/*
 * lib/krb5/ccache/stdio/scc_read.c
 *
 * Copyright 1990,1991 by the Massachusetts Institute of Technology.
 * All Rights Reserved.
 *
 * Export of this software from the United States of America may
 *   require a specific license from the United States Government.
 *   It is the responsibility of any person or organization contemplating
 *   export to obtain such a license before exporting.
 * 
 * WITHIN THAT CONSTRAINT, 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 M.I.T. not be used in advertising or publicity pertaining
 * to distribution of the software without specific, written prior
 * permission.  Furthermore if you modify this software you must label
 * your software as modified software and not distribute it in such a
 * fashion that it might be confused with the original M.I.T. software.
 * M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without express
 * or implied warranty.
 * 
 *
 * This file contains the source code for reading variables from a
 * credentials cache.  These are not library-exported functions.
 */


#include "scc.h"

#define CHECK(ret) if (ret != KRB5_OK) goto errout;
     
/*
 * Effects:
 * Reads len bytes from the cache id, storing them in buf.
 *
 * Errors:
 * KRB5_CC_END - there were not len bytes available
 * system errors (read)
 */
krb5_error_code
krb5_scc_read(context, id, buf, len)
   krb5_context context;
   krb5_ccache id;
   krb5_pointer buf;
   int len;
{
     int ret;

     errno = 0;
     ret = fread((char *) buf, 1, len, ((krb5_scc_data *) id->data)->file);
     if ((ret == 0) && errno)
	  return krb5_scc_interpret(context, errno);
     else if (ret != len)
	  return KRB5_CC_END;
     else
	  return KRB5_OK;
}

/*
 * FOR ALL OF THE FOLLOWING FUNCTIONS:
 *
 * Requires:
 * id is open and set to read at the appropriate place in the file
 *
 * Effects:
 * Fills in the second argument with data of the appropriate type from
 * the file.  In some cases, the functions have to allocate space for
 * variable length fields; therefore, krb5_destroy_<type> must be
 * called for each filled in structure.
 *
 * Errors:
 * system errors (read errors)
 * KRB5_CC_NOMEM
 */

krb5_error_code
krb5_scc_read_principal(context, id, princ)
   krb5_context context;
   krb5_ccache id;
   krb5_principal *princ;
{
    krb5_scc_data *data = (krb5_scc_data *)id->data;
    krb5_error_code kret;
    register krb5_principal tmpprinc;
    krb5_int32 length, type;
    int i;

    if (data->version == KRB5_SCC_FVNO_1) {
	type = KRB5_NT_UNKNOWN;
    } else {
        /* Read principal type */
        kret = krb5_scc_read_int32(context, id, &type);
        if (kret != KRB5_OK)
	    return kret;
    }

    /* Read the number of components */
    kret = krb5_scc_read_int32(context, id, &length);
    if (kret != KRB5_OK)
	return kret;

    /*
     * DCE includes the principal's realm in the count; the new format
     * does not.
     */
    if (data->version == KRB5_SCC_FVNO_1)
	length--;

    tmpprinc = (krb5_principal) malloc(sizeof(krb5_principal_data));
    if (tmpprinc == NULL)
	return KRB5_CC_NOMEM;
    if (length) {
	    tmpprinc->data = (krb5_data *) malloc(length * sizeof(krb5_data));
	    if (tmpprinc->data == 0) {
		    free((char *)tmpprinc);
		    return KRB5_CC_NOMEM;
	    }
    } else
	    tmpprinc->data = 0;
    tmpprinc->magic = KV5M_PRINCIPAL;
    tmpprinc->length = length;
    tmpprinc->type = type;

    kret = krb5_scc_read_data(context, id, krb5_princ_realm(context, tmpprinc));

    i = 0;
    CHECK(kret);

    for (i=0; i < length; i++) {
	kret = krb5_scc_read_data(context, id, krb5_princ_component(context, tmpprinc, i));
	CHECK(kret);
    }
    *princ = tmpprinc;
    return KRB5_OK;

 errout:
    while(--i >= 0)
	free(krb5_princ_component(context, tmpprinc, i)->data);
    free((char *)tmpprinc->data);
    free((char *)tmpprinc);
    return kret;
}

krb5_error_code
krb5_scc_read_addrs(context, id, addrs)
   krb5_context context;
   krb5_ccache id;
   krb5_address ***addrs;
{
     krb5_error_code kret;
     krb5_int32 length;
     int i;

     *addrs = 0;

     /* Read the number of components */
     kret = krb5_scc_read_int32(context, id, &length);
     CHECK(kret);

