Implement titlekey SMCs (with skeleton tkey API)

exosphere/titlekey.h

@@ -0,0 +1,15 @@
+#ifndef EXOSPHERE_TITLEKEY_H
+#define EXOSPHERE_TITLEKEY_H
+
+#include <stdint.h>
+
+void tkey_set_expected_salt(uint64_t *salt);
+void tkey_set_master_key_rev(unsigned int master_key_rev);
+
+size_t tkey_rsa_unwrap(void *dst, size_t dst_size, void *src, size_t src_size);
+
+void tkey_aes_unwrap(void *dst, size_t dst_size, const void *src, size_t src_size);
+void tkey_seal(void *dst, size_t dst_size, const void *src, size_t src_size);
+void tkey_unseal(unsigned int keyslot, const void *src, size_t src_size);
+
+#endif