converting .cer to .pem returns error 'unable to load certificate'

Question

I got an email containing a cert, it looked something like:

-----BEGIN CERTIFICATE-----

MIIHE...

-----END CERTIFICATE-----

I copy/pasted that into notepad and saved it as a .cer file.

What I need now is a .pfx file using this cert. From what I gather I need to first convert my .cer to a .pem.

I tried converting my .cer to a .pem but that only gave error:

OpenSSL> x509 -inform der -in C:\Users\xxx\Desktop\cert.cer -out certificate.pem

unable to load certificate 7320:error:0D0680A8:asn1 encoding routines:ASN1_CHECK_TLEN:wrong tag:.\crypto\asn1\tasn_dec.c:1315: 7320:error:0D07803A:asn1 encoding routines:ASN1_ITEM_EX_D2I:nested asn1 error:.\crypto\asn1\tasn_dec.c:379:Type=X509

I read some answers that also say just changing .cer to .pem is enough, but for me that does not seem to work at all.

Solution

Your certificate is already in PEM format. Just rename it from certificate.cer to certificate.pem

Comments

[eis]

Possible duplicate of OpenSSL encoding errors while converting cer to pem

[Green_qaue]

Hmm, is there anyway I can test that this actually works? If I save it as a .pem my comp just treats it like a .txt file and opens it in notepad. But maybe that is intended. (i.e I cope/paste into notepad and save as .pem)

[Jitrenka]

Use it. that's how you find out :)