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 #include <arpa/inet.h> 19 20 #include "ext4_utils.h" 21 #include "sha1.h" 22 #include "uuid.h" 23 24 struct uuid { 25 u32 time_low; 26 u32 time_mid; 27 u16 time_hi_and_version; 28 u8 clk_seq_hi_res; 29 u8 clk_seq_low; 30 u16 node0_1; 31 u32 node2_5; 32 }; 33 34 static void sha1_hash(const char *namespace, const char *name, 35 unsigned char sha1[SHA1_DIGEST_LENGTH]) 36 { 37 SHA1_CTX ctx; 38 SHA1Init(&ctx); 39 SHA1Update(&ctx, (const u8*)namespace, strlen(namespace)); 40 SHA1Update(&ctx, (const u8*)name, strlen(name)); 41 SHA1Final(sha1, &ctx); 42 } 43 44 void generate_uuid(const char *namespace, const char *name, u8 result[16]) 45 { 46 unsigned char sha1[SHA1_DIGEST_LENGTH]; 47 struct uuid *uuid = (struct uuid *)result; 48 49 sha1_hash(namespace, name, (unsigned char*)sha1); 50 memcpy(uuid, sha1, sizeof(struct uuid)); 51 52 uuid->time_low = ntohl(uuid->time_low); 53 uuid->time_mid = ntohs(uuid->time_mid); 54 uuid->time_hi_and_version = ntohs(uuid->time_hi_and_version); 55 uuid->time_hi_and_version &= 0x0FFF; 56 uuid->time_hi_and_version |= (5 << 12); 57 uuid->clk_seq_hi_res &= ~(1 << 6); 58 uuid->clk_seq_hi_res |= 1 << 7; 59 } 60
