Base64 of encryption

• Is the most widely used encoding system on the network, capable of converting any binary data into a 65-character text file
• a~z,A~Z,0~9,+,/,=
• Base 64The encoded result can be reversed, not safe enough
• Base 64is the basic algorithm for all modern cryptographic algorithms

Terminal commands

# 将 10.jpg 进行 base64 编码，生成 10.txt 文件$ base64 10.jpg -o 10.txt# 将 10.txt 解码生成 1.jpg 文件$ base64 -D 10.txt -o 1.jpg# 将字符串 Man 进行 base64 编码$ echo -n "Man" | base64# 将字符串 TWFu 解码$ echo -n "TWFu" | base64 -D

Code implementation

///  BASE 64 编码- (NSString *)base64Encode:(NSString *)string {    NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];    return [data base64EncodedStringWithOptions:0];}/// BASE 64 解码- (NSString *)base64Decode:(NSString *)string { NSData *data = [[NSData alloc] initWithBase64EncodedString:string options:0]; return [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];}

Save & Load User Information

Save User Information-(void) Saveuserinfo {Nsuserdefaults *defaults = [Nsuserdefaults Standarduserdefaults];IOS 8.0 will be written directly to the sandbox without any further use of ' [Defaults synchronize]; ' [Defaults setobject:self. Username Forkey:hmusernamekey]; NSString *pwd = [selfbase64encode:self. pwd]; [Defaults setobject:pwd forkey:hmuserpasswordkey];} ///load user under information-(void) loaduserinfo { Nsuserdefaults *defaults = [nsuserdefaults standarduserdefaults]; self. Usernametext. Text = [Defaults stringforkey:hmusernamekey]; self. Pwdtext. Text = [selfbase64decode:[defaults stringforkey:hmuserpasswordkey];}   

Problems that exist

1. Use Base64 clear text that does not directly see the user's password
2. But Base64 the algorithm is public, and the algorithm is reversible, the security is not good

Base64 of encryption