte {byte}* */ register u_char *bufp = data; u_long asn_length; register long value = 0; if (intsize != sizeof (long)){ ERROR_MSG("not long"); return NULL; } *type = *bufp++; bufp = asn_parse_length(bufp, &asn_length); if (bufp == NULL){ ERROR_MSG("bad length"); return NULL; } if ((asn_length + (bufp - data)) > (u_long)(*datalength)){ ERROR_MSG("overflow of message"); return NULL; } if ((int)asn_length > intsize){ ERROR_MSG("I don't support such large integers"); return NULL; } *datalength -= (int)asn_length + (bufp - data); if (*bufp & 0x80) value = -1; /* integer is negative */ while(asn_length--) value = (value << 8) | *bufp++; *intp = value; return bufp; } /* * asn_parse_unsigned_int - pulls an unsigned long out of an ASN int type. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the end of this object. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_parse_unsigned_int( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char *type OUT - asn type of object u_long *intp IN/OUT - pointer to start of output buffer int intsize IN - size of output buffer */ u_char * asn_parse_unsigned_int(u_char *data, int *datalength, u_char *type, u_long *intp, int intsize) { /* * ASN.1 integer ::= 0x02 asnlength byte {byte}* */ register u_char *bufp = data; u_long asn_length; register u_long value = 0; if (intsize != sizeof (long)){ ERROR_MSG("not long"); return NULL; } *type = *bufp++; bufp = asn_parse_length(bufp, &asn_length); if (bufp == NULL){ ERROR_MSG("bad length"); return NULL; } if ((asn_length + (bufp - data)) > (u_long)(*datalength)){ ERROR_MSG("overflow of message"); return NULL; } if (((int)asn_length > (intsize + 1)) || (((int)asn_length == intsize + 1) && *bufp != 0x00)){ ERROR_MSG("I don't support such large integers"); return NULL; } *datalength -= (int)asn_length + (bufp - data); if (*bufp & 0x80) value = ~value; /* integer is negative */ while(asn_length--) value = (value << 8) | *bufp++; *intp = value; return bufp; } /* * asn_build_int - builds an ASN object containing an integer. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the end of this object. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_build_int( u_char *data IN - pointer to start of output buffer int *datalength IN/OUT - number of valid bytes left in buffer u_char type IN - asn type of object long *intp IN - pointer to start of long integer int intsize IN - size of input buffer */ u_char * asn_build_int(u_char *data, int *datalength, u_char type, long *intp, int intsize) { /* * ASN.1 integer ::= 0x02 asnlength byte {byte}* */ register long integer; register u_long mask; if (intsize != sizeof (long)) return NULL; integer = *intp; /* * Truncate "unnecessary" bytes off of the most significant end of this * 2's complement integer. There should be no sequence of 9 * consecutive 1's or 0's at the most significant end of the * integer. */ mask = ((u_long) 0x1FF) << ((8 * (sizeof(long) - 1)) - 1); /* mask is 0xFF800000 on a big-endian machine */ while((((integer & mask) == 0) || ((integer & mask) == mask)) && intsize > 1){ intsize--; integer <<= 8; } data = asn_build_header(data, datalength, type, intsize); if (data == NULL) return NULL; if (*datalength < intsize) return NULL; *datalength -= intsize; mask = ((u_long) 0xFF) << (8 * (sizeof(long) - 1)); /* mask is 0xFF000000 on a big-endian machine */ while(intsize--){ *data++ = (u_char)((integer & mask) >> (8 * (sizeof(long) - 1))); integer <<= 8; } return data; } /* * asn_build_unsigned_int - builds an ASN object containing an integer. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the end of this object. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_build_unsigned_int( u_char *data IN - pointer to start of output buffer int *datalength IN/OUT - number of valid bytes left in buffer u_char type IN - asn type of object u_long *intp IN - pointer to start of long integer int intsize IN - size of input buffer */ u_char * asn_build_unsigned_int(u_char *data, int *datalength, u_char type, u_long *intp, int intsize) { /* * ASN.1 integer ::= 0x02 asnlength byte {byte}* */ register u_long integer; register u_long mask; int add_null_byte = 0; if (intsize != sizeof (long)) return NULL; integer = *intp; mask = ((u_long) 0xFF) << (8 * (sizeof(long) - 1)); /* mask is 0xFF000000 on a big-endian machine */ if ((u_char)((integer & mask) >> (8 * (sizeof(long) - 1))) & 0x80){ /* if MSB is set */ add_null_byte = 1; intsize++; } else { /* * Truncate "unnecessary" bytes off of the most significant end of this 2's complement integer. * There should be no sequence of 9 consecutive 1's or 0's at the most significant end of the * integer. */ mask = ((u_long) 0x1FF) << ((8 * (sizeof(long) - 1)) - 1); /* mask is 0xFF800000 on a big-endian machine */ while((((integer & mask) == 0) || ((integer & mask) == mask)) && intsize > 1){ intsize--; integer <<= 8; } } data = asn_build_header(data, datalength, type, intsize); if (data == NULL) return NULL; if (*datalength < intsize) return NULL; *datalength -= intsize; if (add_null_byte == 1){ *data++ = '\0'; intsize--; } mask = ((u_long) 0xFF) << (8 * (sizeof(long) - 1)); /* mask is 0xFF000000 on a big-endian machine */ while(intsize--){ *data++ = (u_char)((integer & mask) >> (8 * (sizeof(long) - 1))); integer <<= 8; } return data; } /* * asn_parse_string - pulls an octet string out of an ASN octet string type. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the beginning of the next object. * * "string" is filled with the octet string. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_parse_string( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char *type OUT - asn type of object u_char *string IN/OUT - pointer to start of output buffer int *strlength IN/OUT - size of output buffer */ u_char * asn_parse_string(u_char *data, int *datalength, u_char *type, u_char *string, int *strlength) { /* * ASN.1 octet string ::= primstring | cmpdstring * primstring ::= 0x04 asnlength byte {byte}* * cmpdstring ::= 0x24 asnlength string {string}* */ register u_char *bufp = data; u_long asn_length; *type = *bufp++; bufp = asn_parse_length(bufp, &asn_length); if (bufp == NULL) return NULL; if ((asn_length + (bufp - data)) > (u_long)(*datalength)){ ERROR_MSG("overflow of message"); return NULL; } if ((int)asn_length > *strlength){ ERROR_MSG("I don't support such long strings"); return NULL; } memmove(string, bufp, (int)asn_length); *strlength = (int)asn_length; *datalength -= (int)asn_length + (bufp - data); return bufp + asn_length; } /* * asn_build_string - Builds an ASN octet string object containing the input string. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the beginning of the next object. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_build_string( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char type IN - asn type of object u_char *string IN - pointer to start of input buffer int strlength IN - size of input buffer */ u_char * asn_build_string(u_char *data, int *datalength, u_char type, u_char *string, int strlength) { /* * ASN.1 octet string ::= primstring | cmpdstring * primstring ::= 0x04 asnlength byte {byte}* * cmpdstring ::= 0x24 asnlength string {string}* * This code will never send a compound string. */ data = asn_build_header(data, datalength, type, strlength); if (data == NULL) return NULL; if (*datalength < strlength) return NULL; memmove(data, string, strlength); *datalength -= strlength; return data + strlength; } /* * asn_parse_header - interprets the ID and length of the current object. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * in this object following the id and length. * * Returns a pointer to the first byte of the contents of this object. * Returns NULL on any error. u_char * asn_parse_header( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char *type OUT - asn type of object */ u_char * asn_parse_header(u_char *data, int *datalength, u_char *type) { register u_char *bufp = data; register int header_len; u_long asn_length; /* this only works on data types < 30, i.e. no extension octets */ if (IS_EXTENSION_ID(*bufp)){ ERROR_MSG("can't process ID >= 30"); return NULL; } *type = *bufp; bufp = asn_parse_length(bufp + 1, &asn_length); if (bufp == NULL) return NULL; header_len = bufp - data; if ((header_len + asn_length) > (u_long)(*datalength)){ ERROR_MSG("asn length too long"); return NULL; } #ifdef OPAQUE_SPECIAL_TYPES if ((*type == ASN_OPAQUE) && (*bufp == ASN_OPAQUE_TAG1)) { /* check if 64-but counter */ switch(*(bufp+1)) { case ASN_OPAQUE_COUNTER64: case ASN_OPAQUE_U64: case ASN_OPAQUE_FLOAT: case ASN_OPAQUE_DOUBLE: case ASN_OPAQUE_I64: *type = *(bufp+1); break; default: /* just an Opaque */ *datalength = (int)asn_length; return bufp; } /* value is encoded as special format */ bufp = asn_parse_length(bufp + 2, &asn_length); if (bufp == NULL) return NULL; header_len = bufp - data; if ((header_len + (int)asn_length) > *datalength){ ERROR_MSG("asn length too long"); return NULL; } } #endif /* OPAQUE_SPECIAL_TYPES */ *datalength = (int)asn_length; return bufp; } /* * asn_build_header - builds an ASN header for an object with the ID and * length specified. