diff options
Diffstat (limited to 'crypto/getuuid.c')
| -rw-r--r-- | crypto/getuuid.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/crypto/getuuid.c b/crypto/getuuid.c new file mode 100644 index 0000000..d973c0f --- /dev/null +++ b/crypto/getuuid.c @@ -0,0 +1,208 @@ +/* Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/* + * This attempts to generate V1 UUIDs according to the Internet Draft + * located at http://www.webdav.org/specs/draft-leach-uuids-guids-01.txt + */ +#include "apr.h" +#include "apr_uuid.h" +#include "apr_md5.h" +#include "apr_general.h" +#include "apr_portable.h" + + +#if APR_HAVE_UNISTD_H +#include <unistd.h> /* for getpid, gethostname */ +#endif +#if APR_HAVE_STDLIB_H +#include <stdlib.h> /* for rand, srand */ +#endif + + +#if APR_HAVE_STRING_H +#include <string.h> +#endif +#if APR_HAVE_STRINGS_H +#include <strings.h> +#endif +#if APR_HAVE_NETDB_H +#include <netdb.h> +#endif +#if APR_HAVE_SYS_TIME_H +#include <sys/time.h> /* for gettimeofday */ +#endif + +#define NODE_LENGTH 6 + +static int uuid_state_seqnum; +static unsigned char uuid_state_node[NODE_LENGTH] = { 0 }; + + +static void get_random_info(unsigned char node[NODE_LENGTH]) +{ +#if APR_HAS_RANDOM + + (void) apr_generate_random_bytes(node, NODE_LENGTH); + +#else + + unsigned char seed[APR_MD5_DIGESTSIZE]; + apr_md5_ctx_t c; + + /* ### probably should revise some of this to be a bit more portable */ + + /* Leach & Salz use Linux-specific struct sysinfo; + * replace with pid/tid for portability (in the spirit of mod_unique_id) */ + struct { + /* Add thread id here, if applicable, when we get to pthread or apr */ + pid_t pid; +#ifdef NETWARE + apr_uint64_t t; +#else + struct timeval t; +#endif + char hostname[257]; + + } r; + + apr_md5_init(&c); +#ifdef NETWARE + r.pid = NXThreadGetId(); + NXGetTime(NX_SINCE_BOOT, NX_USECONDS, &(r.t)); +#else + r.pid = getpid(); + gettimeofday(&r.t, (struct timezone *)0); +#endif + gethostname(r.hostname, 256); + apr_md5_update(&c, (const unsigned char *)&r, sizeof(r)); + apr_md5_final(seed, &c); + + memcpy(node, seed, NODE_LENGTH); /* use a subset of the seed bytes */ +#endif +} + +/* This implementation generates a random node ID instead of a + system-dependent call to get IEEE node ID. This is also more secure: + we aren't passing out our MAC address. +*/ +static void get_pseudo_node_identifier(unsigned char *node) +{ + get_random_info(node); + node[0] |= 0x01; /* this designates a random multicast node ID */ +} + +static void get_system_time(apr_uint64_t *uuid_time) +{ + /* ### fix this call to be more portable? */ + *uuid_time = apr_time_now(); + + /* Offset between UUID formatted times and Unix formatted times. + UUID UTC base time is October 15, 1582. + Unix base time is January 1, 1970. */ + *uuid_time = (*uuid_time * 10) + APR_TIME_C(0x01B21DD213814000); +} + +/* true_random -- generate a crypto-quality random number. */ +static int true_random(void) +{ + apr_uint64_t time_now; + +#if APR_HAS_RANDOM + unsigned char buf[2]; + + if (apr_generate_random_bytes(buf, 2) == APR_SUCCESS) { + return (buf[0] << 8) | buf[1]; + } +#endif + + /* crap. this isn't crypto quality, but it will be Good Enough */ + + time_now = apr_time_now(); + srand((unsigned int)(((time_now >> 32) ^ time_now) & 0xffffffff)); + + return rand() & 0x0FFFF; +} + +static void init_state(void) +{ + uuid_state_seqnum = true_random(); + get_pseudo_node_identifier(uuid_state_node); +} + +static void get_current_time(apr_uint64_t *timestamp) +{ + /* ### this needs to be made thread-safe! */ + + apr_uint64_t time_now; + static apr_uint64_t time_last = 0; + static apr_uint64_t fudge = 0; + + get_system_time(&time_now); + + /* if clock reading changed since last UUID generated... */ + if (time_last != time_now) { + /* The clock reading has changed since the last UUID was generated. + Reset the fudge factor. if we are generating them too fast, then + the fudge may need to be reset to something greater than zero. */ + if (time_last + fudge > time_now) + fudge = time_last + fudge - time_now + 1; + else + fudge = 0; + time_last = time_now; + } + else { + /* We generated two really fast. Bump the fudge factor. */ + ++fudge; + } + + *timestamp = time_now + fudge; +} + +APU_DECLARE(void) apr_uuid_get(apr_uuid_t *uuid) +{ + apr_uint64_t timestamp; + unsigned char *d = uuid->data; + +#if APR_HAS_OS_UUID + if (apr_os_uuid_get(d) == APR_SUCCESS) { + return; + } +#endif /* !APR_HAS_OS_UUID */ + + if (!uuid_state_node[0]) + init_state(); + + get_current_time(×tamp); + + /* time_low, uint32 */ + d[3] = (unsigned char)timestamp; + d[2] = (unsigned char)(timestamp >> 8); + d[1] = (unsigned char)(timestamp >> 16); + d[0] = (unsigned char)(timestamp >> 24); + /* time_mid, uint16 */ + d[5] = (unsigned char)(timestamp >> 32); + d[4] = (unsigned char)(timestamp >> 40); + /* time_hi_and_version, uint16 */ + d[7] = (unsigned char)(timestamp >> 48); + d[6] = (unsigned char)(((timestamp >> 56) & 0x0F) | 0x10); + /* clock_seq_hi_and_reserved, uint8 */ + d[8] = (unsigned char)(((uuid_state_seqnum >> 8) & 0x3F) | 0x80); + /* clock_seq_low, uint8 */ + d[9] = (unsigned char)uuid_state_seqnum; + /* node, byte[6] */ + memcpy(&d[10], uuid_state_node, NODE_LENGTH); +} |