[C++][Gandiva] Modernize AES functions: add authenticated encryption (CBC/GCM) via ENCRYPT/DECRYPT #53776

Describe the enhancement requested

Gandiva's aes_encrypt / aes_decrypt (ARROW-14431) support only AES-ECB and operate on VARCHAR. ECB is deterministic and unauthenticated: identical plaintext blocks give identical ciphertext, there is no IV, and tampering goes undetected. VARCHAR is also a poor fit for ciphertext, which is arbitrary bytes.

This adds binary encrypt / decrypt functions with modern cipher modes:

encrypt(data, key, mode)
encrypt(data, key, mode, iv)
encrypt(data, key, mode, iv, aad)   -- decrypt has the same overloads

All arguments and results are binary.

• Modes: AES-ECB, AES-CBC (PKCS#7 by default, -NONE variants), AES-GCM; 16/24/32-byte keys.
• GCM: caller-supplied nonce and optional AAD. Output is ciphertext || 16-byte tag; decrypt verifies the tag and errors on any key, IV, AAD or ciphertext mismatch.
• IV and AAD are caller-managed and not embedded in the output. A NULL argument yields NULL. Failures are reported as Gandiva function errors with the OpenSSL diagnostic.
• The registry functions aes_encrypt / aes_decrypt are unchanged. They stay ECB-only and are not recommended for new use.

Testing: all modes and key sizes, invalid key/IV/padding, GCM tag and AAD mismatch, block-aligned inputs, and known-answer vectors from the GCM specification (McGrew and Viega, test cases 4-6; 12-, 8- and 60-byte IVs).

Related: #50522 (output sizing in the current aes_encrypt stub; the new implementation sizes buffers independently of key length), #45693, #29995.

A PR will follow.

Component(s)

C++, Gandiva