Can an SSL certificate be on a single line in a file (no line breaks)?

linux apache-2.2 ssl ssl-certificate mod-ssl

76,851

Solution 1

No, the certificate won't be handled properly without the line breaks - software will fail to parse it.

If you're trying to pass it in a string, why not just include them in it? (\n)

Solution 2

I found this script handful in doing that.

awk 'NF {sub(/\r/, ""); printf "%s\\n",$0;}'  ca.pem

This will take a standard PEM file on multiple lines, replace the "hidden" newline characters with \n, and print the output as a single line.

For example, this will make the following PEM file...

look like this output...

I found this useful when trying to upload an SSL certificate via the Rancher REST API, and couldn't get the encoding correct.

Solution 3

It's a standard, and you should follow.

The RSA standards (e.g. RFC 2459) only define a binary representation for keys. In practice, like OpenPGP keys (RFC 4880), they are often encoded in base 64 using the otherwise obsolete PEM standards (RFC 1421).

The PEM printable encoding section says:

To represent the encapsulated text of a PEM message, the encoding function's output is delimited into text lines (using local conventions), with each line except the last containing exactly 64 printable characters and the final line containing 64 or fewer printable characters.

Solution 4

The line length, and so the line breaks, are due to 64-bit encoding used in the certificate files: see this Wikipedia article, for instance, http://en.wikipedia.org/wiki/Base64

Put newline characters (\n) into your string variable, instead.

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76,851

wrangler

Updated on September 18, 2022

Comments

wrangler over 1 year

SSL certificates by default have line breaks after 67 characters. I'm trying to create SSL certificate files using Chef. Essentially I want to create the entire certificate file from a string variable without any line breaks. I've tried this a few times to no avail (Apache complains about not being able to find certificate).

I don't see why line breaks in an SSL cert would be necessary. Any ideas if it's possible to have a cert without any line breaks in the file?
wrangler over 11 years

Yep, should have thought of that. Using the \n character works. Thanks!
dave_thompson_085 over 6 years

2459 is long obsolete (by 3280 in 2002 and 5280 in 2008) but this particular point (using ASN.1 DER which is binary) hasn't changed. OTOH 7468 more recently (2015) makes official the de-facto PEM-style formats for several things including certs.
Dave M over 5 years

A bit more detail on why this is an answer would help
benchuk about 5 years

saved my day! works great!
zymhan about 5 years

@DaveM hopefully that edit helps.
Jacek Sztandera over 4 years

Thanks! I was wondering how to put certificate as an attribute in chef environment json file, this worked great.
hoang almost 4 years

Sorry but the line length of 64 printable characters has nothing to do why the base64 encoding.
José Manuel Blasco over 3 years

For those who need only the inline string without "\n" in each endline use "awk 'NF {sub(/\r/, ""); printf "%s",$0;}' ca.pem"
Thomas B in BDX over 2 years

Example useful usage: embedding a PEM formatted key or certificate in a JSON file where we can't have string spanning multiple lines.