the server sends a 24 charecter string and the messenger has to encrypt the password using this string and send back 2 such 24 charecter strings.
Sorry pentru offtopic, Se da urmatorul text, care este luat din dewscrierea protocolului de Yahoo Messenger: " As always the most difficult part to figure out in any messenger protocol is the login encryption.The earlier version of the yahoo protcol used the MD5 CRYPT function to do the encryption.This was a pretty weak encryption considering that the encrypted data being sent back to the server was always constant.With ver 10 of their protocol yahoo has tried to make the login process more secure.Yahoo introduced a new challenge response mechanism where the server sends a 24 charecter string and the messenger has to encrypt the password using this string and send back 2 such 24 charecter strings. The encryption algorithm used remains MD5.One of the 2 strings is made by encrypting the password hash, the username the challenge string and one charceter of the 24 charecter string,The other string is made by encrypting the crypt hash of the password the username and the challenge string and one charceter of the 24 charecter string.The 2 strings are finally encoded in mac64 encoding format.The Mac64 encoding format is similar to the base64 encoding format except for 3 charecters, the charecters "+ " , "\" & "=" used in the base64 encoding format are replaced by the charecters "." ,"_" & "-" respectively for the mac64 encoding format." Intrebare: Nu inteleg de ce, daca "The encryption algorithm used remains MD5", trebuie trimisa 2 stringuri de cate 24 de caractere, cand rezultatul algoritmului MD5 este un Styring de 32 de caractere (mai exact rezultatul este dat de 4 variabile pe 4 octeti). Citez rfc1321 The MD5 Message-Digest Algorithm: "The message digest produced as output is A, B, C, D. That is, we begin with the low-order byte of A, and end with the high-order byte of D. " unde A, B, C, D sunt cele 4 variabile amintite mai sus definite ca unsigned long int. Imi puteti explica si mie cum trebuie procedat? Best regards, Mihai D. __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com --- Detalii despre listele noastre de mail: http://www.lug.ro/
