GID Key - Revision history

IAdam1n at 12:50, 17 September 2021

2021-09-17T12:50:44Z

AS967 at 01:00, 27 August 2017

2017-08-27T01:00:44Z

Axi0mX: iOS 7.0, not 7.0.1

2017-06-21T23:18:21Z

iOS 7.0, not 7.0.1

Spydar007 at 10:09, 26 March 2017

2017-03-26T10:09:54Z

Britta: adding Category:Malware research

2015-07-08T07:03:06Z

adding Category:Malware research

Britta: clarifying

2015-03-11T23:20:15Z

clarifying

Britta: consistent pronouns; links to more discussion

2015-03-11T23:14:39Z

consistent pronouns; links to more discussion

5urd: better

2015-03-11T21:09:02Z

better

Britta: better phrasing

2015-03-11T08:13:22Z

better phrasing

Britta: a little more context/copyediting

2015-03-11T06:21:43Z

a little more context/copyediting

@@ Line 18: / Line 18: @@
 === CIA research into attacks ===
-[https://firstlook.org/theintercept/2015/03/10/ispy-cia-campaign-steal-apples-secrets/ According to this March 2015 article in ''The Intercept''] based on documents provided by Edward Snowden, the CIA has been particularly interested in figuring out how to extract GID keys as part of their efforts to get access to modifying iOS to insert spy software and to research further vulnerabilities:
+[https://firstlook.org/theintercept/2015/03/10/ispy-cia-campaign-steal-apples-secrets/ According to this {{date|2015|03}} article in ''The Intercept''] based on documents provided by Edward Snowden, the CIA has been particularly interested in figuring out how to extract GID keys as part of their efforts to get access to modifying iOS to insert spy software and to research further vulnerabilities:
 <blockquote>"At the 2011 Jamboree conference, there were two separate presentations on hacking the GID key on Apple’s processors. One was focused on non-invasively obtaining it by studying the electromagnetic emissions of — and the amount of power used by — the iPhone’s processor while encryption is being performed. Careful analysis of that information could be used to extract the encryption key. Such a tactic is known as a "side channel" attack. The second focused on a "method to physically extract the GID key.'"([https://firstlook.org/theintercept/document/2015/03/10/differential-power-analysis-apple-a4-processor/ The first document] and [https://firstlook.org/theintercept/document/2015/03/10/secure-key-extraction-physical-de-processing-apples-a4-processor/ the second one].)</blockquote>
 <blockquote>"According to the 2011 document describing the Jamboree presentations on Apple's processor, the researchers asserted that extracting the GID key could also allow them to look for other potential gateways into Apple devices. 'If successful, it would enable decryption and analysis of the boot firmware for vulnerabilities, and development of associated exploits across the entire A4-based product-line, which includes the iPhone 4, the iPod touch and the iPad.'"</blockquote>
-The 2011 timing is interesting, since [[User:geohot|geohot]] had publicly released a powerful [[bootrom]] exploit ([[limera1n]]) for A4 devices in October 2010, which presumably the CIA was already using (probably one of the "very small number of security flaws, many of which are public, which Apple eventually patches" they mentioned). If a person has a bootrom exploit like limera1n, they can decrypt firmwares by generating the firmware keys from the [[KBAG]]s (since they can use the GID keys on-device even if they can't extract them) - see [[Firmware Keys]]. It's possible this talk had been written earlier and presented as still relevant for A5 and future chips.
+The 2011 timing is interesting, since [[User:geohot|geohot]] had publicly released a powerful [[bootrom]] exploit ([[limera1n]]) for A4 devices in {{date|2010|10}}, which presumably the CIA was already using (probably one of the "very small number of security flaws, many of which are public, which Apple eventually patches" they mentioned). If a person has a bootrom exploit like limera1n, they can decrypt firmwares by generating the firmware keys from the [[KBAG]]s (since they can use the GID keys on-device even if they can't extract them) - see [[Firmware Keys]]. It's possible this talk had been written earlier and presented as still relevant for A5 and future chips.
 === Discussion of CIA research ===

@@ Line 1: / Line 1: @@
 The '''GID key''' ('''Group ID key''') is a 256-bit [[wikipedia:Advanced Encryption Standard|AES]] key shared by all devices with the same application processor. The GID key is part of how iOS encrypts software on the device ([https://books.google.com/books?id=CEzB2avQjR4C&lpg=PA268&vq=gid%20key&dq=GID%20Key&pg=PA268#v=onepage&q&f=false more explanation]). This is one component of the iOS security system, which also includes [[SHSH]] signatures.
-This key is different on each [[Application Processor|processor model]] ([[wikipedia:System on a chip|system on a chip]]) - in other words, the [[S5L8900]] (chip for iPhone 3G for example) has a different key compared to the [[S5L8930]] (A4 chip for iPhone 4, iPod touch (4th generation), etc.).
+This key is different on each [[Application Processor|processor model]] ([[wikipedia:System on a chip|system on a chip]]) - in other words, the [[S5L8900]] (chip for iPhone 3G for example) has a different key compared to the [[S5L8930]] (A4 chip for iPhone 4, iPod touch (4th generation), etc.). On [[S5L8960]] and later processors, the [[Secure Enclave]] has it's own GID that is separate from the AP's which is used to encrypt the SEP Firmware before delivery to the end user.
 Apple explains GID keys in its official [https://www.apple.com/br/privacy/docs/iOS_Security_Guide_Oct_2014.pdf iOS security guide] (page 9, chapter "Encryption and Data Protection"), along with [[UID key]]s:

