[Krystian Galaj]

Let's say I found an ebook somewhere on the Internet. All I have is the filename, the book inside, in some specific format. Or possibly a zip, with a handful of html files inside, which form a single book. I'd like to know if that ebook is an illegally created one, or possibly if it's a legal offering, for example that some site offers it on promotion so I could go there and get it from its real source.

I was thinking there should be a search engine where I could go, upload the book or, as it's usually done, point some web form to it so it can read the file, calculate crc32 or md5 sum from it, and look up those sums in its database, and tell me what is the book's source. Often, when I think of such things, and then look for them, they turn out to be existing sites with big databases already. This time, I could find nothing. Does anybody know of such a site?