Marinade state verification onchain program

Cargo.toml

[package]
name = "test"
version = "0.1.0"
description = "Created with Anchor"
edition = "2021"

[lib]
crate-type = ["cdylib", "lib"]
name = "test"

[features]
no-entrypoint = []
no-idl = []
no-log-ix-name = []
cpi = ["no-entrypoint"]
default = []

[dependencies]
anchor-lang = "0.27.0"
marinade-sdk = { git = "https://github.com/marinade-finance/marinade-sdk" }
micro-anchor = { git = "https://github.com/marinade-finance/marinade-sdk" }

marinade_verification.rs

use crate::error::TestError;
use anchor_lang::prelude::*;
use marinade_sdk::{
    checks::check_owner_program,
    state::{marinade::Marinade, validator_system::ValidatorRecord},
    ID as MARINADE_PROGRAM_ID,
};
use micro_anchor::Discriminator;

/// Check if provided account is Marinade state
pub fn assert_is_marinade_account(account_info: &AccountInfo) -> Result<()> {
    let state_info = account_info.to_account_info();
    let state_data: &[u8] = &state_info.try_borrow_data()?;

    require!(
        state_data[..8] == Marinade::DISCRIMINATOR,
        TestError::MarinadeInvalidDiscriminator
    );
    check_owner_program(&state_info, &MARINADE_PROGRAM_ID, "marinade_state")?;

    Ok(())
}

/// Verification of existence of Marinade validator duplication flag account
/// When a validator vote account
pub fn assert_is_in_marinade(
    marinade_state: &Pubkey,
    validator_duplication_flag: &AccountInfo,
    asserted_validator_vote: &Pubkey,
) -> Result<()> {
    let (duplication_flag_pda_address, _bump) =
        ValidatorRecord::find_duplication_flag(marinade_state, asserted_validator_vote);
    require_keys_eq!(
        *validator_duplication_flag.key,
        duplication_flag_pda_address,
        TestError::MarinadeNotRentExcemptDuplicationFlag
    );

    check_owner_program(
        validator_duplication_flag,
        &MARINADE_PROGRAM_ID,
        "validator_duplication_flag",
    )?;
    require!(
        Rent::get()?.is_exempt(
            validator_duplication_flag.lamports(),
            validator_duplication_flag.data_len()
        ),
        TestError::MarinadeNotRentExcemptDuplicationFlag
    );

    Ok(())
}