Documentation
¶
Overview ¶
Package chacha20poly1305 implements the ChaCha20-Poly1305 AEAD as specified in RFC 7539, and its extended nonce variant XChaCha20-Poly1305.
Index ¶
Examples ¶
Constants ¶
View Source
const ( // KeySize is the size of the key used by this AEAD, in bytes. KeySize = 32 // NonceSize is the size of the nonce used with the standard variant of this // AEAD, in bytes. // // Note that this is too short to be safely generated at random if the same // key is reused more than 2³² times. NonceSize = 12 // NonceSizeX is the size of the nonce used with the XChaCha20-Poly1305 // variant of this AEAD, in bytes. NonceSizeX = 24 )
Variables ¶
This section is empty.
Functions ¶
func NewX ¶
NewX returns a XChaCha20-Poly1305 AEAD that uses the given 256-bit key.
XChaCha20-Poly1305 is a ChaCha20-Poly1305 variant that takes a longer nonce, suitable to be generated randomly without risk of collisions. It should be preferred when nonce uniqueness cannot be trivially ensured, or whenever nonces are randomly generated.
Example ¶
aead, err := NewX(key)
if err != nil {
log.Fatalln("Failed to instantiate XChaCha20-Poly1305:", err)
}
for _, msg := range []string{
"Attack at dawn.",
"The eagle has landed.",
"Gophers, gophers, gophers everywhere!",
} {
// Encryption.
nonce := make([]byte, NonceSizeX)
if _, err := cryptorand.Read(nonce); err != nil {
panic(err)
}
ciphertext := aead.Seal(nil, nonce, []byte(msg), nil)
// Decryption.
plaintext, err := aead.Open(nil, nonce, ciphertext, nil)
if err != nil {
log.Fatalln("Failed to decrypt or authenticate message:", err)
}
fmt.Printf("%s\n", plaintext)
}
Output: Attack at dawn. The eagle has landed. Gophers, gophers, gophers everywhere!
Types ¶
This section is empty.
Source Files
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