nsrls is a server designed to provide access to the National Software Reference Library (NSRL) hash data set. There are two methods to access the data either running as a single process or using a JSON HTTP API. The HTTP JSON API can be used by the nsrlc (NSRL Client) or directly by other applications or processes.

The nsrls application can perform show data manipulation when importing the data set. It can extract a specific field from a CSV file by using the -s or --csvfield parameters, so if the second field is to be used the use the value 2 for the parameter. If the import file has quotes around the hash data then they can be removed when importing by using the -r or --removequotes parameters.

The HTTP API has two different acess methods; a single hash can be checked using a HTTP GET request or a bulk request can be performed using a HTTP POST request.

The IP local IP address and port that the HTTP server runs on are configured using the config file (nsrls.config). The show_requests option in the config file determines whether the HTTP requests against the server are displayed in the console.

The HTTP API is located by default at the following URL's:

    http://127.0.0.1:8080/single (GET)
    http://127.0.0.1:8080/bulk   (POST)

The single API URL takes a hash value in the URL like so:

    http://127.0.0.1:8080/single/392126E756571EBF112CB1C1CDEDF926

The bulk API uses a HTTP POST request like so, with the hashes each separated by a hash (#) character:

    POST http://127.0.0.1:8080/bulk HTTP/1.1
    Content-Type: application/x-www-form-urlencoded
    Content-Length: 65
    
    392126E756571EBF112CB1C1CDEDF926#8E23576EF5AEF2D5457C8A24BF5F740A

The NSRL client application by default sends up to 1000 hashes per batch.

The HTTP API returns data in the JSON format as shown below:

    {"Hash":"8E23576EF5AEF2D5457C8A24BF5F740A","Exists":true}

The server can be used to perform a single use lookup against a input file using the -m parameter and a value of f (file). The server will import the hash data, process the input file containing multiple hashes and extract the data to an output file.

When in single use mode, the application outputs directly to a file. The output format can be defined by the command line parameters. The options for the output format are:

• i: Outputs only the identified hashes
• u: Outputs only the unidentified hashes
• a: Outputs both the identified and unidentified hashes, along with a status column

• Make sure all of the paths specified in the config file are fully qualified
• Ensure that there is a log directory created, and that the user can write to it

     sudo mkdir /var/log/nsrls
     sudo chown <username> /var/log/nsrls