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 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 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
