Secure Enclave

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Revision as of 10:16, 27 December 2013 by M2m (talk | contribs) (Further References)
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The Secure Enclave is part of the A7 chip and a basic part of Apples Touch ID fingerprint technology. Within the Secure Enclave the fingerprint data is stored in an encrypted form which - according to Apple - can only be decrypted by a key available by the Secure Enclave thus making fingerprint data walled off from the rest of A7 Chip and as well as the rest of iOS. The secure enclave itself is a flashable 4MB processore called the secure enclave processor (SEP) as documented in Appple Patent Application 20130308838. The technology used is basically ARM's TrustZone/SecurCore.

The SEP is located in the devicetree under IODeviceTree:/arm-io/sep and manged by the AppleSEPManager driver.

SEP OS

The SEP has its own OS called SEP OS and there exists a tool called seputil which is used to communicate with it.

seputil has the following valid commands:

seputil: seputil [--wait] --load <file>
seputil: seputil '<SEP console command>'
seputil: seputil <command>
seputil: 
seputil: Valid <command> words:
seputil:     --ping        Send a PING operation to the SEP OS
seputil:     --load        Load <file> as the SEP runtime firmware
seputil:     --restore     Load <file> as the SEP runtime firmware in restore mode
seputil:     --restore+art Load <file> as the SEP runtime firmware in restore mode with ART
seputil:     --wait        Pause for kernel driver to load before failing
seputil:     --preflight   Pre-flight load/restore firmware against ART to pre-check for boot failures
seputil:     --log         Dump the mailbox message log
seputil:     --rom status  Get the ROM status
seputil:     --rom tz0     Send a ROM TZ0 command
seputil:     --rom nop     Send a ROM NOP command
seputil:     --rom nonce   Send a ROM nonce request
seputil:     --new-nonce   Request new SEP/OS nonce
seputil:     --kill-nonce  Request invalidate SEP/OS nonce
seputil:     --art get     Dump current ART from Memory
seputil:     --art set     Persist the supplied ART to storage
seputil:     --art clear   Clear the persisted ART
seputil:     --art ctrtest Counter self-test (DESTRUCTIVE - WILL BRICK DEVICE)
seputil:     --sleep       Sleep the SEP NOW!
seputil:     --nap         Nap the SEP NOW!
seputil:     --pingflood   Ping SEP endlessly
seputil:     --clkgate     Enable SEP clock gating
seputil:     --get <obj>   Read obj and write to stdout
seputil:     --put <obj>   Read stdin and write to obj
seputil:     --boot-check <file>  Check whether a firmware might be bootable WRT the current ART
seputil:     --dump-fw <file>     Dump measurements of firmware file
seputil:   Bare words on the commandline are sent to the SEP as a console command

Examples:

./seputil --pingflood
SEP ping #1000
SEP ping #2000
SEP ping #3000
SEP ping #4000

./seputil --new-nonce
Nonce (20 bytes): 0x67fc18385630dc6429726677d196c81466f47b5e

./seputil --art get  
raw ART: 305e0201003037020218340414519c0248f04d316a3d71e03978b4126fbfb2b15c0400041467fc18385630dc6429726677d196c81466f47b5e3103c00100042027b6dadbab356612997af0203cefeae51fe90cd985ee7cdd6211c766b8cc7a60
Successfully parsed ART:
counter: 6196
manifest hash (20 bytes): 519c0248f04d316a3d71e03978b4126fbfb2b15c
sleep hash is absent
restore nonce (20 bytes): 67fc18385630dc6429726677d196c81466f47b5e