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * in this object following the id and length. * * This only works on data types < 30, i.e. no extension octets. * The maximum length is 0xFFFF; * * Returns a pointer to the first byte of the contents of this object. * Returns NULL on any error. u_char * asn_build_header( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char type IN - asn type of object int length IN - length of object */ u_char * asn_build_header (u_char *data, int *datalength, u_char type, int length) { if (*datalength < 1) return NULL; *data++ = type; (*datalength)--; return asn_build_length(data, datalength, length); } /* * asn_build_sequence - builds an ASN header for a sequence with the ID and * length specified. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * in this object following the id and length. * * This only works on data types < 30, i.e. no extension octets. * The maximum length is 0xFFFF; * * Returns a pointer to the first byte of the contents of this object. * Returns NULL on any error. u_char * asn_build_sequence( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char type IN - asn type of object int length IN - length of object */ u_char * asn_build_sequence(u_char *data, int *datalength, u_char type, int length) { *datalength -= 4; if (*datalength < 0){ *datalength += 4; /* fix up before punting */ return NULL; } *data++ = type; *data++ = (u_char)(0x02 | ASN_LONG_LEN); *data++ = (u_char)((length >> 8) & 0xFF); *data++ = (u_char)(length & 0xFF); return data; } /* * asn_parse_length - interprets the length of the current object. * On exit, length contains the value of this length field. * * Returns a pointer to the first byte after this length * field (aka: the start of the data field). * Returns NULL on any error. u_char * asn_parse_length( u_char *data IN - pointer to start of length field u_long *length OUT - value of length field */ u_char * asn_parse_length(u_char *data, u_long *length) { register u_char lengthbyte = *data; if (lengthbyte & ASN_LONG_LEN){ lengthbyte &= ~ASN_LONG_LEN; /* turn MSb off */ if (lengthbyte == 0){ ERROR_MSG("We don't support indefinite lengths"); return NULL; } if (lengthbyte > sizeof(long)){ ERROR_MSG("we can't support data lengths that long"); return NULL; } *length = 0; /* protect against short lengths */ memmove(length, data + 1, (int)lengthbyte); *length = ntohl(*length); *length >>= (8 * ((sizeof(u_long)) - lengthbyte)); return data + lengthbyte + 1; } else { /* short asnlength */ *length = (long)lengthbyte; return data + 1; } } /* u_char * asn_build_length( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer int length IN - length of object */ u_char * asn_build_length(u_char *data, int *datalength, int length) { u_char *start_data = data; /* no indefinite lengths sent */ if (length < 0x80){ if (*datalength < 1){ ERROR_MSG("build_length"); return NULL; } *data++ = (u_char)length; } else if (length <= 0xFF){ if (*datalength < 2){ ERROR_MSG("build_length"); return NULL; } *data++ = (u_char)(0x01 | ASN_LONG_LEN); *data++ = (u_char)length; } else { /* 0xFF < length <= 0xFFFF */ if (*datalength < 3){ ERROR_MSG("build_length"); return NULL; } *data++ = (u_char)(0x02 | ASN_LONG_LEN); *data++ = (u_char)((length >> 8) & 0xFF); *data++ = (u_char)(length & 0xFF); } *datalength -= (data - start_data); return data; } /* * asn_parse_objid - pulls an object indentifier out of an ASN object identifier type. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the beginning of the next object. * * "objid" is filled with the object identifier. