npm install --save @solar-republic/neutrino

npm install --save @cosmjs/crypto @cosmjs/amino @cosmjs/encoding

npm install --save @cosmjs/stargate
# or
npm install --save @cosmjs/cosmwasm-stargate

import { Slip10Curve, Random, Bip39, Slip10, stringToPath, Secp256k1 } from "@cosmjs/crypto"

const seed = await Bip39.mnemonicToSeed(Bip39.encode(Random.getBytes(16)));
const { privateKey } = Slip10.derivePath(Slip10Curve.Secp256k1, seed, stringToPath("m/44'/1'/0'/0"));
const pair = await Secp256k1.makeKeypair(privateKey);
// must be compressed to 33 bytes from 65
const publicKey = Secp256k1.compressPubkey(pair.pubkey);

import { gen_sk, sk_to_pk } from "@solar-republic/neutrino"

const privateKey = gen_sk(); 
const publicKey = sk_to_pk(privateKey);

import { Wallet } from "secretjs";
const { privateKey, publicKey } = new Wallet()

import { SecretContract } from "@solar-republic/neutrino"

// create a contract instantse
const contract = await SecretContract(
    secretNodeEndpoint,
    secretContractAddress
)

// query example:
// get encryption key from a gateway contract
const queryRes = await contract.query({ encryption_key: {} })


// extract res value
const gatewayPublicKey = queryRes[2]

import { SecretNetworkClient } from "secretjs"

// create a client:
const client = new SecretNetworkClient({
    chainId, 
    url // endpoint URL of the node
});

// query the contact and get the value directly
const gatewayPublicKey =  await client.query.compute.queryContract({
    contract_address
    code_hash, // optionally
    { encryption_key: {} } // query msg
});

// window.keplr.signArbi....
signArbitrary(chainId: string, signer: string, data: string | Uint8Array) : Promise<StdSignature>

// In browser environment we can get it from a wallet extension. E.g with Keplr:
const signer = window.keplr.getOfflineSigner(chainId);


//  ...


// In Node environment we can use `Secp256k1Wallet` class that also implements `OfflineAminoSigner` interface
import { Secp256k1Wallet } from "@cosmjs/amino"


// see examples of generating a random above but in this case you will probably be using a persistent one from a .env file 
// you can also pass extra options like prefix as the second argument
const signer = await Secp256k1HdWallet.fromMnemonic(userMnemonic) 


//  ...

// Here we are getting the first accounts from the signer
// accessing the address and renaming it to `signerAddress` 
const [{ address : signerAddress }] =  await signer.getAccounts();

//  ...

function makeSignDoc(msgs: AminoMsg[], fee: StdFee, chainId: string, memo: string | undefined, accountNumber: number | string, sequence: number | string, timeout_height?: bigint): StdSignDoc;

type AminoMsg = {
    // static type url
    type: ;
    value: {
        // signer address
        signer: string;
        // plaintext or base64 encoded message
        data: string;
    }
}

const data = "my message";


const signDoc  = makeSignDoc(
    [{                              // list of amino messages
        type: "sign/MsgSignData", 
        value:  { 
            signer: signerAddress, 
            data:   data 
        }
    }], 
    { gas: "0", amount: [] },      // StdFee
    "",                            // chainId 
    "",                            // memo
    0,                             // accountNumber
    0                              // sequence
    // timeout_height
)

const signRes = await signer.signAmino(signerAddress, signDoc);

import { sha256, Random } from "@cosmjs/crypto"
import { fromBase64, toBase64, toAscii } from "@cosmjs/encoding";
import { chacha20_poly1305_seal, ecdh } from "@solar-republic/neutrino"
// this is a dependency of `@solar-republic/neutrino` so consider importing these methos 
import { concat, json_to_bytes } from "@blake.regalia/belt";


// ...
//   define
//  
//      `clientPrivateKey`
//      `gatewayPublicKey`
//      `signerAddress`
//
//   like described above
// ...


const sharedKey = sha256(ecdh(clientPrivateKey, gatewayPublicKey))

// We also need to generate a one-time nonce, which can be done like this:
const nonce =  Random.getBytes(12)

// Prepare a message for the action you want to take on the contract
const msg = ExecuteMsg { ...}


/// Defining payload structure idential to the Rust data structure
const payload : EncryptedPayload = {
    // e.g, cosmos1...
    user_address: signerAddress,
    // uint8array -> base64  (-> Binary)
    user_pubkey: toBase64(signerPubkey),
    // e.g. "cosmos" from "cosmos1..."
    hrp: signerAddress.split("1")[0], 
    // or to toBinary(msg) from `@cosmjs/cosmwasm-stargate`
    msg: toBase64(json_to_bytes(msg))
}


/// getting the payload ciphertext 
const ciphertext = concat(chacha20_poly1305_seal(
    sharedKey,
    nonce,
    // or toUtf8( JSON.stringify(payload) )  
    json_to_bytes( payload )
));

// finally the payload_hash is sha256 of the ciphertext
const ciphertextHash = sha256(ciphertext);


//    ...

