| crypto/internal/boring | Package boring provides access to BoringCrypto implementation functions. |
| crypto/internal/randutil | Package randutil contains internal randomness utilities for various crypto packages. |
| errors | Package errors implements functions to manipulate errors. |
| internal/syscall/unix | |
| io | Package io provides basic interfaces to I/O primitives. |
| math/big | Package big implements arbitrary-precision arithmetic (big numbers). |
| os | Package os provides a platform-independent interface to operating system functionality. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| sync/atomic | Package atomic provides low-level atomic memory primitives useful for implementing synchronization algorithms. |
| syscall | Package syscall contains an interface to the low-level operating system primitives. |
| time | Package time provides functionality for measuring and displaying time. |