/* message_guid.c -- GUID manipulation
*
* Copyright (c) 1994-2008 Carnegie Mellon University. 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. The name "Carnegie Mellon University" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For permission or any legal
* details, please contact
* Carnegie Mellon University
* Center for Technology Transfer and Enterprise Creation
* 4615 Forbes Avenue
* Suite 302
* Pittsburgh, PA 15213
* (412) 268-7393, fax: (412) 268-7395
* innovation@andrew.cmu.edu
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Computing Services
* at Carnegie Mellon University (http://www.cmu.edu/computing/)."
*
* CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <config.h>
#include <string.h>
#include "assert.h"
#include "global.h"
#include "message_guid.h"
#include "util.h"
#include "xsha1.h"
/* Four possible forms of Message GUID:
*
* Private:
* Used for internal manipulation. Not visible to clients.
*
* Public:
* Opaque handle to GUID that Cyrus can pass around.
*
* OR
*
* Byte sequence of known length (MESSAGE_GUID_SIZE) which can
* be stored on disk.
*
* Textual:
* Textual represenatation for Message GUID for passing over the wire
* Currently BASE64 string + '\0'.
*
*/
/* ====================================================================== */
/* Public interface */
/* message_guid_generate() ***********************************************
*
* Generate GUID from message
*
************************************************************************/
EXPORTED void message_guid_generate(struct message_guid *guid,
const char *msg_base, unsigned long msg_len)
{
guid->status = GUID_NULL;
memset(guid->value, 0, MESSAGE_GUID_SIZE);
guid->status = GUID_NONNULL;
xsha1((const unsigned char *) msg_base, msg_len, guid->value);
}
EXPORTED void message_guid_permute32(struct message_guid *guid, uint32_t val)
{
if (message_guid_isnull(guid))
return;
uint32_t base = ntohl(*((uint32_t *)(guid->value + MESSAGE_GUID_SIZE - 4)));
/* XOR in the 32 bits */
*((uint32_t *)(guid->value + MESSAGE_GUID_SIZE - 4)) = base ^ val;
}
/* message_guid_copy() ***************************************************
*
* Copy GUID
*
************************************************************************/
EXPORTED void message_guid_copy(struct message_guid *dst, const struct message_guid *src)
{
memcpy(dst, src, sizeof(struct message_guid));
}
/* message_guid_equal() **************************************************
*
* Compare a pair of GUIDs: Returns 1 => match.
*
************************************************************************/
EXPORTED int message_guid_equal(const struct message_guid *g1,
const struct message_guid *g2)
{
return (memcmp(g1->value, g2->value, MESSAGE_GUID_SIZE) == 0);
}
EXPORTED int message_guid_cmp(const struct message_guid *g1,
const struct message_guid *g2)
{
return memcmp(g1->value, g2->value, MESSAGE_GUID_SIZE);
}
/* message_guid_hash() ***************************************************
*
* Convert GUID into hash value for hash table lookup
* Returns: positive int in range [0, hash_size-1]
*
************************************************************************/
EXPORTED unsigned long message_guid_hash(const struct message_guid *guid, int hash_size)
{
int i;
unsigned long result = 0;
const unsigned char *s = &guid->value[0];
assert(hash_size > 1);
if (hash_size > 1024) {
/* Pair up chars to get 16 bit values */
for (i = 0; i < MESSAGE_GUID_SIZE; i += 2)
result += (s[i] << 8) + s[i+1];
}
else
for (i = 0; i < MESSAGE_GUID_SIZE; i++)
result += s[i];
return (result % hash_size);
}
/* message_guid_set_null() ***********************************************
*
* Create NULL GUID
*
************************************************************************/
EXPORTED void message_guid_set_null(struct message_guid *guid)
{
guid->status = GUID_NULL;
memset(guid->value, 0, MESSAGE_GUID_SIZE);
}
/* message_guid_isnull() ************************************************
*
* Returns: 1 if GUID is NULL value
*
************************************************************************/
EXPORTED int message_guid_isnull(const struct message_guid *guid)
{
if (guid->status == GUID_UNKNOWN) {
/* allow internal recalculation while still being const */
struct message_guid *backdoor = (struct message_guid *)guid;
const unsigned char *p = guid->value;
int i;
for (i = 0; (i < MESSAGE_GUID_SIZE) && !*p++; i++);
backdoor->status = (i == MESSAGE_GUID_SIZE) ? GUID_NULL : GUID_NONNULL;
}
return (guid->status == GUID_NULL);
}
/* message_guid_export() *************************************************
*
* Export Message GUID as byte sequence (MESSAGE_GUID_SIZE)
* (Wrapper for memcpy() with current implementation)
*
************************************************************************/
EXPORTED void message_guid_export(const struct message_guid *guid, char *buf)
{
memcpy(buf, guid->value, MESSAGE_GUID_SIZE);
}
/* message_guid_import() *************************************************
*
* Import Message GUID from byte sequence (MESSAGE_GUID_SIZE)
* (Wrapper for memcpy() with current implementation)
*
************************************************************************/
EXPORTED const char *message_guid_import(struct message_guid *guid,
const char *buf)
{
assert(guid);
guid->status = GUID_UNKNOWN;
memcpy(guid->value, buf, MESSAGE_GUID_SIZE);
return buf + MESSAGE_GUID_SIZE;
}
/* Routines for manipulating text value (ASCII hex encoding) */
/* message_guid_encode() *************************************************
*
* Returns ptr to '\0' terminated static char * which can be strdup()ed
* NULL => error. Should be impossible as entire range covered
*
************************************************************************/
EXPORTED const char *message_guid_encode(const struct message_guid *guid)
{
static char text[2*MESSAGE_GUID_SIZE+1];
int r = bin_to_hex(&guid->value, MESSAGE_GUID_SIZE, text, BH_LOWER);
assert(r == 2*MESSAGE_GUID_SIZE);
return text;
}
EXPORTED const char *message_guid_encode_short(const struct message_guid *guid, size_t len)
{
assert(len > 0 && len < MESSAGE_GUID_SIZE*2);
char *backdoor = (char *)message_guid_encode(guid);
backdoor[len] = '\0';
return backdoor;
}
/* message_guid_decode() *************************************************
*
* Sets Message GUID from text form. Returns 1 if valid
* Returns: boolean success
*
************************************************************************/
EXPORTED int message_guid_decode(struct message_guid *guid, const char *text)
{
int r = hex_to_bin(text, 0, &guid->value);
guid->status = (r > 0 ? GUID_NONNULL : GUID_NULL);
return (r == MESSAGE_GUID_SIZE);
}