![A is a mathematical relationship between a
message , a private key and a public key .
signature
x sk pk
It consists of two functions:
1. signing function
2. verifying function
t = f (sk, x)
[accept, reject] = g(pk, t, x)
So, given x and t and knowing pk,
we can tell if x is indeed signed by sk.](https://image.slidesharecdn.com/ssltlsformortalsjavaone2017-171006202028/85/SSL-TLS-for-Mortals-JavaOne-2017-21-320.jpg)
![Due to the weak security of Windows
passwords it must be assumed that the
attacker was able to compromise the
passwords [...] of the accounts found on the
system. On the system, [...] the domain
administrator account [...] is present.](https://image.slidesharecdn.com/ssltlsformortalsjavaone2017-171006202028/85/SSL-TLS-for-Mortals-JavaOne-2017-28-320.jpg)
SSL/TLS for Mortals (JavaOne 2017)
- 2. Exception in thread "main" javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun at sun.security.ssl.Alerts.getSSLException(Alerts.java:192) at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1949) at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302) at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296) at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1506) at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:216) at sun.security.ssl.Handshaker.processLoop(Handshaker.java:979) at sun.security.ssl.Handshaker.process_record(Handshaker.java:914) at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1062) at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375) at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1403) at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1387) at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:559) at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185) at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1512) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1440) at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254) at com.infosupport.maartenm.Demo.main(Demo.java:13) Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderExcepti at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:387) at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292) at sun.security.validator.Validator.validate(Validator.java:260) at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324) at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229) at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124) at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1488) ... 13 more Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:146) at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:131) at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280) at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:382) ... 19 more
- 3. WHY BOTHER? Using SSL/TLS correctly is o en hard to achieve ...and understand! Crucial for secure connection between systems Globally deployed (intra-)cloud applications
- 5. SSL 1.0 never released SSL 2.0 1995 - POODLE (2011) SSL 3.0 1996 - POODLE (2014) TLS 1.0 1999 - BEAST (2011) TLS 1.1 2006 TLS 1.2 2008 TLS 1.3 dra
- 6. DEMO TIME! What's the issue?
- 7. HOW TO PREVENT THIS? 1. public/private key encryption 2. signed certificates 3. certificate authorities
- 10. Math time! p = 11, q = 17 // two prime numbers modulus = 187 // p * q e = 3 // random number between 1 and modulus // find d, so that (d * e) - 1 % (p - 1) * (q - 1) is zero 320 % 160 = 0 (321 - 1) % (10 * 16) = 0 (107 * 3) = 321 → d = 107 Note that d varies with e: e = 7 // find d, so that (d * e) - 1 % (p - 1) * (q - 1) is zero 1280 % 160 = 0 (1281 - 1) % (10 * 16) = 0 (183 * 7) = 1281 → d = 183
- 11. Now, what if and are unknown?p q p = 13 // prime number q = 23 // prime number modulus = 299 // p * q e = 5 // random number between 1 and modulus // find d, so that (d * e) - 1 % (p - 1) * (q - 1) is zero 1584 % 264 == 0 (1585 - 1) % (12 * 22) = 0 (317 * 5) = 1585 → d = 317 Turns out this is pretty hard!
- 12. For big enough and , finding those factors will cost an eternity! p q So we can distribute ( p * q ) and even e!
- 13. d = 107 LET'S ENCRYPT THE LETTER 'G' G → 7 7e → 73 → 343 343 % 187 → 156 LET'S DECRYPT THE MESSAGE '156' 156107 → 4.6 * 10234 156107 % 187 → 7 7 → G
- 15. Negotiating a secure connection Client Server 1 ClientHello → 2 ← ServerHello 3 ← Certificate 4 ← ServerKeyExchange 5 ← ServerHelloDone 6 ClientKeyExchange → 7 ChangeCipherSpec → 8 Finished → 9 ← ChangeCipherSpec 10 ← Finished
- 16. DEMO TIME! No-one is eavesdropping!
- 18. Certificate contents Serial Number Subject Validity Usage Public Key Fingerprint Algorithm Fingerprint
- 19. But wait... anyone could create a certificate! So we also need Signature Algorithm Signature Issuer ... and a way to sign stuff
- 21. A is a mathematical relationship between a message , a private key and a public key . signature x sk pk It consists of two functions: 1. signing function 2. verifying function t = f (sk, x) [accept, reject] = g(pk, t, x) So, given x and t and knowing pk, we can tell if x is indeed signed by sk.
- 23. An entity that issues digital certificates, certifying the ownership of a public key by the subject of the certificate.
- 24. "I can trust you, because I trust John, and John trusts Alice, and Alice trusts you" I John ? Alice Who knows who "John" is? Many "John"'s in todays browsers and operating systems!
- 25. Top-notch security procedures, including "key ceremonies" And yet...
- 26. FAIRYTALE TIME! Once upon a time, a Dutch certificate authority named DigiNotar was living happily and carefree in the town of Beverwijk. But on a bad day, evil hurt it... Real hard.
- 27. An attacker compromised a webserver of DigiNotar due to a vulnerability that is present within the DotNetNuke so ware. DotNetNuke version 4.8.2.0 is installed on host winsrv119. This version is affected by a file upload vulnerability.
- 28. Due to the weak security of Windows passwords it must be assumed that the attacker was able to compromise the passwords [...] of the accounts found on the system. On the system, [...] the domain administrator account [...] is present.
- 29. The attacker was able to traverse the infrastructure and obtain access to at least two CA's that were used to generate certificates.
- 30. /** intentionally le blank */
- 31. Google blacklists 247 certificates in Chromium Microso removes the DigiNotar root certificate from all supported Windows-releases * Mozilla revokes trust in the DigiNotar root certificate in all supported versions Apple issued Security Update 2011-005 Update Certificate Revocation Lists (except these are self-signed)
- 32. DEMO TIME! Trust (for what it's worth)
- 33. TOOLS curl -v -k <address> openssl s_client -showcerts -servername <address> -connect <address>:443
- 34. Denotes where a can be found: a file that contains . is the password to that file. JVM SETTINGS (1) -Djavax.net.ssl.trustStore=<file> truststore trusted certs -Djavax.net.ssl.trustStorePassword=...
- 35. Denotes where a can be found: a file that contains . is the password to that file. JVM SETTINGS (2) -Djavax.net.ssl.keyStore=<file> keystore private keys -Djavax.net.ssl.keyStorePassword=...
- 36. Include debug logging for TLS handshake and connections. JVM SETTINGS (3) -Djavax.net.debug=all
- 37. Portecle
- 38. SO LONG AND THANKS FOR ALL THE FISH IMAGE ATTRIBUTIONS Beverwijk by @ .Gerard Hogervorst Wikimedia Commons