## Initializing the signer First, initialize the master seed. ```text #./signer init WARNING! The signer is alpha software, and not yet publically released. This software has _not_ been audited, and there are no guarantees about the workings of this software. It may contain severe flaws. You should not use this software unless you agree to take full responsibility for doing so, and know what you are doing. TLDR; THIS IS NOT PRODUCTION-READY SOFTWARE! Enter 'ok' to proceed: >ok A master seed has been generated into /home/martin/.signer/secrets.dat This is required to be able to store credentials, such as : * Passwords for keystores (used by rule engine) * Storage for javascript rules * Hash of rule-file You should treat that file with utmost secrecy, and make a backup of it. NOTE: This file does not contain your accounts. Those need to be backed up separately! ``` (for readability purposes, we'll remove the WARNING printout in the rest of this document) ## Creating rules Now, you can create a rule-file. ```javascript function ApproveListing(){ return "Approve" } ``` Get the `sha256` hash.... ```text #sha256sum rules.js 6c21d1737429d6d4f2e55146da0797782f3c0a0355227f19d702df377c165d72 rules.js ``` ...And then `attest` the file: ```text #./signer attest 6c21d1737429d6d4f2e55146da0797782f3c0a0355227f19d702df377c165d72 INFO [02-21|12:14:38] Ruleset attestation updated sha256=6c21d1737429d6d4f2e55146da0797782f3c0a0355227f19d702df377c165d72 ``` At this point, we then start the signer with the rule-file: ```text #./signer --rules rules.js INFO [02-21|12:15:18] Using CLI as UI-channel INFO [02-21|12:15:18] Loaded 4byte db signatures=5509 file=./4byte.json INFO [02-21|12:15:18] Could not load rulefile, rules not enabled file=rulefile DEBUG[02-21|12:15:18] FS scan times list=35.335µs set=5.536µs diff=5.073µs DEBUG[02-21|12:15:18] Ledger support enabled DEBUG[02-21|12:15:18] Trezor support enabled INFO [02-21|12:15:18] Audit logs configured file=audit.log INFO [02-21|12:15:18] HTTP endpoint opened url=http://localhost:8550 ------- Signer info ------- * extapi_http : http://localhost:8550 * extapi_ipc : * extapi_version : 2.0.0 * intapi_version : 1.2.0 ``` Any list-requests will now be auto-approved by our rule-file. ## Under the hood While doing the operations above, these files have been created: ```text #ls -laR ~/.signer/ /home/martin/.signer/: total 16 drwx------ 3 martin martin 4096 feb 21 12:14 . drwxr-xr-x 71 martin martin 4096 feb 21 12:12 .. drwx------ 2 martin martin 4096 feb 21 12:14 43f73718397aa54d1b22 -rwx------ 1 martin martin 256 feb 21 12:12 secrets.dat /home/martin/.signer/43f73718397aa54d1b22: total 12 drwx------ 2 martin martin 4096 feb 21 12:14 . drwx------ 3 martin martin 4096 feb 21 12:14 .. -rw------- 1 martin martin 159 feb 21 12:14 config.json #cat /home/martin/.signer/43f73718397aa54d1b22/config.json {"ruleset_sha256":{"iv":"6v4W4tfJxj3zZFbl","c":"6dt5RTDiTq93yh1qDEjpsat/tsKG7cb+vr3sza26IPL2fvsQ6ZoqFx++CPUa8yy6fD9Bbq41L01ehkKHTG3pOAeqTW6zc/+t0wv3AB6xPmU="}} ``` In `~/.signer`, the `secrets.dat` file was created, containing the `master_seed`. The `master_seed` was then used to derive a few other things: - `vault_location` : in this case `43f73718397aa54d1b22` . - Thus, if you use a different `master_seed`, another `vault_location` will be used that does not conflict with each other. - Example: `signer --signersecret /path/to/afile ...