Export openssl cert public key to DER format

androidapache-2.2exportimportopenssl

i'm looking for a way to export my openssl certificate (the public part) used by apache2 (.pem file) to import it to an android device's credential storage (Settings menu> Security > Credential storage > Install from device storage) as explained here http://davdroid.bitfire.at/configuration#c77

what's the proper openssl command line to export it in the desired format (DER)?

Best Answer

OpenSSL maintains a hints page for this:

https://support.ssl.com/Knowledgebase/Article/View/19/0/der-vs-crt-vs-cer-vs-pem-certificates-and-how-to-convert-them :

PEM to DER

openssl x509 -in cert.crt -outform der -out cert.der

Related Solutions

Openssl Subject Public Key Info: RSA Public Key: (1024 bit) vs Public Key: (1024 bit)

Do you really compare output of the same openssl x509 utility given different input files? The different output you ask about apparently just differs between OpenSSL versions. E.g., openssl-0.9.8e has such code:

                    BIO_printf(bp,"%12sRSA Public Key: (%d bit)\n","",
                    BN_num_bits(pkey->pkey.rsa->n));

However, openssl-1.0.0 has slightly different text:

            if (BIO_printf(bp,"Public-Key: (%d bit)\n", mod_len)
                    <= 0) goto err;

(note that the actual text is Public-Key, not Public Key). So the output for the same certificate may be different depending on which OpenSSL version you use to dump the file, and your files containing RSA Public Key: (1024 bit) were just dumped as text using an old version of OpenSSL.

Openssl – What is the public key default MD

md stands for message digest and from openssl version 1.1 the default digest is sha256.

-md alg

the message digest to use. Any digest supported by the OpenSSL dgst command can be used. This option also applies to CRLs.

https://www.openssl.org/docs/manmaster/man1/ca.html

The default digest was changed from MD5 to SHA256 in Openssl 1.1.

https://www.openssl.org/docs/manmaster/man1/dgst.html

Best Answer

Related Solutions

Openssl Subject Public Key Info: RSA Public Key: (1024 bit) vs Public Key: (1024 bit)

Openssl – What is the public key default MD

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