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User Administration Transaction

We can create, update, and delete users of the Orion cluster using the user administration transaction. By issuing a POST /user/tx {txPayload}, we can carry out user administration.

In this document, we present examples for:

  1. Adding users
  2. Updating users
  3. Deleting users

Note that all user administration transactions must be submitted by the admin.

caution

It is recommended to start a fresh Orion server for executing these examples. Otherwise, you must carefully change the block number specified as part of the version in the read-set of the transaction payload. This document explains this issue in detail. Once a fresh Orion server is started after removing the ledger directory, create two databases named db1 and db2. Refer here for an example cURL command for creating databases named db1 and db2.

1) Adding Users

1.1) Adding users alice and bob

When the cluster is started for the first time, it contains only the admin user specified in the config.yml. This admin user can add any other user to the cluster. In the below example, the admin user is adding two users named alice and bob with certain privileges. The crypto materials associated with alice and bob can be found in /deployment/sample/crypto.

curl \
    -H "Content-Type: application/json" \
    -H "TxTimeout: 10s" \
    -X POST http://127.0.0.1:6001/user/tx \
    --data '{
        "payload": {
            "user_id": "admin",
            "tx_id": "7b6d6414-9b58-45d0-9723-1f31712add01",
            "user_writes": [
                {
                    "user": {
                        "id": "alice",
                        "certificate": "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",
                        "privilege": {
                            "db_permission": {
                                "db1": 0,
                                "db2": 1
                            }
                        }
                    }
                },
                {
                    "user": {
                        "id": "bob",
                        "certificate": "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",
                        "privilege": {
                            "db_permission": {
                                "db1": 0,
                                "db2": 0
                            }
                        }
                    },
                    "acl": {
                        "read_users": {
                            "admin": true
                        }
                    }
                }
          ]
    },
    "signature": "MEUCIHLCSwMzwxmnRfB6s1eON2bMfgDwFvxoSqaZ6ACXcbn0AiEA8KhjY56tSRg9Hh9UGchhGybTV2rWl1NcsAPLyW71Vu8="
}'

The user alice has read-only access on the database db1 and read-write access on the database db2. These privileges are defined under db_permission. The "db1":0 denotes that the user has read-only privilege on database db1 while "db2":1 denotes that the user has read-write privilege on database db2. In other words, 0 denotes read-only privilege and 1 denotes read-write privilege. As the access control is not defined for the user, any user can read the credential and privilege of alice, but only the admin user can modify the properties of the alice user.

The user bob has read-only privilege on the database db1 and db2. Furthermore, only the admin user can read the credential and privilege of bob.

Moreover, the user bob cannot be modified as the "read_write_users" section is left empty. This means no user has permission to write to user bob.

The signature for the above transaction payload is computed by executing the following command:

/bin/signer -privatekey=deployment/sample/crypto/admin/admin.key \
    -data='{"user_id":"admin","tx_id":"7b6d6414-9b58-45d0-9723-1f31712add01","user_writes":[{"user":{"id":"alice","certificate":"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","privilege":{"db_permission":{"db1":0,"db2":1}}}},{"user":{"id":"bob","certificate":"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","privilege":{"db_permission":{"db1":0,"db2":0}}},"acl":{"read_users":{"admin":true}}}]}'

Output

MEYCIQCBA3pw0C1wgJMjOYDnhr5C0QeaSfradKdCFVCSWwXFdwIhAP80o5VZY2VBp4Lr5+4lG9hNuFL3Da53LXP9N7uAyNfn

Upon a successful commit of the above transaction, the submitter of the transaction receives the following transaction receipt:

