Does SSL protect documents sent over it?

If I understand correctly, SSL will protect (encrypt) HTTP transfer sent over it. But does this apply only to HTTP commands and respo开发者_如何转开发nses?

If I GET a plain text file and someone intercepts my transaction, do they see plain text or encrypted text?

It applies to the metadata (commands and responses) and the data (the text file). So it will be encrypted. Keep in mind that SSL over HTTP is better known as HTTPS.

Everything in the HTTP message is encrypted, including the headers, and the request/response load. [...] A possible attacker can only know the fact that a connection is taking place between the two, known to him, parties; the domain name and IP addresses.

See also: http://en.wikipedia.org/wiki/Https#Network_layers

SSL (otherwise known as TLS - "Transport Layer Security"), protects everything at the socket-level. That is, everything in a TCP packet is encrypted, meaning that you essentially have an encrypted bytestream between two hosts. So, the plain text transmission will be encrypted.

SSL encryption encrypts all data transferred as part of a session. This includes HTTP commands, responses and all the payload data.

From http://whatismyipaddress.com/ssl

A Secured Socket Layer, or SSL, is the usual way that a website creates a secure connection with a web browser. Whenever a web surfer visits a secure site that uses SSL technology, it creates an encrypted link between their browser session and the web server.

From above they don't see plaint text, text will be encrypted.