PicoPass¶

Description¶

Picopass¶

This application allows you to read, write, save, and emulate legacy HID iClass cards and fobs (based on the picopass chipset). Also supports saving the credential to the Flipper Zero LFRFID data format, changing the keys on the card, performing dictionary attack, and performing the 'online' part of the loclass attack.

Loclass¶

The loclass attack emulates specific CSN and collects responses from the reader which can be used to calculate the elite or (some) custom key configured for that reader. This key is then used to read data on the cards used with that reader.

Online part¶

1. Run loclass from the picopass main menu
2. Present the flipper to the reader. Holding flipper directly to reader may not work, vary distance by a few inches.
3. Collect responses until the progress bar is full.

NOTE: If the screen says “Got std key” AND stays on 0/18, then loclass isn't needed.

Offline part¶

1. Download the loclass log (sdcard/apps_data/picopass/.loclass.log) from your Flipper Zero.
2. Use loclass.ericbetts.dev or a tool of your choice to calculate the key
3. Copy the key to iclass_elite_dict_user.txt and place in sdcard/apps_data/picopass/assets/
4. Run Read from the picopass main menu
5. Present card to the back of the Flipper Zero.

Failure¶

There are some situations when the offline loclass may not find a key, such as: * non-iClass picopass (Circuit Laundry, etc) * iClass SE * Readers configured with Standard-2 keyset * Custom keyed readers using Standard KDF * Custom keyed readers using SE KDF

NR-MAC Attack¶

Due to the nature of how secure mode picopass works, it is possible to emulate some public fields from a card and capture the reader's response, which can be used to authenticate. Two of the pieces involved in this are the 'NR' and 'MAC'. This allows you to get a dump of the card, except for the key, even if you don't know the key. For picopass in non-HID systems this can allow you to see what the data looks like. For iClass SE the data (SIO) is encrypted, but a friend with a HID SAM can decrypt it.

These instructions are intended to be performed all at the same time. If you use the card with the reader between Card Part 1 and Card Part 2, then Card Part 2 will fail.

First: Card Part 1¶

1. Place card against Flipper Zero
2. Run Read from the picopass main menu
3. Get a "Read Failed" message
4. Select the "Menu" option
5. Select "Save Partial" (regardless if this card has been saved previously)
6. Name file something you'll remember
7. Immediately proceed to Reader Part

Second: Reader Part¶

1. Select Saved from the picopass main menu
2. Select the file name you saved in last step of Card Part 1
3. Select Emulate
4. Expose Flipper Zero to reader (It may work better a few inches from the reader, as opposed to physically touching)
5. Flipper will buzz and screen will say "NR-MAC Saved!" (may be very brief)
6. Immediately proceed to Card Part 2

Third: Card Part 2¶

1. Place card against Flipper Zero
2. Run Read from the picopass main menu
3. Card will authenticate and read
4. Suggested to do both "Save" and "Save as Seader"

Elite Keygen Attack¶

Background: https://youtu.be/MKSXSKQHz6o?si=DEKkW60x858pUI0a&t=600

The keys used for early Elite systems used the VB6 (yes, as in Visual Basic) RNG to generate the keys. This attack uses the known VB6 RNG to generate the keys. This attack is only useful for early Elite systems, as later systems are keyed in some other manor. Since this can generate an insanely large number of values (and eventually loop), by default it is limited to the first 2000 keys. Please provide feedback if you would like this increased. Also, the leaked iCopyX dictionary included 700ish of these, so the first 700 are redundant to the System Elite Dictionary attack run during "Read". This attack is not useful for iClass SE systems.

Changelog¶

1.17¶

• CVE-2024-41566: When keys are unknown emulate with a dummy MAC and ignore reader MACs

1.16¶

• Acknowledgements page
• Elite VB6 RNG keygen attack
• Bump plugin version

1.15¶

• Add downgrade from iClass SR to iClass Legacy

1.14¶

• Add plugin to parse some wiegand formats
• Store unknown blocks in picopass file with '??'

1.13¶

• Rework loclass writer with datetime lib

1.12¶

• Add support for non-secure Picopass
• Change Read to use all dictionaries
• Improve saving of cards authenticated with NR-MAC

1.11¶

• Update working with keys with new API
• Display more tag information
• Add additional keys to elite dict
• Correct config card detection so it doesn't happen for SE cards (read using nr-mac partial read)
• Have back button go to start menu instead of read retry

1.10¶

• Fix missing folder in readme
• Allow partial save for any read failure

1.9¶

• Fix bug (#77) with loclass
• Better loclass notes
• Read card using nr-mac
• Save as Seader format

1.8¶

• Minimal changes for recent API updates

1.7¶

• Rework application with new NFC API

1.6¶

• Faster loclass response collection
• Save as LF for all bit lengths
• Removes unvalidated H10301 parsing

1.5¶

• New random filename API

1.4¶

• Optimize crypto speed to fix compatibliity with Signo and OmniKey readers

1.3¶

• Show standard key instead of hex bytes when detected

1.2¶

• Sentinel bit remove

1.1¶

• Key dicts moved to app assets

1.0¶

• Initial release