[BOOTLOADER] Analysis of lk.bin

I previously had downloaded the 5.0.1 and 5.1.1 LK versions, and thought, why not run these through binwalk?

For the old, 5.0.1 bootloader, putting lk.bin through binwalk gave:

Code:

---

DECIMAL      HEXADECIMAL    DESCRIPTION
--------------------------------------------------------------------------------
204256        0x31DE0        SHA256 hash constants, little endian
292292        0x475C4        Android bootimg, kernel size: 0 bytes, kernel addr: 0x5D73255B, ramdisk size: 1869570592 bytes, ramdisk addr: 0x6D692074, product name: ""
330144        0x509A0        Unix path: /mnt/build/workspace/fireos-release_500-patch-build/bootable/bootloader/ufbl-features/project/../features/common_openssl/crypto/
330752        0x50C00        Unix path: /mnt/build/workspace/fireos-release_500-patch-build/bootable/bootloader/ufbl-features/project/../features/common_openssl/crypto/
334248        0x519A8        Unix path: /mnt/build/workspace/fireos-release_500-patch-build/bootable/bootloader/ufbl-features/project/../features/common_openssl/crypto/
339912        0x52FC8        Unix path: /mnt/build/workspace/fireos-release_500-patch-build/bootable/bootloader/ufbl-features/project/../features/common_openssl/crypto/
341028        0x53424        Unix path: /mnt/build/workspace/fireos-release_500-patch-build/bootable/bootloader/ufbl-features/project/../features/common_openssl/crypto/
350360        0x55898        Unix path: /mnt/build/workspace/fireos-release_500-patch-build/bootable/bootloader/ufbl-features/project/../features/common_openssl/crypto/
351732        0x55DF4        Certificate in DER format (x509 v3), header length: 4, sequence length: 1067
353656        0x56578        Certificate in DER format (x509 v3), header length: 4, sequence length: 1069
369736        0x5A448        CRC32 polynomial table, little endian
397548        0x610EC        LZMA compressed data, properties: 0x91, dictionary size: 33554432 bytes, uncompressed size: 134217728 bytes

---

Whilst the 5.1.1 bootloader's lk.bin gave:

Code:

---

DECIMAL      HEXADECIMAL    DESCRIPTION
--------------------------------------------------------------------------------
204960        0x320A0        SHA256 hash constants, little endian
293720        0x47B58        Android bootimg, kernel size: 0 bytes, kernel addr: 0x5D73255B, ramdisk size: 1869570592 bytes, ramdisk addr: 0x6D692074, product name: ""
332024        0x510F8        Unix path: /mnt/build/workspace/fireos-ship_511-patch-build/bootable/bootloader/ufbl-features/project/../features/common_openssl/crypto/cry
332628        0x51354        Unix path: /mnt/build/workspace/fireos-ship_511-patch-build/bootable/bootloader/ufbl-features/project/../features/common_openssl/crypto/mem
336096        0x520E0        Unix path: /mnt/build/workspace/fireos-ship_511-patch-build/bootable/bootloader/ufbl-features/project/../features/common_openssl/crypto/asn
341712        0x536D0        Unix path: /mnt/build/workspace/fireos-ship_511-patch-build/bootable/bootloader/ufbl-features/project/../features/common_openssl/crypto/evp
342820        0x53B24        Unix path: /mnt/build/workspace/fireos-ship_511-patch-build/bootable/bootloader/ufbl-features/project/../features/common_openssl/crypto/obj
352064        0x55F40        Unix path: /mnt/build/workspace/fireos-ship_511-patch-build/bootable/bootloader/ufbl-features/project/../features/common_openssl/crypto/x50
353420        0x5648C        Certificate in DER format (x509 v3), header length: 4, sequence length: 1067
355344        0x56C10        Certificate in DER format (x509 v3), header length: 4, sequence length: 1069
371656        0x5ABC8        CRC32 polynomial table, little endian

---

So there you go! The bootloader uses OpenSSL to check the partition against two DER format certificates. Ignore the LZMA header for now; binwalk thinks almost everything is LZMA compressed.

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