▾ Example

Code:

senderPublicKey, senderPrivateKey, err := box.GenerateKey(crypto_rand.Reader)
if err != nil {
    panic(err)
}

recipientPublicKey, recipientPrivateKey, err := box.GenerateKey(crypto_rand.Reader)
if err != nil {
    panic(err)
}

// You must use a different nonce for each message you encrypt with the
// same key. Since the nonce here is 192 bits long, a random value
// provides a sufficiently small probability of repeats.
var nonce [24]byte
if _, err := io.ReadFull(crypto_rand.Reader, nonce[:]); err != nil {
    panic(err)
}

msg := []byte("Alas, poor Yorick! I knew him, Horatio")
// This encrypts msg and appends the result to the nonce.
encrypted := box.Seal(nonce[:], msg, &nonce, recipientPublicKey, senderPrivateKey)

// The recipient can decrypt the message using their private key and the
// sender's public key. When you decrypt, you must use the same nonce you
// used to encrypt the message. One way to achieve this is to store the
// nonce alongside the encrypted message. Above, we stored the nonce in the
// first 24 bytes of the encrypted text.
var decryptNonce [24]byte
copy(decryptNonce[:], encrypted[:24])
decrypted, ok := box.Open(nil, encrypted[24:], &decryptNonce, senderPublicKey, recipientPrivateKey)
if !ok {
    panic("decryption error")
}
fmt.Println(string(decrypted))

Output:

Alas, poor Yorick! I knew him, Horatio

▾ Example (Precompute)

Code:

senderPublicKey, senderPrivateKey, err := box.GenerateKey(crypto_rand.Reader)
if err != nil {
    panic(err)
}

recipientPublicKey, recipientPrivateKey, err := box.GenerateKey(crypto_rand.Reader)
if err != nil {
    panic(err)
}

// The shared key can be used to speed up processing when using the same
// pair of keys repeatedly.
sharedEncryptKey := new([32]byte)
box.Precompute(sharedEncryptKey, recipientPublicKey, senderPrivateKey)

// You must use a different nonce for each message you encrypt with the
// same key. Since the nonce here is 192 bits long, a random value
// provides a sufficiently small probability of repeats.
var nonce [24]byte
if _, err := io.ReadFull(crypto_rand.Reader, nonce[:]); err != nil {
    panic(err)
}

msg := []byte("A fellow of infinite jest, of most excellent fancy")
// This encrypts msg and appends the result to the nonce.
encrypted := box.SealAfterPrecomputation(nonce[:], msg, &nonce, sharedEncryptKey)

// The shared key can be used to speed up processing when using the same
// pair of keys repeatedly.
var sharedDecryptKey [32]byte
box.Precompute(&sharedDecryptKey, senderPublicKey, recipientPrivateKey)

// The recipient can decrypt the message using the shared key. When you
// decrypt, you must use the same nonce you used to encrypt the message.
// One way to achieve this is to store the nonce alongside the encrypted
// message. Above, we stored the nonce in the first 24 bytes of the
// encrypted text.
var decryptNonce [24]byte
copy(decryptNonce[:], encrypted[:24])
decrypted, ok := box.OpenAfterPrecomputation(nil, encrypted[24:], &decryptNonce, &sharedDecryptKey)
if !ok {
    panic("decryption error")
}
fmt.Println(string(decrypted))

Output:

A fellow of infinite jest, of most excellent fancy

Internal call graph ▾

In the call graph viewer below, each node is a function belonging to this package and its children are the functions it calls—perhaps dynamically.

The root nodes are the entry points of the package: functions that may be called from outside the package. There may be non-exported or anonymous functions among them if they are called dynamically from another package.

Click a node to visit that function's source code. From there you can visit its callers by clicking its declaring func token.

Functions may be omitted if they were determined to be unreachable in the particular programs or tests that were analyzed.