Xbasic
aes_gcm_decrypt Function
Syntax
c aes_gcm_decrypt(c ciphertext, c key[, c nonce])
Arguments
- ciphertext
Colon-separated base64 string returned by `aes_gcm_encrypt` in the form `ciphertext:tag`.
- key
Symmetric key used to encrypt the original plaintext.
- nonce
Nonce used during encryption. Required to successfully decrypt when encryption used an explicit or random nonce.
Returns
- result
Decrypted plaintext when authentication succeeds; otherwise an empty string.
Description
Decrypt ciphertext using AES-GCM with the given key and nonce.
Examples
Decrypt with missing nonce (fails)
txt = aes_gcm_encrypt("Keep it a secret","Shhh!")
? aes_gcm_decrypt(txt,"Shhh!")
= ""If the wrong key or nonce is supplied, or if the ciphertext is tampered with, decryption will fail and return an empty string.
Notes
- The nonce is not embedded in the ciphertext.
- Store the nonce alongside the ciphertext to enable decryption.