Function decrypt [src]

m: Message c: Ciphertext tag: Authentication tag ad: Associated data npub: Public nonce k: Private key Asserts c.len == m.len. Contents of m are undefined if an error is returned.

Prototype

 pub fn decrypt(m: []u8, c: []const u8, tag: [tag_length]u8, ad: []const u8, npub: [nonce_length]u8, key: [key_length]u8) AuthenticationError!void

Parameters

m: []u8c: []const u8tag: [tag_length]u8ad: []const u8npub: [nonce_length]u8key: [key_length]u8

Possible Errors

AuthenticationFailed AuthenticationError

Source

  pub fn decrypt(m: []u8, c: []const u8, tag: [tag_length]u8, ad: []const u8, npub: [nonce_length]u8, key: [key_length]u8) AuthenticationError!void {
    var computed_tag = mac(c, ad, npub, key);
    const verify = crypto.timing_safe.eql([tag_length]u8, computed_tag, tag);
    if (!verify) {
        crypto.secureZero(u8, &computed_tag);
        @memset(m, undefined);
        return error.AuthenticationFailed;
    }
    xor(m, c, npub, key);
}  