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_parse_objid( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char *type OUT - asn type of object oid *objid IN/OUT - pointer to start of output buffer int *objidlength IN/OUT - number of sub-id's in objid */ u_char * asn_parse_objid(u_char *data, int *datalength, u_char *type, oid *objid, int *objidlength) { /* * ASN.1 objid ::= 0x06 asnlength subidentifier {subidentifier}* * subidentifier ::= {leadingbyte}* lastbyte * leadingbyte ::= 1 7bitvalue * lastbyte ::= 0 7bitvalue */ register u_char *bufp = data; register oid *oidp = objid + 1; register u_long subidentifier; register long length; u_long asn_length; *type = *bufp++; bufp = asn_parse_length(bufp, &asn_length); if (bufp == NULL) return NULL; if ((asn_length + (bufp - data)) > (u_long)(*datalength)){ ERROR_MSG("overflow of message"); return NULL; } *datalength -= (int)asn_length + (bufp - data); /* Handle invalid object identifier encodings of the form 06 00 robustly */ if (asn_length == 0) objid[0] = objid[1] = 0; length = asn_length; (*objidlength)--; /* account for expansion of first byte */ while (length > 0 && (*objidlength)-- > 0){ subidentifier = 0; do { /* shift and add in low order 7 bits */ subidentifier = (subidentifier << 7) + (*(u_char *)bufp & ~ASN_BIT8); length--; } while (*(u_char *)bufp++ & ASN_BIT8); /* last byte has high bit clear */ /*?? note, this test will never be true, since the largest value of subidentifier is the value of MAX_SUBID! */ if (subidentifier > (u_long)MAX_SUBID){ ERROR_MSG("subidentifier too long"); return NULL; } *oidp++ = (oid)subidentifier; } /* * The first two subidentifiers are encoded into the first component * with the value (X * 40) + Y, where: * X is the value of the first subidentifier. * Y is the value of the second subidentifier. */ subidentifier = (u_long)objid[1]; if (subidentifier == 0x2B){ objid[0] = 1; objid[1] = 3; } else { if (subidentifier < 40) { objid[0] = 0; objid[1] = subidentifier; } else if (subidentifier < 80) { objid[0] = 1; objid[1] = subidentifier - 40; } else if (subidentifier < 120) { objid[0] = 2; objid[1] = subidentifier - 80; } else { objid[1] = (subidentifier % 40); objid[0] = ((subidentifier - objid[1]) / 40); } } *objidlength = (int)(oidp - objid); return bufp; } /* * asn_build_objid - Builds an ASN object identifier object containing the * input string. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the beginning of the next object. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_build_objid( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char type IN - asn type of object oid *objid IN - pointer to start of input buffer int objidlength IN - number of sub-id's in objid */ u_char * asn_build_objid(u_char *data, int *datalength, u_char type, oid *objid, int objidlength) { /* * ASN.1 objid ::= 0x06 asnlength subidentifier {subidentifier}* * subidentifier ::= {leadingbyte}* lastbyte * leadingbyte ::= 1 7bitvalue * lastbyte ::= 0 7bitvalue */ int asnlength; register oid *op = objid; u_char objid_size[MAX_OID_LEN]; register u_long objid_val; u_long first_objid_val; register int i; /* check if there are at least 2 sub-identifiers */ if (objidlength < 2){ /* there are not, so make OID have two with value of zero */ objid_val = 0; objidlength = 2; } else { /* combine the first two values */ objid_val = (op[0] * 40) + op[1]; op += 2; } first_objid_val = objid_val; /* calculate the number of bytes needed to store the encoded value */ for (i = 1, asnlength = 0;;) { if (objid_val < (unsigned)0x80) { objid_size[i] = 1; asnlength += 1; } else if (objid_val < (unsigned)0x4000) { objid_size[i] = 2; asnlength += 2; } else if (objid_val < (unsigned)0x200000) { objid_size[i] = 3; asnlength += 3; } else if (objid_val < (unsigned)0x10000000) { objid_size[i] = 4; asnlength += 4; } else { objid_size[i] = 5; asnlength += 5; } i++; if (i >= objidlength) break; objid_val = *op++; } /* store the ASN.1 tag and length */ data = asn_build_header(data, datalength, type, asnlength); if (data == NULL) return NULL; if (*datalength < asnlength) return NULL; /* store the encoded OID value */ for (i = 1, objid_val = first_objid_val, op = objid+2; i < objidlength; i++) { if (i != 1) objid_val = *op++; switch (objid_size[i]) { case 1: *data++ = (u_char)objid_val; break; case 2: *data++ = (u_char)((objid_val>>7) | 0x80); *data++ = (u_char)(objid_val & 0x07f); break; case 3: *data++ = (u_char)((objid_val>>14) | 0x80); *data++ = (u_char)((objid_val>>7 & 0x7f) | 0x80); *data++ = (u_char)(objid_val & 0x07f); break; case 4: *data++ = (u_char)((objid_val>>21) | 0x80); *data++ = (u_char)((objid_val>>14 & 0x7f) | 0x80); *data++ = (u_char)((objid_val>>7 & 0x7f) | 0x80); *data++ = (u_char)(objid_val & 0x07f); break; case 5: *data++ = (u_char)((objid_val>>28) | 0x80); *data++ = (u_char)((objid_val>>21 & 0x7f) | 0x80); *data++ = (u_char)((objid_val>>14 & 0x7f) | 0x80); *data++ = (u_char)((objid_val>>7 & 0x7f) | 0x80); *data++ = (u_char)(objid_val & 0x07f); break; } } /* return the length and data ptr */ *datalength -= asnlength; return data; } /* * asn_parse_null - Interprets an ASN null type. