otp.bin is not needed from A9LH, just use the SHA register leftovers

source/crypto.c

@@ -295,8 +295,11 @@ void readFirm0(u8 *outbuf, u32 size){
     u8 CTRtmp[sizeof(CTR)];
     memcpy(CTRtmp, CTR, sizeof(CTR));
 
-    aes_advctr(CTRtmp, 0x0B130000 / 0x10, AES_INPUT_BE | AES_INPUT_NORMAL);
+    //Read FIRM0 data
     sdmmc_nand_readsectors(0x0B130000 / 0x200, size / 0x200, outbuf);
+
+    //Decrypt
+    aes_advctr(CTRtmp, 0x0B130000 / 0x10, AES_INPUT_BE | AES_INPUT_NORMAL);
     aes_use_keyslot(0x06);
     aes(outbuf, outbuf, size / AES_BLOCK_SIZE, CTRtmp, AES_CTR_MODE, AES_INPUT_BE | AES_INPUT_NORMAL);
 }
@@ -307,21 +310,27 @@ void writeFirm(u8 *inbuf, u32 firm, u32 size){
     u8 CTRtmp[sizeof(CTR)];
     memcpy(CTRtmp, CTR, sizeof(CTR));
 
+    //Encrypt FIRM data
     aes_advctr(CTRtmp, offset / 0x10, AES_INPUT_BE | AES_INPUT_NORMAL);
     aes_use_keyslot(0x06);
     aes(inbuf, inbuf, size / AES_BLOCK_SIZE, CTRtmp, AES_CTR_MODE, AES_INPUT_BE | AES_INPUT_NORMAL);
 
+    //Write to NAND
     sdmmc_nand_writesectors(offset / 0x200, size / 0x200, inbuf);
 }
 
 //Setup keyslot 0x11 for key sector de/encryption
-void setupKeyslot0x11(const u8 *otp){
+void setupKeyslot0x11(u32 a9lhBoot, const u8 *otp){
     u8 shasum[0x20];
     u8 keyX[0x10];
     u8 keyY[0x10];
 
+    //If booting via A9LH, use the leftover contents of the SHA register
+    if(a9lhBoot) memcpy((void *)shasum, (void *)REG_SHA_HASH, 0x20);
+    //Else calculate the otp.bin hash
+    else sha(shasum, otp, 0x90, SHA_256_MODE);
+
     //Set keyX and keyY
-    sha(shasum, otp, 0x90, SHA_256_MODE);
     memcpy(keyX, shasum, 0x10);
     memcpy(keyY, shasum + 0x10, 0x10);
     aes_setkey(0x11, keyX, AES_KEYX, AES_INPUT_BE | AES_INPUT_NORMAL);
@@ -340,7 +349,7 @@ void generateSector(u8 *keySector){
 }
 
 //Test the OTP to be correct by verifying key2
-u32 testOtp(u32 mode){
+u32 testOtp(u32 a9lhBoot){
     //Read keysector from NAND
     sdmmc_nand_readsectors(0x96, 0x1, (vu8 *)0x24500000);
 
@@ -349,7 +358,7 @@ u32 testOtp(u32 mode){
     aes((void *)0x24500000 + 0x10, (void *)0x24500000 + 0x10, 1, NULL, AES_ECB_DECRYPT_MODE, 0);
 
     //Test key2
-    if(memcmp((void *)0x24500000 + 0x10, mode ? key2 : a9lhKey2, 0x10) != 0) return 0;
+    if(memcmp((void *)0x24500000 + 0x10, a9lhBoot ? a9lhKey2 : key2, 0x10) != 0) return 0;
     return 1;
 }
 

source/crypto.h

@@ -79,7 +79,7 @@
 void getNandCTR(void);
 void readFirm0(u8 *outbuf, u32 size);
 void writeFirm(u8 *inbuf, u32 offset, u32 size);
-void setupKeyslot0x11(const u8 *otp);
+void setupKeyslot0x11(u32 a9lhBoot, const u8 *otp);
 void generateSector(u8 *keySector);
-u32 testOtp(u32 mode);
+u32 testOtp(u32 a9lhBoot);
 u32 verifyHash(const void *data, u32 size, const u8 *hash);

source/installer.c

@@ -26,7 +26,7 @@ static void installStage2(u32 mode, int pos_y){
     char *path = "a9lh/payload_stage2.bin";
     u32 size = fileSize(path);
     if(!size || size > MAXSTAGE2SIZE)
-        shutdown(1, pos_y, "Error: stage2 doesn't exist or exceeds max size");
+        shutdown(1, pos_y, "Error: stage2.bin doesn't exist or exceeds\nmax size");
     memset((u8 *)STAGE2OFFSET, 0, MAXSTAGE2SIZE);
     fileRead((u8 *)STAGE2OFFSET, path, size);
     if(mode) return;
@@ -35,7 +35,7 @@ static void installStage2(u32 mode, int pos_y){
 }
 