./seputil --log    
Kernel message log has 128 entries
289344381444: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289344385176: 0x0000000000000000 TX interrupt
289344391044: 0x0000000000000000 TX interrupt
289344408988: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289344409016: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289344413132: 0x0000000000000000 RX interrupt
289344413304: 0x0000000000010000 RX message ept 0, tag 0, opcode 1, param 0, data 0
289344413904: 0x0000000000000000 RX interrupt
289344413944: 0x0000000000010000 RX message ept 0, tag 0, opcode 1, param 0, data 0
289344414176: 0x0018000000dd1007 TX message ept 7, tag 10, opcode dd, param 0, data 180000
289344443356: 0x0000000000000000 RX interrupt
289344443428: 0x0068000000dd9007 RX message ept 7, tag 90, opcode dd, param 0, data 680000
289346822748: 0x0000000000130000 TX message ept 0, tag 0, opcode 13, param 0, data 0
289346829480: 0x0000000000000000 RX interrupt
289346829560: 0x0000000000110000 RX message ept 0, tag 0, opcode 11, param 0, data 0
289346830136: 0x0000000000120000 TX message ept 0, tag 0, opcode 12, param 0, data 0
289406511168: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289406511204: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289406538900: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289406538936: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289406543628: 0x0000000000000000 TX interrupt
289406549916: 0x0000000000000000 TX interrupt
289406566580: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289406566612: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289406571220: 0x0000000000000000 RX interrupt
289406571476: 0x0000000000010000 RX message ept 0, tag 0, opcode 1, param 0, data 0
289406571908: 0x0000000000000000 RX interrupt
289406571952: 0x0000000000010000 RX message ept 0, tag 0, opcode 1, param 0, data 0
289406572320: 0x0018000000de1007 TX message ept 7, tag 10, opcode de, param 0, data 180000
289406605068: 0x0000000000000000 RX interrupt
289406605152: 0x0068000000de9007 RX message ept 7, tag 90, opcode de, param 0, data 680000
289407383260: 0x003c000000df0907 TX message ept 7, tag 9, opcode df, param 0, data 3c0000
289407396284: 0x0000000000000000 RX interrupt
289407396380: 0x002c000000df8907 RX message ept 7, tag 89, opcode df, param 0, data 2c0000
289407403656: 0x003c000000e00907 TX message ept 7, tag 9, opcode e0, param 0, data 3c0000
289407411688: 0x0000000000000000 RX interrupt
289407411736: 0x002c000000e08907 RX message ept 7, tag 89, opcode e0, param 0, data 2c0000
289407414732: 0x003c000000e10907 TX message ept 7, tag 9, opcode e1, param 0, data 3c0000
289407422472: 0x0000000000000000 RX interrupt
289407422524: 0x002c000000e18907 RX message ept 7, tag 89, opcode e1, param 0, data 2c0000
289408986276: 0x0000000000130000 TX message ept 0, tag 0, opcode 13, param 0, data 0
289408991756: 0x0000000000000000 RX interrupt
289408991824: 0x0000000000110000 RX message ept 0, tag 0, opcode 11, param 0, data 0
289408992472: 0x0000000000120000 TX message ept 0, tag 0, opcode 12, param 0, data 0
289459393276: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289459393348: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289459423004: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289459423048: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289459452628: 0x0000000000000000 TX interrupt
289459453612: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289459453664: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289459466460: 0x0000000000000000 TX interrupt
289459469548: 0x0000000000000000 RX interrupt
289459470000: 0x0000000000010000 RX message ept 0, tag 0, opcode 1, param 0, data 0
289459470632: 0x0000000000010000 RX message ept 0, tag 0, opcode 1, param 0, data 0
289459471304: 0x0018000000e21007 TX message ept 7, tag 10, opcode e2, param 0, data 180000
289459524572: 0x0000000000000000 RX interrupt
289459524728: 0x0068000000e29007 RX message ept 7, tag 90, opcode e2, param 0, data 680000
289459532644: 0x004c000000e30f07 TX message ept 7, tag f, opcode e3, param 0, data 4c0000
289459552888: 0x0000000000000000 RX interrupt
289459553044: 0x002c000000e38f07 RX message ept 7, tag 8f, opcode e3, param 0, data 2c0000
289459646732: 0x0018000000e41007 TX message ept 7, tag 10, opcode e4, param 0, data 180000
289459681116: 0x0000000000000000 RX interrupt
289459681272: 0x0068000000e49007 RX message ept 7, tag 90, opcode e4, param 0, data 680000
289461898836: 0x0000000000130000 TX message ept 0, tag 0, opcode 13, param 0, data 0
289461906796: 0x0000000000000000 RX interrupt
289461906968: 0x0000000000110000 RX message ept 0, tag 0, opcode 11, param 0, data 0
289461908400: 0x0000000000120000 TX message ept 0, tag 0, opcode 12, param 0, data 0
289526725980: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289526726016: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289526757512: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289526757552: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289526774468: 0x0000000000000000 TX interrupt
289526782688: 0x0000000000000000 TX interrupt
289526786468: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289526786540: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289526795320: 0x0000000000000000 RX interrupt
289526795828: 0x0000000000010000 RX message ept 0, tag 0, opcode 1, param 0, data 0
289526796304: 0x0000000000010000 RX message ept 0, tag 0, opcode 1, param 0, data 0
289526796984: 0x0018000000e51007 TX message ept 7, tag 10, opcode e5, param 0, data 180000
289526847216: 0x0000000000000000 RX interrupt
289526847348: 0x0068000000e59007 RX message ept 7, tag 90, opcode e5, param 0, data 680000
289529224460: 0x0000000000130000 TX message ept 0, tag 0, opcode 13, param 0, data 0
289529235316: 0x0000000000000000 RX interrupt
289529235488: 0x0000000000110000 RX message ept 0, tag 0, opcode 11, param 0, data 0
289529236920: 0x0000000000120000 TX message ept 0, tag 0, opcode 12, param 0, data 0
289584681764: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289584681836: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289584710576: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289584710608: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289584730996: 0x0000000000000000 TX interrupt
289584738992: 0x0000000000000000 TX interrupt
289584739572: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289584739612: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289584748648: 0x0000000000000000 RX interrupt
289584748984: 0x0000000000010000 RX message ept 0, tag 0, opcode 1, param 0, data 0
289584749300: 0x0000000000010000 RX message ept 0, tag 0, opcode 1, param 0, data 0
289584749332: 0x0018000000e61007 TX message ept 7, tag 10, opcode e6, param 0, data 180000
289584790484: 0x0000000000000000 RX interrupt
289584790568: 0x0068000000e69007 RX message ept 7, tag 90, opcode e6, param 0, data 680000
289587176748: 0x0000000000130000 TX message ept 0, tag 0, opcode 13, param 0, data 0
289587185760: 0x0000000000000000 RX interrupt
289587185916: 0x0000000000110000 RX message ept 0, tag 0, opcode 11, param 0, data 0
289587186840: 0x0000000000120000 TX message ept 0, tag 0, opcode 12, param 0, data 0
288741485000: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
288741485084: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
288741514772: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
288741514812: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
288741533984: 0x0000000000000000 TX interrupt
288741541992: 0x0000000000000000 TX interrupt
288741543608: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
288741543680: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
288741552216: 0x0000000000000000 RX interrupt
288741552884: 0x0000000000010000 RX message ept 0, tag 0, opcode 1, param 0, data 0
288741553388: 0x0000000000010000 RX message ept 0, tag 0, opcode 1, param 0, data 0
288741553672: 0x0018000000db1007 TX message ept 7, tag 10, opcode db, param 0, data 180000
288741591912: 0x0000000000000000 RX interrupt
288741592040: 0x0068000000db9007 RX message ept 7, tag 90, opcode db, param 0, data 680000
288741599128: 0x004c000000dc0f07 TX message ept 7, tag f, opcode dc, param 0, data 4c0000
288741620732: 0x0000000000000000 RX interrupt
288741620900: 0x002c000000dc8f07 RX message ept 7, tag 8f, opcode dc, param 0, data 2c0000
288742902624: 0x0000000000130000 TX message ept 0, tag 0, opcode 13, param 0, data 0
288742912320: 0x0000000000000000 RX interrupt
288742912496: 0x0000000000110000 RX message ept 0, tag 0, opcode 11, param 0, data 0
288742913700: 0x0000000000120000 TX message ept 0, tag 0, opcode 12, param 0, data 0
289344354176: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289344354216: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0
289344381416: 0x0000000000000000 TX message ept 0, tag 0, opcode 0, param 0, data 0

