1 /*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <string.h>
18
19 #ifdef USE_MINGW
20 #include <winsock2.h>
21 #else
22 #include <arpa/inet.h>
23 #endif
24
25 #include "ext4_utils.h"
26 #include "sha1.h"
27 #include "uuid.h"
28
29 /* Definition from RFC-4122 */
30 struct uuid {
31 u32 time_low;
32 u16 time_mid;
33 u16 time_hi_and_version;
34 u8 clk_seq_hi_res;
35 u8 clk_seq_low;
36 u16 node0_1;
37 u32 node2_5;
38 };
39
sha1_hash(const char * namespace,const char * name,unsigned char sha1[SHA1_DIGEST_LENGTH])40 static void sha1_hash(const char *namespace, const char *name,
41 unsigned char sha1[SHA1_DIGEST_LENGTH])
42 {
43 SHA1_CTX ctx;
44 SHA1Init(&ctx);
45 SHA1Update(&ctx, (const u8*)namespace, strlen(namespace));
46 SHA1Update(&ctx, (const u8*)name, strlen(name));
47 SHA1Final(sha1, &ctx);
48 }
49
generate_uuid(const char * namespace,const char * name,u8 result[16])50 void generate_uuid(const char *namespace, const char *name, u8 result[16])
51 {
52 unsigned char sha1[SHA1_DIGEST_LENGTH];
53 struct uuid *uuid = (struct uuid *)result;
54
55 sha1_hash(namespace, name, (unsigned char*)sha1);
56 memcpy(uuid, sha1, sizeof(struct uuid));
57
58 uuid->time_low = ntohl(uuid->time_low);
59 uuid->time_mid = ntohs(uuid->time_mid);
60 uuid->time_hi_and_version = ntohs(uuid->time_hi_and_version);
61 uuid->time_hi_and_version &= 0x0FFF;
62 uuid->time_hi_and_version |= (5 << 12);
63 uuid->clk_seq_hi_res &= ~(1 << 6);
64 uuid->clk_seq_hi_res |= 1 << 7;
65 }
66