diff --git a/arm9/source/filesys/filetype.h b/arm9/source/filesys/filetype.h
index 9f207c2..e5d3109 100644
--- a/arm9/source/filesys/filetype.h
+++ b/arm9/source/filesys/filetype.h
@@ -52,6 +52,7 @@
 #define FTYPE_TIKBUILD(tp)      (tp&(GAME_TICKET|SYS_TICKDB|BIN_TIKDB))
 #define FTYPE_KEYBUILD(tp)      (tp&(BIN_KEYDB|BIN_LEGKEY))
 #define FTYPE_TITLEINFO(tp)     (tp&(GAME_SMDH|GAME_NCCH|GAME_NCSD|GAME_CIA|GAME_TMD|GAME_NDS|GAME_GBA|GAME_TAD|GAME_3DSX))
+#define FTYPE_CIACHECK(tp)		(tp&GAME_CIA)
 #define FTYPE_RENAMABLE(tp)     (tp&(GAME_NCCH|GAME_NCSD|GAME_CIA|GAME_NDS|GAME_GBA))
 #define FTYPE_TRIMABLE(tp)      (tp&(IMG_NAND|GAME_NCCH|GAME_NCSD|GAME_NDS|SYS_FIRM))
 #define FTYPE_TRANSFERABLE(tp)  ((u64) (tp&(IMG_FAT|FLAG_CTR)) == (u64) (IMG_FAT|FLAG_CTR))
diff --git a/arm9/source/game/cert.c b/arm9/source/game/cert.c
new file mode 100644
index 0000000..3b01f0f
--- /dev/null
+++ b/arm9/source/game/cert.c
@@ -0,0 +1,21 @@
+#include "cert.h"
+#include "ff.h"
+
+u32 LoadCertFromCertDb(u64 offset, Certificate* cert, u8* mod, u32* exp) {
+	Certificate cert_local;
+    FIL db;
+    UINT bytes_read;
+
+    // not much in terms of error checking here
+    if (f_open(&db, "1:/dbs/certs.db", FA_READ | FA_OPEN_EXISTING) != FR_OK)
+        return 1;
+    f_lseek(&db, offset);
+    if (!cert) cert = &cert_local;
+    f_read(&db, cert, CERT_SIZE, &bytes_read);
+    f_close(&db);
+
+    if (mod) memcpy(mod, cert->mod, 0x100);
+    if (exp) *exp = getle32(cert->exp);
+
+    return 0;
+}
diff --git a/arm9/source/game/cert.h b/arm9/source/game/cert.h
new file mode 100644
index 0000000..ad7e73d
--- /dev/null
+++ b/arm9/source/game/cert.h
@@ -0,0 +1,22 @@
+#pragma once
+
+#include "common.h"
+
+#define CERT_SIZE  sizeof(Certificate)
+
+// from: http://3dbrew.org/wiki/Certificates
+// all numbers in big endian
+typedef struct {
+    u8 sig_type[4]; // expected: 0x010004 / RSA_2048 SHA256
+    u8 signature[0x100];
+    u8 padding0[0x3C];
+    u8 issuer[0x40];
+    u8 keytype[4]; // expected: 0x01 / RSA_2048
+    u8 name[0x40];
+    u8 unknown[4];
+    u8 mod[0x100];
+    u8 exp[0x04];
+    u8 padding1[0x34];
+} __attribute__((packed)) Certificate;
+
+u32 LoadCertFromCertDb(u64 offset, Certificate* cert, u8* mod, u32* exp);
diff --git a/arm9/source/game/ticket.c b/arm9/source/game/ticket.c
index d0170df..f128029 100644
--- a/arm9/source/game/ticket.c
+++ b/arm9/source/game/ticket.c
@@ -1,5 +1,6 @@
 #include "ticket.h"
 #include "unittype.h"
+#include "cert.h"
 #include "sha.h"
 #include "rsa.h"
 #include "ff.h"
@@ -19,19 +20,11 @@ u32 ValidateTicketSignature(Ticket* ticket) {
     static u8 mod[0x100] = { 0 };
     static u32 exp = 0;
     
