node-sarif-builder

node-sarif-builder

Introduction

Until today, every SAST tool (not exhaustive list available at https://analysis-tools.dev/) is using its own custom output format.

In order to unify SAST tools output format, more and more tools and services are implementing SARIF format (example)

SARIF logs can be:

• Uploaded to DevOps tools, like Github, Azure DevOps to show issues directly in their web UI
• Visualized in IDEs, like Visual Studio Code, Visual Studio
• Aggregated by multi-language linters, like MegaLinter

Example of linters that can output logs in SARIF format:

• bandit (python)
• checkov (terraform)
• checkstyle (java)
• cfn-lint (AWS CloudFormation)
• codeql (multi-language)
• devskim (security)
• eslint (javascript,typescript,json)
• gitleaks (security)
• ktlint (Kotlin)
• hadolint (Dockerfile)
• MegaLinter (linters orchestrator)
• psalm (php)
• semgrep (multi-language)
• revive (Go)
• tflint (terraform)
• terrascan (terrasform)
• trivy (security)
• and many more...

If you are a maintainer of any javascript/typescript based SAST tool, but also IaC tool, or any type of tool that can return a list of errors with a level of severity, you can either read the whole OASIS Specification, or simply use this library to add SARIF as additional output format, so your tool will be natively compliant with any of SARIF-compliant tools !

Installation

• with npm

npm install node-sarif-builder

• with yarn

yarn add node-sarif-builder

Use

With node-sarif-builder, you can generate complex SARIF format with simple methods

---

• Start by importing module

const { SarifBuilder, SarifRunBuilder, SarifResultBuilder, SarifRuleBuilder } = require("node-sarif-builder");

---

• Create and init SarifBuilder and SarifRunBuilder objects

// SARIF builder
const sarifBuilder = new SarifBuilder();
// SARIF Run builder
const sarifRunBuilder = new SarifRunBuilder().initSimple({
    name: "npm-groovy-lint",                           // Name of your analyzer tool
    url: "https://nvuillam.github.io/npm-groovy-lint/" // Url of your analyzer tool
});

---

• Add all rules that can be found in your results (recommended but optional)

// Add SARIF rules
for (const rule of rules) {                           // rules from your linter in any format
    const sarifRuleBuiler = new SarifRuleBuilder().initSimple({
        ruleId: rule.id,                              // ex: "no-any"
        shortDescriptionText: rule.description,       // ex: "Do not use any in your code !"
        helpUri: rule.docUrl                          // ex: "http://my.linter.com/rules/no-any"
    });
    sarifRunBuilder.addRule(sarifRuleBuiler);
}

---

• For each found issue, create a SarifResultBuilder and add it to the SarifRunBuilder object

// Add results
for (const issue of issues) { // issues from your linter in any format
    const sarifResultBuilder = new SarifResultBuilder();
    const sarifResultInit = {
         // Transcode to a SARIF level:  can be "warning" or "error" or "note"
        level: issue.severity === "info" ? "note" : issue.severity,
        messageText: err.msg,                                     // Ex: "any is forbidden !"
        ruleId: err.rule,                                         // Ex: "no-any"
        fileUri: process.env.SARIF_URI_ABSOLUTE                   // Ex: src/myfile.ts
            ? "file:///" + fileNm.replace(/\\/g, "/")
            : path.relative(process.cwd(), fileNm)
    };
    // When possible, provide location of the issue in the source code
    if (issue.range) {
        sarifResultInit.startLine = issue.range.start.line;        // any integer >= 1 (optional)
        sarifResultInit.startColumn = issue.range.start.character; // any integer >= 1 (optional)
        sarifResultInit.endLine = issue.range.end.line;            // any integer >= 1 (optional)
        sarifResultInit.endColumn = issue.range.end.character;     // any integer >= 1 (optional)
    }
    // Init sarifResultBuilder
    sarifResultBuilder.initSimple(sarifResultInit); 
    // Add result to sarifRunBuilder
    sarifRunBuilder.addResult(sarifResultBuilder);
}

---

• Add run to sarifBuilder then generate JSON SARIF output file

    sarifBuilder.addRun(sarifRunBuilder);
    const sarifJsonString = sarifBuilder.buildSarifJsonString({ indent: false }); // indent:true if you like
    fs.writeFileSync(outputSarifFile,sarifJsonString);
    // const sarifObj = sarifBuilder.buildSarifOutput();                          // You could also just get the Sarif log as an object and not a string

Full example

• Working in npm-groovy-lint

function buildSarifResult(lintResult) {
    // SARIF builder
    const sarifBuilder = new SarifBuilder();
    // SARIF Run builder
    const sarifRunBuilder = new SarifRunBuilder().initSimple({
        name: "npm-groovy-lint",
        url: "https://nvuillam.github.io/npm-groovy-lint/"
    });
    // SARIF rules
    for (const ruleId of Object.keys(lintResult.rules || {})) {
        const rule = lintResult.rules[ruleId];
        const sarifRuleBuiler = new SarifRuleBuilder().initSimple({
            ruleId: ruleId,
            shortDescriptionText: rule.description,
            helpUri: rule.docUrl
        });
        sarifRunBuilder.addRule(sarifRuleBuiler);
    }
    // Add SARIF results (individual errors)
    for (const fileNm of Object.keys(lintResult.files)) {
        const fileErrors = lintResult.files[fileNm].errors;
        for (const err of fileErrors) {
            const sarifResultBuilder = new SarifResultBuilder();
            const sarifResultInit = {
                level: err.severity === "info" ? "note" : err.severity, // Other values can be "warning" or "error"
                messageText: err.msg,
                ruleId: err.rule,
                fileUri: process.env.SARIF_URI_ABSOLUTE
                    ? "file:///" + fileNm.replace(/\\/g, "/")
                    : path.relative(process.cwd(), fileNm)
            };
            if (err.range) {
                sarifResultInit.startLine = fixLine(err.range.start.line);
                sarifResultInit.startColumn = fixCol(err.range.start.character);
                sarifResultInit.endLine = fixLine(err.range.end.line);
                sarifResultInit.endColumn = fixCol(err.range.end.character);
            }
            sarifResultBuilder.initSimple(sarifResultInit);
            sarifRunBuilder.addResult(sarifResultBuilder);
        }
    }
    sarifBuilder.addRun(sarifRunBuilder);
    return sarifBuilder.buildSarifJsonString({ indent: false });
}

function fixLine(val) {
    if (val === null) {
        return undefined;
    }
    return val === 0 ? 1 : val;
}

function fixCol(val) {
    if (val === null) {
        return undefined;
    }
    return val === 0 ? 1 : val + 1;
}