@@ Line 6: / Line 6: @@
 <blockquote>"The device’s unique ID (UID) and a device group ID (GID) are AES 256-bit keys fused (UID) or compiled (GID) into the application processor during manufacturing. No software or firmware can read them directly; they can see only the results of encryption or decryption operations performed using them. The UID is unique to each device and is not recorded by Apple or any of its suppliers. The GID is common to all processors in a class of devices (for example, all devices using the Apple A8 processor), and is used as an additional level of protection when delivering system software during installation and restore. Integrating these keys into the silicon helps prevent them from being tampered with or bypassed, or accessed outside the AES engine. The UID and GID are also not available via JTAG or other debugging interfaces."</blockquote>
-On [[S5L8900]], the GID key was used to generate [[AES Keys#Key 0x837|AES Key 0x837]], used as the encryption key for [[S5L File Formats#IMG2|IMG2 files]]. With the introduction of [[IMG3 File Format|IMG3]] in iOS 2.0, iOS started using [[KBAG]]s instead of the 0x837 key. iOS 7.0.1 introduced the [[IM4P File Format]] and [[IMG4 File Format]] for [[A7]] and newer devices.
+On [[S5L8900]], the GID key was used to generate [[AES Keys#Key 0x837|AES Key 0x837]], used as the encryption key for [[S5L File Formats#IMG2|IMG2 files]]. With the introduction of [[IMG3 File Format|IMG3]] in iOS 2.0, iOS started using [[KBAG]]s instead of the 0x837 key. iOS 7.0 introduced the [[IM4P File Format]] and [[IMG4 File Format]] for [[A7]] and newer devices.
 In [[iOS]] 3.0GM/3.0, a pseudo GID Key was used, which allowed getting [[Firmware Keys|firmware decryption keys]] for these firmwares without the device and with tools such as GitKeys or OpenSSL. See [[Decrypting Firmwares#S5L8900]].

@@ Line 1: / Line 1: @@
 The '''GID key''' ('''Group ID key''') is a 256-bit [[wikipedia:Advanced Encryption Standard|AES]] key shared by all devices with the same application processor. The GID key is part of how iOS encrypts software on the device ([https://books.google.com/books?id=CEzB2avQjR4C&lpg=PA268&vq=gid%20key&dq=GID%20Key&pg=PA268#v=onepage&q&f=false more explanation]). This is one component of the iOS security system, which also includes [[SHSH]] signatures.
-This key is different on each [[Application Processor|processor model]] ([[wikipedia:System on a chip|system on a chip]]) - in other words, the [[S5L8900]] (chip for iPhone 3G for example) has a different key compared to the [[S5L8930]] (A4 chip for iPhone 4, iPod touch 4G, etc.).
+This key is different on each [[Application Processor|processor model]] ([[wikipedia:System on a chip|system on a chip]]) - in other words, the [[S5L8900]] (chip for iPhone 3G for example) has a different key compared to the [[S5L8930]] (A4 chip for iPhone 4, iPod touch (4th generation), etc.).
 Apple explains GID keys in its official [https://www.apple.com/br/privacy/docs/iOS_Security_Guide_Oct_2014.pdf iOS security guide] (page 9, chapter "Encryption and Data Protection"), along with [[UID key]]s:

← Older revision		Revision as of 07:03, 8 July 2015
Line 47:		Line 47:

	[[Category:Decryption]]		[[Category:Decryption]]
		+	[[Category:Malware research]]

