At wolfSSL we are always trying to make the security developer’s job easier. We’ve found that a common problem facing our customers is the need to convert between PEM and DER.
PEM is a Base64, ASCII encoding that is used for X.509 certificates, certificate requests and cryptographic keys. DER is a binary encoding and is much more compact.
CAs commonly supply X5.09 certificates in PEM format. For embedded applications, a DER formatted version is stored for use instead. The new PEM example makes this easy.
The example is compiled as part of the standard distribution, assuming the required features are built into wolfSSL. To convert a PEM file to DER, use the following command line:
./examples/pem/pem -in <file.pem> -out <file.der>
Another common customer situation is that they have an encrypted private key and want to get the unencrypted key as DER. To decrypt a PEM encoded private key:
./examples/pem/pem -in <enckey.pem> —pass <password> -out <key.der>
On the other hand, you may want to encrypt a private key before putting in a public place. To encrypt a DER encode private key into PEM:
./examples/pem/pem -in <key.der> —pass <password> -out <enckey.pem>
There are a number of options you can pass in to choose the algorithms you want to use.
If you have any questions or run into any issues, contact us at facts@wolfssl.com, or call us at +1 425 245 8247.