| bytes | Package bytes implements functions for the manipulation of byte slices. |
| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| crypto | Package crypto collects common cryptographic constants. |
| crypto/tls | Package tls partially implements TLS 1.2, as specified in RFC 5246, and TLS 1.3, as specified in RFC 8446. |
| crypto/x509 | Package x509 implements a subset of the X.509 standard. |
| crypto/x509/pkix | Package pkix contains shared, low level structures used for ASN.1 parsing and serialization of X.509 certificates, CRL and OCSP. |
| encoding/asn1 | Package asn1 implements parsing of DER-encoded ASN.1 data structures, as defined in ITU-T Rec X.690. |
| errors | Package errors implements functions to manipulate errors. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| golang.org/x/crypto/ocsp | Package ocsp parses OCSP responses as specified in RFC 2560. |
| golang.org/x/sync/errgroup | Package errgroup provides synchronization, error propagation, and Context cancelation for groups of goroutines working on subtasks of a common task. |
| io/ioutil | Package ioutil implements some I/O utility functions. |
| math/big | Package big implements arbitrary-precision arithmetic (big numbers). |
| net/http | Package http provides HTTP client and server implementations. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| time | Package time provides functionality for measuring and displaying time. |