@@ Line 18: / Line 18: @@
 === CIA research into attacks ===
-[https://firstlook.org/theintercept/2015/03/10/ispy-cia-campaign-steal-apples-secrets/ According to this March 2015 article] based on documents provided by Edward Snowden, the CIA has been particularly interested in figuring out how to extract GID keys as part of their efforts to get access to modifying iOS to insert spy software and to research further vulnerabilities:
+[https://firstlook.org/theintercept/2015/03/10/ispy-cia-campaign-steal-apples-secrets/ According to this March 2015 article in ''The Intercept''] based on documents provided by Edward Snowden, the CIA has been particularly interested in figuring out how to extract GID keys as part of their efforts to get access to modifying iOS to insert spy software and to research further vulnerabilities:
 <blockquote>"At the 2011 Jamboree conference, there were two separate presentations on hacking the GID key on Apple’s processors. One was focused on non-invasively obtaining it by studying the electromagnetic emissions of — and the amount of power used by — the iPhone’s processor while encryption is being performed. Careful analysis of that information could be used to extract the encryption key. Such a tactic is known as a "side channel" attack. The second focused on a "method to physically extract the GID key.'"([https://firstlook.org/theintercept/document/2015/03/10/differential-power-analysis-apple-a4-processor/ The first document] and [https://firstlook.org/theintercept/document/2015/03/10/secure-key-extraction-physical-de-processing-apples-a4-processor/ the second one].)</blockquote>
@@ Line 39: / Line 39: @@
 * [https://twitter.com/i0n1c/status/575347464934420480 "With limera1n millions of people had access to the GID key via bootrom code. Not a single person managed to create a bad accepted firmware"]
-The overall article was somewhat controversial among security researchers, with comments in [https://twitter.com/jeremyscahill/status/575509558556237825 this Twitter thread] and [http://blog.erratasec.com/2015/03/no-cia-isnt-stealing-apples-secrets.html this post] with [https://twitter.com/i0n1c/status/575550172815618049 responses], with disagreements about the goals of the CIA research and about which people should have been consulted as experts on the subject.
+The overall ''Intercept'' article was somewhat controversial among security researchers, with comments in [https://twitter.com/jeremyscahill/status/575509558556237825 this Twitter thread] and [http://blog.erratasec.com/2015/03/no-cia-isnt-stealing-apples-secrets.html this post] with [https://twitter.com/i0n1c/status/575550172815618049 responses], with disagreements about the goals of the CIA research and about which people should have been consulted as experts on the subject.
 == Related tools ==

← Older revision		Revision as of 21:09, 11 March 2015
Line 1:		Line 1:
−	The '''GID key''' ('''Group ID key''') is an [[wikipedia:Advanced Encryption Standard\|AES]] ~~256-bit~~ key shared by all devices with the same application processor. The GID key is part of how iOS encrypts software on the device ([https://books.google.com/books?id=CEzB2avQjR4C&lpg=PA268&vq=gid%20key&dq=GID%20Key&pg=PA268#v=onepage&q&f=false more explanation]). This is one component of the iOS security system, which also includes [[SHSH]] signatures.	+	The '''GID key''' ('''Group ID key''') is a 256-bit [[wikipedia:Advanced Encryption Standard\|AES]] key shared by all devices with the same application processor. The GID key is part of how iOS encrypts software on the device ([https://books.google.com/books?id=CEzB2avQjR4C&lpg=PA268&vq=gid%20key&dq=GID%20Key&pg=PA268#v=onepage&q&f=false more explanation]). This is one component of the iOS security system, which also includes [[SHSH]] signatures.

	This key is different on each [[Application Processor\|processor model]] ([[wikipedia:System on a chip\|system on a chip]]) - in other words, the [[S5L8900]] (chip for iPhone 3G for example) has a different key compared to the [[S5L8930]] (A4 chip for iPhone 4, iPod touch 4G, etc.).		This key is different on each [[Application Processor\|processor model]] ([[wikipedia:System on a chip\|system on a chip]]) - in other words, the [[S5L8900]] (chip for iPhone 3G for example) has a different key compared to the [[S5L8930]] (A4 chip for iPhone 4, iPod touch 4G, etc.).

← Older revision		Revision as of 08:13, 11 March 2015
Line 1:		Line 1:
−	The '''GID key''' ('''Group ID key''') is an [[wikipedia:Advanced Encryption Standard\|AES]] 256-bit key shared by all devices with the same application processor. The GID key is part of how iOS encrypts software on the device ([https://books.google.com/books?id=CEzB2avQjR4C&lpg=PA268&vq=gid%20key&dq=GID%20Key&pg=PA268#v=onepage&q&f=false more explanation]), ~~which~~ is one component of the iOS security system, which also includes [[SHSH]] signatures.	+	The '''GID key''' ('''Group ID key''') is an [[wikipedia:Advanced Encryption Standard\|AES]] 256-bit key shared by all devices with the same application processor. The GID key is part of how iOS encrypts software on the device ([https://books.google.com/books?id=CEzB2avQjR4C&lpg=PA268&vq=gid%20key&dq=GID%20Key&pg=PA268#v=onepage&q&f=false more explanation]). This is one component of the iOS security system, which also includes [[SHSH]] signatures.

	This key is different on each [[Application Processor\|processor model]] ([[wikipedia:System on a chip\|system on a chip]]) - in other words, the [[S5L8900]] (chip for iPhone 3G for example) has a different key compared to the [[S5L8930]] (A4 chip for iPhone 4, iPod touch 4G, etc.).		This key is different on each [[Application Processor\|processor model]] ([[wikipedia:System on a chip\|system on a chip]]) - in other words, the [[S5L8900]] (chip for iPhone 3G for example) has a different key compared to the [[S5L8930]] (A4 chip for iPhone 4, iPod touch 4G, etc.).