./seputil --boot-check sep-firmware.img4 
preflight: manifest hash matches sepi
bootCheck: SEP may boot with ART

./seputil --dump-fw sep-firmware.img4 
manifest digest (20 bytes): 519c0248f04d316a3d71e03978b4126fbfb2b15c
sepi digest (20 bytes): a22813c5ceaeada5b7eeaa55808f3019814e8b8e
sepi nonce (20 bytes): e5074bd1befefc685c6b5ec6797ffc851366f76f
rsep digest (20 bytes): cb9f4c6520889e2582414c5969fb0abc3b0d8277
rsep nonce (20 bytes): e5074bd1befefc685c6b5ec6797ffc851366f76f

ART Object

Example:

305e0201003037020218340414519c0248f04d316a3d71e03978b4126fbfb2b15c0400041467fc18385630dc6429726677d196c81466f47b5e3103c00100042027b6dadbab356612997af0203cefeae51fe90cd985ee7cdd6211c766b8cc7a60

This is also a DER encoded ASN.1 object:

30 — type tag indicating SEQUENCE
5e — length in octets of value that follows (92)
   02 — type tag indicating INTEGER
   01 — length in octets of value that follows
      00 — value (0)
   30 — type tag indicating SEQUENCE
   37 — length in octets of value that follows (55)
      02 — type tag indicating INTEGER
      02 — length in octets of value that follows
         1834 — value (6196)
 

Further References

www.forbes.com