title: Can a TLS 1.2 server/client get by with just TLS_RSA_WITH_AES_128_CBC_SHA?
body: <p>I'm updating an embedded TLS 1.0 implementation to TLS 1.2 (devices with 1MB of code space or less, and no OS).  At this point, I have AES-128 and AES-256 CBC ciphers working with SHA-1 and SHA-256 digests for a minimal implementation.  The library cannot negotiate an SSLv2, SSLv3, TLS 1.0 or TLS 1.1 connection.</p>
  
  <p>I felt this would be sufficient, given that RFC 5246 states, "TLS_RSA_WITH_AES_128_CBC_SHA is now the mandatory to implement cipher suite."</p>
  
  <p>Yet as I read various postings on security blogs, I'm seeing recommendations that would have users disable that suite, and (for example) only allow the ECDHE_RSA or DHE_RSA variants.</p>
  
  <p>So my question is whether devices using our library will interoperate with modern web browsers (as a server) and modern https/smtps/pop servers (as a client).  <strong>Are there TLS 1.2 clients/servers that fail to negotiate a TLS_RSA_WITH_AES_128_CBC_SHA connection?</strong></p>