// calling `makeSignDoc` with nullifed fields like described earlier
const signDoc = getArb36SignDoc(signerAddress, ciphertextHash);
// signing the message
const signRes = await signer.signAmino(signerAddress, signDoc);

const encrypted = {
    // uint8array -> base64  (-> Binary)
    nonce              :     toBase64(nonce),
    // public key of a pair that was used in deriving a shread key 
    user_key           :     toBase64(clientPublicKey),
    // ciphertext of with the user data and actual message
    payload            :     toBase64(ciphertext),
    // sha256 hash of the ciphertext
    payload_hash       :     toBase64(ciphertextHash),
    // signatire over sha256( getArb36SignDoc( payload_hash ) ) already in base64
    payload_signature  :     signRes.signature.signature,
}

import { MsgTransfer } from "cosmjs-types/ibc/applications/transfer/v1/tx";
import { SigningStargateClient, MsgTransferEncodeObject } from "@cosmjs/stargate";

/// creating a client
const client = await SigningStargateClient(
    "https://rpc.cosmoshub.io"    //  endpoint of the remote network 
    signer,                       // offlineSigner  
)


// defining the IBC transfer message
const msg : MsgTransferEncodeObject = {
    typeUrl: "/ibc.applications.transfer.v1.MsgTransfer",
    value: MsgTransfer.fromPartial({
      sender:   signerAddress,
      receiver: secretGatewayContractAddress,
      sourceChannel: "channel-0",
      sourcePort: "transfer",
      timeoutTimestamp:  BigInt(
        // 5 minutes from now           |  ms -> ns
        Math.floor(Date.now() + 300_000) * 1_000_000
      ),
      // IBC Hook memo msg
      memo: JSON.stringify({
        wasm: {
            // must be same as receiver
            contract: secretGatewayContractAddress,
            // encrypted message defined above
            msg: encrypted
        }
      })
    })
}

// signing and broadcasting the message
const res = await client.signAndBroadcast(signerAddress, [msg])

/// A data structure that is safe to be visible by all network participants and can be transmited over non-secure channels
struct EncryptedParams {
    /// Encrypted payload containging hidden message
    pub payload            :   Binary,
    /// Sha256 hash of the payload
    pub payload_hash       :   Binary,
    /// Signed base64 digest of the payload_hash being wrapped
    /// in an cosmos arbitrary (036) object and rehashed again with sha256
    pub payload_signature  :   Binary,
    /// Public key of wallet used for deriving a shared key for chacha20_poly1305
    /// Not necessary the same as user's public key 
    pub user_key           :   Binary,
    /// One-time nonce used for chacha20_poly1305 encryption
    pub nonce              :   Binary,
}

/// Data meant to be encrypted and stored in the payload field of [EncryptedParams]
#[cw_serde]
pub struct EncryptedPayload {
    /// bech32 prefix address of a wallet used for signing hash of the payload 
    pub user_address   :  String,
    /// Public key of a wallet used for signing hash of the payload 
    pub user_pubkey   :   Binary,
    /// Human readable prefix for the bech32 address on the remote cosmos chain
    pub hrp           :   String,
    /// Plaintext message e.g. normal `ExecuteMsg` of your contract
    pub msg           :   Binary,
}

pub enum ExecuteMsg {
    ...

    Encrypted {
        payload             :   Binary,
        payload_signature   :   Binary,
        payload_hash        :   Binary,
        user_key            :   Binary,
        nonce               :   Binary,
    }
    ...

}

trait WithEncryption : Serialize + Clone  {
    fn encrypted(&self)     -> EncryptedParams;
    fn is_encrypted(&self)  -> bool;
}

impl WithEncryption for ExecuteMsg {
   fn encrypted(&self)     -> EncryptedParams {
       match self.clone() {
           ExecuteMsg::Encrypted {
               payload,
               payload_signature,
               payload_hash,
               user_key,
               nonce,
           } => EncryptedParams {
               payload,
               payload_signature,
               payload_hash,
               user_key,
               nonce
           },
           _ => panic!("Not encrypted")

       }
   }

   fn is_encrypted(&self)  -> bool {
       if ExecuteMsg::Encrypted{..} = self {
           true
       } else {
           false
       }
   }
}

pub enum GatewayExecuteMsg<E = Option<Empty>> 
    where E: JsonSchema
{
    ResetEncryptionKey  {} ,

    Encrypted {
        payload             :   Binary,
        payload_signature   :   Binary,
        payload_hash        :   Binary,
        user_key            :   Binary,
        nonce               :   Binary,
    },