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the beginning of the next object. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_parse_null( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char *type OUT - asn type of object */ u_char * asn_parse_null(u_char *data, int *datalength, u_char *type) { /* * ASN.1 null ::= 0x05 0x00 */ register u_char *bufp = data; u_long asn_length; *type = *bufp++; bufp = asn_parse_length(bufp, &asn_length); if (bufp == NULL) return NULL; if (asn_length != 0){ ERROR_MSG("Malformed NULL"); return NULL; } *datalength -= (bufp - data); return bufp + asn_length; } /* * asn_build_null - Builds an ASN null object. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the beginning of the next object. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_build_null( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char type IN - asn type of object */ u_char * asn_build_null(u_char *data, int *datalength, u_char type) { /* * ASN.1 null ::= 0x05 0x00 */ return asn_build_header(data, datalength, type, 0); } /* * asn_parse_bitstring - pulls a bitstring out of an ASN bitstring type. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the beginning of the next object. * * "string" is filled with the bit string. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_parse_bitstring( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char *type OUT - asn type of object u_char *string IN/OUT - pointer to start of output buffer int *strlength IN/OUT - size of output buffer */ u_char * asn_parse_bitstring(u_char *data, int *datalength, u_char *type, u_char *string, int *strlength) { /* * bitstring ::= 0x03 asnlength unused {byte}* */ register u_char *bufp = data; u_long asn_length; *type = *bufp++; bufp = asn_parse_length(bufp, &asn_length); if (bufp == NULL) return NULL; if ((asn_length + (bufp - data)) > (u_long)(*datalength)){ ERROR_MSG("overflow of message"); return NULL; } if ((int)asn_length > *strlength){ ERROR_MSG("I don't support such long bitstrings"); return NULL; } if (asn_length < 1){ ERROR_MSG("Invalid bitstring"); return NULL; } if (*bufp > 7){ ERROR_MSG("Invalid bitstring"); return NULL; } memmove(string, bufp, (int)asn_length); *strlength = (int)asn_length; *datalength -= (int)asn_length + (bufp - data); return bufp + asn_length; } /* * asn_build_bitstring - Builds an ASN bit string object containing the * input string. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the beginning of the next object. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_build_bitstring( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char type IN - asn type of object u_char *string IN - pointer to start of input buffer int strlength IN - size of input buffer */ u_char * asn_build_bitstring(u_char *data, int *datalength, u_char type, u_char *string, int strlength) { /* * ASN.1 bit string ::= 0x03 asnlength unused {byte}* */ if (strlength < 1 || *string > 7){ ERROR_MSG("Building invalid bitstring"); return NULL; } data = asn_build_header(data, datalength, type, strlength); if (data == NULL) return NULL; if (*datalength < strlength) return NULL; memmove(data, string, strlength); *datalength -= strlength; return data + strlength; } /* * asn_parse_unsigned_int64 - pulls a 64 bit unsigned long out of an ASN int * type. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the end of this object. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_parse_unsigned_int64( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char *type OUT - asn type of object struct counter64 *cp IN/OUT - pointer to counter struct int countersize IN - size of output buffer */ u_char * asn_parse_unsigned_int64(u_char *data, int *datalength, u_char *type, struct counter64 *cp, int countersize) { /* * ASN.1 integer ::= 0x02 asnlength byte {byte}* */ register u_char *bufp = data; u_long asn_length; register u_long low = 0, high = 0; int intsize = 4; if (countersize != sizeof(struct counter64)){ ERROR_MSG("not right size"); return NULL; } *type = *bufp++; bufp = asn_parse_length(bufp, &asn_length); if (bufp == NULL){ ERROR_MSG("bad length"); return NULL; } if ((asn_length + (bufp - data)) > (u_long)(*datalength)){ ERROR_MSG("overflow of message"); return NULL; } #ifdef OPAQUE_SPECIAL_TYPES /* 64 bit counters as opaque */ if ((*type == ASN_OPAQUE) && (asn_length <= ASN_OPAQUE_COUNTER64_MX_BER_LEN) && (*bufp == ASN_OPAQUE_TAG1) && ((*(bufp+1) == ASN_OPAQUE_COUNTER64) || (*(bufp+1) == ASN_OPAQUE_U64))) { /* change type to Counter64 or U64 */ *type = *(bufp+1); /* value is encoded as special format */ bufp = asn_parse_length(bufp + 2, &asn_length); if (bufp == NULL) return NULL; if ((int)(asn_length + (bufp - data)) > *datalength){ ERROR_MSG("overflow of message"); return NULL; } } #endif /* OPAQUE_SPECIAL_TYPES */ if (((int)asn_length > (intsize * 2 + 1)) || (((int)asn_length == (intsize * 2 + 1)) && *bufp != 0x00)){ ERROR_MSG("I don't support such large integers"); return NULL; } *datalength -= (int)asn_length + (bufp - data); if (*bufp & 0x80){ low = ~low; /* integer is negative */ high = ~high; } while(asn_length--){ high = (high << 8) | ((low & 0xFF000000) >> 24); low = (low << 8) | *bufp++; } cp->low = low; cp->high = high; return bufp; } /* * asn_build_unsigned_int64 - builds an ASN object containing a 64 bit integer. * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the end of this object. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_build_unsigned_int64( u_char *data IN - pointer to start of output buffer int *datalength IN/OUT - number of valid bytes left in buffer u_char type IN - asn type of object struct counter64 *cp IN - pointer to counter struct int countersize IN - size of input buffer */ u_char * asn_build_unsigned_int64(u_char *data, int *datalength, u_char type, struct counter64 *cp, int countersize) { /* * ASN.1 integer ::= 0x02 asnlength byte {byte}* */ register u_long low, high; register u_long mask, mask2; int add_null_byte = 0; int intsize; if (countersize != sizeof (struct counter64)) return NULL; intsize = 8; low = cp->low; high = cp->high; mask = ((u_long) 0xFF) << (8 * (sizeof(long) - 1)); /* mask is 0xFF000000 on a big-endian machine */ if ((u_char)((high & mask) >> (8 * (sizeof(long) - 1))) & 0x80){ /* if MSB is set */ add_null_byte = 1; intsize++; } else { /* * Truncate "unnecessary" bytes off of the most significant end of this 2's * complement integer. * There should be no sequence of 9 consecutive 1's or 0's at the most * significant end of the integer. */ mask2 = ((u_long) 0x1FF) << ((8 * (sizeof(long) - 1)) - 1); /* mask2 is 0xFF800000 on a big-endian machine */ while((((high & mask2) == 0) || ((high & mask2) == mask2)) && intsize > 1){ intsize--; high = (high << 8) | ((low & mask) >> (8 * (sizeof(long) - 1))); low <<= 8; } } #ifdef OPAQUE_SPECIAL_TYPES /* encode a Counter64 as an opaque (it also works in SNMPv1) */ /* turn into Opaque holding special tagged value */ if (type == ASN_OPAQUE_COUNTER64) { /* put the tag and length for the Opaque wrapper */ data = asn_build_header(data, datalength, ASN_OPAQUE, intsize+3); if (data == NULL) return NULL; if (*datalength < (intsize+3)) return NULL; /* put the special tag and length */ *data++ = ASN_OPAQUE_TAG1; *data++ = ASN_OPAQUE_COUNTER64; *data++ = (u_char)intsize; *datalength = *datalength - 3; } else /* Encode the Unsigned int64 in an opaque */ /* turn into Opaque holding special tagged value */ if (type == ASN_OPAQUE_U64) { /* put the tag and length for the Opaque wrapper */ data = asn_build_header(data, datalength, ASN_OPAQUE, intsize+3); if (data == NULL) return NULL; if (*datalength < (intsize+3)) return NULL; /* put the special tag and length */ *data++ = ASN_OPAQUE_TAG1; *data++ = ASN_OPAQUE_U64; *data++ = (u_char)intsize; *datalength = *datalength - 3; } else { #endif /* OPAQUE_SPECIAL_TYPES */ data = asn_build_header(data, datalength, type, intsize); if (data == NULL) return NULL; if (*datalength < intsize) return NULL; #ifdef OPAQUE_SPECIAL_TYPES } #endif /* OPAQUE_SPECIAL_TYPES */ *datalength -= intsize; if (add_null_byte == 1){ *data++ = '\0'; intsize--; } while(intsize--){ *data++ = (u_char)((high & mask) >> (8 * (sizeof(long) - 1))); high = (high << 8) | ((low & mask) >> (8 * (sizeof(long) - 1))); low <<= 8; } return data; } #ifdef OPAQUE_SPECIAL_TYPES /* u_char * asn_parse_signed_int64( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char *type OUT - asn type of object struct counter64 *cp IN/OUT - pointer to counter struct int countersize IN - size of output buffer */ u_char * asn_parse_signed_int64(u_char *data, int *datalength, u_char *type, struct counter64 *cp, int countersize) { register u_char *bufp = data; u_long asn_length; register u_int low = 0, high = 0; int intsize = 4; if (countersize != sizeof(struct counter64)){ ERROR_MSG("not right size"); return