Update Non-SAN Certificates for 4.7.52 Version

Overview

RFC 2818 published in May 2000, deprecates using the Common Name (CN) field in HTTPS certificates for subject name verification. Instead, it recommends using the “Subject Alternative Name” extension (SAN) of the “DNS name” type.

Automate is moving the product builds from Golang version 1.15 to 1.19 to keep the language features up to date. The change in the Golang version will impact the custom certificates used for interaction with external systems. The common name field of X.509 certificates will no longer be considered the hostname when the Subject Alternative Name (SAN) is absent. Refer to Go 1.15 Release Notes and our blog for more information.

From version 4.7.52 onwards, Chef Automate requires public certificates as SAN certificates. Automate or Automate HA may stop working if you upgrade to this version with certificates that don’t contain the SAN field.

Update non-SAN Certificates involves:

Update internal Public Certificates
Update the public certificates of external PostgreSQL/OpenSearch servers, if using

Update Internal Public Certificates

Copy the SAN validator script and store it in a file, say san_validator.sh
Run the SAN validator script to validate whether all the internal public certificates are SAN-based.
```
bash san_validator.sh
```
If your setup has non-SAN certificates, the above script returns the list of non-SAN certificates as a response, as shown below.
If the script does not return any values as invalid certificates, as below, your setup has valid internal certificates.
If you have non-SAN certificates, run the command
```
chef-automate internal-ca regenerate root
```

Update PG/OS Public Certificate

Get the existing PG/OS public certificate.
Check whether the certificate is a SAN certificate or not.
If the certificate is a non-SAN certificate, regenerate the new set of certificates and apply it to the external PG/OS server.
Update the corresponding Root-CA configuration in Automate configuration.

How to check whether the certificate is SAN-based or non-SAN based

Copy the SAN validator script and store it in a file, say san_validator.sh
Get the certificate and store it in a file, say my_cert.crt
Run the script by providing the certificate as an argument to the script.
```
bash san_validator.sh <path/my_cert.crt>
```
If the certificate is a SAN certificate, the above script gives the response as Pass: your certificate is a valid SAN certificate
If the certificate is a non-SAN certificate, the above script gives the response as Fail: your certificate is not a valid SAN certificate

SAN Validator Script

#!/bin/bash

cert_path="$1"

validate_cert() {
input_path="$1"
cert_info=$(openssl x509 -in "$input_path" -noout -text 2>/dev/null)
if echo "$cert_info" | grep -q "Subject Alternative Name"; then
return 0
else
return 1
fi
}

is_root_ca() {
input_path="$1"

    #Check the certificate is RootCA is not
    is_self_signed=$(openssl verify -CAfile "$cert" "$cert" 2>&1)

    #enable case insensitive match for reg-ex
    shopt -s nocasematch
    if [[ ! -z $(cat "$cert") ]] && [[ $is_self_signed == *error* ]]; then
            #disable case insensitive match for reg-ex
            shopt -u nocasematch
            return 1
    else
            #disable case insensitive match for reg-ex
            shopt -u nocasematch
            return 0
    fi

}

# If the certificate path provides validation only that certificate
if [ "$cert_path" ]; then
# Check for the certificate file exists
if [ ! -f "$cert_path" ]; then
echo "Error: Certificate file not found."
exit 1
fi

    if validate_cert "$cert_path"; then
        echo "Pass: your certificate is a valid SAN certificate"
    else
        echo "Fail: your certificate is not a valid SAN certificate"
    fi
    exit 1
fi

# Get all the internal certificates with extension(.crt), gets the RootCA and public certificates
certs=$(find /hab/svc -type f -name "*.crt")
invalid_certs=()

for cert in $certs; do
if ! is_root_ca "$cert" && ! validate_cert "$cert"; then
invalid_certs+=("$cert")
fi
done

# Print the list of invalid certs
echo "Invalid certificates:"
for cert in "${invalid_certs[@]}"; do
echo "$cert"
done