Return CAS error instead of HTTP 500 on malformed tickets

 integrationTest/suite.sh

@@ -80,6 +80,20 @@
fi
echo

echo "Testing CAS 2.0 - malformed ticket..."
response=$(curl --silent --write-out '%{http_code}' --output /dev/null "${keycloak_cas_url}/serviceValidate?service=http://localhost&ticket=ST-x--zz--y")
if [ "$response" != "400" ]; then
    echo "Malformed ticket returned HTTP ${response} instead of 400"
    exit 1
fi

echo "Testing CAS 2.0 - proxyValidate without ticket..."
response=$(curl --silent --write-out '%{http_code}' --output /dev/null "${keycloak_cas_url}/proxyValidate?service=http://localhost")
if [ "$response" != "400" ]; then
    echo "Missing ticket returned HTTP ${response} instead of 400"
    exit 1
fi

# SAML 1.1
echo "Testing SAML 1.1..."
ticket=$(get_ticket SAML)

 src/main/java/org/keycloak/protocol/cas/endpoints/AbstractValidateEndpoint.java

@@ -330,7 +330,12 @@
    }

    private String hexDecode(String hex) {
        byte[] bytes = HexFormat.of().parseHex(hex);
        return new String(bytes, StandardCharsets.US_ASCII);
        try {
            byte[] bytes = HexFormat.of().parseHex(hex);
            return new String(bytes, StandardCharsets.US_ASCII);
        } catch (IllegalArgumentException e) {
            event.error(Errors.INVALID_CODE);
            throw new CASValidationException(CASErrorCode.INVALID_TICKET_SPEC, "Invalid format of the code", Response.Status.BAD_REQUEST);
        }
    }
}