NULL; } *type = *bufp++; bufp = asn_parse_length(bufp, &asn_length); if (bufp == NULL){ ERROR_MSG("bad length"); return NULL; } if ((asn_length + (bufp - data)) > (u_int)(*datalength)){ ERROR_MSG("overflow of message"); return NULL; } if ((*type == ASN_OPAQUE) && (asn_length <= ASN_OPAQUE_COUNTER64_MX_BER_LEN) && (*bufp == ASN_OPAQUE_TAG1) && (*(bufp+1) == ASN_OPAQUE_I64)) { /* change type to Int64 */ *type = *(bufp+1); /* value is encoded as special format */ bufp = asn_parse_length(bufp + 2, &asn_length); if (bufp == NULL) return NULL; if ((int)(asn_length + (bufp - data)) > *datalength){ ERROR_MSG("overflow of message"); return NULL; } } /* this should always have been true until snmp gets int64 PDU types */ else { ERROR_MSG("wrong type"); return NULL; } if (((int)asn_length > (intsize * 2 + 1)) || (((int)asn_length == (intsize * 2 + 1)) && *bufp != 0x00)){ ERROR_MSG("I don't support such large integers"); return NULL; } *datalength -= (int)asn_length + (bufp - data); if (*bufp & 0x80){ low = ~low; /* integer is negative */ high = ~high; } while(asn_length--){ high = (high << 8) | ((low & 0xFF000000) >> 24); low = (low << 8) | *bufp++; } cp->low = low; cp->high = high; return bufp; } /* u_char * asn_build_signed_int64( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char type IN - asn type of object struct counter64 *cp IN - pointer to counter struct int countersize IN - size of input buffer */ u_char * asn_build_signed_int64(u_char *data, int *datalength, u_char type, struct counter64 *cp, int countersize) { /* * ASN.1 integer ::= 0x02 asnlength byte {byte}* */ struct counter64 c64; register u_int mask, mask2; u_long low, high; int intsize; if (countersize != sizeof (struct counter64)) return NULL; intsize = 8; memcpy(&c64, cp, sizeof(struct counter64)); /* we're may modify it */ low = c64.low; high = c64.high; /* * Truncate "unnecessary" bytes off of the most significant end of this * 2's complement integer. There should be no sequence of 9 * consecutive 1's or 0's at the most significant end of the * integer. */ mask = ((u_int) 0xFF) << (8 * (sizeof(u_int) - 1)); mask2 = ((u_int) 0x1FF) << ((8 * (sizeof(u_int) - 1)) - 1); /* mask is 0xFF800000 on a big-endian machine */ while((((high & mask2) == 0) || ((high & mask2) == mask2)) && intsize > 1){ intsize--; high = (high << 8) | ((low & mask) >> (8 * (sizeof(u_int) - 1))); low <<= 8; } /* until a real int64 gets incorperated into SNMP, we are going to encode it as an opaque instead. First, we build the opaque header and then the int64 tag type we use to mark it as an int64 in the opaque string. */ data = asn_build_header(data, datalength, ASN_OPAQUE, intsize+3); if (data == NULL) return NULL; if (*datalength < (intsize+3)) return NULL; *data++ = ASN_OPAQUE_TAG1; *data++ = ASN_OPAQUE_I64; *data++ = (u_char)intsize; *datalength -= (3 + intsize); while(intsize--){ *data++ = (u_char)((high & mask) >> (8 * (sizeof(u_int) - 1))); high = (high << 8) | ((low & mask) >> (8 * (sizeof(u_int) - 1))); low <<= 8; } return data; } /* * asn_parse_float - pulls a single precision floating-point out of an opaque type. * * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the end of this object. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_parse_float( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char *type OUT - asn type of object float *floatp IN/OUT - pointer to float int floatsize IN - size of output buffer */ u_char * asn_parse_float(u_char *data, int *datalength, u_char *type, float *floatp, int floatsize) { register u_char *bufp = data; u_long asn_length; union { float floatVal; long longVal; u_char c[sizeof(float)]; } fu; if (floatsize != sizeof(float)){ ERROR_MSG("not right size"); return NULL; } *type = *bufp++; bufp = asn_parse_length(bufp, &asn_length); if (bufp == NULL){ ERROR_MSG("bad length"); return NULL; } if ((int)(asn_length + (bufp - data)) > *datalength){ ERROR_MSG("overflow of message"); return NULL; } /* the float is encoded as an opaque */ if ((*type == ASN_OPAQUE) && (asn_length == ASN_OPAQUE_FLOAT_BER_LEN) && (*bufp == ASN_OPAQUE_TAG1) && (*(bufp+1) == ASN_OPAQUE_FLOAT)) { /* value is encoded as special format */ bufp = asn_parse_length(bufp + 2, &asn_length); if (bufp == NULL) return NULL; if ((int)(asn_length + (bufp - data)) > *datalength){ ERROR_MSG("overflow of message"); return NULL; } /* change type to Float */ *type = ASN_OPAQUE_FLOAT; } if (asn_length != sizeof(float)) { ERROR_MSG("Size