🚧 EXPERIMENTAL 🚧

IAM policy generation from application code

npm i -g iamfast

You can also install iamfast as a Visual Studio Code extension.

Execute iamfast with the first argument being the file or directory (currently slow, not yet recommended) to be scanned.

iamfast yourfile.js

iamfast supports the following programming languages:

• JavaScript (v2 SDK)
• Python 3 (Boto3 SDK)
• Go (v1 SDK)
• Java (v2 SDK)
• C/C++ (v1 SDK)
• Amazon States Language / Step Functions State Machines (JSON)

--format <type>: Sets the format of the output, currently supporting json (default), yaml, hcl and sam

> cat tests/js/test1.js
// Load the AWS SDK for Node.js
var AWS = require('aws-sdk');
// Set the region 
AWS.config.update({region: 'us-east-1'});

// Create the DynamoDB service object
var ddb = new AWS.DynamoDB({apiVersion: '2012-08-10'});

var params = {
  TableName: 'CUSTOMER_LIST',
  Item: {
    'CUSTOMER_ID' : {N: '001'},
    'CUSTOMER_NAME' : {S: 'Richard Roe'}
  }
};

// Call DynamoDB to add the item to the table
ddb.putItem(params, function(err, data) {
  if (err) {
    console.log("Error", err);
  } else {
    console.log("Success", data);
  }
});

> iamfast tests/js/test1.js
{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": "dynamodb:PutItem",
            "Resource": [
                "arn:aws:dynamodb:us-east-1:123456789012:table/CUSTOMER_LIST"
            ]
        }
    ]
}

To run tests:

npm test

• src/AWSParser.js - Generates token streams and calls walkers for individual languages, also maps resource instantiations
• src/EnvironmentVariable.js - Dedicated class for environment variable type
• src/IAMFast.js - Generates the actual policies / outputs by referencing the action map and calling AWSParser.js functions
• src/main.js - CLI setup and entrypoint for non-module use
• src/lib/<Language>ScopeListener.js - Custom listener hooks to track variable and function declarations (1st pass)
• src/lib/<Language>AWSListener.js - Custom listener hooks to track client calls etc. (2nd pass)
• src/lib/<Language>Parser.js - Auto-generated (ANTLR) language parser logic
• grammars/<Language>Parser.js - Individual ANTLR language definitions, used to generate src/lib/<Language>Parser.js

• Gather test cases
• Environment variable referencing in SAM output
• Online tool for quick evaluation
• GitHub app
• Variable redeclaration

• Lexing & parsing with ANTLR
• Custom tree walker
• Identify standard SDK definitions
• Identify SDK region
• Identify advanced SDK definitions
• Identify client instantiations
• Identify client calls
• Identify client calls with advanced method chaining
• Identify resource instantiations (AWS.S3.ManagedUpload, AWS.DynamoDB.DocumentClient)
• Identify resource calls
• Interpret call arguments (top-level, static)
• Interpret call arguments (top-level, variable)
• Interpret call arguments (deep, static)
• Interpret call arguments (deep, variable)
• Track literal variables
• Track object variables
• Track environmental variables
• Understand scope (build the call stack)
• Cross-file relationships
• Understand entrypoints and code accessibility
• Performance tuning

• Lexing & parsing with ANTLR
• Custom tree walker
• Identify standard SDK definitions
• Identify SDK region
• Identify advanced SDK definitions ("as x" etc.)
• Identify client instantiations
• Identify client calls
• Identify client calls with advanced method chaining
• Identify resource instantiations
• Identify resource calls
• Interpret call arguments (top-level, static)
• Interpret call arguments (top-level, variable)
• Interpret call arguments (deep, static)
• Interpret call arguments (deep, variable)
• Track literal variables
• Track object variables
• Track environmental variables
• Understand scope (build the call stack)
• Cross-file relationships
• Understand entrypoints and code accessibility
• Performance tuning

• Lexing & parsing with ANTLR
• Custom tree walker
• Identify standard SDK definitions
• Identify SDK region
• Identify advanced SDK definitions
• Identify client instantiations
• Identify client calls
• Identify client calls with advanced method chaining
• Interpret call arguments (top-level, static)
• Interpret call arguments (top-level, variable)
• Interpret call arguments (deep, static)
• Interpret call arguments (deep, variable)
• Track literal variables
• Track object variables
• Track environmental variables
• Understand scope (build the call stack)
• Cross-file relationships
• Understand entrypoints and code accessibility
• Performance tuning

• Lexing & parsing with ANTLR
• Custom tree walker
• Identify standard SDK definitions
• Identify SDK region
• Identify advanced SDK definitions
• Identify client instantiations
• Identify client calls
• Identify client calls with advanced method chaining
• Interpret call arguments (top-level, static)
• Interpret call arguments (top-level, variable)
• Interpret call arguments (deep, static)
• Interpret call arguments (deep, variable)
• Track literal variables
• Track object variables
• Track environmental variables
• Understand scope (build the call stack)
• Cross-file relationships
• Understand entrypoints and code accessibility
• Performance tuning

• Lexing & parsing with ANTLR
• Custom tree walker
• Identify standard SDK definitions
• Identify SDK region
• Identify advanced SDK definitions
• Identify client instantiations
• Identify client calls
• Identify client calls with advanced method chaining
• Interpret call arguments (top-level, static)
• Interpret call arguments (top-level, variable)
• Interpret call arguments (deep, static)
• Interpret call arguments (deep, variable)
• Track literal variables
• Track object variables
• Track environmental variables
• Understand scope (build the call stack)
• Cross-file relationships
• Understand entrypoints and code accessibility
• Performance tuning