Decrypt XChaCha20-Poly1305 ciphertext.
Expects the format produced by aeadEncrypt: base64(nonce || ciphertext || tag).
aeadEncrypt
nonce || ciphertext || tag
Decrypt XChaCha20-Poly1305 ciphertext.
Expects the format produced by
aeadEncrypt: base64(nonce || ciphertext || tag).