     /* Make *addrs able to hold length pointers to krb5_address structs
      * Add one extra for a null-terminated list
      */
     *addrs = (krb5_address **) calloc(length+1, sizeof(krb5_address *));
     if (*addrs == NULL)
	  return KRB5_CC_NOMEM;

     for (i=0; i < length; i++) {
	  (*addrs)[i] = (krb5_address *) malloc(sizeof(krb5_address));
	  if ((*addrs)[i] == NULL) {
	      krb5_free_addresses(context, *addrs);
	      return KRB5_CC_NOMEM;
	  }	  
	  kret = krb5_scc_read_addr(context, id, (*addrs)[i]);
	  CHECK(kret);
     }

     return KRB5_OK;
 errout:
     if (*addrs)
	 krb5_free_addresses(context, *addrs);
     return kret;
}

krb5_error_code
krb5_scc_read_keyblock(context, id, keyblock)
   krb5_context context;
   krb5_ccache id;
   krb5_keyblock *keyblock;
{
     krb5_scc_data *data = (krb5_scc_data *)id->data;
     krb5_error_code kret;
     krb5_ui_2 ui2;
     krb5_int32 int32;

     keyblock->magic = KV5M_KEYBLOCK;
     keyblock->contents = 0;

     kret = krb5_scc_read_ui_2(context, id, &ui2);
     keyblock->enctype = ui2;
     CHECK(kret);
     if (data->version == KRB5_SCC_FVNO_3) {
		/* This works because the old etype is the same as the new enctype. */
	     kret = krb5_scc_read_ui_2(context, id, &ui2);
	     /* keyblock->enctype = ui2; */
	     CHECK(kret);
     }

     kret = krb5_scc_read_int32(context, id, &int32);
     CHECK(kret);
#ifdef _MSDOS
     int32 &= VALID_INT_BITS;    /* Gradient does not write  correctly */     
#else
     if ((int32 & VALID_INT_BITS) != int32)     /* Overflow size_t??? */
	  return KRB5_CC_NOMEM;
#endif
     keyblock->length = int32;
     if ( keyblock->length == 0 )
	     return KRB5_OK;
     keyblock->contents = (unsigned char *) malloc(keyblock->length*
						   sizeof(krb5_octet));
     if (keyblock->contents == NULL)
	  return KRB5_CC_NOMEM;
     
     kret = krb5_scc_read(context, id, keyblock->contents, keyblock->length);
     if (kret)
	 goto errout;

     return KRB5_OK;
 errout:
     if (keyblock->contents)
	 krb5_xfree(keyblock->contents);
     return kret;
}

krb5_error_code
krb5_scc_read_data(context, id, data)
   krb5_context context;
   krb5_ccache id;
   krb5_data *data;
{
     krb5_error_code kret;
     krb5_int32 len;

     data->magic = KV5M_DATA;
     data->data = 0;

     kret = krb5_scc_read_int32(context, id, &len);
     CHECK(kret);
#ifdef _MSDOS
     len &= VALID_INT_BITS;
#else
     if ((len & VALID_INT_BITS) != len)
        return KRB5_CC_NOMEM;
#endif
     data->length = (int) len;

     if (data->length == 0) {
	data->data = 0;
	return KRB5_OK;
     }

     data->data = (char *) malloc(data->length+1);
     if (data->data == NULL)
	  return KRB5_CC_NOMEM;

     kret = krb5_scc_read(context, id, data->data, data->length);
     CHECK(kret);
     
     data->data[data->length] = 0; /* Null terminate, just in case.... */
     return KRB5_OK;
 errout:
     if (data->data)
	 krb5_xfree(data->data);
     return kret;
}

krb5_error_code
krb5_scc_read_addr(context, id, addr)
   krb5_context context;
   krb5_ccache id;
   krb5_address *addr;
{
     krb5_error_code kret;
     krb5_ui_2 ui2;
     krb5_int32 int32;

     addr->magic = KV5M_ADDRESS;
     addr->contents = 0;

     kret = krb5_scc_read_ui_2(context, id, &ui2);
     CHECK(kret);
     addr->addrtype = ui2;
     
     kret = krb5_scc_read_int32(context, id, &int32);
     CHECK(kret);
#ifdef _MSDOS
     int32 &= VALID_INT_BITS;	/* Gradient DCE does this wrong */
#else
     if ((int32 & VALID_INT_BITS) != int32)     /* Overflow int??? */
	  return KRB5_CC_NOMEM;
#endif
     addr->length = int32;

     if (addr->length == 0)
	     return KRB5_OK;

     addr->contents = (krb5_octet *) malloc(addr->length);
     if (addr->contents == NULL)
	  return KRB5_CC_NOMEM;

     kret = krb5_scc_read(context, id, addr->contents, addr->length);
     CHECK(kret);

     return KRB5_OK;
 errout:
     if (addr->contents)
	 krb5_xfree(addr->contents);
     return kret;
}

krb5_error_code
krb5_scc_read_int32(context, id, i)
   krb5_context context;
   krb5_ccache id;
   krb5_int32 *i;
{
    krb5_scc_data *data = (krb5_scc_data *)id->data;
    krb5_error_code retval;
    unsigned char buf[4];

