The decrypt()
method of the SubtleCrypto
interface decrypts some encrypted data. It takes as arguments a key to decrypt with, some optional extra parameters, and the data to decrypt (also known as "ciphertext"). It returns a Promise
which will be fulfilled with the decrypted data (also known as "plaintext").
decrypt(algorithm, key, data)
A Promise
that fulfills with an ArrayBuffer
containing the plaintext.
The promise is rejected when the following exceptions are encountered:
-
InvalidAccessError
DOMException
-
Raised when the requested operation is not valid for the provided key (e.g. invalid encryption algorithm, or invalid key for the specified encryption algorithm*)*.
-
OperationError
DOMException
-
Raised when the operation failed for an operation-specific reason (e.g. algorithm parameters of invalid sizes, or there was an error decrypting the ciphertext).
The decrypt()
method supports the same algorithms as the encrypt()
method.
This code decrypts ciphertext
using RSA-OAEP. See the complete code on GitHub.
function decryptMessage(privateKey, ciphertext) {
return window.crypto.subtle.decrypt(
{
name: "RSA-OAEP"
},
privateKey,
ciphertext
);
}
This code decrypts ciphertext
using AES in CTR mode. Note that counter
must match the value that was used for encryption. See the complete code on GitHub.
function decryptMessage(key, ciphertext) {
return window.crypto.subtle.decrypt(
{
name: "AES-CTR",
counter,
length: 64
},
key,
ciphertext
);
}
This code decrypts ciphertext
using AES in CBC mode. Note that iv
must match the value that was used for encryption. See the complete code on GitHub.
function decryptMessage(key, ciphertext) {
return window.crypto.subtle.decrypt(
{
name: "AES-CBC",
iv: iv
},
key,
ciphertext
);
}
This code decrypts ciphertext
using AES in GCM mode. Note that iv
must match the value that was used for encryption. See the complete code on GitHub.
function decryptMessage(key, ciphertext) {
return window.crypto.subtle.decrypt(
{
name: "AES-GCM",
iv: iv
},
key,
ciphertext
);
}