Add new HCA key derivation

Thanks to FZFalzar, Thealexbarney and hozuki for the key and algorithm

README.md

@@ -162,6 +162,7 @@ a companion file:
 - .adx: .adxkey (derived 6 byte key, in start/mult/add format)
 - .ahx: .ahxkey (derived 6 byte key, in start/mult/add format)
 - .hca: .hcakey (8 byte decryption key, a 64-bit number)
+  - May be followed by 2 byte AWB derivation value for newer HCA
 - .fsb: .fsbkey (decryption key, in hex)
 
 The key file can be ".(ext)key" (for the whole folder), or "(name).(ext)key"
@@ -240,7 +241,7 @@ are used in few games.
 - AAC
 - Bink
 - AC3/SPDIF
-- Xiph Opus (Ogg, Switch)
+- Xiph Opus (Ogg, Switch, EA, UE4)
 - Xiph CELT (FSB)
 - Musepack
 - FLAC

src/libvgmstream.vcproj

@@ -204,6 +204,10 @@
                     RelativePath=".\meta\hca_keys.h"
                     >
                 </File>
+                <File
+                    RelativePath=".\meta\hca_keys_awb.h"
+                    >
+                </File>
                 <File
                     RelativePath=".\meta\fsb_keys.h"
                     >

src/libvgmstream.vcxproj

@@ -107,9 +107,11 @@
     <ClInclude Include="meta\ps2_psh_streamfile.h" />
     <ClInclude Include="meta\opus_interleave_streamfile.h" />
     <ClInclude Include="meta\sqex_scd_streamfile.h" />
-    <ClInclude Include="meta\xvag_streamfile.h" />
+    <ClInclude Include="meta\sqex_scd_streamfile.h" />
+    <ClInclude Include="meta\ubi_lyn_ogg_streamfile.h" />
     <ClInclude Include="meta\meta.h" />
     <ClInclude Include="meta\hca_keys.h" />
+    <ClInclude Include="meta\hca_keys_awb.h" />
     <ClInclude Include="meta\fsb_keys.h" />
     <ClInclude Include="coding\acm_decoder_libacm.h" />
     <ClInclude Include="coding\coding.h" />

src/libvgmstream.vcxproj.filters

@@ -113,6 +113,9 @@
     <ClInclude Include="meta\hca_keys.h">
       <Filter>meta\Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="meta\hca_keys_awb.h">
+      <Filter>meta\Header Files</Filter>
+    </ClInclude>
     <ClInclude Include="meta\fsb_keys.h">
       <Filter>meta\Header Files</Filter>
     </ClInclude>
@@ -1306,7 +1309,7 @@
     <ClCompile Include="meta\sqex_scd.c">
       <Filter>meta\Source Files</Filter>
     </ClCompile>
-    <ClCompile Include="meta\sqex_scd_sscfs.c">
+    <ClCompile Include="meta\sqex_scd_sscf.c">
       <Filter>meta\Source Files</Filter>
     </ClCompile>
     <ClCompile Include="meta\sqex_sead.c">

src/meta/hca.c

@@ -21,10 +21,19 @@ VGMSTREAM * init_vgmstream_hca(STREAMFILE *streamFile) {
 
     /* find decryption key in external file or preloaded list */
     if (hca_data->info.encryptionEnabled) {
-        uint8_t keybuf[8];
-        if (read_key_file(keybuf, 8, streamFile) == 8) {
+        uint8_t keybuf[0x08+0x02];
+        size_t keysize;
+
+        keysize = read_key_file(keybuf, 0x08+0x04, streamFile);
+        if (keysize == 0x08) { /* standard */
             keycode = (uint64_t)get_64bitBE(keybuf+0x00);
-        } else {
+        }
+        else if (keysize == 0x08+0x02) { /* seed key + AWB subkey */
+            uint64_t key = (uint64_t)get_64bitBE(keybuf+0x00);
+            uint16_t sub = (uint16_t)get_16bitBE(keybuf+0x08);
+            keycode = key * ( ((uint64_t)sub << 16u) | ((uint16_t)~sub + 2u) );
+        }
+        else {
             find_hca_key(hca_data, &keycode);
         }
 
@@ -63,46 +72,61 @@ fail:
 }
 
 
-/* Try to find the decryption key from a list. */
-static void find_hca_key(hca_codec_data * hca_data, unsigned long long * out_keycode) {
-    const size_t keys_length = sizeof(hcakey_list) / sizeof(hcakey_info);
-    unsigned long long best_keycode;
-    int best_score = -1;
-    int i;
-
-    best_keycode = 0xCC55463930DBE1AB; /* defaults to PSO2 key, most common */
-
-
-    /* find a candidate key */
-    for (i = 0; i < keys_length; i++) {
+static inline void test_key(hca_codec_data * hca_data, uint64_t key, uint16_t subkey, int *best_score, uint64_t *best_keycode) {
     int score;
-        unsigned long long keycode = (unsigned long long)hcakey_list[i].key;
 
