dotnet/runtime · critical · Error

Using node without crypto support. To enable current operati

Error message

Using node without crypto support. To enable current operation, either provide polyfill for 'globalThis.crypto.getRandomValues' or enable 'node:crypto' module.

What it means

initPolyfillsEarly() in Node detects that globalThis.crypto.getRandomValues is missing and that dynamic import('node:crypto') failed. It then installs a getRandomValues stub that throws this exact message when called. So the error fires later, at the first crypto use, not at polyfill install time. Node 18+ has webcrypto built-in; older or stripped Node builds may not.

Source

Thrown at src/native/libs/Common/JavaScript/loader/polyfills.ts:53

        }
    }
    if (ENVIRONMENT_IS_NODE) {
        if (!globalThis.crypto) {
            globalThis.crypto = <any>{};
        }
        if (!globalThis.crypto.getRandomValues) {
            let nodeCrypto: any = undefined;
            try {
                // eslint-disable-next-line @typescript-eslint/ban-ts-comment
                // @ts-ignore:
                nodeCrypto = await import(/*! webpackIgnore: true */"node:crypto");
            } catch (err: any) {
                // Noop, error throwing polyfill provided bellow
            }

            if (!nodeCrypto) {
                globalThis.crypto.getRandomValues = () => {
                    throw new Error("Using node without crypto support. To enable current operation, either provide polyfill for 'globalThis.crypto.getRandomValues' or enable 'node:crypto' module.");
                };
            } else if (nodeCrypto.webcrypto) {
                globalThis.crypto = nodeCrypto.webcrypto;
            } else if (nodeCrypto.randomBytes) {
                const getRandomValues = (buffer: Uint8Array) => {
                    if (buffer) {
                        buffer.set(nodeCrypto.randomBytes(buffer.length));
                    }
                };
                globalThis.crypto.getRandomValues = getRandomValues as any;
            }
        }
        if (!globalThis.performance) {
            // eslint-disable-next-line @typescript-eslint/ban-ts-comment
            // @ts-ignore:
            globalThis.performance = (await import(/*! webpackIgnore: true */"perf_hooks")).performance;
        }
    }

View on GitHub (pinned to 290d5ab72c)

Solutions

1. Ensure node:crypto is resolvable: configure bundlers with { externals: ['node:crypto'] } or target:'node'.
2. Upgrade to Node 18+ where globalThis.crypto.webcrypto is available natively.
3. Provide a polyfill before bootstrapping: globalThis.crypto.getRandomValues = require('crypto').randomFillSync, or use the 'crypto' package's webcrypto.
4. If you cannot enable node:crypto, install a custom getRandomValues backed by any secure RNG available in your host.

Example fix

// before
const dotnet = await dotnet.create(); // throws inside runtime when crypto used

// after — polyfill before create
const { webcrypto } = require('node:crypto');
globalThis.crypto = webcrypto;
const dotnet = await dotnet.create();

if (typeof globalThis.crypto?.getRandomValues !== 'function') {
  try { await import('node:crypto'); }
  catch { throw new Error('node:crypto unavailable — polyfill globalThis.crypto.getRandomValues before boot'); }
}

function hasSecureRandom(g: any): g is { crypto: { getRandomValues: (b: Uint8Array) => Uint8Array } } {
  return typeof g?.crypto?.getRandomValues === 'function';
}

When it happens

Trigger: Running under Node.js where node:crypto is unavailable (custom Node build with crypto disabled, a bundler that stubbed out node:crypto, a sandboxed runtime), and the .NET runtime then invokes crypto.getRandomValues for GUID/random generation.

Common situations: Bundling the loader with webpack/rollup without marking node:crypto as external; running in a restricted sandbox (e.g. some serverless runtimes); very old Node (<15) without webcrypto; an environment that deleted globalThis.crypto before startup.

Related errors

• No fetch implementation available
• Please install `node-fetch` and `node-abort-controller` npm
• NodeJS at '${process.execPath}' has too low version '${proce
• NotImplementedException
• No fetch implementation available

AI-assisted analysis of dotnet/runtime@290d5ab72c (2026-08-06). Data as JSON: /api/errors/3780686cde33acb2. Report an issue: GitHub.