/* * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved. * * The contents of this file constitute Original Code as defined in and are * subject to the Apple Public Source License Version 1.2 (the 'License'). * You may not use this file except in compliance with the License. Please obtain * a copy of the License at http://www.apple.com/publicsource and read it before * using this file. * * This Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the * specific language governing rights and limitations under the License. */ // file: .../c++-lib/src/asn-len.C - ASN.1 Length manipluation routines // // MS 92/06/18 // Copyright (C) 1992 Michael Sample and the University of British Columbia // // This library is free software; you can redistribute it and/or // modify it provided that this copyright/license information is retained // in original form. // // If you modify this file, you must clearly indicate your changes. // // This source code is distributed in the hope that it will be // useful, but WITHOUT ANY WARRANTY; without even the implied warranty // of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. // #include "asn-config.h" #include "asn-len.h" /* * Encodes the given length to the given buffer. * returns the number of octets written to the buffer. */ AsnLen BEncDefLen (BUF_TYPE b, AsnLen len) { /* * unrolled for efficiency * (check each possibitlity of the 4 byte integer) */ if (len < 128) { b.PutByteRvs (len); return 1; } else if (len < 256) { b.PutByteRvs (len); b.PutByteRvs (0x81); return 2; } else if (len < 65536) { b.PutByteRvs (len); b.PutByteRvs (len >> 8); b.PutByteRvs (0x82); return 3; } else if (len < 16777126) { b.PutByteRvs (len); b.PutByteRvs (len >> 8); b.PutByteRvs (len >> 16); b.PutByteRvs (0x83); return 4; } else { b.PutByteRvs (len); b.PutByteRvs (len >> 8); b.PutByteRvs (len >> 16); b.PutByteRvs (len >> 24); b.PutByteRvs (0x84); return 5; } } /* EncodeDefLen */ /* * Decode a BER length from the given buffer. Increments bytesDecoded * by the number of octets of the encoded length. Flags an * error if the length is too large or a read error occurs */ AsnLen BDecLen (BUF_TYPE b, AsnLen &bytesDecoded, ENV_TYPE env) { AsnLen len; unsigned char byte; unsigned lenBytes; byte = b.GetByte(); if (b.ReadError()) { Asn1Error << "BDecLen: decoded past end of data" << endl; #if SNACC_EXCEPTION_ENABLE SnaccExcep::throwMe(-9); #else longjmp (env, -9); #endif } bytesDecoded++; if (byte < 128) /* short length */ return byte; else if (byte == (unsigned char) 0x080) /* indef len indicator */ return INDEFINITE_LEN; else /* long len form */ { /* * strip high bit to get # bytes left in len */ lenBytes = byte & (unsigned char) 0x7f; if (lenBytes > sizeof (long int)) { Asn1Error << "BDecLen: ERROR - length overflow" << endl; #if SNACC_EXCEPTION_ENABLE SnaccExcep::throwMe(-10); #else longjmp (env, -10); #endif } bytesDecoded += lenBytes; for (len = 0; lenBytes > 0; lenBytes--) len = (len << 8) | (unsigned long int) b.GetByte(); if (b.ReadError()) { Asn1Error << "BDecLen: decoded past end of data" << endl; #if SNACC_EXCEPTION_ENABLE SnaccExcep::throwMe(-11); #else longjmp (env, -11); #endif } return len; } /* not reached */ } /* * Encodes an End of Contents (EOC) to the given buffer. * Returns the encoded length. */ AsnLen BEncEoc (BUF_TYPE b) { b.PutByteRvs (0); b.PutByteRvs (0); return 2; } /* BEncEoc */ /* * Decodes an EOC from the given buffer. flags an error if the * octets are non-zero or if read error occured. */ void BDecEoc (BUF_TYPE b, AsnLen &bytesDecoded, ENV_TYPE env) { if ((b.GetByte() != 0) || (b.GetByte() != 0) || b.ReadError()) { Asn1Error << "BDecEoc: ERROR - non zero byte in EOC or end of data reached" << endl; #if SNACC_EXCEPTION_ENABLE SnaccExcep::throwMe(-12); #else longjmp (env, -12); #endif } bytesDecoded += 2; } /* BDecEoc */