1 | // Copyright (c) Microsoft. All rights reserved.
|
---|
2 | // Licensed under the MIT license. See LICENSE file in the project root for full license information.
|
---|
3 |
|
---|
4 | #include <stdlib.h>
|
---|
5 | #include <stdint.h>
|
---|
6 | #include "azure_c_shared_utility/uniqueid.h"
|
---|
7 | #include "azure_c_shared_utility/xlogging.h"
|
---|
8 | #include <time.h>
|
---|
9 |
|
---|
10 | MU_DEFINE_ENUM_STRINGS(UNIQUEID_RESULT, UNIQUEID_RESULT_VALUES);
|
---|
11 |
|
---|
12 | static const char tochar[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
|
---|
13 | static void generate128BitUUID(unsigned char* arrayOfByte)
|
---|
14 | {
|
---|
15 | size_t arrayIndex;
|
---|
16 |
|
---|
17 | for (arrayIndex = 0; arrayIndex < 16; arrayIndex++)
|
---|
18 | {
|
---|
19 | arrayOfByte[arrayIndex] = (unsigned char)rand();
|
---|
20 | }
|
---|
21 |
|
---|
22 | //
|
---|
23 | // Stick in the version field for random uuid.
|
---|
24 | //
|
---|
25 | arrayOfByte[7] &= 0x0f; //clear the bit field
|
---|
26 | arrayOfByte[7] |= 0x40; //set the ones we care about
|
---|
27 |
|
---|
28 | //
|
---|
29 | // Stick in the variant field for the random uuid.
|
---|
30 | //
|
---|
31 | arrayOfByte[8] &= 0xf3; // Clear
|
---|
32 | arrayOfByte[8] |= 0x08; // Set
|
---|
33 |
|
---|
34 | }
|
---|
35 |
|
---|
36 | // TODO: The User will need to call srand before calling this function
|
---|
37 | UNIQUEID_RESULT UniqueId_Generate(char* uid, size_t len)
|
---|
38 | {
|
---|
39 | UNIQUEID_RESULT result;
|
---|
40 | unsigned char arrayOfChar[16];
|
---|
41 |
|
---|
42 | /* Codes_SRS_UNIQUEID_07_002: [If uid is NULL then UniqueId_Generate shall return UNIQUEID_INVALID_ARG] */
|
---|
43 | /* Codes_SRS_UNIQUEID_07_003: [If len is less then 37 then UniqueId_Generate shall return UNIQUEID_INVALID_ARG] */
|
---|
44 | if (uid == NULL || len < 37)
|
---|
45 | {
|
---|
46 | result = UNIQUEID_INVALID_ARG;
|
---|
47 | LogError("Buffer Size is Null or length is less then 37 bytes");
|
---|
48 | }
|
---|
49 | else
|
---|
50 | {
|
---|
51 | size_t arrayIndex;
|
---|
52 | size_t shiftCount;
|
---|
53 | size_t characterPosition = 0;
|
---|
54 |
|
---|
55 | /* Codes_SRS_UNIQUEID_07_001: [UniqueId_Generate shall create a unique Id 36 character long string.] */
|
---|
56 | generate128BitUUID(arrayOfChar);
|
---|
57 | for (arrayIndex = 0; arrayIndex < 16; arrayIndex++)
|
---|
58 | {
|
---|
59 | for (shiftCount = 0; shiftCount <= 1; shiftCount++)
|
---|
60 | {
|
---|
61 | char hexChar = tochar[arrayOfChar[arrayIndex] & 0xf];
|
---|
62 | if ((characterPosition == 8) || (characterPosition == 13) || (characterPosition == 18) || (characterPosition == 23))
|
---|
63 | {
|
---|
64 | uid[characterPosition] = '-';
|
---|
65 | characterPosition++;
|
---|
66 | }
|
---|
67 | uid[characterPosition] = hexChar;
|
---|
68 | characterPosition++;
|
---|
69 | arrayOfChar[arrayIndex] = arrayOfChar[arrayIndex] >> 4;
|
---|
70 | }
|
---|
71 | }
|
---|
72 | uid[characterPosition] = 0;
|
---|
73 | result = UNIQUEID_OK;
|
---|
74 | }
|
---|
75 | return result;
|
---|
76 | }
|
---|