 void installer(void){
-    drawString("Safe A9LH Installer v1.1", 10, 10, 0x0000FF);
+    drawString("Safe A9LH Installer v1.2", 10, 10, 0x0000FF);
     int pos_y = drawString("Thanks to delebile, #cakey and StandardBus", 10, 40, 0xFFFFFF);
     pos_y = drawString("Press SELECT for a full install", 10, pos_y + SPACING_VERT, 0xFFFFFF);
     pos_y = drawString("Press START to only update stage2", 10, pos_y, 0xFFFFFF);
@@ -50,28 +50,38 @@ void installer(void){
     //Detect the console being used
     u32 console = (PDN_MPCORE_CFG == 1) ? 0 : 1;
 
+    const char *path;
+
+    //If making a first install, we need the OTP
+    if(!a9lhBoot){
+        //Read OTP
+        path = "a9lh/otp.bin";
+        if(fileSize(path) != 256)
+            shutdown(1, pos_y, "Error: otp.bin doesn't exist or has a wrong size");
+        fileRead((u8 *)OTPOFFSET, path, 256);
+    }
+
+    //Setup the key sector de/encryption with the SHA register or otp.bin
+    setupKeyslot0x11(a9lhBoot, (u8 *)OTPOFFSET);
+
+    if(a9lhBoot && !testOtp(a9lhBoot))
+        shutdown(1, pos_y, "Error: the OTP hash is invalid");
+
+    if(!a9lhBoot && console && !testOtp(a9lhBoot))
+        shutdown(1, pos_y, "Error: otp.bin is invalid or corrupted");
+
     //Calculate the CTR for the 3DS partitions
     getNandCTR();
 
     //Test that the CTR is correct
     readFirm0((u8 *)TEMPOFFSET, 0x200);
     if(memcmp((void *)TEMPOFFSET, "FIRM", 4) != 0)
-        shutdown(1, pos_y, "Error: couldn't setup NAND FIRM encryption");
+        shutdown(1, pos_y, "Error: failed to setup FIRM encryption");
-
-    //Read OTP
-    const char *path = "a9lh/otp.bin";
-    if(fileSize(path) != 256)
-        shutdown(1, pos_y, "Error: otp.bin doesn't exist or has a wrong size");
-    fileRead((u8 *)OTPOFFSET, path, 256);
-
-    setupKeyslot0x11((u8 *)OTPOFFSET);
-    if((a9lhBoot && !testOtp(0)) || (!a9lhBoot && console && !testOtp(1)))
-        shutdown(1, pos_y, "Error: your OTP is invalid or corrupted");
 
     //Read decrypted key sector
     path = "a9lh/secret_sector.bin";
     if(fileSize(path) != 0x200)
-        shutdown(1, pos_y, "Error: secret_sector.bin doesn't exist or has a wrong size");
+        shutdown(1, pos_y, "Error: secret_sector.bin doesn't exist or has\na wrong size");
     fileRead((u8 *)SECTOROFFSET, path, 0x200);
     if(!verifyHash((u8 *)SECTOROFFSET, 0x200, sectorHash))
         shutdown(1, pos_y, "Error: secret_sector is invalid");
@@ -86,7 +96,7 @@ void installer(void){
         shutdown(1, pos_y, "Error: firm0.bin doesn't exist");
     fileRead((u8 *)FIRM0OFFSET, path, firm0Size);
     if(!verifyHash((u8 *)FIRM0OFFSET, firm0Size, firm0Hash))
-        shutdown(1, pos_y, "Error: firmo is invalid");
+        shutdown(1, pos_y, "Error: firm0.bin is invalid or corrupted");
 
     //Read FIRM1
     path = "a9lh/firm1.bin";
@@ -95,13 +105,13 @@ void installer(void){
         shutdown(1, pos_y, "Error: firm1.bin doesn't exist");
     fileRead((u8 *)FIRM1OFFSET, path, firm1Size);
     if(!verifyHash((u8 *)FIRM1OFFSET, firm1Size, firm1Hash))
-        shutdown(1, pos_y, "Error: firm1 is invalid");
+        shutdown(1, pos_y, "Error: firm1.bin is invalid or corrupted");
 
     //Inject stage1
     path = "a9lh/payload_stage1.bin";
     u32 size = fileSize(path);
     if(!size || size > MAXSTAGE1SIZE)
-        shutdown(1, pos_y, "Error: stage1 doesn't exist or exceeds max size");
+        shutdown(1, pos_y, "Error: stage1.bin doesn't exist or exceeds\nmax size");
     fileRead((u8 *)STAGE1OFFSET, path, size);
 
     installStage2(1, pos_y);