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Implementing SSL/TLS Using Cryptography and PKI

by Joshua Davies

January 2011

Intermediate to advanced

696 pages

16h 56m

English

Wiley

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Supplemental Web SitesRoadmap and Companion Source CodeOutline of the BookHow to Read This Book
What Are Secure Sockets?Insecure Communications: Understanding the HTTP ProtocolRoadmap for the Rest of This Book
Understanding Block Cipher Cryptography AlgorithmsUnderstanding Stream Cipher Algorithms
Understanding the Theory Behind the RSA AlgorithmPerforming Arbitrary Precision Binary Math to Implement Public-Key CryptographyEncryption and Decryption with RSAAchieving Perfect Forward Secrecy with Diffie-Hellman Key ExchangeGetting More Security per Key Bit: Elliptic Curve CryptographyMaking ECC Work with Whole Integers: Elliptic-Curve Cryptography over Fp
Using Message Digests to Create Secure Document Surrogates
Putting It Together: The Secure Channel ProtocolEncoding with ASN.1Developing an ASN.1 ParserManaging CertificatesOther Problems with Certificates
Implementing the TLS 1.0 Handshake (Client Perspective)Secure Data Transfer with TLSImplementing TLS ShutdownExamining HTTPS End-to-End Examples (TLS 1.0)Differences Between SSL 3.0 and TLS 1.0Differences Between TLS 1.0 and TLS 1.1
Implementing the TLS 1.0 Handshake from the Server's PerspectiveAvoiding Common Pitfalls When Adding HTTPS Support to a ServerWhen a Browser Displays Errors: Browser Trust Issues
Passing Additional Information with Client Hello ExtensionsSafely Reusing Key Material with Session ResumptionAvoiding Fixed Parameters with Ephemeral Key ExchangeVerifying Identity with Client AuthenticationDealing with Legacy Implementations: Exportable CiphersDiscarding Key Material Through Session Renegotiation
Supporting TLS 1.2 When You Use RSA for the Key ExchangeImpact to Diffie-Hellman Key ExchangeAdding Support for AEAD Mode CiphersWorking ECC Extensions into the TLS LibraryThe Current State of TLS 1.2
Adding the NTTPS Extension to the NTTP AlgorithmImplementing "Multi-hop" SMTP over TLS and Protecting Email Content with S/MIMESecuring Datagram TrafficSupporting SSL When Proxies Are InvolvedSSL with OpenSSL
The Decimal and Binary Numbering SystemsUnderstanding Binary Logical OperationsTwo's-Complement Representation of Negative NumbersBig-Endian versus Little-Endian Number Formats
Installing TCPDumpInstalling OpenSSL
Implementing the SSL Handshake

Content preview from Implementing SSL/TLS Using Cryptography and PKI

CHAPTER 3 Secure Key Exchange over an Insecure Medium with Public Key Cryptography

Chapter 2 examined symmetric or private/shared key algorithms. The fundamental challenge in applying private key algorithms is keeping the private key private — or, to put it another way, exchanging keys without letting an interested eavesdropper see them. This may seem like an insoluble problem; you can't establish keys over an insecure channel, and you can't establish a secure channel without keys. Perhaps surprisingly, there is a solution: public-key cryptography. With public-key algorithms, there are actually two keys, which are mathematically related such that an encrypt operation performed with one can only be decrypted using the other one. Furthermore, to be usable in a cryptography setting, it must be impossible, or at least mathematically infeasible, to compute one from the other after the fact. By far the most common public-key algorithm is the RSA algorithm, named after its inventors Ron Rivest, Adi Shamir, and Leonard Adleman. You may recall Rivest from Chapter 2 as the inventor of RC4.

You may notice a difference in the technical approach between this chapter and the last. Whereas symmetric/shared key algorithms are based on shifting and XORing bits, asymmetric/public key algorithms are based entirely on properties of natural numbers. Whereas symmetric encryption algorithms aim to be as complex as their designers can get away with while still operating reasonably quickly, public-key ...