` - `config.json` which is the encrypted key/value storage for configuration data, containing the key `ruleset_sha256`. ## Adding credentials In order to make more useful rules; sign transactions, the signer needs access to the passwords needed to unlock keystores. ```text #./signer addpw 0x694267f14675d7e1b9494fd8d72fefe1755710fa test INFO [02-21|13:43:21] Credential store updated key=0x694267f14675d7e1b9494fd8d72fefe1755710fa ``` ## More advanced rules Now let's update the rules to make use of credentials ```javascript function ApproveListing(){ return "Approve" } function ApproveSignData(r){ if( r.address.toLowerCase() == "0x694267f14675d7e1b9494fd8d72fefe1755710fa") { if(r.message.indexOf("bazonk") >= 0){ return "Approve" } return "Reject" } // Otherwise goes to manual processing } ``` In this example, * any requests to sign data with the account `0x694...` will be * auto-approved if the message contains with `bazonk`, * and auto-rejected if it does not. * Any other signing-requests will be passed along for manual approve/reject. ..attest the new file ```text #sha256sum rules.js 2a0cb661dacfc804b6e95d935d813fd17c0997a7170e4092ffbc34ca976acd9f rules.js #./signer attest 2a0cb661dacfc804b6e95d935d813fd17c0997a7170e4092ffbc34ca976acd9f INFO [02-21|14:36:30] Ruleset attestation updated sha256=2a0cb661dacfc804b6e95d935d813fd17c0997a7170e4092ffbc34ca976acd9f ``` And start the signer: ``` #./signer --rules rules.js --rpc INFO [02-21|14:41:56] Using CLI as UI-channel INFO [02-21|14:41:56] Loaded 4byte db signatures=5509 file=./4byte.json INFO [02-21|14:41:56] Rule engine configured file=rules.js DEBUG[02-21|14:41:56] FS scan times list=34.607µs set=4.509µs diff=4.87µs DEBUG[02-21|14:41:56] Ledger support enabled DEBUG[02-21|14:41:56] Trezor support enabled INFO [02-21|14:41:56] Audit logs configured file=audit.log INFO [02-21|14:41:56] HTTP endpoint opened url=http://localhost:8550 ------- Signer info ------- * extapi_version : 2.0.0 * intapi_version : 1.2.0 * extapi_http : http://localhost:8550 * extapi_ipc : INFO [02-21|14:41:56] error occurred during execution error="ReferenceError: 'OnSignerStartup' is not defined" ``` And then test signing, once with `bazonk` and once without: ``` #curl -H "Content-Type: application/json" -X POST --data "{\"jsonrpc\":\"2.0\",\"method\":\"account_sign\",\"params\":[\"0x694267f14675d7e1b9494fd8d72fefe1755710fa\",\"0x$(xxd -pu <<< ' bazonk baz gaz')\"],\"id\":67}" http://localhost:8550/ {"jsonrpc":"2.0","id":67,"result":"0x93e6161840c3ae1efc26dc68dedab6e8fc233bb3fefa1b4645dbf6609b93dace160572ea4ab33240256bb6d3dadb60dcd9c515d6374d3cf614ee897408d41d541c"} #curl -H "Content-Type: application/json" -X POST --data "{\"jsonrpc\":\"2.0\",\"method\":\"account_sign\",\"params\":[\"0x694267f14675d7e1b9494fd8d72fefe1755710fa\",\"0x$(xxd -pu <<< ' bonk baz gaz')\"],\"id\":67}" http://localhost:8550/ {"jsonrpc":"2.0","id":67,"error":{"code":-32000,"message":"Request denied"}} ``` Meanwhile, in the signer output: ```text INFO [02-21|14:42:41] Op approved INFO [02-21|14:42:56] Op rejected ``` The signer also stores all traffic over the external API in a log file. The last 4 lines shows the two requests and their responses: ```text #tail -n 4 audit.log t=2018-02-21T14:42:41+0100 lvl=info msg=Sign api=signer type=request metadata="{\"remote\":\"127.0.0.1:49706\",\"local\":\"localhost:8550\",\"scheme\":\"HTTP/1.1\"}" addr="0x694267f14675d7e1b9494fd8d72fefe1755710fa [chksum INVALID]" data=202062617a6f6e6b2062617a2067617a0a t=2018-02-21T14:42:42+0100 lvl=info msg=Sign api=signer type=response data=93e6161840c3ae1efc26dc68dedab6e8fc233bb3fefa1b4645dbf6609b93dace160572ea4ab33240256bb6d3dadb60dcd9c515d6374d3cf614ee897408d41d541c error=nil t=2018-02-21T14:42:56+0100 lvl=info msg=Sign api=signer type=request metadata="{\"remote\":\"127.0.0.1:49708\",\"local\":\"localhost:8550\",\"scheme\":\"HTTP/1.1\"}" addr="0x694267f14675d7e1b9494fd8d72fefe1755710fa [chksum INVALID]" data=2020626f6e6b2062617a2067617a0a t=2018-02-21T14:42:56+0100 lvl=info msg=Sign api=signer type=response data= error="Request denied" ```