-    // grab cert from cert.db
     if (!got_modexp) {
-        Certificate cert;
-        FIL db;
-        UINT bytes_read;
-        if (f_open(&db, "1:/dbs/certs.db", FA_READ | FA_OPEN_EXISTING) != FR_OK)
-            return 1;
-        f_lseek(&db, 0x3F10);
-        f_read(&db, &cert, CERT_SIZE, &bytes_read);
-        f_close(&db);
-        memcpy(mod, cert.mod, 0x100);
-        exp = getle32(cert.exp);
-        got_modexp = true;
+        // grab mod/exp from cert from cert.db
+        if (LoadCertFromCertDb(0x3F10, NULL, mod, &exp) == 0)
+            got_modexp = true;
+        else return 1;
     }
     
     if (!RSA_setKey2048(3, mod, exp) ||
diff --git a/arm9/source/game/ticket.h b/arm9/source/game/ticket.h
index d66f695..ae6fcec 100644
--- a/arm9/source/game/ticket.h
+++ b/arm9/source/game/ticket.h
@@ -3,7 +3,6 @@
 #include "common.h"
 
 #define TICKET_SIZE         sizeof(Ticket)
-#define CERT_SIZE           sizeof(Certificate)
 #define TICKET_CDNCERT_SIZE 0x700
 
 #define TICKET_ISSUER       "Root-CA00000003-XS0000000c"
@@ -44,21 +43,6 @@ typedef struct {
     u8 content_index[0xAC];
 } __attribute__((packed)) Ticket;
 
-// from: http://3dbrew.org/wiki/Certificates
-// all numbers in big endian
-typedef struct {
-    u8 sig_type[4]; // expected: 0x010004 / RSA_2048 SHA256
-    u8 signature[0x100];
-    u8 padding0[0x3C];
-    u8 issuer[0x40];
-    u8 keytype[4]; // expected: 0x01 / RSA_2048
-    u8 name[0x40];
-    u8 unknown[4];
-    u8 mod[0x100];
-    u8 exp[0x04];
-    u8 padding1[0x34];
-} __attribute__((packed)) Certificate;
-
 u32 ValidateTicket(Ticket* ticket);
 u32 ValidateTicketSignature(Ticket* ticket);
 u32 BuildFakeTicket(Ticket* ticket, u8* title_id);
diff --git a/arm9/source/game/tmd.c b/arm9/source/game/tmd.c
index 42d2d5e..adac28d 100644
--- a/arm9/source/game/tmd.c
+++ b/arm9/source/game/tmd.c
@@ -1,6 +1,8 @@
 #include "tmd.h"
 #include "unittype.h"
+#include "cert.h"
 #include "sha.h"
+#include "rsa.h"
 #include "ff.h"
 
 u32 ValidateTmd(TitleMetaData* tmd) {
@@ -12,6 +14,25 @@ u32 ValidateTmd(TitleMetaData* tmd) {
     return 0;
 }
 
+u32 ValidateTmdSignature(TitleMetaData* tmd) {
+    static bool got_modexp = false;
+    static u8 mod[0x100] = { 0 };
+    static u32 exp = 0;
+    
+    if (!got_modexp) {
+        // grab mod/exp from cert from cert.db
+        if (LoadCertFromCertDb(0x3C10, NULL, mod, &exp) == 0)
+            got_modexp = true;
+        else return 1;
+    }
+    
+    if (!RSA_setKey2048(3, mod, exp) ||
+        !RSA_verify2048((void*) &(tmd->signature), (void*) &(tmd->issuer), 0xC4))
+        return 1;
+        
+    return 0;
+}
+
 u32 GetTmdCtr(u8* ctr, TmdContentChunk* chunk) {
     memset(ctr, 0, 16);
     memcpy(ctr, chunk->index, 2);
diff --git a/arm9/source/game/tmd.h b/arm9/source/game/tmd.h
index afdcf08..823e18f 100644
--- a/arm9/source/game/tmd.h
+++ b/arm9/source/game/tmd.h
@@ -58,6 +58,7 @@ typedef struct {
 } __attribute__((packed)) TitleMetaData;
 
