encryption

README

NIP-44 implementation in Go

NIP-44 specification: https://github.com/nostr-protocol/nips/blob/master/44.md

To use as library: go get -u github.com/ekzyis/nip44

To run tests, clone repository and then run go test.

Documentation

Overview

Package encryption contains the message encryption schemes defined in NIP-04 and NIP-44, used for encrypting the content of nostr messages.

Index

• Variables
• func Decrypt(conversationKey []byte, ciphertext string) (plaintext string, err error)
• func DecryptNip4(content, key []byte) (msg []byte, err error)
• func Encrypt(conversationKey []byte, plaintext []byte, options *EncryptOptions) (ciphertext string, err error)
• func EncryptNip4(msg, key []byte) (ct []byte, err error)
• func GenerateConversationKey(sendPrivkey []byte, recvPubkey []byte) (conversationKey []byte, err error)
• func GenerateNip4Key(sendPrivkey, recvPubkey []byte) (sharedKey []byte, err error)
• func MessageKeys(conversationKey []byte, salt []byte) ([]byte, []byte, []byte, error)
• type EncryptOptions

Variables

var (
	MinPlaintextSize = 0x0001 // 1b msg => padded to 32b
	MaxPlaintextSize = 0xffff // 65535 (64kb-1) => padded to 64kb
)

Functions

func Decrypt

func Decrypt(conversationKey []byte, ciphertext string) (
	plaintext string, err error,
)

func DecryptNip4

func DecryptNip4(content, key []byte) (msg []byte, err error)

DecryptNip4 decrypts a content string using the shared secret key. The inverse operation to message -> EncryptNip4(message, key).

func Encrypt

func Encrypt(
	conversationKey []byte, plaintext []byte, options *EncryptOptions,
) (ciphertext string, err error)

func EncryptNip4

func EncryptNip4(msg, key []byte) (ct []byte, err error)

EncryptNip4 encrypts message with key using aes-256-cbc. key should be the shared secret generated by ComputeSharedSecret.

Returns: base64(encrypted_bytes) + "?iv=" + base64(initialization_vector).

func GenerateConversationKey

func GenerateConversationKey(
	sendPrivkey []byte, recvPubkey []byte,
) (conversationKey []byte, err error)

func GenerateNip4Key

func GenerateNip4Key(sendPrivkey, recvPubkey []byte) (sharedKey []byte, err error)

GenerateNip4Key computes the raw ECDH shared secret for NIP-04 decryption. This is the x-coordinate of the ECDH point, without the HKDF step used by NIP-44.

func MessageKeys

func MessageKeys(conversationKey []byte, salt []byte) (
	[]byte, []byte, []byte, error,
)

Types

type EncryptOptions

type EncryptOptions struct {
	Salt    []byte
	Version int
}