SecretStore: secretstore_generateDocumentKey RPC

[svyatonik]

Brief overview:

1. this is needed to support encryption/decryption in service contract
2. this is required to actually use Document key storing session by only calling Parity RPCs and SS API
3. using Document key storing session via HTTP API is not safe now (it is vulnerable to MITM attack and HTTP API will be changed later). It should be OK to use it via service contract, though

Usage example (in this example document key is both generated and restored at the Parity node, which executes RPC requests - it is not known to any SS node):

1. generate signature for key id:

curl --data-binary '{"jsonrpc": "2.0", "method": "secretstore_signRawHash", "params": ["0x00a329c0648769A73afAc7F9381E08FB43dBEA72", "", "0x0000000000000000000000000000000000000000000000000000000000000009"], "id":1 }' -H 'content-type: application/json' http://127.0.0.1:8545/

{"jsonrpc":"2.0","result":"0xae42e6f9efdba7e3e33b8aa7edf46da4a36094725d6d86e8905515d5b713b81b6958e09ba5c8dfe5fe4f6d705d8968bed73f27a638edfff75b6d76a48a98514901","id":1}

2. generate server key:

curl -X POST http://localhost:8082/shadow/0000000000000000000000000000000000000000000000000000000000000009/ae42e6f9efdba7e3e33b8aa7edf46da4a36094725d6d86e8905515d5b713b81b6958e09ba5c8dfe5fe4f6d705d8968bed73f27a638edfff75b6d76a48a98514901/${1:-1}

"0x2eabc29df5b62c75011bf1016237212b6305f8bae0f979b7b92250cfea06c20fe1689fc6d98964be64532598e3db7fc5712ad24b95e161f95bcfe1c6f859da3a"

3. generate document key (this PR):

curl --data-binary '{"jsonrpc": "2.0", "method": "secretstore_generateDocumentKey", "params": ["0x00a329c0648769A73afAc7F9381E08FB43dBEA72", "","0x2eabc29df5b62c75011bf1016237212b6305f8bae0f979b7b92250cfea06c20fe1689fc6d98964be64532598e3db7fc5712ad24b95e161f95bcfe1c6f859da3a"], "id":1 }' -H 'content-type: application/json' http://127.0.0.1:8545/

{"jsonrpc":"2.0","result":{"common_point":"0x18b8eb0ce96d3bb53141be03b7c411b6a5c506329bae2b10f5844134ca14207e0bb835155b38d649aab87f85e0e155e154f7c1e20143467d4a2890f8d9c08dc0","encrypted_key":"0x04300287a477e08dfe6e8202f56671ce9398063aee90ba54bdf6c03da924544637b260b9aae0bef9b779890e1885a2e67de636ee0fc6e2bcfb46aeda12c9e684979dd16d0d496b932f169e5a859516f9ac46a2575583162c357357f29aa525641ab6a5ddb898ff6b89b899a67c37833ccd7574fea76717005655ea7d6543e5ae4c56d6d088036a7e84b46dd18d2f8867bd351a8e2eddf24790544347c80727541b822dd351ed99d53b9a4fc88944908236","encrypted_point":"0x35457eeb38f9f3c2538492a5740f96cc70ea343210675d9821935dfa9e32a678ae260a2ae45df48c9fadb2abcc1be88dc2fcb15b3ddfa9db51d9a0e298a0cefd"},"id":1}

4. encrypt document using encrypted_key field from secretstore_generateDocumentKey call:

curl --data-binary '{"jsonrpc": "2.0", "method": "secretstore_encrypt", "params": ["0x00a329c0648769A73afAc7F9381E08FB43dBEA72", "", "0x04300287a477e08dfe6e8202f56671ce9398063aee90ba54bdf6c03da924544637b260b9aae0bef9b779890e1885a2e67de636ee0fc6e2bcfb46aeda12c9e684979dd16d0d496b932f169e5a859516f9ac46a2575583162c357357f29aa525641ab6a5ddb898ff6b89b899a67c37833ccd7574fea76717005655ea7d6543e5ae4c56d6d088036a7e84b46dd18d2f8867bd351a8e2eddf24790544347c80727541b822dd351ed99d53b9a4fc88944908236", "0xdeadbeef"], "id":1 }' -H 'content-type: application/json' http://127.0.0.1:8545/

