Asymmetric encryption · RSA

RSA-OAEP File Encryption

Upload a small file, paste a PEM-formatted public key, and generate RSA-OAEP ciphertext entirely in the browser. Ideal for testing key handling or wrapping session keys.

Choose a file

Upload a file

Click to browse or drag & drop files here

RSA-OAEP is best for small blobs or session keys. Large uploads will likely exceed the modulus limit.

Processed output

Encrypted RSA bundles will appear here once processing completes.

Hash algorithm

Generate test keys

Generated keys appear in the PEM editors below so you can experiment end-to-end.

Public key (PEM)

Private key (PEM)

Use the recipient's PEM-formatted public key. RSA-OAEP is best suited for tiny blobs, such as session keys.

Usage notes

This RSA-OAEP page lets you encrypt fixtures or short-lived assets with a recipient’s public key without leaving the browser. The tool automatically handles chunking so you can work with files that exceed RSA’s native block limit, but the equivalent command-line example below shows the direct RSA flow for very small payloads (roughly 214 bytes on a 2048-bit/SHA-256 key). Either way, keep the tab open until processing completes so the browser can package and stream the ciphertext back to you.

Equivalent OpenSSL workflow

Mirror the on-page RSA workflow by running openssl pkeyutl with OAEP padding against a small file:

# Encrypt a small file directly with RSA-OAEP
openssl pkeyutl -encrypt -inkey public.pem -pubin \
  -pkeyopt rsa_padding_mode:oaep -pkeyopt rsa_oaep_md:sha256 \
  -in secret.bin -out secret.bin.rsa

# Optional: base64 for easy transport
base64 secret.bin.rsa > secret.bin.rsa.b64