enum {
           change_cipher_spec(20), alert(21), handshake(22),
           application_data(23), (255)
       } ContentType;

       struct {
           ContentType type;
           ProtocolVersion version;
           uint16 length;
           opaque fragment[TLSPlaintext.length];
       } TLSPlaintext;

   type
       The higher level protocol used to process the enclosed fragment.

   version
       The version of the protocol being employed. This document
       describes TLS Version 1.0, which uses the version { 3, 1 }. The
       version value 3.1 is historical: TLS version 1.0 is a minor
       modification to the SSL 3.0 protocol, which bears the version
       value 3.0. (See Appendix A.1).

   length
       The length (in bytes) of the following TLSPlaintext.fragment.
       The length should not exceed 2^14.

   fragment
       The application data. This data is transparent and treated as an
       independent block to be dealt with by the higher level protocol
       specified by the type field.

 Note: Data of different TLS Record layer content types may be
       interleaved. Application data is generally of lower precedence
       for transmission than other content types.

6.2.2. Record compression and decompression

   All records are compressed using the compression algorithm defined in
   the current session state. There is always an active compression
   algorithm; however, initially it is defined as
   CompressionMethod.null. The compression algorithm translates a
   TLSPlaintext structure into a TLSCompressed structure. Compression
   functions are initialized with default state information whenever a
   connection state is made active.








 
RFC 2246              The TLS Protocol Version 1.0          January 1999


   Compression must be lossless and may not increase the content length
   by more than 1024 bytes. If the decompression function encounters a
   TLSCompressed.fragment that would decompress to a length in excess of
   2^14 bytes, it should report a fatal decompression failure error.

       struct {
           ContentType type;       /* same as TLSPlaintext.type */
           ProtocolVersion version;/* same as TLSPlaintext.version */
           uint16 length;
           opaque fragment[TLSCompressed.length];
       } TLSCompressed;

   length
       The length (in bytes) of the following TLSCompressed.fragment.
       The length should not exceed 2^14 + 1024.

   fragment
       The compressed form of TLSPlaintext.fragment.

 Note: A CompressionMethod.null operation is an identity operation; no
       fields are altered.

   Implementation note:
       Decompression functions are responsible for ensuring that
       messages cannot cause internal buffer overflows.

6.2.3. Record payload protection

   The encryption and MAC functions translate a TLSCompressed structure
   into a TLSCiphertext. The decryption functions reverse the process.
   The MAC of the record also includes a sequence number so that
   missing, extra or repeated messages are detectable.

       struct {
           ContentType type;
           ProtocolVersion version;
           uint16 length;
           select (CipherSpec.cipher_type) {
               case stream: GenericStreamCipher;
               case block: GenericBlockCipher;
           } fragment;
       } TLSCiphertext;