roupSession.t</a> Ctypes_static.ptr</span> <span>&#45;&gt;</span> <span>Unsigned.uint8 Ctypes_static.ptr</span> <span>&#45;&gt;</span> Unsigned.size_t <span>&#45;&gt;</span> <span>Unsigned.uint8 Ctypes_static.ptr</span> <span>&#45;&gt;</span> Unsigned.size_t <span>&#45;&gt;</span> <span>Unsigned.uint32 Ctypes_static.ptr</span> <span>&#45;&gt;</span> Unsigned.size_t</code></dt><dd><p><code>group_decrypt sess msg msg_len plaintext max_plaintext_len msg_index</code></p><p>Decrypt a message. The input message b