xref: /onnv-gate/usr/src/cmd/gss/gsscred/gsscred_file.c (revision 114:ba10d60d4eda)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>
#include "gsscred.h"

/*
 *  gsscred utility
 *  Manages mapping between a security principal name and unix uid.
 *  Implementation file for the file based gsscred utility.
 */

#define	MAX_ENTRY_LEN 1024
static const char credFile[] = "/etc/gss/gsscred_db";
static const char credFileTmp[] = "/etc/gss/gsscred_db.tmp";
static const int expNameTokIdLen = 2;
static const int mechOidLenLen = 2;
static const int mechOidTagLen = 1;

static int matchEntry(const char *entry, const gss_buffer_t name,
		const char *uid, uid_t *uidOut);

/* From g_glue.c */
extern int
get_der_length(unsigned char **, unsigned int, unsigned int *);

/*
 * file_addGssCredEntry
 *
 * Adds a new entry to the gsscred table.
 * Does not check for duplicate entries.
 */
int file_addGssCredEntry(const gss_buffer_t hexName, const char *uid,
		const char *comment, char **errDetails)
{
	FILE *fp;
	char tmpBuf[256];

	if ((fp = fopen(credFile, "a")) == NULL) {
		if (errDetails) {
			(void) snprintf(tmpBuf, sizeof (tmpBuf),
				gettext("Unable to open gsscred file [%s]"),
				credFile);
			*errDetails = strdup(tmpBuf);
		}
		return (0);
	}

	(void) fprintf(fp,
		    "%s\t%s\t%s\n", (char *)hexName->value, uid, comment);
	(void) fclose(fp);
	return (1);
}  /* *******  file_addGssCredEntry ****** */



/*
 * file_getGssCredEntry
 *
 * Searches the file for the file matching the name.  Since the name
 * contains a mechanism identifier, to search for all names for a given
 * mechanism just supply the mechanism portion in the name buffer.
 * To search by uid only, supply a non-null value of uid.
 */
int file_getGssCredEntry(const gss_buffer_t name, const char *uid,
		char **errDetails)
{
	FILE *fp;
	char entry[MAX_ENTRY_LEN+1];

	if ((fp = fopen(credFile, "r")) == NULL) {

		if (errDetails) {
			(void) snprintf(entry, sizeof (entry),
				gettext("Unable to open gsscred file [%s]"),
				credFile);
			*errDetails = strdup(entry);
		}

		return (0);
	}

	/* go through the file in sequential order */
	while (fgets(entry, MAX_ENTRY_LEN, fp) != NULL) {
		/* is there any search criteria */
		if (name == NULL && uid == NULL) {
			(void) fprintf(stdout, "%s", entry);
			continue;
		}

		if (matchEntry(entry, name, uid, NULL))
			(void) fprintf(stdout, "%s", entry);

	}	 /* while */

	(void) fclose(fp);
	return (1);
}  /* file_getGssCredEntry */

/*
 * file_getGssCredUid
 *
 * GSS entry point for retrieving user uid information.
 * We need to go through the entire file to ensure that
 * the last matching entry is retrieved - this is because
 * new entries are added to the end, and in case of
 * duplicates we want to get the latest entry.
 */
int
file_getGssCredUid(const gss_buffer_t expName, uid_t *uidOut)
{
	FILE *fp;
	char entry[MAX_ENTRY_LEN+1];
	int retVal = 0;

	if ((fp = fopen(credFile, "r")) == NULL)
		return (0);

	/* go through the entire file in sequential order */
	while (fgets(entry, MAX_ENTRY_LEN, fp) != NULL) {
		if (matchEntry(entry, expName, NULL, uidOut)) {
			retVal = 1;
		}
	} /* while */

	(void) fclose(fp);
	return (retVal);
} /* file_getGssCredUid */



/*
 *
 * file_deleteGssCredEntry
 *
 * removes entries form file that match the delete criteria
 */
int file_deleteGssCredEntry(const gss_buffer_t name, const char *uid,
		char **errDetails)
{
	FILE *fp, *tempFp;
	char entry[MAX_ENTRY_LEN+1];
	int foundOne = 0;

	/* are we deleting everyone? */
	if (name == NULL && uid == NULL) {

		if ((fp = fopen(credFile, "w")) == NULL) {

			if (errDetails) {
				(void) snprintf(entry, sizeof (entry),
					gettext("Unable to open gsscred"
						" file [%s]"),
					credFile);
				*errDetails = strdup(entry);
			}
			return (0);
		}

		(void) fclose(fp);
		return (1);
	}

	/* selective delete - might still be everyone */
	if ((fp = fopen(credFile, "r")) == NULL) {

		if (errDetails) {
			(void) snprintf(entry, sizeof (entry),
				gettext("Unable to open gsscred file [%s]"),
				credFile);
			*errDetails = strdup(entry);
		}
		return (0);
	}

