| 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/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. |
| crypto/rsa | Package rsa implements RSA encryption as specified in PKCS #1 and RFC 8017. |
| crypto/x509 | Package x509 implements a subset of the X.509 standard. |
| encoding/asn1 | Package asn1 implements parsing of DER-encoded ASN.1 data structures, as defined in ITU-T Rec X.690. |
| encoding/base64 | Package base64 implements base64 encoding as specified by RFC 4648. |
| encoding/json | Package json implements encoding and decoding of JSON as defined in RFC 7159. |
| encoding/pem | Package pem implements the PEM data encoding, which originated in Privacy Enhanced Mail. |
| errors | Package errors implements functions to manipulate errors. |
| math/big | Package big implements arbitrary-precision arithmetic (big numbers). |
| net/http | Package http provides HTTP client and server implementations. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| time | Package time provides functionality for measuring and displaying time. |