starknet_os: only hash public key if not 0

[einat-starkware]

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[reviewable-StarkWare]

This change is 

[einat-starkware]

• starknet_os: only hash public key if not 0 #8717 👈 (View in Graphite)
• main-v0.14.1

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[noaov1]

@noaov1 reviewed 2 of 2 files at r1, all commit messages.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @avi-starkware)

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crates/apollo_starknet_os_program/src/cairo/starkware/starknet/core/os/os_config/os_config.cairo line 7 at r1 (raw file):

const STARKNET_OS_CONFIG_VERSION = 'StarknetOsConfig3';
// The pedersen hash of 0, 0.

Note that we also add the length to the hash (i.e. we calculate hash(hash(0,0),2)

Suggestion:

// The pedersen hash of data = [0, 0].

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crates/apollo_starknet_os_program/src/cairo/starkware/starknet/core/os/os_config/os_config.cairo line 16 at r1 (raw file):

    // The (L2) address of the fee token contract.
    fee_token_address: felt,
    // The hash of POTC's public key. Default key is 0, 0 for SN environment.

Suggestion:

    // The hash of the public key used to decrypt the state diff. 
    // The default key is the elliptic-curve point (x = 0, y = 0), as used in StarkNet environments.