{"jsonrpc":"2.0","result":"0xd2e72c288778658a73cee7d7eb6d2b2bcb5fcc3d","id":1}

5. store document key in SS:

curl -X POST http://localhost:8082/shadow/0000000000000000000000000000000000000000000000000000000000000009/ae42e6f9efdba7e3e33b8aa7edf46da4a36094725d6d86e8905515d5b713b81b6958e09ba5c8dfe5fe4f6d705d8968bed73f27a638edfff75b6d76a48a98514901/18b8eb0ce96d3bb53141be03b7c411b6a5c506329bae2b10f5844134ca14207e0bb835155b38d649aab87f85e0e155e154f7c1e20143467d4a2890f8d9c08dc0/35457eeb38f9f3c2538492a5740f96cc70ea343210675d9821935dfa9e32a678ae260a2ae45df48c9fadb2abcc1be88dc2fcb15b3ddfa9db51d9a0e298a0cefd

6. query document key shadow:

curl http://localhost:8082/shadow/0000000000000000000000000000000000000000000000000000000000000009/ae42e6f9efdba7e3e33b8aa7edf46da4a36094725d6d86e8905515d5b713b81b6958e09ba5c8dfe5fe4f6d705d8968bed73f27a638edfff75b6d76a48a98514901

{"decrypted_secret":"0x02f3b9ebfef040947e556b2751e44e8ea7a116f0cb63bd5b65fd010f42e5f593ab11cbddd329dca762bfd2c799315232308a7ec5d1e488e3015d46d2af7ef14f","common_point":"0x18b8eb0ce96d3bb53141be03b7c411b6a5c506329bae2b10f5844134ca14207ef447caeaa4c729b65547807a1f1eaa1eab083e1dfebcb982b5d76f06263f6e6f","decrypt_shadows":["0x04bd1ad33241a2647629003b8093d08ee60f1c2042e5e923572485bc6e0cde1c2ecbe5a5b6fc7ce5732958ae4d2e824b2017cb4f69ff622237c72b62d3b05fa78e26e025507c383d2a9affc502ce86284caed3ed310d232dcd9794b97145ffc58bdc8c96b44a578b4d0ba2fc48610982bc6c3e214c338e27170e628f27670cc4d234bffbfe5388054cd3c710c30b89cc99","0x04add58de09275090905507af45d3367c25ac225769cc669a7e1b8e39368f61574067846148ffd7066339d367a87170609720bf57b1d61f61d19260e18a4ab0da0a1eb5e7f2790d34ac591bafb8f02409038d1ab2ad4233aae6132d64409f5898d8194e453f2d965f044740238d4911618bf2879492b84fbf0635d235cc4211f10e2ea71412cb0c5fe37de42d8e7fefd1b"]}

7. decrypt document using document key shadow:

curl --data-binary '{"jsonrpc": "2.0", "method": "secretstore_shadowDecrypt", "params": ["0x00a329c0648769A73afAc7F9381E08FB43dBEA72", "", "0x02f3b9ebfef040947e556b2751e44e8ea7a116f0cb63bd5b65fd010f42e5f593ab11cbddd329dca762bfd2c799315232308a7ec5d1e488e3015d46d2af7ef14f", "0x18b8eb0ce96d3bb53141be03b7c411b6a5c506329bae2b10f5844134ca14207ef447caeaa4c729b65547807a1f1eaa1eab083e1dfebcb982b5d76f06263f6e6f", ["0x04bd1ad33241a2647629003b8093d08ee60f1c2042e5e923572485bc6e0cde1c2ecbe5a5b6fc7ce5732958ae4d2e824b2017cb4f69ff622237c72b62d3b05fa78e26e025507c383d2a9affc502ce86284caed3ed310d232dcd9794b97145ffc58bdc8c96b44a578b4d0ba2fc48610982bc6c3e214c338e27170e628f27670cc4d234bffbfe5388054cd3c710c30b89cc99","0x04add58de09275090905507af45d3367c25ac225769cc669a7e1b8e39368f61574067846148ffd7066339d367a87170609720bf57b1d61f61d19260e18a4ab0da0a1eb5e7f2790d34ac591bafb8f02409038d1ab2ad4233aae6132d64409f5898d8194e453f2d965f044740238d4911618bf2879492b84fbf0635d235cc4211f10e2ea71412cb0c5fe37de42d8e7fefd1b"], "0xd2e72c288778658a73cee7d7eb6d2b2bcb5fcc3d"], "id":1 }' -H 'content-type: application/json' http://127.0.0.1:8545/

{"jsonrpc":"2.0","result":"0xdeadbeef","id":1}

I'll make a PR in wiki repo after/if this PR will be accepted.