sflicense

"Cracking Cisco’s Sourcefire license system" writeup code

Project structure

.
├── LICENSE
├── README.md
├── checklic
│   └── checklic.go
├── crypto
│   └── rsaGen.go
├── licgen
│   └── sflicgen.go
└── tools
    └── interceptor.sh

Cracking guide

Do this at your own risk!

Cracking software is illegal and unmoral, please use this only for testing and educational purposes.

RSA key generation

Execute:

go run rsaGen.go

This will generate a public and a private RSA key of 4096 bits.

Format the public key for the patchline with:

hexdump -ve '1/1 "_x%.2x"' public.der |sed 's/_/\\/g'

Calculate the SHA1 of the public key

On macos:

shasum -a1 crypto/public.der |cut -d" " -f1 |sed -E 's/(.{2})/\1\\x/g' |rev |cut -d"\\" -f2- |rev

Prepare the patchlines (x86-64 version)

printf '${your_formated_public_key}' | dd seek=$((0x10b48)) conv=notrunc bs=1 of=${target}

printf '${your_formated_sha1}' | dd seek=$((0x10f48)) conv=notrunc bs=1 of=${target}

Patch!

SSH into the FSM and get sudo, execute the two patchlines changing the ${target} for the checklic binary.

Repeat the same process on all your Sensors.

Generate your license

For a FSM license run:

go run sflicgen.go -l 66:00:11:22:33:44:55 -k ../crypto/private.pem -fsm

and for a sensor license run:

go run sflicgen.go -l 66:00:11:22:33:44:55 -k ../crypto/private.pem -n 6 -mid 63E -mod 3D8120

Upload it to your FSM and enjoy

Known models:

Model ID	Model Name
63E	3D8120
63F	3D7120
63G	3d7110
63H	3D7030
63J	3D7010
63L	3D7125
63P	3D7150

hcninja/sflicense