asn1.c

eCos操作系统源码

	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 large");
	    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);

    DEBUGMSG(("dump_recv", "  ASN ObjID: "));
    DEBUGMSGOID(("dump_recv", objid, *objidlength));
    DEBUGMSG(("dump_recv", "\n"));
    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
      int        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,
		size_t *datalength,
		u_char type,
		oid *objid,
		size_t objidlength)
{
/*
 * ASN.1 objid ::= 0x06 asnlength subidentifier {subidentifier}*
 * subidentifier ::= {leadingbyte}* lastbyte
 * leadingbyte ::= 1 7bitvalue
 * lastbyte ::= 0 7bitvalue
 */
    size_t 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 == 0){
        /* there are not, so make OID have two with value of zero */
        objid_val = 0;
	objidlength = 2;
    } else if (objidlength == 1){
        /* encode the first value */
	objid_val = (op[0] * 40);
	objidlength = 2;
	op++;
    } else {
        /* combine the first two values */
	if ( op[1] > 40 ) {
	    ERROR_MSG("build objid: bad second subidentifier");
	    return NULL;
	}
	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 >= (int)objidlength)
            break;
        objid_val = *op++;
    } 

    /* store the ASN.1 tag and length */
    data = asn_build_header(data, datalength, type, asnlength);
    if (_asn_build_header_check("build objid", data, *datalength, asnlength))
	return NULL;

    /* store the encoded OID value */
    for (i = 1, objid_val = first_objid_val, op = objid+2;
				i < (int)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,
	       size_t *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){
	ERROR_MSG("parse null: bad length");
	return NULL;
    }
    if (asn_length != 0){
	ERROR_MSG("parse null: malformed ASN.1 null");
	return NULL;
    }

    *datalength -= (bufp - data);

    DEBUGDUMPSETUP("dump_recv", data, bufp - data);
    DEBUGMSG(("dump_recv", "  ASN NULL\n"));

    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,
	       size_t *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
      size_t     *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
      size_t     *strlength    IN/OUT - size of output buffer
 */
u_char *
asn_parse_bitstring(u_char *data,
		    size_t *datalength,
		    u_char *type,
		    u_char *string,
		    size_t *strlength)
{
/*
 * bitstring ::= 0x03 asnlength unused {byte}*
 */
    static const char *errpre = "parse bitstring";
    register u_char *bufp = data;
    u_long	    asn_length;

    *type = *bufp++;
    bufp = asn_parse_length(bufp, &asn_length);
    if (_asn_parse_length_check(errpre, bufp, data,
               asn_length, *datalength))
	return NULL;

    if ((size_t)asn_length > *strlength){
	_asn_length_err(errpre, (size_t)asn_length, *strlength);
	return NULL;
    }
    if (_asn_bitstring_check(errpre, asn_length, *bufp))
	return NULL;

    DEBUGDUMPSETUP("dump_recv", data, bufp - data);
    DEBUGMSG(("dump_recv", "  ASN Bitstring: "));
    DEBUGMSGHEX(("dump_recv", data, asn_length));

    memmove(string, bufp, 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,
		    size_t *datalength,
		    u_char type,
		    u_char *string,
		    size_t strlength)
{
/*
 * ASN.1 bit string ::= 0x03 asnlength unused {byte}*
 */
    static const char *errpre = "build bitstring";
    if (_asn_bitstring_check(errpre, strlength, *string))
	return NULL;

    data = asn_build_header(data, datalength, type, strlength);
    if (_asn_build_header_check(errpre,data,*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,
			 size_t *datalength,
			 u_char *type, 
			 struct counter64 *cp,
			 size_t countersize)
{
/*
 * ASN.1 integer ::= 0x02 asnlength byte {byte}*
 */
    static const char *errpre = "parse uint64";
    const int uint64sizelimit = (4 * 2) + 1;
    register u_char *bufp = data;
    u_long	    asn_length;
    register u_long low = 0, high = 0;
    
    if (countersize != sizeof(struct counter64)){
	_asn_size_err(errpre, countersize, sizeof(struct counter64));
	return NULL;
    }
    *type = *bufp++;
    bufp = asn_parse_length(bufp, &asn_length);
    if (_asn_parse_length_check(errpre, bufp, data, asn_length, *datalength))
        return NULL;

    DEBUGDUMPSETUP("dump_recv", data, bufp - data);
#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))) {
        DEBUGMSG(("dump_recv", "Opaque %.2x %.2x: ", *bufp, *(bufp+1)));

	/* change type to Counter64 or U64 */
        *type = *(bufp+1);
        /* value is encoded as special format */
	bufp = asn_parse_length(bufp + 2, &asn_length);
	if (_asn_parse_length_check("parse opaque uint64", bufp, data,
                  asn_length, *datalength))
        return NULL;
    }
#endif /* OPAQUE_SPECIAL_TYPES */
    if (((int)asn_length > uint64sizelimit) ||
	(((int)asn_length == uint64sizelimit) && *bufp != 0x00)){
	_asn_length_err(errpre, (size_t)asn_length, uint64sizelimit);
	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;

    DEBUGIF("dump_recv") {
      char i64buf[I64CHARSZ+1];
      printU64(i64buf, cp);
    }

    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
      size_t     *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
      size_t      countersize  IN - size of input buffer
 */
u_char *
asn_build_unsigned_int64(u_char *data,
			 size_t *datalength,
			 u_char type,
			 struct counter64 *cp,
			 size_t countersize)
{
/*
 * ASN.1 integer ::= 0x02 asnlength byte {byte}*
 */

    register u_long low, high;
    register u_long mask, mask2;
    int add_null_byte = 0;
    size_t intsize;

  if (countersize != sizeof(struct counter64)){
    _asn_size_err("build uint64", 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.