Add read and write support to tls_buffer.

tls_buffer was original created for a specific use case, namely reading in
length prefixed messages. This adds read and write support, along with a
capacity limit, allowing it to be used in additional use cases.

ok beck@ tb@

Rename tls13_buffer to tls_buffer.

This code will soon be used in the DTLSv1.2 and TLSv1.2 stack. Also
introduce tls_internal.h and move/rename the read/write/flush callbacks.

ok beck@ tb@

Avoid pulling ssl_locl.h into self-contained code.

Make local header inclusion consistent.

Consistently include local headers in the same location, using the same
grouping/sorting across all files.

Propagate record overflows to the record layer and alert.

ok beck@ tb@

Add record version checks.

When legacy version is below TLSv1.2 ensure that the record version is
SSL3/TLS, however when the legacy version is set to TLSv1.2 require this
specifically.

ok beck@ tb@

Remove #include that is not needed.

Store the record version and make it available for use.

While here correct an int vs size_t mismatch.

ok tb@

Provide a way to get just the record header.

Also check record size limits when reading records and setting data.

ok tb@

Provide a TLS record handling implementation.

This is a self-contained struct and set of functions that knows how to
decode and read a TLS record from data supplied via a read callback, and
send itself via a write callback.

This will soon be used to build the TLSv1.3 record layer handling code.

ok beck@ tb@

Rename tls13_buffer to tls_buffer.

This code will soon be used in the DTLSv1.2 and TLSv1.2 stack. Also
introduce tls_internal.h and move/rename the read/write/flush callbacks.

ok beck@ tb@

Avoid pulling ssl_locl.h into self-contained code.

Make local header inclusion consistent.

Consistently include local headers in the same location, using the same
grouping/sorting across all files.

Propagate record overflows to the record layer and alert.

ok beck@ tb@

Add record version checks.

When legacy version is below TLSv1.2 ensure that the record version is
SSL3/TLS, however when the legacy version is set to TLSv1.2 require this
specifically.

ok beck@ tb@

Remove #include that is not needed.

Store the record version and make it available for use.

While here correct an int vs size_t mismatch.

ok tb@

Provide a way to get just the record header.

Also check record size limits when reading records and setting data.

ok tb@

Provide a TLS record handling implementation.

This is a self-contained struct and set of functions that knows how to
decode and read a TLS record from data supplied via a read callback, and
send itself via a write callback.

This will soon be used to build the TLSv1.3 record layer handling code.

ok beck@ tb@

Avoid pulling ssl_locl.h into self-contained code.

Make local header inclusion consistent.

Consistently include local headers in the same location, using the same
grouping/sorting across all files.

Propagate record overflows to the record layer and alert.

ok beck@ tb@

Add record version checks.

When legacy version is below TLSv1.2 ensure that the record version is
SSL3/TLS, however when the legacy version is set to TLSv1.2 require this
specifically.

ok beck@ tb@

Remove #include that is not needed.

Store the record version and make it available for use.

While here correct an int vs size_t mismatch.

ok tb@

Provide a way to get just the record header.

Also check record size limits when reading records and setting data.

ok tb@

Provide a TLS record handling implementation.

This is a self-contained struct and set of functions that knows how to
decode and read a TLS record from data supplied via a read callback, and
send itself via a write callback.

This will soon be used to build the TLSv1.3 record layer handling code.

ok beck@ tb@

Propagate record overflows to the record layer and alert.

ok beck@ tb@

Add record version checks.

When legacy version is below TLSv1.2 ensure that the record version is
SSL3/TLS, however when the legacy version is set to TLSv1.2 require this
specifically.

ok beck@ tb@

Remove #include that is not needed.

Store the record version and make it available for use.

While here correct an int vs size_t mismatch.

ok tb@

Provide a way to get just the record header.

Also check record size limits when reading records and setting data.

ok tb@

Provide a TLS record handling implementation.

This is a self-contained struct and set of functions that knows how to
decode and read a TLS record from data supplied via a read callback, and
send itself via a write callback.

This will soon be used to build the TLSv1.3 record layer handling code.

ok beck@ tb@

Remove #include that is not needed.

Store the record version and make it available for use.

While here correct an int vs size_t mismatch.

ok tb@

Provide a way to get just the record header.

Also check record size limits when reading records and setting data.

ok tb@

Provide a TLS record handling implementation.

This is a self-contained struct and set of functions that knows how to
decode and read a TLS record from data supplied via a read callback, and
send itself via a write callback.

This will soon be used to build the TLSv1.3 record layer handling code.

ok beck@ tb@

Store the record version and make it available for use.

While here correct an int vs size_t mismatch.

ok tb@

Provide a way to get just the record header.

Also check record size limits when reading records and setting data.

ok tb@

Provide a TLS record handling implementation.

This is a self-contained struct and set of functions that knows how to
decode and read a TLS record from data supplied via a read callback, and
send itself via a write callback.

This will soon be used to build the TLSv1.3 record layer handling code.

ok beck@ tb@