Asymmetric cryptography use cases

STSAFE-A110

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Figure 6. Key Establishment command flow

2.3

TLS Handshake protocol

This use case shows how the STSAFE-A110 can be used by a local host for implementing

the transport layer security (TLS) protocol version 1.2. that is specified in RFC 5246.

All details of the TLS handshake protocol are explained in RFC 5246. The intention of this

section is not to re-explain all details or all TLS-specific terminology; the main focus is on the

interaction of the local host with the STSAFE-A110 while briefly illustrating how it fits in the

overall TLS protocol flow.

A local host can use the STSAFE-A110 on the TLS client and TLS server side for

implementing the following cryptographic mechanisms of the TLS handshake protocol:

•

Secure random generation. It is useful in the Client Hello and Server Hello messages.

•

Signature generation with ECDSA using a private key that is securely stored in the

STSAFE-A110. It is useful for generating the signatures in the Server Key Exchange

message and Certificate Verify message. The local host is responsible for generating

the SHA-256 or SHA-384 message digest and for sending the digest to the STSAFE-

A110 in the command data.