    Extension {
        msg : E
    }
}

// Degine your custom message
#[cw_serde]
pub enum MyCustomMessage {
    HandleFoo {}
    HandleBar {}
}
// Extend the GatewayExecuteMsg
pub type MyGatewayExecuteMsg = GatewayExecuteMsg<MyCustomMessage>;

/// MyGatewayExecuteMsg
match msg {
    ... 
    ResetEncryptionKey => { ... },

    MyGatewayExecuteMsg::Extension{msg} => {

        /// MyCustomMessage
        match msg {
            MyCustomMessage::HandleFoo{} => {
                // Do something
            }
            MyCustomMessage::HandleBar{} => {
                // Do something
            }
        }
    }
    
    ...
}

      let decrypted  = wallet.decrypt_to_payload(
            &params.payload,
            &params.user_key,
            &params.nonce,
        )?;

pub fn chacha20poly1305_decrypt(
    ciphertext    :     &impl Deref<Target = [u8]>,
    key           :     &impl Deref<Target = [u8]>,
    nonce         :     &impl Deref<Target = [u8]>,
) -> StdResult<Vec<u8>> {
    ...
}

fn verify_arbitrary<M : Display>(api:  &dyn Api, cred: &CosmosCredential<M>) -> StdResult<String>

pub struct CosmosCredential<M = String> 
    where M: Display
{
    /// public key matching the respective secret that was used to sign message
    pub pubkey    :   Binary,
    /// signed sha256 digest of a message wrapped in arbitary data (036) object
    pub signature :   Binary,
    /// signed inner message before being wrapped with 036
    pub message   :   M,
    /// prefix for the bech32 address on remote cosmos chain
    pub hrp       :   String
}

fn preamble_msg_arb_036(signer: &str, data: &str) -> String

{
  //... other ibc fields omitted for example
  "data": {
    "denom": "denom on counterparty chain (e.g. uatom)", // will be transformed to the local denom (ibc/...)
    "amount": "1000",
    "sender": "addr on counterparty chain", // will be ignored and shown to the contract as a null sender (cannot be verifed over IBC)
    "receiver": "secret1contractAddr",
    "memo": {
      "wasm": {
        "contract": "secret1contractAddr",
        "msg": {
          "raw_message_fields": "raw_message_data"
        }
      }
    }
  }
}

#[entry_point]
pub fn execute(_deps: DepsMut, env: Env, info: MessageInfo, msg: Msg) -> StdResult<Response> {
    match msg {
        Msg::WrapDeposit {
            snip20_address,
            snip20_code_hash,
            recipient_address,
        } => Ok(Response::default().add_messages(vec![
            CosmosMsg::Wasm(cosmwasm_std::WasmMsg::Execute {
                contract_addr: snip20_address.clone(),
                code_hash: snip20_code_hash.clone(),
                msg: to_binary(&secret_toolkit::snip20::HandleMsg::Deposit { padding: None })
                    .unwrap(),
                funds: info.funds.clone(),
            }),
            CosmosMsg::Wasm(cosmwasm_std::WasmMsg::Execute {
                contract_addr: snip20_address,
                code_hash: snip20_code_hash,
                msg: to_binary(&secret_toolkit::snip20::HandleMsg::Transfer {
                    recipient: recipient_address,
                    amount: info.funds[0].amount,
                    memo: None,
                    padding: None,
                })
                .unwrap(),
                funds: vec![],
            }),
        ])),
        }
    }

#[cw_serde]
pub enum IBCLifecycleComplete {
    #[serde(rename = "ibc_ack")]
    IBCAck {
        /// The source channel (secret side) of the IBC packet
        channel: String,
        /// The sequence number that the packet was sent with
        sequence: u64,
        /// String encoded version of the ack as seen by OnAcknowledgementPacket(..)
        ack: String,
        /// Weather an ack is a success of failure according to the transfer spec
        success: bool,
    },
    #[serde(rename = "ibc_timeout")]
    IBCTimeout {
        /// The source channel (secret side) of the IBC packet
        channel: String,
        /// The sequence number that the packet was sent with
        sequence: u64,
    },
}

/// Message type for `sudo` entry_point
#[cw_serde]
pub enum SudoMsg {
    #[serde(rename = "ibc_lifecycle_complete")]
    IBCLifecycleComplete(IBCLifecycleComplete),
}

#[entry_point]
pub fn sudo(_deps: DepsMut, _env: Env, msg: SudoMsg) -> StdResult<Response> {
    match msg {
        SudoMsg::IBCLifecycleComplete(IBCLifecycleComplete::IBCAck {
            channel,
            sequence,
            ack,
            success,
        }) => todo!(),
        SudoMsg::IBCLifecycleComplete(IBCLifecycleComplete::IBCTimeout {
            channel,
            sequence,
        }) => todo!(),
    }
}