iOS常用加密算法

AES(对称加密)

代码：

#import <Foundation/Foundation.h>

@interface NSString (AES)

- (NSString *)aes256_encrypt:(NSString *)key;

- (NSString *)aes256_decrypt:(NSString *)key;

- (NSString *)aes128_encrypt:(NSString *)key;

- (NSString *)aes128_decrypt:(NSString *)key;

@end

#import "NSString+AES.h"
#import <CommonCrypto/CommonCryptor.h>

@implementation NSString (AES)

- (NSString *)aes256_encrypt:(NSString *)key {
    const char *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding];
    NSData *data = [NSData dataWithBytes:cstr length:self.length];
    
    //对数据进行加密
    char keyPtr[kCCKeySizeAES256+1];
    bzero(keyPtr, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    NSUInteger dataLength = [data length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    size_t numBytesEncrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES,
                                          kCCOptionPKCS7Padding | kCCOptionECBMode,
                                          keyPtr, kCCKeySizeAES256,
                                          NULL,
                                          [data bytes], dataLength,
                                          buffer, bufferSize,
                                          &numBytesEncrypted);
    if (cryptStatus == kCCSuccess)
    {
        NSData *result = [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
        //base64
        return [result base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
    }else
    {
        return nil;
    }
    
}


- (NSString *)aes256_decrypt:(NSString *)key {
    NSData *data = [[NSData alloc] initWithBase64EncodedData:[self dataUsingEncoding:NSASCIIStringEncoding] options:NSDataBase64DecodingIgnoreUnknownCharacters];
    
    //对数据进行解密
    char keyPtr[kCCKeySizeAES256+1];
    bzero(keyPtr, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    NSUInteger dataLength = [data length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    size_t numBytesDecrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES,
                                          kCCOptionPKCS7Padding | kCCOptionECBMode,
                                          keyPtr, kCCKeySizeAES256,
                                          NULL,
                                          [data bytes], dataLength,
                                          buffer, bufferSize,
                                          &numBytesDecrypted);
    if (cryptStatus == kCCSuccess)
    {
        NSData* result = [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
        
        return [[NSString alloc] initWithData:result encoding:NSUTF8StringEncoding];
        
    }else
    {
        return nil;
    }
    
}

- (NSString *)aes128_encrypt:(NSString *)key {
    const char *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding];
    NSData *data = [NSData dataWithBytes:cstr length:self.length];
    
    //对数据进行加密
    char keyPtr[kCCKeySizeAES128+1];
    bzero(keyPtr, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    NSUInteger dataLength = [data length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    size_t numBytesEncrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES,
                                          kCCOptionPKCS7Padding | kCCOptionECBMode,
                                          keyPtr, kCCKeySizeAES128,
                                          NULL,
                                          [data bytes], dataLength,
                                          buffer, bufferSize,
                                          &numBytesEncrypted);
    if (cryptStatus == kCCSuccess)
    {
        NSData *result = [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
        //base64
        return [result base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
    }else
    {
        return nil;
    }
    
}


- (NSString *)aes128_decrypt:(NSString *)key {
    NSData *data = [[NSData alloc] initWithBase64EncodedData:[self dataUsingEncoding:NSASCIIStringEncoding] options:NSDataBase64DecodingIgnoreUnknownCharacters];
    
    //对数据进行解密
    char keyPtr[kCCKeySizeAES128+1];
    bzero(keyPtr, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    NSUInteger dataLength = [data length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    size_t numBytesDecrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES,
                                          kCCOptionPKCS7Padding | kCCOptionECBMode,
                                          keyPtr, kCCKeySizeAES128,
                                          NULL,
                                          [data bytes], dataLength,
                                          buffer, bufferSize,
                                          &numBytesDecrypted);
    if (cryptStatus == kCCSuccess)
    {
        NSData* result = [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
        
        return [[NSString alloc] initWithData:result encoding:NSUTF8StringEncoding];
        
    }else
    {
        return nil;
    }
    
}



@end

使用：

#import "NSString+AES.h"

    NSString *str = @"name=14513525132&pwd=145361313";
    NSLog(@"str=%@",str);
    NSString *aesStr = [str aes256_encrypt:@"key"];
    NSLog(@"aseencryptstring=%@",aesStr);
    NSString *newStr = [aesStr aes256_decrypt:@"key"];
    NSLog(@"asedecryptStr=%@",newStr);
    
    NSString *aes128Str = [str aes128_encrypt:@"key"];
    NSLog(@"ase128encryptstring=%@",aes128Str);
    NSString *new128Str = [aes128Str aes128_decrypt:@"key"];
    NSLog(@"ase128decryptStr=%@",new128Str);

RSA（非对称加密）

参考文章