iOS经常使用的加密算法

<span style="font-size:18px;">+ (NSString *)md5Hash:(NSString *)str {
const char *cStr = [str UTF8String];
unsigned char result[16];
CC_MD5( cStr, strlen(cStr), result );
NSString *md5Result = [NSString stringWithFormat:
@"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
result[0], result[1], result[2], result[3],
result[4], result[5], result[6], result[7],
result[8], result[9], result[10], result[11],
result[12], result[13], result[14], result[15]
];
return md5Result;
}</span>

<span style="font-size:18px;">const char *cstr = [str cStringUsingEncoding:NSUTF8StringEncoding];
NSData *data = [NSData dataWithBytes:cstr length:str.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;
</span>

<span style="font-size:18px;">- (NSData *)AES256EncryptWithKey:(NSString *)key {//加密
char keyPtr[kCCKeySizeAES256+1];
bzero(keyPtr, sizeof(keyPtr));
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
NSUInteger dataLength = [self length];
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128,
kCCOptionPKCS7Padding | kCCOptionECBMode,
keyPtr, kCCBlockSizeAES128,
NULL,
[self bytes], dataLength,
buffer, bufferSize,
&numBytesEncrypted);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
}
free(buffer);
return nil;
}

- (NSData *)AES256DecryptWithKey:(NSString *)key {//解密
char keyPtr[kCCKeySizeAES256+1];
bzero(keyPtr, sizeof(keyPtr));
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
NSUInteger dataLength = [self length];
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
size_t numBytesDecrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128,
kCCOptionPKCS7Padding | kCCOptionECBMode,
keyPtr, kCCBlockSizeAES128,
NULL,
[self bytes], dataLength,
buffer, bufferSize,
&numBytesDecrypted);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
}
free(buffer);
return nil;
}
</span>

<span style="font-size:18px;">+ (NSString*)encodeBase64String:(NSString * )input {
NSData *data = [input dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
data = [GTMBase64 encodeData:data];
NSString *base64String = [[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] autorelease];
return base64String;
}

+ (NSString*)decodeBase64String:(NSString * )input {
NSData *data = [input dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
data = [GTMBase64 decodeData:data];
NSString *base64String = [[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] autorelease];
return base64String;
}

+ (NSString*)encodeBase64Data:(NSData *)data {
data = [GTMBase64 encodeData:data];
NSString *base64String = [[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] autorelease];
return base64String;
}

+ (NSString*)decodeBase64Data:(NSData *)data {
data = [GTMBase64 decodeData:data];
NSString *base64String = [[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] autorelease];
return base64String;
}</span>