{
  "response": {
    "header": {
      "node_id": "bdb-node-1"
    },
    "receipt": {
      "header": {
        "base_header": {
          "number": 4,
          "previous_base_header_hash": "gc2T0zndfbSAsw9J/67Pzjk1IAVBjE9Ih93qjwYro1k=",
          "last_committed_block_hash": "eUxPHg5TFfTU3CRmYISAHDPI6DRHxbiQccaeytl4WBk=",
          "last_committed_block_num": 3
        },
        "skipchain_hashes": [
          "eUxPHg5TFfTU3CRmYISAHDPI6DRHxbiQccaeytl4WBk="
        ],
        "tx_merkle_tree_root_hash": "5nu+kdyEzZOIcy6qDDCls+GSRKK0aRdp6lbZJBUnZJQ=",
        "state_merkle_tree_root_hash": "milzir+V4vvodu+e2BPv/j5XKlh6SfJmy3cRsBlJttw=",
        "validation_info": [
          {}
        ]
      }
    }
  },
  "signature": "MEYCIQDxAuuukwThUp5ytZikobfQ0iBLMYLI6TRoK7322eNuqAIhAI5SkomPRnxH0K3iF6xqNFJUCgTHVuyelFgb9u1B4a8D"
}

1.2) Check the existence of alice

Once the transaction gets committed, we can query the user information as follows:

Let's fetch the user alice.

./bin/signer -privatekey=deployment/sample/crypto/admin/admin.key \
    -data='{"user_id":"admin","target_user_id":"alice"}'

Output

MEYCIQDioRVRhtdaLEjFSeCPqrVCCtdwq+hvy7Y+i3cXaqhZ3wIhAK/gmdftR4x0KF3w8V86hSYXPehf/rlO8QcSnU9sFnvC
curl \
     -H "Content-Type: application/json" \
     -H "UserID: admin" \
     -H "Signature: MEYCIQDioRVRhtdaLEjFSeCPqrVCCtdwq+hvy7Y+i3cXaqhZ3wIhAK/gmdftR4x0KF3w8V86hSYXPehf/rlO8QcSnU9sFnvC" \
     -X GET http://127.0.0.1:6001/user/alice | jq .

Output

{
  "response": {
    "header": {
      "node_id": "bdb-node-1"
    },
    "user": {
      "id": "alice",
      "certificate": "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",
      "privilege": {
        "db_permission": {
          "db1": 0,
          "db2": 1
        }
      }
    },
    "metadata": {
      "version": {
        "block_num": 4
      }
    }
  },
  "signature": "MEYCIQDY3OV2xzqe22X7PzO6UIeDY6t3Qn7DcMk5z/G8SGshvQIhAN8DnATYxIQyoj3jPufgoHuOJDTCnvpEj4kF0WtLHGRq"
}

1.3) Check the existence of bob

Let's fetch the user bob.

./bin/signer -privatekey=deployment/sample/crypto/admin/admin.key -data='{"user_id":"admin","target_user_id":"bob"}'

Output

MEQCICeSXCL6Atyf3hgbd0XtC4L6HT0qXTxLyvUslAv5pYMqAiAxirniW1NW1lS2pUT8G0XeWYUhUKCjjWlq6WTuGAOxEQ==
curl \
     -H "Content-Type: application/json" \
     -H "UserID: admin" \
     -H "Signature: MEQCICeSXCL6Atyf3hgbd0XtC4L6HT0qXTxLyvUslAv5pYMqAiAxirniW1NW1lS2pUT8G0XeWYUhUKCjjWlq6WTuGAOxEQ==" \
     -X GET http://127.0.0.1:6001/user/bob | jq .

Output

{
  "response": {
    "header": {
      "node_id": "bdb-node-1"
    },
    "user": {
      "id": "bob",
      "certificate": "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",
      "privilege": {
        "db_permission": {
          "db1": 0
        }
      }
    },
    "metadata": {
      "version": {
        "block_num": 4
      },
      "access_control": {
        "read_users": {
          "admin": true
        }
      }
    }
  },
  "signature": "MEUCIEuGxnvi2nwzJ1AZdUBhFBkOkv26kOupKZbCgt03S85zAiEAwiyE1xJEl0F9Kx/CyylKP6dogKrcNRiVXMJcqknrOE4="
}

2) Updating a User

2.1) Remove all privileges of alice

Let's remove all privileges given to alice. To do that, we can execute the following steps:

  1. Fetch the current committed information of the user alice.
  2. Remove the privilege section and construct the transaction payload.
  3. Add the digital signature on the new transaction payload.
  4. Submit the transaction payload by issuing a POST /user/tx {txPayload}

Though we can update multiple users within a transaction, for the sake of simplicity in this example, we are only updating a single user, alice.

