IMG3 File Format - Revision history

Ethan0l.5 at 18:35, 2 March 2023

2023-03-02T18:35:05Z

B1n4r1b01: img3 is ded but still...

2018-10-19T14:42:48Z

img3 is ded but still...

Npupyshev: Move CEPO tag down

2017-04-19T17:57:06Z

Move CEPO tag down

Npupyshev at 17:56, 19 April 2017

2017-04-19T17:56:33Z

5urd at 23:45, 7 October 2015

2015-10-07T23:45:25Z

5urd at 18:47, 18 March 2015

2015-03-18T18:47:10Z

Britta: moving explanation to top

2015-03-10T09:15:24Z

moving explanation to top

IAdam1n: Minor wording change.

2014-09-15T09:06:44Z

Minor wording change.

Dialexio: Reworded for a little more future-proofing.

2013-12-26T19:37:31Z

Reworded for a little more future-proofing.

IAdam1n at 12:20, 26 December 2013

2013-12-26T12:20:56Z

← Older revision		Revision as of 18:35, 2 March 2023
Line 1:		Line 1:
−	The '''IMG3''' file format was introduced with [[iOS\|iPhone OS]] 2.0b4 to replace the broken [[S5L File Formats\|IMG2 format]]. This format is used on all devices with an [[~~S5L8955\|A6X~~]] or older; [[S5L8960\|A7]] and newer devices use [[IM4P File Format\|IM4P]] and [[IMG4 File Format\|IMG4]] files.	+	The '''IMG3''' file format was introduced with [[iOS\|iPhone OS]] 2.0b4 to replace the broken [[S5L File Formats\|IMG2 format]]. This format is used on all devices with an [[S5L8920]] or older; [[S5L8960\|A7]] and newer devices use [[IM4P File Format\|IM4P]] and [[IMG4 File Format\|IMG4]] files.

	==Encryption==		==Encryption==

@@ Line 45: / Line 45: @@
  [[Nonce|NONC]]: [[Nonce]] used when file was signed.
  [[CEPO]]: Chip epoch
 ==Signature Check==

@@ Line 33: / Line 33: @@
  [[VERS]]: [[iBoot]] version of the image
  [[SEPO]]: Security Epoch
  [[SDOM]]: Security Domain
  [[PROD]]: Production Mode
@@ Line 45: / Line 44: @@
  [[DATA]]: Real content of the file
  [[Nonce|NONC]]: [[Nonce]] used when file was signed.
 ==Signature Check==

@@ Line 33: / Line 33: @@
  [[VERS]]: [[iBoot]] version of the image
  [[SEPO]]: Security Epoch
  [[SDOM]]: Security Domain
  [[PROD]]: Production Mode
@@ Line 43: / Line 44: @@
  [[TYPE]]: Type of image, should contain the same string as the header's <code>ident</code>
  [[DATA]]: Real content of the file
 ==Signature Check==

@@ Line 30: / Line 30: @@
 == Tags ==
  [[VERS]]: [[iBoot]] version of the image
  [[SEPO]]: Security Epoch

