ac_tag_len
length_needed = ulDataLen + aes_ctx->ac_tag_len;
length_needed = ulEncryptedDataLen - aes_ctx->ac_tag_len;
length_needed = aes_ctx.ac_tag_len;
length_needed = plaintext->cd_length + aes_ctx.ac_tag_len;
length_needed = ciphertext->cd_length - aes_ctx.ac_tag_len;
length_needed = plaintext->cd_length + aes_ctx->ac_tag_len;
length_needed = aes_ctx->ac_tag_len;
length_needed = ciphertext->cd_length - aes_ctx->ac_tag_len;
data->cd_length = aes_ctx->ac_tag_len;