asn_octs.c

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/*
 * asn_octs.c - BER encode, decode, print and free routines for the 
 *              ASN.1 OCTET STRING type.
 *
 * MS 92
 * 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.
 * 
 */

#if HAVE_CONFIG_H
#include <config.h>
#endif

#include "asn_config.h"
#include "asn_len.h"
#include "asn_tag.h"
#include "str_stk.h"
#include "asn_bits.h" /* for TO_HEX macro */
#include "asn_octs.h"



/*
 * encodes universal TAG LENGTH and Contents of and ASN.1 OCTET STRING
 */
AsnLen
BEncAsnOcts PARAMS((b, data),
BUF_TYPE     b _AND_
AsnOcts* data)
{
    AsnLen len;

    len =  BEncAsnOctsContent(b, data);
    len += BEncDefLen(b, len);
    len += BEncTag1(b, UNIV, PRIM, OCTETSTRING_TAG_CODE);
    return(len);
}  /* BEncAsnOcts */


/*
 * decodes universal TAG LENGTH and Contents of and ASN.1 OCTET STRING
 */
void
BDecAsnOcts PARAMS((b, result, bytesDecoded, env),
BUF_TYPE   b _AND_
AsnOcts*    result _AND_
AsnLen* bytesDecoded _AND_
jmp_buf env)
{
    AsnTag tag;
    AsnLen elmtLen;

    if (( (tag =BDecTag(b, bytesDecoded, env)) !=
        MAKE_TAG_ID(UNIV, PRIM, OCTETSTRING_TAG_CODE)) &&
        (tag != MAKE_TAG_ID(UNIV, CONS, OCTETSTRING_TAG_CODE)))
    {
         Asn1Error("BDecAsnOcts: ERROR - wrong tag on OCTET STRING.\n");
         longjmp(env, -40);
    }

    elmtLen = BDecLen (b, bytesDecoded, env);
    BDecAsnOctsContent( b, tag, elmtLen, result, bytesDecoded, env);

}  /* BDecAsnOcts */

/*
 * BER encodes just the content of an OCTET STRING.
 */
AsnLen
BEncAsnOctsContent PARAMS((b, o),
BUF_TYPE b _AND_
AsnOcts* o)
{
    BufPutSegRvs(b, o->octs, o->octetLen);
    return(o->octetLen);
}  /* BEncAsnOctsContent */



/*
 * Used for decoding constructed OCTET STRING values into
 * a contiguous local rep.
 * fills string stack with references to the pieces of a
 * construced octet string
 */
static void
FillOctetStringStk PARAMS((b, elmtLen0, bytesDecoded, env),
BUF_TYPE b _AND_
AsnLen elmtLen0 _AND_
AsnLen* bytesDecoded _AND_
jmp_buf env)
{
    unsigned long int refdLen;
    unsigned long int totalRefdLen;
    char* strPtr;
    unsigned long int totalElmtsLen1 = 0;
    unsigned long int tagId1;
    unsigned long int elmtLen1;

    for ( ; (totalElmtsLen1 < elmtLen0) || (elmtLen0 == INDEFINITE_LEN);)
    {
        tagId1 = BDecTag(b, &totalElmtsLen1, env);

        if ( (tagId1 == EOC_TAG_ID) && (elmtLen0 == INDEFINITE_LEN))
        {
            BDEC_2ND_EOC_OCTET(b, &totalElmtsLen1, env);
            break;
        }

        elmtLen1 = BDecLen (b, &totalElmtsLen1, env);
        if ( tagId1 == MAKE_TAG_ID( UNIV, PRIM, OCTETSTRING_TAG_CODE))
        {
            /*
             * primitive part of string, put references to piece(s) in
             * str stack
             */
            totalRefdLen = 0;
            refdLen = elmtLen1;
            while (1)
            {
                strPtr = BufGetSeg( b, &refdLen);

                PUSH_STR(strPtr, refdLen, env);
                totalRefdLen += refdLen;
                if (totalRefdLen == elmtLen1)
                    break; /* exit this while loop */

                if (refdLen == 0) /* end of data */
                {
                    Asn1Error("BDecConsOctetString: ERROR - attempt to decode past end of data\n");
                    longjmp(env, -18);
                }
                refdLen = elmtLen1 - totalRefdLen;
            }
            totalElmtsLen1 += elmtLen1;
        } 

    
        else if ( tagId1 == MAKE_TAG_ID( UNIV, CONS, OCTETSTRING_TAG_CODE))
        {
            /*
             * constructed octets string embedding in this constructed
             * octet string. decode it.
             */
            FillOctetStringStk( b, elmtLen1, &totalElmtsLen1, env);
        }
        else  /* wrong tag */
        {
            Asn1Error("BDecConsOctetString: ERROR - decoded non-OCTET STRING tag inside a constructed OCTET STRING\n");
            longjmp(env, -19);
        }
    } /* end of for */