Important for Successful Execution of this Example: The user_reads section in the below transaction payload contains a version of the read information. If this does not match the committed version, the transaction would be invalidated. This is useful because the alice user can be updated by any other admin between step 1 and 2 listed above. To ensure serializability isolation, we must pass the read version. In our example, we use the version present in this returned result. To be specific, we can see the version in the metadata section of the query result as shown below:

    "metadata": {
      "version": {
        "block_num": 3
      }
    }

This version might be different for you. Hence, provide the appropriate version number in the transaction payload and compute the digital signature.

The user_reads section states you should commit this transaction only if the users specified in the user_reads list are at a specified version as per the current committed state. Otherwise, invalidate the transaction and do not apply the changes requested by the transaction.

Note that it is not necessary to pass the version in user_reads. If the user_reads is left out, the write would be considered as a blind write.

Within a single transaction, we can update more than a single user. For the sake of simplicity, the example updates a single user only.

 curl \
   -H "Content-Type: application/json" \
   -H "TxTimeout: 2s" \
   -X POST http://127.0.0.1:6001/user/tx \
   --data '{
    "payload": {
        "user_id": "admin",
        "tx_id": "1b6d6414-9b58-45d0-9723-1f31712add02",
        "user_reads": [
            {
                "user_id": "alice",
                "version": {
                    "block_num": 3
                }
            }
        ],
        "user_writes": [
            {
                "user": {
                    "id": "alice",
                    "certificate": "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"
                }
            }
        ]
    },
    "signature": "MEUCIDTrlQ8fKu2ZeVWincE8RzWd/Y/MWjZGHEu37EckcTFnAiEA/kmKAOc2LK2GHFIA1wU+9/oog0Nqj3GLYPjSFGCeOOk="
}'

In the above transaction, we removed the privilege section from the user information (compare against the query result provided here). The signature is computed using the following command:

./bin/signer -privatekey=deployment/sample/crypto/admin/admin.key -data='{"user_id":"admin","tx_id":"1b6d6414-9b58-45d0-9723-1f31712add02","user_reads":[{"user_id":"alice","version":{"block_num":3}}],"user_writes":[{"user":{"id":"alice","certificate":"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"}}]}'

Output

MEQCIGy62qM0ZGdCd5FsCvgKJ0wVQi/uL5Gy0IXhevsNxUaeAiA2pOfu5vVuQ9MJnYakFyw8HcgHR6AA3NqyxF8p3E6exw==

2.2) Check the privilege of alice

Once the transaction get committed, we can query the user information as follows to check whether all privileges given to the alice user have been removed:

curl \
     -H "Content-Type: application/json" \
     -H "UserID: admin" \
     -H "Signature: MEYCIQDioRVRhtdaLEjFSeCPqrVCCtdwq+hvy7Y+i3cXaqhZ3wIhAK/gmdftR4x0KF3w8V86hSYXPehf/rlO8QcSnU9sFnvC" \
     -X GET http://127.0.0.1:6001/user/alice | jq .

Output

{
  "response": {
    "header": {
      "node_id": "bdb-node-1"
    },
    "user": {
      "id": "alice",
      "certificate": "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",
    },
    "metadata": {
      "version": {
        "block_num": 5
      }
    }
  },
  "signature": "MEYCIQDY3OV2xzqe22X7PzO6UIeDY6t3Qn7DcMk5z/G8SGshvQIhAN8DnATYxIQyoj3jPufgoHuOJDTCnvpEj4kF0WtLHGRq"
}

As we can see, the privilege section is no longer present and the version has been increased too.

3) Deleting a User

3.1) Delete the user alice

Let's delete alice from the cluster. In order to do that, we execute the following steps:

  1. Fetch the current committed information of the alice user to get the committed version.
  2. Add the committed version to the user_reads.
  3. Add the alice user to the user_deletes.
  4. Compute and add the digital signature to the transaction payload.
  5. Submit the transaction payload by issuing a POST /user/tx {txPayload}.

The example uses "block_num": 4 as the version. While executing this example, query the user alice and use the version provided in the output of that query. Refer here for the query result of alice after being updated. In the query result, we have

    "metadata": {
      "version": {
        "block_num": 4
      }
    }

Hence, this example uses "block_num": 4 as the version.

