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| author | TreeHugger Robot <treehugger-gerrit@google.com> | 2020-07-23 20:22:53 +0000 |
|---|---|---|
| committer | Android (Google) Code Review <android-gerrit@google.com> | 2020-07-23 20:22:53 +0000 |
| commit | 5627d35a86a3c8604f59f19b82db92c82482285a (patch) | |
| tree | 960400704e6e7bcdf7e1fd6f99fb95aef825d46b /9_security-model | |
| parent | ab73a927ad5bc4b3609e95c0006a03279b30717e (diff) | |
| parent | 7cee8f29c2df1afcea04b02386726f0c1fae8b69 (diff) | |
| download | platform_compatibility_cdd-5627d35a86a3c8604f59f19b82db92c82482285a.tar.gz platform_compatibility_cdd-5627d35a86a3c8604f59f19b82db92c82482285a.tar.bz2 platform_compatibility_cdd-5627d35a86a3c8604f59f19b82db92c82482285a.zip | |
Merge "CDD: mandate non-reversible FBE key derivation function" into rvc-dev
Diffstat (limited to '9_security-model')
| -rw-r--r-- | 9_security-model/9_9_full-disk-encryption.md | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/9_security-model/9_9_full-disk-encryption.md b/9_security-model/9_9_full-disk-encryption.md index 55d6f19d..365cf375 100644 --- a/9_security-model/9_9_full-disk-encryption.md +++ b/9_security-model/9_9_full-disk-encryption.md @@ -36,7 +36,7 @@ https://source.android.com/security/encryption/file-based.html) (FBE). ### 9.9.3\. File Based Encryption -Encrypted devices: +If device implementations are encrypted, they: * [C-1-1] MUST boot up without challenging the user for credentials and allow Direct Boot aware apps to access to the Device Encrypted (DE) storage @@ -61,6 +61,16 @@ file names (instead of Adiantum) if the device has Advanced Encryption Standard (AES) instructions. AES instructions are ARMv8 Cryptography Extensions on ARM-based devices, or AES-NI on x86-based devices. If the device does not have AES instructions, the device MAY use Adiantum. +* [C-1-13] MUST use a cryptographically strong and non-reversible key +derivation function (e.g. HKDF-SHA512) to derive any needed subkeys (e.g. +per-file keys) from the CE and DE keys. "Cryptographically strong and +non-reversible" means that the key derivation function has a security strength +of at least 256 bits and behaves as a [pseudorandom function +family](https://en.wikipedia.org/w/index.php?title=Pseudorandom_function_family&oldid=928163524) +over its inputs. +* [C-1-14] MUST NOT use the same File Based Encryption (FBE) keys or subkeys +for different cryptographic purposes (e.g. for both encryption and key +derivation, or for two different encryption algorithms). * The keys protecting CE and DE storage areas: |