@@ Line 1: / Line 1: @@
-The '''IMG3 File Format''' is the replacement for the [[S5L File Formats#IMG2|IMG2 file format]] for iOS 2.0 and onward. iOS 7.0.1 introduced the [[IM4P File Format]] and the [[IMG4 File Format]] for [[A7]] and newer devices.
+The '''IMG3''' file format was introduced with [[iOS|iPhone OS]] 2.0b4 to replace the broken [[S5L File Formats|IMG2 format]]. This format is used on all devices with an [[S5L8955|A6X]] or older; [[S5L8960|A7]] and newer devices use [[IM4P File Format|IM4P]] and [[IMG4 File Format|IMG4]] files.
 ==Encryption==
@@ Line 6: / Line 6: @@
 In the current method, iBoot will always use the first 16 bytes of the [[KBAG]] as the IV, then the remaining 16 (aes-128, used with [[S5L8900]] and [[S5L8720]]), 24 (aes-192), or 32 (aes-256, used with [[S5L8920]]) bytes for the key.
-==Header==
+== Contents ==
      uint32_t fullSize;    // full size of fw image
      uint32_t sizeNoPack;  // size of fw image without header
@@ Line 14: / Line 15: @@
                            // size of the start of the data section (the code) up to
                            // the start of the RSA signature (SHSH section)
-     uint32_t iden;        // identifier of image, used when bootrom is parsing images
+     uint32_t ident;       // identifier of image, used when bootrom is parsing images
                            // list to find LLB (illb), LLB parsing it to find iBoot (ibot),
                            // etc.
-     Img3Tag_t tags[];     // continues until end of file
+     img3Tag  tags[];      // continues until end of file
  };
-     uint32_t magic;             // [[#Tags|see below]]
+     uint32_t totalLength;      // length of tag including "magic" and these two length values
-     uint32_t total_length;      // length of tag including "magic"
+     uint32_t dataLength;       // length of tag data
  };
-==Tags==
+== Tags ==
- [[VERS]]: iBoot version of the image
+ [[VERS]]: [[iBoot]] version of the image
  [[SEPO]]: Security Epoch
  [[SDOM]]: Security Domain
  [[PROD]]: Production Mode
- [[CHIP]]: Chip to be used with. example: "0x8900" for [[S5L8900]].
+ [[CHIP]]: Chip to be used with. example: <code>0x8900</code> for [[S5L8900]].
  [[BORD]]: Board to be used with
- [[KBAG]]: contains the KEY and IV required to decrypt encrypted with the [[GID Key]]
+ [[KBAG]]: Contains the IV and key required to decrypt; encrypted with the [[GID Key]]
  [[SHSH]]: RSA encrypted SHA1 hash of the file
  [[CERT]]: Certificate
- [[ECID]]: Exclusive Chip ID unique to every device with iPhone OS.
+ [[ECID]]: Exclusive Chip ID unique to every device
- [[TYPE]]: Type of image, should contain the same string as 'iden' of the header
+ [[TYPE]]: Type of image, should contain the same string as the header's <code>ident</code>
  [[DATA]]: Real content of the file

@@ Line 1: / Line 1: @@
-This is the replacement for the [[S5L File Formats#IMG2|IMG2 file format]] for iOS 2.0 and onward. iOS 7.0.1 introduced the [[IM4P File Format]] and the [[IMG4 File Format]] for [[A7]] and newer devices.
+The '''IMG3 File Format''' is the replacement for the [[S5L File Formats#IMG2|IMG2 file format]] for iOS 2.0 and onward. iOS 7.0.1 introduced the [[IM4P File Format]] and the [[IMG4 File Format]] for [[A7]] and newer devices.
 ==Header==
@@ Line 42: / Line 47: @@
  Decryption is done using the modulus at cert + 0xA15
 xC to [[SHSH]] is SHAed
 [[Category:File Formats]]

← Older revision		Revision as of 09:06, 15 September 2014
Line 1:		Line 1:
−	This is the replacement for the [[S5L File Formats#IMG2\|IMG2 file format]] for iOS 2.0 and onward. iOS 7 introduced the [[IM4P File Format]] and the [[IMG4 File Format]] for [[A7]] devices.	+	This is the replacement for the [[S5L File Formats#IMG2\|IMG2 file format]] for iOS 2.0 and onward. iOS 7.0.1 introduced the [[IM4P File Format]] and the [[IMG4 File Format]] for [[A7]] and newer devices.

	==Header==		==Header==

← Older revision		Revision as of 19:37, 26 December 2013
Line 1:		Line 1:
−	This is the replacement for the [[S5L File Formats#IMG2\|IMG2 file format]] for iOS 2.0 and onward. iOS 7.x introduced [[IM4P File Format]] and the [[IMG4 File Format]]~~, exclusive~~ to [[A7]] devices.	+	This is the replacement for the [[S5L File Formats#IMG2\|IMG2 file format]] for iOS 2.0 and onward. iOS 7 introduced the [[IM4P File Format]] and the [[IMG4 File Format]] for [[A7]] devices.

	==Header==		==Header==

← Older revision		Revision as of 12:20, 26 December 2013
Line 1:		Line 1:
−	This is the replacement for the [[S5L File Formats#IMG2\|IMG2 file format]] for iOS 2.0 and onward. iOS 7.~~0.1~~ introduced [[IM4P File Format]] and the [[IMG4 File Format]], exclusive to ~~the iPhone 5c and iPhone~~ 5s.	+	This is the replacement for the [[S5L File Formats#IMG2\|IMG2 file format]] for iOS 2.0 and onward. iOS 7.x introduced [[IM4P File Format]] and the [[IMG4 File Format]], exclusive to [[A7]] devices.

	==Header==		==Header==