[aes] Connect EDN interface #700
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Signed-off-by: Pirmin Vogel <[email protected]>
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| default swmod = true; | ||
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| field {desc = "Entropy Interface Seed field";} ENTROPY_IF_SEED[32]; | ||
| } ENTROPY_IF_SEED @0x00000110; |
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"firmware has to perform 9 subsequent writes to the register."
To address this requirement, could you increase this register to 9 dwords? and then firmware will write 9*32 bits seed to this address?
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Hi @mojtaba-bisheh , thanks for the feedback!
Yes, that is possible at the cost of additional area (Instead of 320 FFs, we will need 576 FFs).
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np, that makes the seed interface like other blocks from a firmware perspective.
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Okay, sounds good. I'll change the implementation accordingly.
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This PR connects the entropy distribution network (EDN) interface of AES to a Trivium stream cipher primitive which can be reseeded by firmware. The stream cipher primitive is required to decouple AES from firmware as AES can repeatedly request fresh entropy via the EDN interface while doing encryptions/decryptions. This entropy is required for the internal masking SCA countermeasure.