| crypto | Package crypto collects common cryptographic constants. |
| crypto/ecdsa | Package ecdsa implements the Elliptic Curve Digital Signature Algorithm, as defined in [FIPS 186-5]. |
| crypto/ed25519 | Package ed25519 implements the Ed25519 signature algorithm. |
| crypto/elliptic | Package elliptic implements the standard NIST P-224, P-256, P-384, and P-521 elliptic curves over prime fields. |
| crypto/rand | Package rand implements a cryptographically secure random number generator. |
| 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/pem | Package pem implements the PEM data encoding, which originated in Privacy Enhanced Mail. |
| errors | Package errors implements functions to manipulate errors. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| math/big | Package big implements arbitrary-precision arithmetic (big numbers). |
| net | Package net provides a portable interface for network I/O, including TCP/IP, UDP, domain name resolution, and Unix domain sockets. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| path/filepath | Package filepath implements utility routines for manipulating filename paths in a way compatible with the target operating system-defined file paths. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| time | Package time provides functionality for measuring and displaying time. |