[388] | 1 | // Copyright (c) Microsoft. All rights reserved.
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| 2 | // Licensed under the MIT license. See LICENSE file in the project root for full license information.
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| 3 |
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| 4 | #include <stdlib.h>
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| 5 | #include <stdint.h>
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| 6 | #include "azure_c_shared_utility/uniqueid.h"
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| 7 | #include "azure_c_shared_utility/xlogging.h"
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| 8 | #include <time.h>
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| 9 |
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| 10 | MU_DEFINE_ENUM_STRINGS(UNIQUEID_RESULT, UNIQUEID_RESULT_VALUES);
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| 11 |
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| 12 | static const char tochar[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
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| 13 | static void generate128BitUUID(unsigned char* arrayOfByte)
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| 14 | {
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| 15 | size_t arrayIndex;
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| 16 |
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| 17 | for (arrayIndex = 0; arrayIndex < 16; arrayIndex++)
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| 18 | {
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| 19 | arrayOfByte[arrayIndex] = (unsigned char)rand();
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| 20 | }
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| 21 |
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| 22 | //
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| 23 | // Stick in the version field for random uuid.
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| 24 | //
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| 25 | arrayOfByte[7] &= 0x0f; //clear the bit field
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| 26 | arrayOfByte[7] |= 0x40; //set the ones we care about
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| 27 |
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| 28 | //
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| 29 | // Stick in the variant field for the random uuid.
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| 30 | //
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| 31 | arrayOfByte[8] &= 0xf3; // Clear
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| 32 | arrayOfByte[8] |= 0x08; // Set
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| 33 |
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| 34 | }
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| 35 |
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| 36 | // TODO: The User will need to call srand before calling this function
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| 37 | UNIQUEID_RESULT UniqueId_Generate(char* uid, size_t len)
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| 38 | {
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| 39 | UNIQUEID_RESULT result;
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| 40 | unsigned char arrayOfChar[16];
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| 41 |
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| 42 | /* Codes_SRS_UNIQUEID_07_002: [If uid is NULL then UniqueId_Generate shall return UNIQUEID_INVALID_ARG] */
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| 43 | /* Codes_SRS_UNIQUEID_07_003: [If len is less then 37 then UniqueId_Generate shall return UNIQUEID_INVALID_ARG] */
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| 44 | if (uid == NULL || len < 37)
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| 45 | {
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| 46 | result = UNIQUEID_INVALID_ARG;
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| 47 | LogError("Buffer Size is Null or length is less then 37 bytes");
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| 48 | }
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| 49 | else
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| 50 | {
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| 51 | size_t arrayIndex;
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| 52 | size_t shiftCount;
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| 53 | size_t characterPosition = 0;
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| 54 |
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| 55 | /* Codes_SRS_UNIQUEID_07_001: [UniqueId_Generate shall create a unique Id 36 character long string.] */
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| 56 | generate128BitUUID(arrayOfChar);
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| 57 | for (arrayIndex = 0; arrayIndex < 16; arrayIndex++)
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| 58 | {
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| 59 | for (shiftCount = 0; shiftCount <= 1; shiftCount++)
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| 60 | {
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| 61 | char hexChar = tochar[arrayOfChar[arrayIndex] & 0xf];
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| 62 | if ((characterPosition == 8) || (characterPosition == 13) || (characterPosition == 18) || (characterPosition == 23))
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| 63 | {
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| 64 | uid[characterPosition] = '-';
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| 65 | characterPosition++;
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| 66 | }
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| 67 | uid[characterPosition] = hexChar;
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| 68 | characterPosition++;
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| 69 | arrayOfChar[arrayIndex] = arrayOfChar[arrayIndex] >> 4;
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| 70 | }
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| 71 | }
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| 72 | uid[characterPosition] = 0;
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| 73 | result = UNIQUEID_OK;
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| 74 | }
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| 75 | return result;
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| 76 | }
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