Base64 Encoding

Base64 Encoding

Encode binary data to base64 strings and decode base64 back to binary. Uses standard base64 encoding per RFC 4648.

Loading

local base64 = require("base64")

Encoding

Encode Data

Encodes a string (including binary data) to base64.

-- Encode text
local encoded = base64.encode("Hello, World!")
print(encoded)  -- "SGVsbG8sIFdvcmxkIQ=="

-- Encode binary data (e.g., from file)
local image_data = fs.read_binary("photo.jpg")
local image_b64 = base64.encode(image_data)

-- Encode JSON for transport
local json = require("json")
local payload = json.encode({user = "alice", action = "login"})
local token_part = base64.encode(payload)

-- Encode credentials
local credentials = base64.encode("username:password")
local auth_header = "Basic " .. credentials

Parameter	Type	Description
data	string	Data to encode (text or binary)

Returns: string, error - Empty string input returns empty string.

Decoding

Decode Data

Decodes a base64 string back to original data.

-- Decode text
local decoded = base64.decode("SGVsbG8sIFdvcmxkIQ==")
print(decoded)  -- "Hello, World!"

-- Decode with error handling
local data, err = base64.decode(user_input)
if err then
    return nil, errors.new("INVALID", "Invalid base64 data")
end

-- Decode binary data
local image_b64 = request.body
local image_data, err = base64.decode(image_b64)
if err then
    return nil, err
end
fs.write_binary("output.jpg", image_data)

-- Decode JWT parts
local parts = string.split(jwt_token, ".")
local header = json.decode(base64.decode(parts[1]))
local payload = json.decode(base64.decode(parts[2]))

Parameter	Type	Description
data	string	Base64 encoded string

Returns: string, error - Empty string input returns empty string.

Errors

Condition	Kind	Retryable
Input not a string	errors.INVALID	no
Invalid base64 characters	errors.INVALID	no
Corrupted padding	errors.INVALID	no

See Error Handling for working with errors.