 u32 ValidateTmd(TitleMetaData* tmd);
+u32 ValidateTmdSignature(TitleMetaData* tmd);
 u32 GetTmdCtr(u8* ctr, TmdContentChunk* chunk);
 u32 FixTmdHashes(TitleMetaData* tmd);
 u32 BuildFakeTmd(TitleMetaData* tmd, u8* title_id, u32 n_contents, u32 save_size);
diff --git a/arm9/source/godmode.c b/arm9/source/godmode.c
index 19ac675..a400032 100644
--- a/arm9/source/godmode.c
+++ b/arm9/source/godmode.c
@@ -1028,6 +1028,7 @@ u32 FileHandlerMenu(char* current_path, u32* cursor, u32* scroll, PaneData** pan
     bool tik_buildable = (FTYPE_TIKBUILD(filetype)) && !in_output_path;
     bool key_buildable = (FTYPE_KEYBUILD(filetype)) && !in_output_path && !((drvtype & DRV_VIRTUAL) && (drvtype & DRV_SYSNAND));
     bool titleinfo = (FTYPE_TITLEINFO(filetype));
+    bool ciacheckable = (FTYPE_CIACHECK(filetype)); 
     bool renamable = (FTYPE_RENAMABLE(filetype));
     bool trimable = (FTYPE_TRIMABLE(filetype)) && !(drvtype & DRV_VIRTUAL) && !(drvtype & DRV_ALIAS) &&
         !(drvtype & DRV_CTRNAND) && !(drvtype & DRV_TWLNAND) && !(drvtype & DRV_IMAGE);
@@ -1230,6 +1231,7 @@ u32 FileHandlerMenu(char* current_path, u32* cursor, u32* scroll, PaneData** pan
     // stuff for special menu starts here
     n_opt = 0;
     int show_info = (titleinfo) ? ++n_opt : -1;
+    int ciacheck = (ciacheckable) ? ++n_opt : -1;
     int mount = (mountable) ? ++n_opt : -1;
     int restore = (restorable) ? ++n_opt : -1;
     int ebackup = (ebackupable) ? ++n_opt : -1;
@@ -1266,6 +1268,7 @@ u32 FileHandlerMenu(char* current_path, u32* cursor, u32* scroll, PaneData** pan
     if (ebackup > 0) optionstr[ebackup-1] = "Update embedded backup";
     if (ncsdfix > 0) optionstr[ncsdfix-1] = "Rebuild NCSD header";
     if (show_info > 0) optionstr[show_info-1] = "Show title info";
+    if (ciacheck > 0) optionstr[ciacheck-1] = "CIA checker tool";
     if (decrypt > 0) optionstr[decrypt-1] = (cryptable_inplace) ? "Decrypt file (...)" : "Decrypt file (" OUTPUT_PATH ")";
     if (encrypt > 0) optionstr[encrypt-1] = (cryptable_inplace) ? "Encrypt file (...)" : "Encrypt file (" OUTPUT_PATH ")";
     if (cia_build > 0) optionstr[cia_build-1] = (cia_build_legit < 0) ? "Build CIA from file" : "Build CIA (standard)";
@@ -1647,6 +1650,10 @@ u32 FileHandlerMenu(char* current_path, u32* cursor, u32* scroll, PaneData** pan
             ShowPrompt(false, "Title info: not found");
         return 0;
     }
+    else if (user_select == ciacheck) { // -> CIA checker tool
+        ShowCiaCheckerInfo(file_path);
+        return 0;
+    }
     else if (user_select == hsinject) { // -> Inject to Health & Safety
         char* destdrv[2] = { NULL };
         n_opt = 0;
diff --git a/arm9/source/utils/gameutil.c b/arm9/source/utils/gameutil.c
index 3f4bf80..3f2ce9f 100644
--- a/arm9/source/utils/gameutil.c
+++ b/arm9/source/utils/gameutil.c
@@ -1816,6 +1816,73 @@ u32 ShowGameFileTitleInfo(const char* path) {
     return ret;
 }
 
