aead_aes_gcm_ctx
struct aead_aes_gcm_ctx *gcm_ctx;
if ((gcm_ctx = calloc(1, sizeof(struct aead_aes_gcm_ctx))) == NULL)
struct aead_aes_gcm_ctx *gcm_ctx = ctx->aead_state;
const struct aead_aes_gcm_ctx *gcm_ctx = ctx->aead_state;
const struct aead_aes_gcm_ctx *gcm_ctx = ctx->aead_state;