How to Extract the Full Subject Distinguished Name from an X.509 Certificate in Go?

How to Extract Complete Subject DN from X509 Certificates in Go

Obtaining the subject DN (Distinguished Name) or issuer DN from an X509 certificate in Go as a string can be a challenge. However, there is a convenient method that can simplify this task.

Solution

Thanks to the contributions of a colleague, a custom function called getDNFromCert has been developed to extract the complete DN from an X509 certificate. This function takes a pkix.Name namespace as input and returns a string representation of the DN:

<code class="go">func getDNFromCert(namespace pkix.Name, sep string) (string, error) {
    subject := []string{}
    for _, s := range namespace.ToRDNSequence() {
        for _, i := range s {
            if v, ok := i.Value.(string); ok {
                if name, ok := oid[i.Type.String()]; ok {
                    // <oid name>=<value>
                    subject = append(subject, fmt.Sprintf("%s=%s", name, v))
                } else {
                    // <oid>=<value> if no <oid name> is found
                    subject = append(subject, fmt.Sprintf("%s=%s", i.Type.String(), v))
                }
            } else {
                // <oid>=<value in default format> if value is not string
                subject = append(subject, fmt.Sprintf("%s=%v", i.Type.String, v))
            }
        }
    }
    return sep + strings.Join(subject, sep), nil
}</code>

Using the Function

To extract the subject DN from an X509 certificate named x509Cert, you can call the getDNFromCert function as follows:

<code class="go">subj, err := getDNFromCert(x509Cert.Subject, "/")
if err != nil {
    // Do error handling
}
fmt.Println(subj)</code>

Example Output

For a sample certificate with the following subject DN:

CN=common name,OU=unit,O=some organization,C=US

The getDNFromCert function will return the following string:

/C=US/O=some organization/OU=unit/CN=common name

This method provides an easy and efficient way to extract the complete subject or issuer DN from an X509 certificate in Go. It simplifies the task and eliminates the need for manual string manipulation.

The above is the detailed content of How to Extract the Full Subject Distinguished Name from an X.509 Certificate in Go?. For more information, please follow other related articles on the PHP Chinese website!