| bytes | Package bytes implements functions for the manipulation of byte slices. |
| crypto/hmac | Package hmac implements the Keyed-Hash Message Authentication Code (HMAC) as defined in U.S. Federal Information Processing Standards Publication 198. |
| crypto/rand | Package rand implements a cryptographically secure random number generator. |
| encoding/base64 | Package base64 implements base64 encoding as specified by RFC 4648. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| hash | Package hash provides interfaces for hash functions. |
| strconv | Package strconv implements conversions to and from string representations of basic data types. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |