CODEWITHSUNDEEP
gox509
decodebytes
decodebytes

Reputation: 421

Format x509 PEM by removing headers and parsing block into a single line in GoLang

I have a standard x509 PEM certificate

-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

And I need to strip -----BEGIN CERTIFICATE----- & -----END CERTIFICATE----- and place the body into a single line.

Now I could write some regex to perform this, but I was wondering if there is already a GoLang idiomatic way of performing this, perhaps using the x509 or crypto modules. I had a good search through the docs, but could not see anything.

Upvotes: 3

Views: 2207

Answers (1)

Peter
Peter

Reputation: 31720

PEM is essentially just base64 formatted in a particular way, and with support for metadata (which isn't used here). If you remove all that you're left with plain old base64:

package main

import (
    "encoding/base64"
    "encoding/pem"
    "fmt"
)

var cert = []byte(`-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----`)

func main() {
    block, _ := pem.Decode(cert)
    fmt.Println(base64.StdEncoding.EncodeToString(block.Bytes))
}

Playground: https://play.golang.org/p/03HfOsC1J8X

Upvotes: 5

Related Questions