    (*bytesDecoded) += totalElmtsLen1;

}  /* FillOctetStringStk */


/*
 * Decodes a seq of universally tagged octets strings until either EOC is 
 * encountered or the given len is decoded.  Merges them into a single
 * string. puts a NULL terminator on the string but does not include 
 * this in the length.
 */
static void
BDecConsAsnOcts PARAMS((b, len, result, bytesDecoded, env),
BUF_TYPE b _AND_
AsnLen len _AND_
AsnOcts* result _AND_
AsnLen* bytesDecoded _AND_
jmp_buf env)
{
    char* bufCurr;
    unsigned long int curr;

    RESET_STR_STK();
        
    /*
     * decode each piece of the octet string, puting
     * an entry in the octet string stack for each 
     */
    FillOctetStringStk(b, len, bytesDecoded, env);
    
    result->octetLen = strStkG.totalByteLen;

    /* alloc str for all octs pieces with extra byte for null terminator */
    bufCurr = result->octs = Asn1Alloc(strStkG.totalByteLen +1); 

    /* copy octet str pieces into single blk */
    for (curr = 0; curr < strStkG.nextFreeElmt; curr++)
    {
        memcpy(bufCurr, strStkG.stk[curr].str, strStkG.stk[curr].len);
        bufCurr += strStkG.stk[curr].len;
    }

    /* add null terminator - this is not included in the str's len */
    *bufCurr = '\0';
       
}  /* BDecConsAsnOcts */

/*
 * Decodes the content of a BER OCTET STRING value 
 */
void
BDecAsnOctsContent PARAMS((b, tagId, len, result, bytesDecoded, env),
BUF_TYPE b _AND_
AsnTag tagId _AND_
AsnLen len _AND_
AsnOcts* result _AND_
AsnLen* bytesDecoded _AND_
jmp_buf env)
{
    char* tmp;

    /*
     * tagId is encoded tag shifted into long int.
     * if CONS bit is set then constructed octet string
     */
    if (TAG_IS_CONS(tagId))
        BDecConsAsnOcts(b, len, result, bytesDecoded, env);

    else /* primitive octet string */
    {
        result->octetLen = len;
        result->octs =  Asn1Alloc(len+1);
        BufCopy(result->octs, b, len);

        if (BufReadError(b))
        {
            Asn1Error("BDecOctetString: ERROR - decoded past end of data\n");
            longjmp(env, -20);
        }

        /* add null terminator - this is not included in the str's len */
        result->octs[len] = '\0';
        (*bytesDecoded) += len;
    }
}  /* BDecAsnOctsContent */


/*
 * Frees the string part of the given OCTET STRING
 */
void
FreeAsnOcts PARAMS((v),
AsnOcts* v)
{
    Asn1Free(v->octs);
}  /* FreeAsnOcts */
 
/*
 * Prints the given OCTET STRING value to the given FILE* in ASN.1
 * Value Notation.  Since the value notation uses the hard to read
 * hex format, the ASCII version is included in an ASN.1 comment.
 */
void
PrintAsnOcts PARAMS((f,v, indent),
FILE* f _AND_
AsnOcts* v _AND_
unsigned short indent)
{
    int i;

    /* print hstring value */
    fprintf(f,"'");
    
    for(i = 0; i < v->octetLen; i++)
	  fprintf(f,"%c%c", TO_HEX(v->octs[i] >> 4), TO_HEX(v->octs[i]));

    fprintf(f,"'H");

    /* show printable chars in comment */
    fprintf(f,"  -- \"");

    for(i = 0; i < v->octetLen; i++)
    {
	if (isprint(v->octs[i]))
	    fprintf(f,"%c", v->octs[i]);
	else
	  fprintf(f,".");
    }
    fprintf(f,"\" --");

}


/*
 * Returns TRUE if the given OCTET STRING values are identical.
 * Returns FALSE otherwise.
 */
int
AsnOctsEquiv PARAMS((o1, o2),
AsnOcts* o1 _AND_
AsnOcts* o2)
{
    return( (o1->octetLen == o2->octetLen) && (memcmp(o1->octs, o2->octs, o1->octetLen) == 0));
} /* AsnOctsEquiv */