From 3121a5bf08cd81d3a99719feb2cab3b60767afd5 Mon Sep 17 00:00:00 2001
From: Michael Scire <SciresM@gmail.com>
Date: Mon, 1 Jun 2020 17:14:12 -0700
Subject: [PATCH] pki: implement mariko key derivation

---
 extkeys.c  |  7 +++++++
 pki.c      | 16 ++++++++++++++++
 settings.h |  1 +
 3 files changed, 24 insertions(+)

diff --git a/extkeys.c b/extkeys.c
index 0d227fe..db7c2f2 100644
--- a/extkeys.c
+++ b/extkeys.c
@@ -364,6 +364,13 @@ void extkeys_initialize_settings(hactool_settings_t *settings, FILE *f) {
                         break;
                     }
 
+                    snprintf(test_name, sizeof(test_name), "mariko_master_kek_source_%02"PRIx32, i);
+                    if (strcmp(key, test_name) == 0) {
+                        parse_hex_key(keyset->mariko_master_kek_sources[i], value, sizeof(keyset->mariko_master_kek_sources[i]));
+                        matched_key = 1;
+                        break;
+                    }
+
                     snprintf(test_name, sizeof(test_name), "package1_mac_key_%02"PRIx32, i);
                     if (strcmp(key, test_name) == 0) {
                         parse_hex_key(keyset->package1_mac_keys[i], value, sizeof(keyset->package1_mac_keys[i]));
diff --git a/pki.c b/pki.c
index ae0b506..7ddab66 100644
--- a/pki.c
+++ b/pki.c
@@ -386,6 +386,18 @@ void pki_derive_keys(nca_keyset_t *keyset) {
         aes_decrypt(tsec_root_ctx, keyset->master_keks[i], keyset->master_kek_sources[i], 0x10);
         free_aes_ctx(tsec_root_ctx);
     }
+    /* Derive master keks with mariko keydata -- these are always preferred to other sources. */
+    for (unsigned int i = 0; i < 0x20; i++) {
+        if (memcmp(keyset->mariko_kek, zeroes, 0x10) == 0) {
+            continue;
+        }
+        if (memcmp(keyset->mariko_master_kek_sources[i], zeroes, 0x10) == 0) {
+            continue;
+        }
+        aes_ctx_t *mariko_kek_ctx = new_aes_ctx(keyset->mariko_kek, 0x10, AES_MODE_ECB);
+        aes_decrypt(mariko_kek_ctx, keyset->master_keks[i], keyset->mariko_master_kek_sources[i], 0x10);
+        free_aes_ctx(mariko_kek_ctx);
+    }
     for (unsigned int i = 0; i < 0x20; i++) {
         /* Then we derive master keys. */
         if (memcmp(keyset->master_key_source, zeroes, 0x10) == 0) {
@@ -514,6 +526,10 @@ void pki_print_keys(nca_keyset_t *keyset) {
         PRINT_KEY_WITH_NAME_IDX(keyset->mariko_aes_class_keys[i], mariko_aes_class_key, i);
     }
     printf("\n");
+    for (unsigned int i = 0x0; i < 0x20; i++) {
+        PRINT_KEY_WITH_NAME_IDX(keyset->mariko_master_kek_sources[i], mariko_master_kek_source, i);
+    }
+    printf("\n");
     for (unsigned int i = 0x0; i < 0x20; i++) {
         PRINT_KEY_WITH_NAME_IDX(keyset->master_keks[i], master_kek, i);
     }
diff --git a/settings.h b/settings.h
index 202f89a..2fa7ce6 100644
--- a/settings.h
+++ b/settings.h
@@ -34,6 +34,7 @@ typedef struct {
     unsigned char tsec_auth_signatures[0x20][0x10];      /* Auth signatures, seeds for tsec root key/package1 mac kek/package1 key on 6.2.0+. */
     unsigned char tsec_root_keys[0x20][0x10];            /* Key for master kek decryption, from TSEC firmware on 6.2.0+. */
     unsigned char master_kek_sources[0x20][0x10];        /* Seeds for firmware master keks. */
+    unsigned char mariko_master_kek_sources[0x20][0x10]; /* Seeds for firmware master keks (Mariko). */
     unsigned char master_keks[0x20][0x10];               /* Firmware master keks, stored in keyblob prior to 6.2.0. */
     unsigned char master_key_source[0x10];               /* Seed for master key derivation. */
     unsigned char master_keys[0x20][0x10];               /* Firmware master keys. */