Parsing private key with x509 package

[Andreas_Iosifelis]

Hey everyone.

I’m using the x509 package and I’m trying to parse the private key stored in my .env file using the x509.ParsePKCS8PrivateKey method.

The method throws the following error: “asn1: structure error: tags don’t match (2 vs {class:0 tag:16 length:95 isCompound:true}) {optional:false explicit:false application:false private:false defaultValue: tag: stringType:0 timeType:0 set:false omitEmpty:false} int @2”.

I asume that the error is caused due to the format of the private key in the .env file and the fact that a passphrase was used to generated. (I used the openssl command).
The format of the private key the .env file is the following
PRIVATE_KEY="-----BEGIN ENCRYPTED PRIVATE KEY-----
blablablabla
-----END ENCRYPTED PRIVATE KEY-----
"
Here’s is my code

privateKeyPEM := os.Getenv("PRIVATE_KEY")

	// get private key from .env file
	block, _ := pem.Decode([]byte(privateKeyPEM))
	if block == nil {
		http.Error(w, "{\"error\": \"Error decoding private key\"}", http.StatusBadRequest)
		return
	}

	privateKey, err := x509.ParsePKCS8PrivateKey(block.Bytes)
	if err != nil {
		fmt.Println(err.Error())
		http.Error(w, "{\"error\": \"Error parsing private key\"}", http.StatusBadRequest)
		return
	}

The goal of this code is to use the private key inside an http handler in order to decrypt some data coming from the client. After I receive the data I call the rsa.DecryptPKCS1v15(rand.Reader, privateKey, ecryptedData) to decrypt the data, but the code never reaches this point.

Any ideas would be appreciated. My Go version is 1.21

Thank you in advance