| crypto | Package crypto collects common cryptographic constants. |
| crypto/aes | Package aes implements AES encryption (formerly Rijndael), as defined in U.S. Federal Information Processing Standards Publication 197. |
| crypto/cipher | Package cipher implements standard block cipher modes that can be wrapped around low-level block cipher implementations. |
| crypto/sha256 | Package sha256 implements the SHA224 and SHA256 hash algorithms as defined in FIPS 180-4. |
| crypto/tls | Package tls partially implements TLS 1.2, as specified in RFC 5246, and TLS 1.3, as specified in RFC 8446. |
| encoding/binary | Package binary implements simple translation between numbers and byte sequences and encoding and decoding of varints. |
| 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/chacha20 | Package chacha20 implements the ChaCha20 and XChaCha20 encryption algorithms as specified in RFC 8439 and draft-irtf-cfrg-xchacha-01. |
| golang.org/x/crypto/chacha20poly1305 | Package chacha20poly1305 implements the ChaCha20-Poly1305 AEAD and its extended nonce variant XChaCha20-Poly1305, as specified in RFC 8439 and draft-irtf-cfrg-xchacha-01. |
| golang.org/x/crypto/cryptobyte | Package cryptobyte contains types that help with parsing and constructing length-prefixed, binary messages, including ASN.1 DER. |
| golang.org/x/crypto/hkdf | Package hkdf implements the HMAC-based Extract-and-Expand Key Derivation Function (HKDF) as defined in RFC 5869. |
| hash | Package hash provides interfaces for hash functions. |
| math | Package math provides basic constants and mathematical functions. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| time | Package time provides functionality for measuring and displaying time. |