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+t_* stuff is from the srp 1.7.1 dist
+bn_* stuff is from openssl 0.9.6
+
+(The 7 in libtinysrp's version number reflects the srp version.)
+
+Licensing and copyright for srp and openssl are as indicated in the relevant
+source files. Everything else here is GPL, including the tinysrp protocol.
+
+Changelog since initial release:
+
+0.7.4 more robust terminal modes in t_getpass
+ a potential buffer overflow in tinysrp
+0.7.5 uninitialized pointer bug in tconf
+
+Changes from the base srp and openssl distributions:
+
+I've removed everything that's not needed for client/server operations, and
+all the bn_* stuff that's only used for prime generation has been moved to
+t_conf.c, which isn't part of the library anymore. Also, all the routines
+used for passphrase file maintenance have been moved to tphrase.c.
+
+The library has been optimized (a bit) for space instead of speed. Since
+authentication is usually only done once, this isn't a big problem. Modern
+CPUs are plenty fast for this task, and even 100 MHz CPUs are fine. If you
+really need the speed, get the regular distributions.
+
+Note that if the server sends the client a prime that the client doesn't
+know about, the client MUST test for primality. Since this is pretty
+expensive, and takes 30 seconds on a 100 MHz machine, and uses lots of code,
+I've removed that ability from the client. So only KNOWN primes can be
+used. You can still generate new ones with tconf, but you have to install
+them in the table of known primes (pre_params) in t_getconf.c that's common
+to the client and server, and recompile. The configuration file is gone.
+
+The default prime (the last entry in the table) is 1024 bits; there are
+others with more bits but they will be correspondingly slower.
+
+The default tpasswd file (which is an ascii file that may be editted with a
+regular text editor) contains two users: moo (passphrase "glub glub") and
+"new user" (passphrase "this is a test"). Passphrases may be added or
+changed with tphrase; you can also change the user's prime. To delete a
+user, edit the tpasswd file and remove that line. The tpasswd file's
+default name is DEFAULT_PASSWD in t_pwd.h. Note that you can't change a
+user's username by editting the file: the username is encoded in the
+verifier. If you change a username you must set a new passphrase with
+tphrase.
+
+Here is an example session, using the supplied srvtest and clitest. First,
+start both programs in different windows, and enter the user names. Normally,
+the client would send the username to the server. Server lines are marked
+with S>, client lines with C>.
+
+S> % srvtest
+S> Enter username: moo
+S> index (to client): 5
+S> salt (to client): 19AI0Hc9jEkdFc
+
+C> % clitest
+C> Enter username: moo
+C> Enter index (from server): 5
+C> Enter salt (from server): 19AI0Hc9jEkdFc
+
+The server reports the index and salt values used for that user. They
+are sent over the network to the client. (Simulate this by cutting and
+pasting from one window to the other.)
+
+C> A (to server): 5wCDXRxLIv/zLazYfKupV/OY3BlhTZuJ71wVgI0HcL1kSJEpkMuWF.xEz/BV2wlJl7vk5Eoz9KMS1ccnaatsVP5D6CBm7UA.yVB59EQFN0dNBirvX29NAFdtdMsMppo5tHRy987XjJWrWSLpeibq6emr.gP8nYyX75GQqSiMY1j
+C> Enter password:
+
+S> Enter A (from client): 5wCDXRxLIv/zLazYfKupV/OY3BlhTZuJ71wVgI0HcL1kSJEpkMuWF.xEz/BV2wlJl7vk5Eoz9KMS1ccnaatsVP5D6CBm7UA.yVB59EQFN0dNBirvX29NAFdtdMsMppo5tHRy987XjJWrWSLpeibq6emr.gP8nYyX75GQqSiMY1j
+
+Now the client calculates A and sends it to the server, and while the
+server is munching on that, the client gets the password from the user.
+
+S> B (to client): 9dcCpulxQAbaDXI0NHWY6B.QH6B9fsoXs/x/5SCNBNJm/6H6bYfbVrwNmdquhLZjYMvpcgGc2mBYqL77RNfw1kVQo17//GfsByECBIjRnrAn02ffX9Y/llJcfscAQiii0hyZhJf9PT5wE7pC7WUjIgSqckIZ0JLNDbSr7fJcrgw
+S> Session key: ebbcf3a45c968defdcfff6e144ad8d4f5412167c9716e79cbf7cacfe18257947ad46fa5d6418a1fd
+
+The server now calculates B and sends it to the client. The session key
+is not sent -- it is a shared secret that can be used for encryption.
+
+C> Enter B (from server): 9dcCpulxQAbaDXI0NHWY6B.QH6B9fsoXs/x/5SCNBNJm/6H6bYfbVrwNmdquhLZjYMvpcgGc2mBYqL77RNfw1kVQo17//GfsByECBIjRnrAn02ffX9Y/llJcfscAQiii0hyZhJf9PT5wE7pC7WUjIgSqckIZ0JLNDbSr7fJcrgw
+C> Session key: ebbcf3a45c968defdcfff6e144ad8d4f5412167c9716e79cbf7cacfe18257947ad46fa5d6418a1fd
+C> Response (to server): b9ea99094a176c4be28eb469982066cc7146d180
+
+The client uses the B value to calculate its own copy of the shared secret
+session key, and sends a response to the server proving that it does know
+the correct key.
+
+S> Enter response (from client): b9ea99094a176c4be28eb469982066cc7146d180
+S> Authentication successful.
+S> Response (to client): cd46c839ccad2d0c76f3ca1905ae8ceda8d1c1dc
+
+The server authenticates the client. (You're in!)
+
+C> Enter server response: cd46c839ccad2d0c76f3ca1905ae8ceda8d1c1dc
+C> Server authentication successful.
+
+The client authenticates the server (prevents server spoofing in the case
+where the session key isn't used to encrypt the channel -- a spoofed server
+might just respond with random values and _pretend_ to authenticate the
+client; but the spoofed server won't know the session key and this check
+catches that).
+
+Final note:
+
+Remember that many breaches of security involve buggy software, such as
+servers susceptible to buffer overflow exploits that totally bypass any
+passphrase, secure or not. If an attacker roots your client, or the server,
+no form of authentication will work. Consider MAC-based schemes if this
+worries you.