iOS开发之Objective-c的MD5/SHA1加密算法的实现

Objective-c实现MD5和SHA1算法相对还是比较简单的，可以直接调用系统的C/C++共享库来实现调用
MD5即Message Digest Algorithm 5（信息-摘要算法 5），用于确保信息传输完整一致。是计算机广泛使用的杂凑算法之一
SHA即Secure Hash Algorithm（安全散列算法) 是美国国家安全局 (NSA) 设计，美国国家标准与技术研究院 (NIST) 发布的一系列密码散列函数。

使用方式如下:
MD5加密方式

-(NSString *) md5{    const char *cStr = [self UTF8String];    unsigned char digest[CC_MD5_DIGEST_LENGTH];    CC_MD5( cStr, strlen(cStr), digest );     NSMutableString *output = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];     for(int i = 0; i < CC_MD5_DIGEST_LENGTH; i++)        [output appendFormat:@"%02x", digest[i]];     return output;}

SHA1加密方式

- (NSString*) sha1{    const char *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding];    NSData *data = [NSData dataWithBytes:cstr length:self.length];     uint8_t digest[CC_SHA1_DIGEST_LENGTH];     CC_SHA1(data.bytes, data.length, digest);     NSMutableString* output = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH * 2];     for(int i = 0; i < CC_SHA1_DIGEST_LENGTH; i++)        [output appendFormat:@"%02x", digest[i]];     return output;}

当然也可以结合BASE64来使用,这里的BASE64编码使用 GTMBase64实现，需要导入

- (NSString *) sha1_base64{    const char *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding];    NSData *data = [NSData dataWithBytes:cstr length:self.length];     uint8_t digest[CC_SHA1_DIGEST_LENGTH];     CC_SHA1(data.bytes, data.length, digest);     NSData * base64 = [[NSData alloc]initWithBytes:digest length:CC_SHA1_DIGEST_LENGTH];    base64 = [GTMBase64 encodeData:base64];     NSString * output = [[NSString alloc] initWithData:base64 encoding:NSUTF8StringEncoding];     return output; } - (NSString *) md5_base64{    const char *cStr = [self UTF8String];    unsigned char digest[CC_MD5_DIGEST_LENGTH];    CC_MD5( cStr, strlen(cStr), digest );     NSData * base64 = [[NSData alloc]initWithBytes:digest length:CC_MD5_DIGEST_LENGTH];    base64 = [GTMBase64 encodeData:base64];     NSString * output = [[NSString alloc] initWithData:base64 encoding:NSUTF8StringEncoding];     return output;}

通过拓展NSString，实现完整功能，全部代码

@interface NSString (encrypto)- (NSString *) md5;- (NSString *) sha1;- (NSString *) sha1_base64;- (NSString *) md5_base64;- (NSString *) base64; @end@implementation NSString (encrypto)- (NSString*) sha1{    const char *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding];    NSData *data = [NSData dataWithBytes:cstr length:self.length];     uint8_t digest[CC_SHA1_DIGEST_LENGTH];     CC_SHA1(data.bytes, data.length, digest);     NSMutableString* output = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH * 2];     for(int i = 0; i < CC_SHA1_DIGEST_LENGTH; i++)        [output appendFormat:@"%02x", digest[i]];     return output;} -(NSString *) md5{    const char *cStr = [self UTF8String];    unsigned char digest[CC_MD5_DIGEST_LENGTH];    CC_MD5( cStr, strlen(cStr), digest );     NSMutableString *output = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];     for(int i = 0; i < CC_MD5_DIGEST_LENGTH; i++)        [output appendFormat:@"%02x", digest[i]];     return output;} - (NSString *) sha1_base64{    const char *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding];    NSData *data = [NSData dataWithBytes:cstr length:self.length];     uint8_t digest[CC_SHA1_DIGEST_LENGTH];     CC_SHA1(data.bytes, data.length, digest);     NSData * base64 = [[NSData alloc]initWithBytes:digest length:CC_SHA1_DIGEST_LENGTH];    base64 = [GTMBase64 encodeData:base64];     NSString * output = [[NSString alloc] initWithData:base64 encoding:NSUTF8StringEncoding];     return output; } - (NSString *) md5_base64{    const char *cStr = [self UTF8String];    unsigned char digest[CC_MD5_DIGEST_LENGTH];    CC_MD5( cStr, strlen(cStr), digest );     NSData * base64 = [[NSData alloc]initWithBytes:digest length:CC_MD5_DIGEST_LENGTH];    base64 = [GTMBase64 encodeData:base64];     NSString * output = [[NSString alloc] initWithData:base64 encoding:NSUTF8StringEncoding];     return output;} - (NSString *) base64{        NSData * data = [self dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];     data = [GTMBase64 encodeData:data];     NSString * output = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];     return output; }@end

实现时候不要忘记导入CC相关的库的头文件
CommonCrypto/CommonDigest.h