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Diffstat (limited to 'package/ead/src/tinysrp/Notes')
| -rw-r--r-- | package/ead/src/tinysrp/Notes | 110 |
1 files changed, 0 insertions, 110 deletions
diff --git a/package/ead/src/tinysrp/Notes b/package/ead/src/tinysrp/Notes deleted file mode 100644 index a8620aa700..0000000000 --- a/package/ead/src/tinysrp/Notes +++ /dev/null @@ -1,110 +0,0 @@ -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. |