Create CSR in Java with DER format

Question

I need to convert a CSR file in PEM encoding to a DER encoded file.

This is the openssl command for that but I need to do it in Java without BouncyCastle.

openssl req -inform pem -outform der -in file_one.csr -out file_two.der

What is the equivalent code for this in Java?

Not a duplicate. – President James K. Polk Jan 02 '18 at 00:05 — President James K. Polk, Jan 02 '18 at 00:05

score 1 · Answer 1 · answered Jan 01 '18 at 12:28

1

The PEM is the Base64 encoding of the binary DER with header an trailer lines. Just ignore the header and trailer and use Base64.Decoder on the content and there you are.

answered Jan 01 '18 at 12:28

Jonathan Rosenne

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I would recommend to parse instead of ignore header and trailer. Otherwise you won't recognize special cases like multiple certificates in one PEM files (not uncommon). – Robert Jan 01 '18 at 13:07
So when we use Base64 decoder, it is DER format? – Shadow May 12 '23 at 04:29
Unless it contains multiple certificates. – Jonathan Rosenne May 13 '23 at 15:35

Create CSR in Java with DER format

1 Answers1