cryptographic-hash-function

问题 One concept I\'ve always wondered about is the use of cryptographic hash functions and values. I understand that these functions can generate a hash value that is unique and virtually impossible to reverse, but here\'s what I\'ve always wondered: If on my server, in PHP I produce: md5(\"stackoverflow.com\") = \"d0cc85b26f2ceb8714b978e07def4f6e\" When you run that same string through an MD5 function, you get the same result on your PHP installation. A process is being used to produce some

问题 How to calculate the MD5 in Objective-C? 回答1: md5 is available on the iPhone and can be added as an addition for ie NSString and NSData like below. MyAdditions.h @interface NSString (MyAdditions) - (NSString *)md5; @end @interface NSData (MyAdditions) - (NSString*)md5; @end MyAdditions.m #import "MyAdditions.h" #import <CommonCrypto/CommonDigest.h> // Need to import for CC_MD5 access @implementation NSString (MyAdditions) - (NSString *)md5 { const char *cStr = [self UTF8String]; unsigned char

问题 I need to hash passwords for storage in a database. How can I do this in Java? I was hoping to take the plain text password, add a random salt, then store the salt and the hashed password in the database. Then when a user wanted to log in, I could take their submitted password, add the random salt from their account information, hash it and see if it equates to the stored hash password with their account information. 回答1: You can actually use a facility built in to the Java runtime to do this