Feature request: Rijndael Crypto suite (with configurable KeySize/BlockSize)

### Summary
Include support for Rijndael crypto algorithm atop of AES, with configurable Key, Block Sizes

### Example

Existing AES Decrypt with extra textboxes to specify Key/Block size

The issue names no files, tests, or entry points. Start by locating the existing AES Decrypt operation and determine how key and block sizes are currently handled; completion would require agreed Rijndael support with configurable sizes and corresponding verification, but the request does not define the supported combinations or expected interface.

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