-        score = test_hca_key(hca_data, keycode);
+    if (subkey) {
+        key = key * ( ((uint64_t)subkey << 16u) | ((uint16_t)~subkey + 2u) );
+    }
 
-        //;VGM_LOG("HCA: test key=%08x%08x, score=%i\n",
-        //        (uint32_t)((keycode >> 32) & 0xFFFFFFFF), (uint32_t)(keycode & 0xFFFFFFFF), score);
+    score = test_hca_key(hca_data, (unsigned long long)key);
+
+    //;VGM_LOG("HCA: test key=%08x%08x, subkey=%04x, score=%i\n",
+    //        (uint32_t)((key >> 32) & 0xFFFFFFFF), (uint32_t)(key & 0xFFFFFFFF), subkey, score);
 
     /* wrong key */
     if (score < 0)
-            continue;
+        return;
 
     /* score 0 is not trustable, update too if something better is found */
-        if (best_score < 0 || score < best_score || (best_score == 0 && score == 1)) {
-            best_score = score;
-            best_keycode = keycode;
-        }
-
-        /* best possible score */
-        if (score == 1) {
-            break;
+    if (*best_score < 0 || (score < *best_score && score > 0) || (*best_score == 0 && score == 1)) {
+        *best_score = score;
+        *best_keycode = key;
     }
 }
 
+/* Try to find the decryption key from a list. */
+static void find_hca_key(hca_codec_data * hca_data, unsigned long long * out_keycode) {
+    const size_t keys_length = sizeof(hcakey_list) / sizeof(hcakey_info);
+    int best_score = -1;
+    int i,j;
+
+    *out_keycode = 0xCC55463930DBE1AB; /* defaults to PSO2 key, most common */
+
+    /* find a candidate key */
+    for (i = 0; i < keys_length; i++) {
+        uint64_t key = hcakey_list[i].key;
+        size_t subkeys_size = hcakey_list[i].subkeys_size;
+        const uint16_t *subkeys = hcakey_list[i].subkeys;
+
+        if (subkeys_size > 0) {
+            for (j = 0; j < subkeys_size; j++) {
+                test_key(hca_data, key, subkeys[j], &best_score, out_keycode);
+                if (best_score == 1) /* best possible score */
+                    goto done;
+            }
+        }
+        else {
+            test_key(hca_data, key, 0, &best_score, out_keycode);
+            if (best_score == 1) /* best possible score */
+                goto done;
+        }
+    }
+
+done:
     //;VGM_LOG("HCA: best key=%08x%08x (score=%i)\n",
-    //        (uint32_t)((best_keycode >> 32) & 0xFFFFFFFF), (uint32_t)(best_keycode & 0xFFFFFFFF), best_score);
+    //        (uint32_t)((*out_keycode >> 32) & 0xFFFFFFFF), (uint32_t)(*out_keycode & 0xFFFFFFFF), best_score);
 
     VGM_ASSERT(best_score > 1, "HCA: best key=%08x%08x (score=%i)\n",
-            (uint32_t)((best_keycode >> 32) & 0xFFFFFFFF), (uint32_t)(best_keycode & 0xFFFFFFFF), best_score);
-    *out_keycode = best_keycode;
+            (uint32_t)((*out_keycode >> 32) & 0xFFFFFFFF), (uint32_t)(*out_keycode & 0xFFFFFFFF), best_score);
 }

src/meta/hca_keys.h

@@ -1,14 +1,23 @@
 #ifndef _HCA_KEYS_H_
 #define _HCA_KEYS_H_
 
+#include "hca_keys_awb.h"
+
 typedef struct {
-    uint64_t key;
+    uint64_t key;               /* hca key or seed key */
+    const uint16_t *subkeys;    /* derivation subkey table for seed key */
+    size_t subkeys_size;        /* size of the derivation subkey table */
 } hcakey_info;
 
+
 /**
  * List of known keys, extracted from the game files (mostly found in 2ch.net).
  * CRI's tools expect an unsigned 64 bit number string, but keys are commonly found online in hex form.
  * Keys only use 56 bits though, so the upper 8 bits can be ignored.
+ *
+ * ACB+AWB after mid 2018 use a master seed key + a derivation subkey in the AWB (normally 16b LE at 0x0e)
+ * to create the final HCA key, which means there is one key per AWB (so most HCA have a unique key).
+ * vgmstream derives the key if subkey table is provided.
  */
 static const hcakey_info hcakey_list[] = {
 
@@ -249,6 +258,9 @@ static const hcakey_info hcakey_list[] = {
         // Onsen Musume: Yunohana Kore Kushon (Android) voices
         {6667},                     // 0000000000001A0B
 
+        /* Dragalia Lost (Android) */
+        {2967411924141,         subkeys_dgl, sizeof(subkeys_dgl) / sizeof(subkeys_dgl[0]) },    // 000002B2E7889CAD
+
 };
 
 #endif/*_HCA_KEYS_H_*/