    if ((data->version == KRB5_SCC_FVNO_1) ||
	(data->version == KRB5_SCC_FVNO_2)) 
	return krb5_scc_read(context, id, (krb5_pointer) i, sizeof(krb5_int32));
    else {
	retval = krb5_scc_read(context, id, buf, 4);
	if (retval)
	    return retval;
	*i = (((((buf[0] << 8) + buf[1]) << 8 ) + buf[2]) << 8) + buf[3];
	return 0;
    }
}

krb5_error_code
krb5_scc_read_ui_2(context, id, i)
   krb5_context context;
   krb5_ccache id;
   krb5_ui_2 *i;
{
    krb5_scc_data *data = (krb5_scc_data *)id->data;
    krb5_error_code retval;
    unsigned char buf[2];
    
    if ((data->version == KRB5_SCC_FVNO_1) ||
	(data->version == KRB5_SCC_FVNO_2))
	return krb5_scc_read(context, id, (krb5_pointer) i, sizeof(krb5_ui_2));
    else {
	retval = krb5_scc_read(context, id, buf, 2);
	if (retval)
	    return retval;
	*i = (buf[0] << 8) + buf[1];
	return 0;
    }
}    

krb5_error_code
krb5_scc_read_octet(context, id, i)
   krb5_context context;
   krb5_ccache id;
   krb5_octet *i;
{
    return krb5_scc_read(context, id, (krb5_pointer) i, 1);
}    


krb5_error_code
krb5_scc_read_times(context, id, t)
   krb5_context context;
   krb5_ccache id;
   krb5_ticket_times *t;
{
    krb5_scc_data *data = (krb5_scc_data *)id->data;
    krb5_error_code retval;
    krb5_int32 i;
    
    if ((data->version == KRB5_SCC_FVNO_1) ||
	(data->version == KRB5_SCC_FVNO_2))
	return krb5_scc_read(context, id, (krb5_pointer) t, sizeof(krb5_ticket_times));
    else {
	retval = krb5_scc_read_int32(context, id, &i);
	CHECK(retval);
	t->authtime = i;
	
	retval = krb5_scc_read_int32(context, id, &i);
	CHECK(retval);
	t->starttime = i;

	retval = krb5_scc_read_int32(context, id, &i);
	CHECK(retval);
	t->endtime = i;

	retval = krb5_scc_read_int32(context, id, &i);
	CHECK(retval);
	t->renew_till = i;
    }
    return 0;
errout:
    return retval;
}

krb5_error_code
krb5_scc_read_authdata(context, id, a)
   krb5_context context;
    krb5_ccache id;
    krb5_authdata ***a;
{
     krb5_error_code kret;
     krb5_int32 length;
     int i;

     *a = 0;

     /* Read the number of components */
     kret = krb5_scc_read_int32(context, id, &length);
     CHECK(kret);

     if (length == 0)
	 return KRB5_OK;

     /* Make *a able to hold length pointers to krb5_authdata structs
      * Add one extra for a null-terminated list
      */
     *a = (krb5_authdata **) calloc(length+1, sizeof(krb5_authdata *));
     if (*a == NULL)
	  return KRB5_CC_NOMEM;

     for (i=0; i < length; i++) {
	  (*a)[i] = (krb5_authdata *) malloc(sizeof(krb5_authdata));
	  if ((*a)[i] == NULL) {
	      krb5_free_authdata(context, *a);
	      return KRB5_CC_NOMEM;
	  }	  
	  kret = krb5_scc_read_authdatum(context, id, (*a)[i]);
	  CHECK(kret);
     }

     return KRB5_OK;
 errout:
     if (*a)
	 krb5_free_authdata(context, *a);
     return kret;
}

krb5_error_code
krb5_scc_read_authdatum(context, id, a)
   krb5_context context;
    krb5_ccache id;
    krb5_authdata *a;
{
    krb5_error_code kret;
    krb5_int32 int32;
    krb5_ui_2 ui2;
    
    a->magic = KV5M_AUTHDATA;
    a->contents = NULL;

    kret = krb5_scc_read_ui_2(context, id, &ui2);
    CHECK(kret);
    a->ad_type = (krb5_authdatatype)ui2;
    kret = krb5_scc_read_int32(context, id, &int32);
    CHECK(kret);
#ifdef _MSDOS
    int32 &= VALID_INT_BITS;
#else
    if ((int32 & VALID_INT_BITS) != int32)     /* Overflow int??? */
          return KRB5_CC_NOMEM;
#endif
    a->length = int32;
    
    if (a->length == 0 )
	    return KRB5_OK;

    a->contents = (krb5_octet *) malloc(a->length);
    if (a->contents == NULL)
	return KRB5_CC_NOMEM;

    kret = krb5_scc_read(context, id, a->contents, a->length);
    CHECK(kret);
    
     return KRB5_OK;
 errout:
     if (a->contents)
	 krb5_xfree(a->contents);
     return kret;
    
}