+u32 ShowCiaCheckerInfo(const char* path) {
+	CiaStub* cia = (CiaStub*) malloc(sizeof(CiaStub));
+    if (!cia) return 1;
+    
+     // path string
+    char pathstr[32 + 1];
+    TruncateString(pathstr, path, 32, 8);
+    
+    // load CIA stub
+    if (LoadCiaStub(cia, path) != 0) {
+        ShowPrompt(false, "%s\nError: Probably not a CIA file", pathstr);
+        free(cia);
+        return 1;
+    }
+
+    // states: 0 -> invalid / 1 -> valid / badsig / 2 -> valid / goodsig
+    u32 state_ticket = 0;
+    u32 state_tmd = 0;
+    u32 content_count = getbe16(cia->tmd.content_count);
+    u32 content_found = 0;
+    u64 title_id = getbe64(cia->ticket.title_id);
+    u32 console_id = getbe32(cia->ticket.console_id);
+    bool missing_first = false;
+    bool is_dlc = ((title_id >> 32) == 0x0004008C);
+
+    // check ticket
+    if (ValidateTicket(&(cia->ticket)) == 0)
+    	state_ticket = (ValidateTicketSignature(&(cia->ticket)) == 0) ? 2 : 1;
+
+    // check tmd
+    if (ValidateTmd(&(cia->tmd)) == 0)
+    	state_tmd = (ValidateTmdSignature(&(cia->tmd)) == 0) ? 2 : 1;
+
+    // check for available contents
+    u8* cnt_index = cia->header.content_index;
+    for (u32 i = 0; (i < content_count) && (i < TMD_MAX_CONTENTS); i++) {
+        TmdContentChunk* chunk = &(cia->content_list[i]);
+        u16 index = getbe16(chunk->index);
+        if (cnt_index[index/8] & (1 << (7-(index%8)))) content_found++; 
+        else if (i == 0) missing_first = true;
+    }
+
+    // CIA type string
+    char typestr[32];
+    if (!state_ticket || !state_tmd || missing_first || (!is_dlc && (content_found != content_count)))
+    	snprintf(typestr, 32, "Possibly Broken");
+    else snprintf(typestr, 32, "%s %s%s",
+    	console_id ? "Personal" : "Universal",
+    	(state_ticket == 2) ? "Legit" : (state_tmd == 2) ? "Pirate Legit" : "Custom",
+    	is_dlc ? " DLC" : "");
+
+    // output results
+    s32 state_verify = -1;
+	while (true) {
+		if (!ShowPrompt(state_verify < 0, "%s\n%s CIA File\n \nTitle ID: %016llX\nConsole ID: %08lX\nContents in CIA: %lu/%lu\nTicket/TMD: %s/%s\nVerification: %s",
+			pathstr, typestr, title_id, console_id,
+			content_found, content_count,
+			(state_ticket == 0) ? "invalid" : (state_ticket == 2) ? "legit" : "illegit",
+			(state_tmd == 0) ? "invalid" : (state_tmd == 2) ? "legit" : "illegit",
+			(state_verify < 0) ? "pending\n \nProceed with verification?" : (state_verify == 0) ? "passed" : "failed") ||
+			(state_verify >= 0)) break;
+		state_verify = VerifyCiaFile(path);
+	}
+
+	return (state_ticket && state_tmd) ? 0 : 1; 
+}
+
 u32 BuildNcchInfoXorpads(const char* destdir, const char* path) {
     FIL fp_info;
     FIL fp_xorpad;
diff --git a/arm9/source/utils/gameutil.h b/arm9/source/utils/gameutil.h
index 5d28d67..b97d34b 100644
--- a/arm9/source/utils/gameutil.h
+++ b/arm9/source/utils/gameutil.h
@@ -12,6 +12,7 @@ u32 ExtractDataFromDisaDiff(const char* path);
 u64 GetGameFileTrimmedSize(const char* path);
 u32 TrimGameFile(const char* path);
 u32 ShowGameFileTitleInfo(const char* path);
+u32 ShowCiaCheckerInfo(const char* path);
 u32 GetTmdContentPath(char* path_content, const char* path_tmd);
 u32 BuildNcchInfoXorpads(const char* destdir, const char* path);
 u32 CheckHealthAndSafetyInject(const char* hsdrv);