subsmt

Sparse Merkle tree implementation in ink and substrate. Provide permanent storage off-chain backend based on rocksdb and paritydb.

It can be applied in scenarios where Sparse Merkle Trees are used to save on-chain storage or computation resources, such as airdrops, game reward claims, and more. It provides a complete web backend functionality and the option to choose custom hash algorithms. Developers only need to modify the specific implementation of keys and values in the kv database, allowing them to quickly set up a web backend tailored to their project, along with on-chain verification templates or smart contracts. Its design follows the principle of minimizing the abuse of on-chain resources, ensuring that only the final verification needs to be implemented on-chain.

Tech stack

• rust
• python
• ink
• polkadot-sdk
• actix-web
• swagger-ui
• parity-scale-codec
• sha3
• kvdb-rocksdb
• sparse-merkle-tree

apis

1. update_value

    curl -X 'POST' \
    'http://localhost:8080/update' \
    -H 'accept: application/json' \
    -H 'Content-Type: application/json' \
    -d '{
    "address": "1H4GsGKaAv6VCwgx7gRgPm9AmCKqzEDjb2GyWoERj9xBRAH",
    "balance": "1000000000000",
    "nonce": 1,
    "prefix": "test"
    }'
   

   result:

   "9978dd715a13f27c42fc832b6997cfd7013341790e651eb3781d4a7706e3a323"

2. get_value

   curl -X 'POST' \
   'http://localhost:8080/value' \
   -H 'accept: application/json' \
   -H 'Content-Type: application/json' \
   -d '{
   "address": "1H4GsGKaAv6VCwgx7gRgPm9AmCKqzEDjb2GyWoERj9xBRAH",
   "prefix": "test" 
   }'

   result:

   {
   "nonce": 1,
   "balance": "1000000000000"
   }

3. get_merkle_proof

    curl -X 'POST' \
    'http://localhost:8080/merkle_proof' \
    -H 'accept: application/json' \
    -H 'Content-Type: application/json' \
    -d '{
    "address": "1H4GsGKaAv6VCwgx7gRgPm9AmCKqzEDjb2GyWoERj9xBRAH",
    "prefix": "test"
    }'
   
   

   result:

    {
    "address": "1H4GsGKaAv6VCwgx7gRgPm9AmCKqzEDjb2GyWoERj9xBRAH",
    "nonce": 1,
    "balance": "1000000000000",
    "path": "71bf72e9e47f9a3bc183d7247bb87eb20cc7f5321d49a13f1210da88187efb80",
    "value_hash": "8300cd832a2edcbe835a1e918116c52226cd5202b2f8f8523949772f52970c85",
    "root": "9978dd715a13f27c42fc832b6997cfd7013341790e651eb3781d4a7706e3a323",
    "leave_bitmap": "0000000000000000000000000000000000000000000000000000000000000000",
    "siblings": []
    }
   

4. verify

    curl -X 'POST' \
    'http://localhost:8080/verify' \
    -H 'accept: application/json' \
    -H 'Content-Type: application/json' \
    -d '{
    "address": "1H4GsGKaAv6VCwgx7gRgPm9AmCKqzEDjb2GyWoERj9xBRAH",
    "nonce": 1,
    "balance": "1000000000000",
    "path": "71bf72e9e47f9a3bc183d7247bb87eb20cc7f5321d49a13f1210da88187efb80",
    "value_hash": "8300cd832a2edcbe835a1e918116c52226cd5202b2f8f8523949772f52970c85",
    "root": "9978dd715a13f27c42fc832b6997cfd7013341790e651eb3781d4a7706e3a323",
    "leave_bitmap": "0000000000000000000000000000000000000000000000000000000000000000",
    "siblings": []
    }'

   result:

   true

5. remove_value

    curl -X 'POST' \
    'http://localhost:8080/remove' \
    -H 'accept: application/json' \
    -H 'Content-Type: application/json' \
    -d '{
    "address": "test",
    "prefix": "1H4GsGKaAv6VCwgx7gRgPm9AmCKqzEDjb2GyWoERj9xBRAH"
    }'

   result:

   "0000000000000000000000000000000000000000000000000000000000000000"

6. get_next_root

   curl -X 'POST' \
   'http://localhost:8080/next_root' \
   -H 'accept: application/json' \
   -H 'Content-Type: application/json' \
   -d '{
   "address": "1H4GsGKaAv6VCwgx7gRgPm9AmCKqzEDjb2GyWoERj9xBRAH",
   "balance": "100",
   "nonce": 2,
   "prefix": "test"
   }'

   result:

   "6f4c5710e5ed2982d6c409d8b43693176086bfde7f01aeba64731a8a84a82ca2"

7. get_root

    curl -X 'POST' \
    'http://localhost:8080/root' \
    -H 'accept: application/json' \
    -H 'Content-Type: application/json' \
    -d '{
    "prefix": "test"
    }'

   result:

   "9978dd715a13f27c42fc832b6997cfd7013341790e651eb3781d4a7706e3a323" # fixme
   

8. clear

    curl -X 'POST' \
    'http://localhost:8080/clear' \
    -H 'accept: application/json' \
    -H 'Content-Type: application/json' \
    -d '{
    "prefix": "test"
    }'

   result:

   "0000000000000000000000000000000000000000000000000000000000000000"

---

DEV

install environment

https://docs.substrate.io/install/

Clone the project

git clone https://github.com/farcloud-labs/subsmt.git

cd subsmt 
git submodule update --init --recursive

As a developer, you don't even need to understand the specific implementation of the sparse Merkle tree, you can simply write a small amount of code to customize and extend your own Merkle tree backend. If you have such a need, you can modify the code in these few places.

build

cargo build --release

run

cargo run

or

./target/release/smt

Testing

Manual Testing

http://localhost:8080/swagger-ui/

Unit Test Case

cargo test -- --nocapture

docker

local build

docker buildx build -t smt:latest . --load

run docker

docker-compose up

or

docker run -it --name smt-backend -p 8080:8080 smt:latest

stop docker

docker-compose down

License

This project is licensed under the LICENSE_APACHE2. See the LICENSE file for details.