cache.c

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/*
 * Copyright (c) 1997 - 2007 Kungliga Tekniska H鰃skolan
 * (Royal Institute of Technology, Stockholm, Sweden). 
 * All rights reserved. 
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions 
 * are met: 
 *
 * 1. Redistributions of source code must retain the above copyright 
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright 
 *    notice, this list of conditions and the following disclaimer in the 
 *    documentation and/or other materials provided with the distribution. 
 *
 * 3. Neither the name of the Institute nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software 
 *    without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
 * SUCH DAMAGE. 
 */

#include "krb5_locl.h"

RCSID("$Id: cache.c 22127 2007-12-04 00:54:37Z lha $");

/**
 * Add a new ccache type with operations `ops', overwriting any
 * existing one if `override'.
 *
 * @param context a Keberos context
 * @param ops type of plugin symbol
 * @param override flag to select if the registration is to overide
 * an existing ops with the same name.
 *
 * @return Return an error code or 0.
 *
 * @ingroup krb5_ccache
 */

krb5_error_code KRB5_LIB_FUNCTION
krb5_cc_register(krb5_context context, 
		 const krb5_cc_ops *ops, 
		 krb5_boolean override)
{
    int i;

    for(i = 0; i < context->num_cc_ops && context->cc_ops[i].prefix; i++) {
	if(strcmp(context->cc_ops[i].prefix, ops->prefix) == 0) {
	    if(!override) {
		krb5_set_error_string(context,
				      "ccache type %s already exists",
				      ops->prefix);
		return KRB5_CC_TYPE_EXISTS;
	    }
	    break;
	}
    }
    if(i == context->num_cc_ops) {
	krb5_cc_ops *o = realloc(context->cc_ops,
				 (context->num_cc_ops + 1) *
				 sizeof(*context->cc_ops));
	if(o == NULL) {
	    krb5_set_error_string(context, "malloc: out of memory");
	    return KRB5_CC_NOMEM;
	}
	context->num_cc_ops++;
	context->cc_ops = o;
	memset(context->cc_ops + i, 0, 
	       (context->num_cc_ops - i) * sizeof(*context->cc_ops));
    }
    memcpy(&context->cc_ops[i], ops, sizeof(context->cc_ops[i]));
    return 0;
}

/*
 * Allocate the memory for a `id' and the that function table to
 * `ops'. Returns 0 or and error code.
 */

krb5_error_code
_krb5_cc_allocate(krb5_context context, 
		  const krb5_cc_ops *ops,
		  krb5_ccache *id)
{
    krb5_ccache p;

    p = malloc (sizeof(*p));
    if(p == NULL) {
	krb5_set_error_string(context, "malloc: out of memory");
	return KRB5_CC_NOMEM;
    }
    p->ops = ops;
    *id = p;

    return 0;
}

/*
 * Allocate memory for a new ccache in `id' with operations `ops'
 * and name `residual'. Return 0 or an error code.
 */

static krb5_error_code
allocate_ccache (krb5_context context,
		 const krb5_cc_ops *ops,
		 const char *residual,
		 krb5_ccache *id)
{
    krb5_error_code ret;

    ret = _krb5_cc_allocate(context, ops, id);
    if (ret)
	return ret;
    ret = (*id)->ops->resolve(context, id, residual);
    if(ret)
	free(*id);
    return ret;
}

/**
 * Find and allocate a ccache in `id' from the specification in `residual'.
 * If the ccache name doesn't contain any colon, interpret it as a file name.
 *
 * @param context a Keberos context.
 * @param name string name of a credential cache.
 * @param id return pointer to a found credential cache.
 *
 * @return Return 0 or an error code. In case of an error, id is set
 * to NULL.
 *
 * @ingroup krb5_ccache
 */


krb5_error_code KRB5_LIB_FUNCTION
krb5_cc_resolve(krb5_context context,
		const char *name,
		krb5_ccache *id)
{
    int i;

    *id = NULL;

    for(i = 0; i < context->num_cc_ops && context->cc_ops[i].prefix; i++) {
	size_t prefix_len = strlen(context->cc_ops[i].prefix);

	if(strncmp(context->cc_ops[i].prefix, name, prefix_len) == 0
	   && name[prefix_len] == ':') {
	    return allocate_ccache (context, &context->cc_ops[i],
				    name + prefix_len + 1,
				    id);
	}
    }
    if (strchr (name, ':') == NULL)
	return allocate_ccache (context, &krb5_fcc_ops, name, id);
    else {
	krb5_set_error_string(context, "unknown ccache type %s", name);
	return KRB5_CC_UNKNOWN_TYPE;
    }
}

/**
 * Generate a new ccache of type `ops' in `id'.
 *
 * @return Return 0 or an error code.
 *
 * @ingroup krb5_ccache
 */


krb5_error_code KRB5_LIB_FUNCTION
krb5_cc_gen_new(krb5_context context,
		const krb5_cc_ops *ops,
		krb5_ccache *id)
{
    return krb5_cc_new_unique(context, ops->prefix, NULL, id);
}

/**
 * Generates a new unique ccache of `type` in `id'. If `type' is NULL,
 * the library chooses the default credential cache type. The supplied
 * `hint' (that can be NULL) is a string that the credential cache
 * type can use to base the name of the credential on, this is to make
 * it easier for the user to differentiate the credentials.
 *
 * @return Returns 0 or an error code.
 *
 * @ingroup krb5_ccache
 */

krb5_error_code KRB5_LIB_FUNCTION
krb5_cc_new_unique(krb5_context context, const char *type, 
		   const char *hint, krb5_ccache *id)
{
    const krb5_cc_ops *ops = KRB5_DEFAULT_CCTYPE;
    krb5_error_code ret;

    if (type) {
	ops = krb5_cc_get_prefix_ops(context, type);
	if (ops == NULL) {
	    krb5_set_error_string(context,
				  "Credential cache type %s is unknown", type);
	    return KRB5_CC_UNKNOWN_TYPE;
	}
    }

    ret = _krb5_cc_allocate(context, ops, id);
    if (ret)
	return ret;
    return (*id)->ops->gen_new(context, id);
}

/**
 * Return the name of the ccache `id'
 *
 * @ingroup krb5_ccache
 */


const char* KRB5_LIB_FUNCTION
krb5_cc_get_name(krb5_context context,
		 krb5_ccache id)
{
    return id->ops->get_name(context, id);
}

/**
 * Return the type of the ccache `id'.
 *
 * @ingroup krb5_ccache
 */


const char* KRB5_LIB_FUNCTION
krb5_cc_get_type(krb5_context context,
		 krb5_ccache id)
{
    return id->ops->prefix;
}

/**
 * Return the complete resolvable name the ccache `id' in `str