Module aes 

AES-IGE (Infinite Garble Extension): used by Telegram’s MTProto.

Functions

ctr_crypt

Encrypt/decrypt buffer in-place with AES-256-CTR (symmetric). key = 32 bytes, iv = 16 bytes (full block = counter starting value).

ctr_iv_at_offset

Return the effective AES-CTR IV for a CDN chunk starting at byte_offset. Telegram CDN increments the counter (big-endian uint128) by byte_offset / 16.

ige_decrypt

Decrypt buffer in-place with AES-256-IGE. buffer.len() must be a multiple of 16.

ige_encrypt

Encrypt buffer in-place with AES-256-IGE. buffer.len() must be a multiple of 16.