CVE-2017-10135

app("2017 JULY CPU"):
    requires(version: "ARMR/2.6")

    /***************************************************************************
        CVE-2017-10135 (2017 JULY CPU)

        CVSS 3.0 Summary:
            Base Score              | 5.9 MEDIUM
            Attack Vector           | Network
            Attack Complexity       | High
            Privileges Required     | None
            User Interaction        | None
            Scope                   | Unchanged
            Confidentiality Impact  | High
            Integrity Impact        | None
            Availability Impact     | None

        Description:
            A covert timing channel flaw was found in the PKCS#8 implementation
            in the JCE component of OpenJDK. A remote attacker able to make a
            Java application repeatedly compared PKCS#8 key against an attacker
            controlled value could possibly use this flaw to determine the key
            via a timing side channel.

        Resources:
            https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-10135
            hg diff -c 7c12c25a18d5 (jdk6)

        Affected Versions:
            6u151, 7u141, 8u131, JRockit R28.3.14

        Tested Versions:
            6u0 - 6u151
            7u0 - 7u141
            8u0 - 8u131

        Protection Provided:
            Functional

        Patch Version:
            1.0
    ***************************************************************************/

    patch("CVE-2017-10135 :01"):
        function("sun/security/pkcs/PKCS8Key.equals(Ljava/lang/Object;)Z",
            checksums: ["6ff581b8a2",   // 6u0  - 6u60
                        "0c4961b363",   // 6u65 - 6u151
                        "adc7dc0a01",   // 7u0  - 7u40
                        "95a4795e68",   // 7u45 - 7u141
                        "0fcba0da94"])  // 8u0  - 8u131
        entry()

        code(language: java,   import: ["java.security.MessageDigest",
                                        "java.security.Key"]):
            private static JavaField encodedKeyField;
            private static JavaMethod getEncodedMethod;

            public void load() {
                encodedKeyField =
                    JavaField.load("sun/security/pkcs/PKCS8Key.encodedKey");
                getEncodedMethod =
                    JavaMethod.load("sun/security/pkcs/PKCS8Key.getEncoded()[B");
            }

            public void patch(JavaFrame frame) {
                Object self = frame.loadThisVariable();
                Object other = frame.loadObjectParam(1);

                if (self == other) {
                    frame.returnBoolean(true);
                    return;
                }

                if (other instanceof Key){
                    byte [] encodedKey = (byte[]) encodedKeyField.readObject(self);
                    byte[] b1;
                    if (encodedKey != null) {
                        b1 = encodedKey;
                    } else {
                          b1 = (byte []) getEncodedMethod.call(self);
                    }

                    byte[] b2 = (byte[]) getEncodedMethod.call(other);

                    frame.returnBoolean(MessageDigest.isEqual(b1, b2));
                    return;
                }
                frame.returnBoolean(false);
            }
        endcode
    endpatch

endapp