of float incorrect"); return NULL; } *datalength -= (int)asn_length + (bufp - data); memcpy(&fu.c[0], bufp, asn_length); /* correct for endian differences */ fu.longVal = ntohl(fu.longVal); *floatp = fu.floatVal; return bufp; } /* * asn_build_float - builds an ASN object containing a single precision floating-point * number in an Opaque value. * * On entry, datalength is input as the number of valid bytes following * "data". On exit, it is returned as the number of valid bytes * following the end of this object. * * Returns a pointer to the first byte past the end * of this object (i.e. the start of the next object). * Returns NULL on any error. u_char * asn_build_float( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char type IN - asn type of object float *floatp IN - pointer to float int floatsize IN - size of input buffer */ u_char * asn_build_float(u_char *data, int *datalength, u_char type, float *floatp, int floatsize) { union { float floatVal; int intVal; u_char c[sizeof(float)]; } fu; if (floatsize != sizeof (float)) return NULL; /* encode the float as an opaque */ /* turn into Opaque holding special tagged value */ /* put the tag and length for the Opaque wrapper */ data = asn_build_header(data, datalength, ASN_OPAQUE, floatsize+3); if (data == NULL) return NULL; if (*datalength < (floatsize+3)) return NULL; /* put the special tag and length */ *data++ = ASN_OPAQUE_TAG1; *data++ = ASN_OPAQUE_FLOAT; *data++ = (u_char)floatsize; *datalength = *datalength - 3; fu.floatVal = *floatp; /* correct for endian differences */ fu.intVal = htonl(fu.intVal); *datalength -= floatsize; memcpy(data, &fu.c[0], floatsize); data += floatsize; return data; } /* u_char * asn_parse_double( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char *type OUT - asn type of object double *doublep IN/OUT - pointer to double int doublesize IN - size of output buffer */ u_char * asn_parse_double(u_char *data, int *datalength, u_char *type, double *doublep, int doublesize) { register u_char *bufp = data; u_long asn_length; long tmp; union { double doubleVal; int intVal[2]; u_char c[sizeof(double)]; } fu; if (doublesize != sizeof(double)){ ERROR_MSG("not right size"); return NULL; } *type = *bufp++; bufp = asn_parse_length(bufp, &asn_length); if (bufp == NULL){ ERROR_MSG("bad length"); return NULL; } if ((int)(asn_length + (bufp - data)) > *datalength){ ERROR_MSG("overflow of message"); return NULL; } /* the double is encoded as an opaque */ if ((*type == ASN_OPAQUE) && (asn_length == ASN_OPAQUE_DOUBLE_BER_LEN) && (*bufp == ASN_OPAQUE_TAG1) && (*(bufp+1) == ASN_OPAQUE_DOUBLE)) { /* value is encoded as special format */ bufp = asn_parse_length(bufp + 2, &asn_length); if (bufp == NULL) return NULL; if ((int)(asn_length + (bufp - data)) > *datalength){ ERROR_MSG("overflow of message"); return NULL; } /* change type to Double */ *type = ASN_OPAQUE_DOUBLE; } if (asn_length != sizeof(double)) { ERROR_MSG("Size of double incorrect"); return NULL; } *datalength -= (int)asn_length + (bufp - data); memcpy(&fu.c[0], bufp, asn_length); /* correct for endian differences */ tmp = ntohl(fu.intVal[0]); fu.intVal[0] = ntohl(fu.intVal[1]); fu.intVal[1] = tmp; *doublep = fu.doubleVal; return bufp; } /* u_char * asn_build_double( u_char *data IN - pointer to start of object int *datalength IN/OUT - number of valid bytes left in buffer u_char type IN - asn type of object double *doublep IN - pointer to double int doublesize IN - size of input buffer */ u_char * asn_build_double(u_char *data, int *datalength, u_char type, double* doublep, int doublesize) { long tmp; union { double doubleVal; int intVal[2]; u_char c[sizeof(double)]; } fu; if (doublesize != sizeof (double)) return NULL; /* encode the double as an opaque */ /* turn into Opaque holding special tagged value */ /* put the tag and length for the Opaque wrapper */ data = asn_build_header(data, datalength, ASN_OPAQUE, doublesize+3); if (data == NULL) return NULL; if (*datalength < (doublesize+3)) return NULL; /* put the special tag and length */ *data++ = ASN_OPAQUE_TAG1; *data++ = ASN_OPAQUE_DOUBLE; *data++ = (u_char)doublesize; *datalength = *datalength - 3; fu.doubleVal = *doublep; /* correct for endian differences */ tmp = htonl(fu.intVal[0]); fu.intVal[0] = htonl(fu.intVal[1]); fu.intVal[1] = tmp; *datalength -= doublesize; memcpy(data, &fu.c[0], doublesize); data += doublesize; return data; } #endif /* OPAQUE_SPECIAL_TYPES */