unpack PSP pkg files to CSO

Author: mmozeiko

pkg2zip.c

@@ -275,6 +275,7 @@ int main(int argc, char* argv[])
     printf("pkg2zip v1.8\n");
 
     int zipped = 1;
+    int cso = 5;
     const char* pkg_arg = NULL;
     const char* zrif_arg = NULL;
     for (int i = 1; i < argc; i++)
@@ -283,6 +284,14 @@ int main(int argc, char* argv[])
         {
             zipped = 0;
         }
+        else if (strncmp(argv[i], "-c", 2) == 0)
+        {
+            if (argv[i][2] != 0)
+            {
+                cso = atoi(argv[i] + 2);
+                cso = cso > 9 ? 9 : cso < 0 ? 0 : cso;
+            }
+        }
         else
         {
             if (pkg_arg != NULL)
@@ -300,7 +309,7 @@ int main(int argc, char* argv[])
     if (pkg_arg == NULL)
     {
         fprintf(stderr, "ERROR: no pkg file specified\n");
-        fatal("Usage: %s [-x] file.pkg [zRIF]\n", argv[0]);
+        fatal("Usage: %s [-x] [-c[N]] file.pkg [zRIF]\n", argv[0]);
     }
 
     printf("[*] loading...\n");
@@ -706,8 +715,8 @@ int main(int argc, char* argv[])
             {
                 if (strcmp("USRDIR/CONTENT/EBOOT.PBP", name) == 0)
                 {
-                    snprintf(path, sizeof(path), "pspemu/ISO/%s [%.9s].iso", title, id);
-                    unpack_psp_eboot(path, item_key, iv, pkg, enc_offset, data_offset, data_size);
+                    snprintf(path, sizeof(path), "pspemu/ISO/%s [%.9s].%s", title, id, cso ? "cso" : "iso");
+                    unpack_psp_eboot(path, item_key, iv, pkg, enc_offset, data_offset, data_size, cso);
                     continue;
                 }
                 else if (strcmp("USRDIR/CONTENT/PSP-KEY.EDAT", name) == 0)

pkg2zip_crc32.c

@@ -258,3 +258,70 @@ uint32_t crc32_done(crc32_ctx* ctx)
 
     return ~ctx->crc[0];
 }
+
+static uint32_t crc32_gfmulv(const uint32_t* m, uint32_t v)
+{
+    uint32_t r = 0;
+    while (v)
+    {
+        if (v & 1)
+        {
+            r ^= *m;
+        }
+        v >>= 1;
+        m++;
+    }
+    return r;
+}
+
+static void crc32_gfsq(const uint32_t* m, uint32_t* r)
+{
+    for (size_t i = 0; i < 32; i++)
+    {
+        r[i] = crc32_gfmulv(m, m[i]);
+    }
+}
+
+uint32_t crc32_combine(uint32_t a, uint32_t b, uint32_t blen)
+{
+    uint32_t m1[32];
+    uint32_t m2[32];
+
+    m1[0] = 0xedb88320;
+    for (uint32_t i = 1; i < 32; i++)
+    {
+        m1[i] = 1 << (i - 1);
+    }
+
+    crc32_gfsq(m1, m2);
+    crc32_gfsq(m2, m1);
+
+    for (;;)
+    {
+        crc32_gfsq(m1, m2);
+        if (blen & 1)
+        {
+            a = crc32_gfmulv(m2, a);
+        }
+        blen >>= 1;
+
+        if (blen == 0)
+        {
+            break;
+        }
+
+        crc32_gfsq(m2, m1);
+        if (blen & 1)
+        {
+            a = crc32_gfmulv(m1, a);
+        }
+        blen >>= 1;
+
+        if (blen == 0)
+        {
+            break;
+        }
+    }
+
+    return a ^ b;
+}

pkg2zip_crc32.h

@@ -9,3 +9,8 @@ typedef struct {
 void crc32_init(crc32_ctx* ctx);
 void crc32_update(crc32_ctx* ctx, const void* buffer, size_t size);
 uint32_t crc32_done(crc32_ctx* ctx);
+
+// returns crc32(x||y)
+// where a=crc32(x) and b=crc32(y)
+// crc32(x||y) = crc32(x||z) ^ crc32(y), where z=00...00 (same length as y)
+uint32_t crc32_combine(uint32_t a, uint32_t b, uint32_t blen);

pkg2zip_out.c

@@ -36,16 +36,17 @@ void out_add_folder(const char* path)
     }
 }
 
-void out_begin_file(const char* name, int compress)
+uint64_t out_begin_file(const char* name, int compress)
 {
     if (out_zipped)
     {
-        zip_begin_file(&out_zip, name, compress);
+        return zip_begin_file(&out_zip, name, compress);
     }
     else
     {
         out_file = sys_create(name);
         out_file_offset = 0;
+        return 0;
     }
 }
 
@@ -73,3 +74,45 @@ void out_write(const void* buffer, uint32_t size)
         out_file_offset += size;
     }
 }
+
+void out_write_at(uint64_t offset, const void* buffer, uint32_t size)
+{
+    if (out_zipped)
+    {
+        zip_write_file_at(&out_zip, offset, buffer, size);
+    }
+    else
+    {
+        sys_write(out_file, offset, buffer, size);
+    }
+}
+
+void out_set_offset(uint64_t offset)
+{
+    if (out_zipped)
+    {
+        zip_set_offset(&out_zip, offset);
+    }
+    else
+    {
+        out_file_offset = offset;
+
+    }
+}
+
+uint32_t out_zip_get_crc32(void)
+{
+    if (out_zipped)
+    {
+        return zip_get_crc32(&out_zip);
+    }
+    return 0;
+}
+
+void out_zip_set_crc32(uint32_t crc)
+{
+    if (out_zipped)
+    {
+        zip_set_crc32(&out_zip, crc);
+    }
+}

pkg2zip_out.h

@@ -5,6 +5,12 @@
 void out_begin(const char* name, int zipped);
 void out_end(void);
 void out_add_folder(const char* path);
-void out_begin_file(const char* name, int compress);
+uint64_t out_begin_file(const char* name, int compress);
 void out_end_file(void);
 void out_write(const void* buffer, uint32_t size);
+
+// hacky solution to be able to write cso header after the data is written
+void out_write_at(uint64_t offset, const void* buffer, uint32_t size);
+void out_set_offset(uint64_t offset);
+uint32_t out_zip_get_crc32(void);
+void out_zip_set_crc32(uint32_t crc);