	/* also need to open temp file */
	if ((tempFp = fopen(credFileTmp, "w")) == NULL) {
		if (errDetails) {
			(void) snprintf(entry, sizeof (entry),
				gettext("Unable to open gsscred temporary"
					" file [%s]"),
				credFileTmp);
			*errDetails = strdup(entry);
		}

		(void) fclose(fp);
		return (0);
	}

	/* go through all the entries sequentially removing ones that match */
	while (fgets(entry, MAX_ENTRY_LEN, fp) != NULL) {

		if (!matchEntry(entry, name, uid, NULL))
			(void) fputs(entry, tempFp);
		else
			foundOne = 1;
	}
	(void) fclose(tempFp);
	(void) fclose(fp);

	/* now make the tempfile the gsscred file */
	(void) rename(credFileTmp, credFile);
	(void) unlink(credFileTmp);

	if (!foundOne) {
		*errDetails = strdup(gettext("No users found"));
		return (0);
	}
	return (1);
}  /* file_deleteGssCredEntry */



/*
 *
 * match entry
 *
 * checks if the specified entry matches the supplied criteria
 * returns 1 if yes, 0 if no
 * uidOut value can be used to retrieve the uid from the entry
 * when the uid string is passed in, the uidOut value is not set
 */
static int matchEntry(const char *entry, const gss_buffer_t name,
		const char *uid, uid_t *uidOut)
{
	char fullEntry[MAX_ENTRY_LEN+1], *item;
	unsigned char *buf;
	char dilims[] = "\t \n";
	int length;
	unsigned int dummy;
	OM_uint32 minor, result;
	gss_buffer_desc mechOidDesc = GSS_C_EMPTY_BUFFER;
	gss_name_t intName;
	gss_buffer_desc expName;
	char *krb5_oid = "\052\206\110\206\367\022\001\002\002";

	if (entry == NULL || isspace(*entry))
		return (0);

	/* save the entry since strtok will chop it up */
	(void) strcpy(fullEntry, entry);

	if ((item = strtok(fullEntry, dilims)) == NULL)
		return (0);

	/* do wee need to search the name */
	if (name != NULL) {
		/* we can match the prefix of the string */
		if (strlen(item) < name->length)
			return (0);

		if (memcmp(item, name->value, name->length) != 0) {

			buf = (unsigned char *)name->value;
			buf += expNameTokIdLen;

			/* skip oid length - get to der */
			buf += 2;

			/* skip oid tag */
			buf++;

			/* get oid length */
			length = get_der_length(&buf,
				(name->length - expNameTokIdLen
				- mechOidLenLen - mechOidTagLen), &dummy);

			if (length == -1)
				return (0);

			mechOidDesc.length = length;

			/*
			 * check whether exported name length is within the
			 * boundary.
			 */
			if (name->length <
				(expNameTokIdLen + mechOidLenLen + length
					+ dummy + mechOidTagLen))
				return (0);

			mechOidDesc.value = buf;

			buf += dummy + mechOidDesc.length;

			/*
			 * If the mechoid is that of Kerberos and if the
			 * "display" part of the exported file name starts and
			 * ends with a zero-valued byte, then we are dealing
			 * with old styled gsscred entries. We will then match
			 * them in the following manner:
			 *	- gss_import_name() the name from the file
			 *	- gss_export_name() the result
			 *	- mem_cmp() the result with the name we are
			 *		trying to match.
			 */
			if (mechOidDesc.length == 9 &&
				(memcmp(buf, krb5_oid,
						mechOidDesc.length) == 0) &&
				(*buf == '\0' && buf[length] == '\0')) {
				if (gss_import_name(&minor, name,
						GSS_C_NT_EXPORT_NAME,
						&intName) != GSS_S_COMPLETE)
					return (0);
				result = gss_export_name(&minor, intName,
								&expName);
				(void) gss_release_name(&minor, &intName);
				if (result != GSS_S_COMPLETE)
					return (0);
				result = memcmp(item, expName.value,
							expName.length);
				(void) gss_release_buffer(&minor, &expName);
				if (result != 0)
					return (0);
			}
		}

		/* do we need to check the uid - if not then we found it */
		if (uid == NULL) {
			/* do we ned to parse out the uid ? */
			if (uidOut) {
				if ((item = strtok(NULL, dilims)) == NULL)
					return (0);
				*uidOut = atol(item);
			}
			return (1);
		}

		/* continue with checking the uid */
	}

	if (uid == NULL)
		return (1);

	/* get the next token from the string - the uid */
	if ((item = strtok(NULL, dilims)) == NULL)
		return (0);

	if (strcmp(item, uid) == 0)
		return (1);

	return (0);
}  /* *******  matchEntry ****** */