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john:OpenCL-BitLocker [2017/12/19 10:31] elenago |
john:OpenCL-BitLocker [2024/11/09 04:35] (current) solar [Step 3: Attack!] Sync with today's README.BitLocker update |
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| With this authentication method, the user can choose to encrypt a memory device by means of a password. | With this authentication method, the user can choose to encrypt a memory device by means of a password. | ||
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| {{:john:bitcracker_img1.png?direct&400|}} | {{:john:bitcracker_img1.png?direct&400|}} | ||
| - | To find the password used during the encryption with BitCracker, you need to specify the -u option (see the How To section). | + | |
| + | To find the password used during the encryption, see [[#Step 2: Extract the hash|Step 2: Extract the hash]] | ||
| ===== Recovery Password authentication method ===== | ===== Recovery Password authentication method ===== | ||
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| </code> | </code> | ||
| - | To find the correct Recovery Password with BitCracker, you need to specify the -r option (see How To section). See Microsoft docs for further details. | + | To find the correct Recovery Password, see [[#Step 2: Extract the hash|Step 2: Extract the hash]]. |
| + | For further details, see also [[https://docs.microsoft.com/en-us/windows/device-security/bitlocker/bitlocker-recovery-guide-plan|Microsoft docs]]. | ||
| ===== Step 1: Get the image of your encrypted memory device ===== | ===== Step 1: Get the image of your encrypted memory device ===== | ||
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| ===== Step 2: Extract the hash ===== | ===== Step 2: Extract the hash ===== | ||
| + | In order to use the BitLocker-OpenCL format, you must produce a well-formatted hash of your encrypted image. | ||
| Use the //bitlocker2john// tool (john repo) to extract the hash from the password protected BitLocker encrypted volumes. | Use the //bitlocker2john// tool (john repo) to extract the hash from the password protected BitLocker encrypted volumes. | ||
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| As shown in the example, it returns 4 output hashes with different prefix: | As shown in the example, it returns 4 output hashes with different prefix: | ||
| - | * If the device was encrypted using the User Password authentication methods, bitlocker2john prints those 2 hashes: | + | * If the device was encrypted using the User Password authentication method, bitlocker2john prints those 2 hashes: |
| * $bitlocker$0$... : it starts the User Password fast attack mode (see [[#User Password authentication method|User Password Section]]) | * $bitlocker$0$... : it starts the User Password fast attack mode (see [[#User Password authentication method|User Password Section]]) | ||
| * $bitlocker$1$... : it starts the User Password attack mode with MAC verification (slower execution, no false positives) | * $bitlocker$1$... : it starts the User Password attack mode with MAC verification (slower execution, no false positives) | ||
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| * $bitlocker$3$... : it starts the Recovery Password attack mode with MAC verification (slower execution, no false positives) | * $bitlocker$3$... : it starts the Recovery Password attack mode with MAC verification (slower execution, no false positives) | ||
| - | ===== How To ===== | + | Samples BitLocker images for testing are available here: |
| + | * https://github.com/e-ago/bitcracker/tree/master/Images | ||
| + | * https://github.com/kholia/libbde/tree/bitlocker2john/samples | ||
| - | In order to use the BitLocker-OpenCL format, you must produce a well-formatted hash of your encrypted image. | + | ===== Step 3: Attack! ===== |
| - | Samples BitLocker images for testing are available at https://github.com/kholia/libbde/tree/bitlocker2john/samples and here: https://github.com/e-ago/bitcracker/tree/master/Images | + | |
| + | Use the BitLocker-OpenCL format specifying the hash file: | ||
| + | <code> | ||
| + | ./john --format=bitlocker-opencl --wordlist=wordlist target_hash | ||
| + | </code> | ||
| + | Currently, this format is able to evaluate passwords having length between 8 (minimum password length) and 55 characters (implementation reasons). | ||
| - | ==== Cracking Process ==== | + | To avoid wasting compute resources, choose just one hash for this attack - either $bitlocker$0$... or $bitlocker$1$... |
| - | Use the BitLocker-OpenCL format specifying the previous hash: | + | ===== Recovery Passwords (but you're out of luck cracking these, so just don't) ===== |
| + | |||
| + | The mask you can use to generate Recovery Passwords is: | ||
| <code> | <code> | ||
| - | ./john --format=bitlocker-opencl --wordlist=wordlist target_hash | + | --mask=?d?d?d?d?d?d-?d?d?d?d?d?d-?d?d?d?d?d?d-?d?d?d?d?d?d-?d?d?d?d?d?d-?d?d?d?d?d?d-?d?d?d?d?d?d-?d?d?d?d?d?d |
| </code> | </code> | ||
| - | Currently, this format is able to evaluate passwords having length between 8 (minimum password length) and 27 characters (implementation reasons). | + | Please note that the number of possible Recovery Passwords is **way** too large, so there's effectively **no chance** that this will find yours unless you recall almost all of it (except for just a handful of digits) and replace most of the "?d" above with the known digits. |
| - | We will increase the max passwords size in the next release. | + | |
| + | Recovery Passwords are currently only supported by the BitLocker-OpenCL format (for use on GPUs), not by the corresponding BitLocker CPU format, but like the above paragraph says it's a controversial feature anyhow, which is unlikely to ever help. | ||
| + | |||
| + | To avoid wasting compute resources, choose just one hash for this attack - either $bitlocker$2$... or $bitlocker$3$... | ||
| + | Samples of User Password/Recovery Passwords dictionaries you can user are available here: https://github.com/e-ago/bitcracker/tree/master/Dictionary | ||
| ===== Output ===== | ===== Output ===== | ||
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| </code> | </code> | ||
| - | This OpenCL implementation has been tested on a GPU GeForce Titan X (Openwall), GPU AMD Radeon HD 7990 Malta and an Intel Core i7 Kaby Lake CPU. | + | This OpenCL implementation has been tested on a GPU NVIDIA GeForce Titan X (Openwall), GPU AMD Radeon HD 7990 Malta and an Intel Core i7 CPU. |
| + | For additional information about performance, see https://github.com/e-ago/bitcracker#performance | ||
| ===== Updates and changelog ===== | ===== Updates and changelog ===== | ||
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| 12/19/2017 | 12/19/2017 | ||
| * Now BitLocker-OpenCL supports 4 different attack modes: User Password fast attack, User Password with MAC verification (performance decreased), Recovery Password, Recovery Password with MAC verification (performance decreased) | * Now BitLocker-OpenCL supports 4 different attack modes: User Password fast attack, User Password with MAC verification (performance decreased), Recovery Password, Recovery Password with MAC verification (performance decreased) | ||
| + | * Max password length increased to 55 | ||
| Next Update: | Next Update: | ||