Bluetooth: Host: Fix checking for sufficient encryption key size #18659
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
jhedberg
added
bug
jhedberg
commented
Aug 26, 2019
subsys/bluetooth/host/hci_core.c
Outdated
There was a problem hiding this comment.
We can argue about the usage of 4 here rather than the enum name. I went with the integer to make something that applies easily both to master and LTS, since we've recently renamed/deprecated the security level enum values.
jhedberg
force-pushed
the
enc_key_size
branch
2 times, most recently
from
c7356c2 to
8d1512d
Compare
|
Tested to work on Broadcom & CSR dual-mode adapters, so I've now removed the DNM label. |
jhedberg
force-pushed
the
enc_key_size
branch
3 times, most recently
from
bcf4113 to
5dd99bf
Compare
|
Updated the PR by moving the check to the |
added 2 commits
August 27, 2019 13:30
In case sufficient security level wasn't reached the error propagation was missing, which could lead to incorrect state transitions when update_sec_level_br() returns. Return true/false and make sure to abort any further operations in case the update fails. Signed-off-by: Johan Hedberg <[email protected]>
A security vulnerability in the Bluetooth BR/EDR Bluetooth Core specification versions 1.0 through 5.1 has been identified as CVE-2019-9506. The Bluetooth BR/EDR encryption key negotiation protocol is vulnerable to packet injection that could allow an unauthenticated user to decrease the size of the entropy of the encryption key, potentially causing information disclosure and/or escalation of privileges via adjacent access. There is not currently any knowledge of this being exploited. From Core spec erratum 11838: A device shall enforce an encryption key with at least 128-bit equivalent strength for all services that require Security Mode 4, Level 4. For all other services that require encryption, a device should enforce an encryption key with at least 56-bit equivalent strength, irrespective of whether the remote device supports Secure Simple Pairing. After encryption has been enabled, the Host should check the encryption key size using either the HCI_Read_Encryption_Key_Size command (see [Vol 2] Part E, Section 7.5.7) or a vendor-specific method. Fixes zephyrproject-rtos#18658 Signed-off-by: Johan Hedberg <[email protected]>
joerchan
approved these changes
Aug 27, 2019
carlescufi
approved these changes
Aug 27, 2019
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
A security vulnerability in the Bluetooth BR/EDR Bluetooth Core
specification versions 1.0 through 5.1 has been identified as
CVE-2019-9506. The Bluetooth BR/EDR encryption key negotiation
protocol is vulnerable to packet injection that could allow an
unauthenticated user to decrease the size of the entropy of the
encryption key, potentially causing information disclosure and/or
escalation of privileges via adjacent access. There is not currently
any knowledge of this being exploited.
From Core spec erratum 11838:
A device shall enforce an encryption key with at least 128-bit
equivalent strength for all services that require Security Mode 4,
Level 4. For all other services that require encryption, a device
should enforce an encryption key with at least 56-bit equivalent
strength, irrespective of whether the remote device supports Secure
Simple Pairing.
After encryption has been enabled, the Host should check the
encryption key size using either the HCI_Read_Encryption_Key_Size
command (see [Vol 2] Part E, Section 7.5.7) or a vendor-specific
method.
Fixes #18658
Signed-off-by: Johan Hedberg [email protected]