RouterOS-Backup-Tools

Tools to encrypt/decrypt and pack/unpack RouterOS v6.13+ backup files

Usage examples

Info

cargo run -- info -i MikroTik.backup

Decrypt

Convert an encrypted backup to a plaintext backup
cargo run -- decrypt -i MikroTik-encrypted.backup -o MikroTik-plaintext.backup -p password

Encrypt

Convert a plaintext backup to an encrypted backup
cargo run -- encrypt -i MikroTik-plaintext.backup -o MikroTik-encrypted.backup -e AES -p password

Unpack

Extract all IDX and DAT files from a plaintext backup in a given directory cargo run -- unpack -i MikroTik-plaintext.backup -d unpacked_backup

Caution

Do not use on untrusted backups, can likely write anywhere: Be very careful here!

Pack

Pack all IDX and DAT files from a given directory in a plaintext backup cargo run -- pack -d unpacked_backup -o MikroTik-plaintext.backup

Bruteforce

Bruteforce the password of an encrypted backup using a wordlist file
cargo run --release -- bruteforce -i MikroTik-encrypted.backup -w wordlist.txt
If you have very large wordlist files, you can use parallel brute forcing
cargo run --release -- bruteforce -i MikroTik-encrypted.backup -w wordlist.txt -p

Header structure

Plaintext version

Size (byte)	Type	Name	Description
4	Unsigned LE Int	Magic	0xB1A1AC88
4	Unsigned LE Int	File size	length in bytes

Encrypted version (RC4)

Size (byte)	Type	Name	Description
4	Unsigned LE Int	Magic	0x7291A8EF
4	Unsigned LE Int	File size	length in bytes
32	Byte array	Salt	Random salt added to password
4	Unsigned LE Int	Magic check	Encrypted Magic 0xB1A1AC88 to verify if password is correct

Encryption setup (RC4)

1. A random salt of 32 bytes is generated (RouterOS only populates the first 16 bytes, mistake?) (Fixed)
2. The password is appended to the salt
3. salt+password result is hashed using SHA1
4. RC4 cipher is keyed with the SHA1 hash
5. RC4 cipher is used to encrypt or decrypt 0x300 (256 * 3 = 768) bytes (of arbitrary value)
6. The first 4 bytes are decrypted and compared to 0xB1A1AC88 to check if password is correct before performing a decryption

Encrypted version (AES128-CTR)

RouterOS v6.43+ only

Size (byte)	Type	Name	Description
4	Unsigned LE Int	Magic	0x7391A8EF
4	Unsigned LE Int	File size	length in bytes
32	Byte array	Salt	Random salt added to password
32	Byte array	Signature	SHA256 HMAC
4	Unsigned LE Int	Magic check	Encrypted Magic 0xB1A1AC88 to verify if password is correct

Encryption setup (AES128-CTR)

1. A random salt of 32 bytes is generated
2. The password is appended to the salt
3. salt+password result is hashed using SHA256
4. AES128-CTR cipher is keyed with the first half of the SHA256 hash
5. CTR mode's nonce is initialized with the first half of the salt
6. HMAC-SHA256 is keyed with the second half of the SHA256 hash
7. AES cipher is used to encrypt or decrypt 16 bytes (of arbitrary value)
8. The first 4 bytes are decrypted and compared to 0xB1A1AC88 to check if password is correct before performing a decryption
9. The HMAC result is verified against what's stored in the file when performing a decryption

Body structure

In the body are saved all file pair with extension .idx and .dat inside /flash/rw/store/
For each file:

Size (byte)	Type	Name	Description
4	Unsigned LE Int	Filename length	Filename length without extension (.idx .dat)
Filename length	String	Filename	String without null byte terminator (and without extension .idx .dat)
4	Unsigned LE Int	IDX File size	length in bytes
IDX File size	Byte array	IDX File	content of IDX file
4	Unsigned LE Int	DAT File size	length in bytes
DAT File size	Byte array	DAT File	content of DAT file

IDX file structure

The index file contains infos about each entry of DAT file. For each entry:

Size (byte)	Type	Name	Description
4	Signed Int	Entry Index	The position of this entry in the Webfig/Winbox list, if -1 it means the entry was deleted and it won't be shown on Webfig/Winbox.
4	Signed Int	Entry Size	The size of this entry in bytes
4	Signed Int	Unused	It's always 5 (but in net/devices.idx it's 6 and in port_lock.idx it's -1) for each entry

Comments

• When you delete some config (in Webfig or Winbox), they are not really deleted, they are only disabled and hidden, so if you unpack your backup, you can still recover them