open-consul/vendor/github.com/hashicorp/go-uuid/uuid.go

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package uuid
import (
"crypto/rand"
"encoding/hex"
"fmt"
)
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// GenerateRandomBytes is used to generate random bytes of given size.
func GenerateRandomBytes(size int) ([]byte, error) {
buf := make([]byte, size)
if _, err := rand.Read(buf); err != nil {
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return nil, fmt.Errorf("failed to read random bytes: %v", err)
}
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return buf, nil
}
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// GenerateUUID is used to generate a random UUID
func GenerateUUID() (string, error) {
buf, err := GenerateRandomBytes(16)
if err != nil {
return "", err
}
return FormatUUID(buf)
}
func FormatUUID(buf []byte) (string, error) {
if len(buf) != 16 {
return "", fmt.Errorf("wrong length byte slice (%d)", len(buf))
}
return fmt.Sprintf("%08x-%04x-%04x-%04x-%12x",
buf[0:4],
buf[4:6],
buf[6:8],
buf[8:10],
buf[10:16]), nil
}
func ParseUUID(uuid string) ([]byte, error) {
if len(uuid) != 36 {
return nil, fmt.Errorf("uuid string is wrong length")
}
hyph := []byte("-")
if uuid[8] != hyph[0] ||
uuid[13] != hyph[0] ||
uuid[18] != hyph[0] ||
uuid[23] != hyph[0] {
return nil, fmt.Errorf("uuid is improperly formatted")
}
hexStr := uuid[0:8] + uuid[9:13] + uuid[14:18] + uuid[19:23] + uuid[24:36]
ret, err := hex.DecodeString(hexStr)
if err != nil {
return nil, err
}
if len(ret) != 16 {
return nil, fmt.Errorf("decoded hex is the wrong length")
}
return ret, nil
}