Note that it is not necessary to pass the version in user_reads. If the user_reads is left out, the delete would be considered as a blind delete. For blind deletes, steps 1 and 2 are not needed.

Within a single transaction, we can delete more than a single user. For the sake of simplicity, the example deletes a single user only.

 curl \
   -H "Content-Type: application/json" \
   -H "TxTimeout: 2s" \
   -X POST http://127.0.0.1:6001/user/tx \
   --data '{
    "payload": {
        "user_id": "admin",
        "tx_id": "1b6d6414-9b58-45d0-9723-1f31712add04",
        "user_reads": [
            {
                "user_id": "alice",
                "version": {
                    "block_num": 4
                }
            }
        ],
        "user_deletes": [
            {
                "user_id": "alice"
            }
        ]
    },
    "signature": "MEQCID1O2vmSxgzJT8KNMws/ckV1oIf1R4oml6aWeZNzvjI9AiAphdfNAn+VKCJPPh+d0oW4/MH+cXy4xwQXXU5FQ8LpMQ=="
}'

The section user_deletes is an array and we can pass many users in it if we want, and all will be deleted if they exist. The signature on the payload is computed using the following command:

./bin/signer -privatekey=deployment/sample/crypto/admin/admin.key -data='{"user_id":"admin","tx_id":"1b6d6414-9b58-45d0-9723-1f31712add04","user_reads":[{"user_id":"alice","version":{"block_num":4}}],"user_deletes":[{"user_id":"alice"}]}'

Output

MEQCID1O2vmSxgzJT8KNMws/ckV1oIf1R4oml6aWeZNzvjI9AiAphdfNAn+VKCJPPh+d0oW4/MH+cXy4xwQXXU5FQ8LpMQ==

Once the transaction is validated and committed, the submitter of the transaction receives the following transaction receipt:

{
  "response": {
    "header": {
      "node_id": "bdb-node-1"
    },
    "receipt": {
      "header": {
        "base_header": {
          "number": 7,
          "previous_base_header_hash": "+KCuJm2x9LzsIBFmAVkW6w/Hmw7IRjl52aZjNI7juR8=",
          "last_committed_block_hash": "7nEaUCRBiGvmrhbhl7tzupb0K/KjGdS/SSJtCLjvsjA=",
          "last_committed_block_num": 6
        },
        "skipchain_hashes": [
          "7nEaUCRBiGvmrhbhl7tzupb0K/KjGdS/SSJtCLjvsjA=",
          "IHP38VOoGoVHAHROXPZJ8ZWG3pZ6rmqQYovVzm5i7rw="
        ],
        "tx_merkle_tree_root_hash": "iz84iY89BolcBkVD8okAAqg5duGT/+eivcTO4OcpnNM=",
        "state_merkle_tree_root_hash": "tAb0KTsd9JgCQ1YZMwYLs2O3wpo0ynA7h22B8pKzBC0=",
        "validation_info": [
          {}
        ]
     }
    }
  },
  "signature": "MEUCIGWLKxgnxwlznZyBbKbpiFcnbUv32CbkBaFitOxEWnSMAiEAqcNh9pswgvF7f1leWrteozij2zSlG78gcfP5+eAfHhA="
}

3.2) Check the non-existence of the user alice

If we query the user, the response does not contain any details associated with the user.

curl \
     -H "Content-Type: application/json" \
     -H "UserID: admin" \
     -H "Signature: MEYCIQDioRVRhtdaLEjFSeCPqrVCCtdwq+hvy7Y+i3cXaqhZ3wIhAK/gmdftR4x0KF3w8V86hSYXPehf/rlO8QcSnU9sFnvC" \
     -X GET http://127.0.0.1:6001/user/alice | jq .

Output

{
  "response": {
    "header": {
      "node_id": "bdb-node-1"
    }
  },
  "signature": "MEUCIDV6UgjPLtM5c+WqQ+Ue5xcKe/w85nAdwwRl7qPqJByVAiEA4RTqXa8Xf8S+O8YPRpFgIHzOCH5jOHkL2jMmLG7Zdpw="
}