Scott Baker | 8461e15 | 2019-10-01 14:44:30 -0700 | [diff] [blame] | 1 | package uuid |
| 2 | |
| 3 | import ( |
| 4 | "crypto/rand" |
| 5 | "encoding/hex" |
| 6 | "fmt" |
khenaidoo | d948f77 | 2021-08-11 17:49:24 -0400 | [diff] [blame^] | 7 | "io" |
Scott Baker | 8461e15 | 2019-10-01 14:44:30 -0700 | [diff] [blame] | 8 | ) |
| 9 | |
| 10 | // GenerateRandomBytes is used to generate random bytes of given size. |
| 11 | func GenerateRandomBytes(size int) ([]byte, error) { |
khenaidoo | d948f77 | 2021-08-11 17:49:24 -0400 | [diff] [blame^] | 12 | return GenerateRandomBytesWithReader(size, rand.Reader) |
| 13 | } |
| 14 | |
| 15 | // GenerateRandomBytesWithReader is used to generate random bytes of given size read from a given reader. |
| 16 | func GenerateRandomBytesWithReader(size int, reader io.Reader) ([]byte, error) { |
| 17 | if reader == nil { |
| 18 | return nil, fmt.Errorf("provided reader is nil") |
| 19 | } |
Scott Baker | 8461e15 | 2019-10-01 14:44:30 -0700 | [diff] [blame] | 20 | buf := make([]byte, size) |
khenaidoo | d948f77 | 2021-08-11 17:49:24 -0400 | [diff] [blame^] | 21 | if _, err := io.ReadFull(reader, buf); err != nil { |
Scott Baker | 8461e15 | 2019-10-01 14:44:30 -0700 | [diff] [blame] | 22 | return nil, fmt.Errorf("failed to read random bytes: %v", err) |
| 23 | } |
| 24 | return buf, nil |
| 25 | } |
| 26 | |
khenaidoo | d948f77 | 2021-08-11 17:49:24 -0400 | [diff] [blame^] | 27 | |
Scott Baker | 8461e15 | 2019-10-01 14:44:30 -0700 | [diff] [blame] | 28 | const uuidLen = 16 |
| 29 | |
| 30 | // GenerateUUID is used to generate a random UUID |
| 31 | func GenerateUUID() (string, error) { |
khenaidoo | d948f77 | 2021-08-11 17:49:24 -0400 | [diff] [blame^] | 32 | return GenerateUUIDWithReader(rand.Reader) |
| 33 | } |
| 34 | |
| 35 | // GenerateUUIDWithReader is used to generate a random UUID with a given Reader |
| 36 | func GenerateUUIDWithReader(reader io.Reader) (string, error) { |
| 37 | if reader == nil { |
| 38 | return "", fmt.Errorf("provided reader is nil") |
| 39 | } |
| 40 | buf, err := GenerateRandomBytesWithReader(uuidLen, reader) |
Scott Baker | 8461e15 | 2019-10-01 14:44:30 -0700 | [diff] [blame] | 41 | if err != nil { |
| 42 | return "", err |
| 43 | } |
| 44 | return FormatUUID(buf) |
| 45 | } |
| 46 | |
| 47 | func FormatUUID(buf []byte) (string, error) { |
| 48 | if buflen := len(buf); buflen != uuidLen { |
| 49 | return "", fmt.Errorf("wrong length byte slice (%d)", buflen) |
| 50 | } |
| 51 | |
| 52 | return fmt.Sprintf("%x-%x-%x-%x-%x", |
| 53 | buf[0:4], |
| 54 | buf[4:6], |
| 55 | buf[6:8], |
| 56 | buf[8:10], |
| 57 | buf[10:16]), nil |
| 58 | } |
| 59 | |
| 60 | func ParseUUID(uuid string) ([]byte, error) { |
| 61 | if len(uuid) != 2 * uuidLen + 4 { |
| 62 | return nil, fmt.Errorf("uuid string is wrong length") |
| 63 | } |
| 64 | |
| 65 | if uuid[8] != '-' || |
| 66 | uuid[13] != '-' || |
| 67 | uuid[18] != '-' || |
| 68 | uuid[23] != '-' { |
| 69 | return nil, fmt.Errorf("uuid is improperly formatted") |
| 70 | } |
| 71 | |
| 72 | hexStr := uuid[0:8] + uuid[9:13] + uuid[14:18] + uuid[19:23] + uuid[24:36] |
| 73 | |
| 74 | ret, err := hex.DecodeString(hexStr) |
| 75 | if err != nil { |
| 76 | return nil, err |
| 77 | } |
| 78 | if len(ret) != uuidLen { |
| 79 | return nil, fmt.Errorf("decoded hex is the wrong length") |
| 80 | } |
| 81 | |
| 82 | return ret, nil |
| 83 | } |