CreateCA+Script-to-create-self-signed-certificates-with-given-CA

#first create CA
#!/bin/bash

# Generate private key for CA
openssl genpkey -algorithm RSA -out ca.key

# Generate self-signed certificate for CA
openssl req -new -x509 -key ca.key -out ca.crt -days 3650





#this is the script to create the self signed certificates and sign them with the CA created earlier:
#!/bin/bash

# Function to validate Common Name against regex pattern
validate_common_name() {
    local pattern="^[^.][A-Za-z0-9.-]+\.([A-Za-z]{2,}|(org|net|com|gov|tv|me|ai|idf|se|ru|hu|io|pt)\.il)$"
    if [[ ! $1 =~ $pattern ]]; then
        echo "The input is not valid. It must be in the pattern of *.domain.com or sub.domain.com"
        return 1
    fi
    return 0
}

# Prompt for the Common Name until a valid input is given
while true; do
    read -p "Enter Common Name for the certificate: " COMMON_NAME
    if [[ -z $COMMON_NAME ]]; then
        echo "Error: Common Name cannot be empty."
    elif ! validate_common_name "$COMMON_NAME"; then
        continue
    else
        break
    fi
done

# Create a directory for the certificate files
CERT_DIR="${COMMON_NAME}_cert"
VALID_DAYS=3650
mkdir -p "$CERT_DIR"

# Generate private key for the certificate
openssl genpkey -algorithm RSA -out "$CERT_DIR/${COMMON_NAME}.key"

# Generate certificate signing request
openssl req -new -key "$CERT_DIR/${COMMON_NAME}.key" -out "$CERT_DIR/${COMMON_NAME}.csr" -subj "/CN=${COMMON_NAME}"

# Sign the certificate with the CA
openssl x509 -req -in "$CERT_DIR/${COMMON_NAME}.csr" -CA "ca.crt" -CAkey "ca.key" -CAcreateserial -out "$CERT_DIR/${COMMON_NAME}.crt" -days "$VALID_DAYS"

# Create .pem file (certificate + private key)
cat "$CERT_DIR/${COMMON_NAME}.crt" "$CERT_DIR/${COMMON_NAME}.key" > "$CERT_DIR/${COMMON_NAME}.pem"

# Create .cer file (certificate only)
openssl x509 -inform PEM -in "$CERT_DIR/${COMMON_NAME}.crt" -outform DER -out "$CERT_DIR/${COMMON_NAME}.cer"

# Create .pfx file (PKCS#12 format, includes certificate and private key)
openssl pkcs12 -export -out "$CERT_DIR/${COMMON_NAME}.pfx" -inkey "$CERT_DIR/${COMMON_NAME}.key" -in "$CERT_DIR/${COMMON_NAME}.crt"

echo "Certificate generated successfully in '$CERT_DIR' folder."