ios加密算法汇总

把相关算法的代码也贴一下吧 （其实使用一些成熟的第三方库或许会来得更加简单，不过自己写，自由点）。注，这里的大部分加密算法都是参考一些现有成熟的算法，或者直接拿来用的。

1、MD5

//因为是使用category，所以木有参数传入啦

-(NSString *)
stringFromMD5 {

if(self == nil ||
[self length]
== 0) {

return nil;

}

const char *value
= [self UTF8String];

unsigned char outputBuffer[CC_MD5_DIGEST_LENGTH];

CC_MD5(value, strlen(value),
outputBuffer);

NSMutableString *outputString
= [[NSMutableString alloc] initWithCapacity:CC_MD5_DIGEST_LENGTH * 2];

for(NSInteger count
= 0;
count < CC_MD5_DIGEST_LENGTH;
count++){

[outputString appendFormat:@"%02x",outputBuffer[count]];

}

return [outputString autorelease];

}

2、Base64

+ (NSString *)
base64EncodeData: (NSData *)
objData {

const unsigned char *
objRawData = [objData bytes];

char *
objPointer;

char *
strResult;

//
Get the Raw Data length and ensure we actually have data

int intLength
= [objData length];

if (intLength
== 0) return nil;

//
Setup the String-based Result placeholder and pointer within that placeholder

strResult = (char *)calloc(((intLength
+ 2)
/ 3)
* 4, sizeof(char));

objPointer = strResult;

//
Iterate through everything

while (intLength
> 2)
{ // keep going until we have less than 24 bits

*objPointer++ = _base64EncodingTable[objRawData[0]
>> 2];

*objPointer++ = _base64EncodingTable[((objRawData[0]
& 0x03)
<< 4)
+ (objRawData[1]
>> 4)];

*objPointer++ = _base64EncodingTable[((objRawData[1]
& 0x0f)
<< 2)
+ (objRawData[2]
>> 6)];

*objPointer++ = _base64EncodingTable[objRawData[2]
& 0x3f];

//
we just handled 3 octets (24 bits) of data

objRawData += 3;

intLength -= 3;

}

//
now deal with the tail end of things

if (intLength
!= 0)
{

*objPointer++ = _base64EncodingTable[objRawData[0]
>> 2];

if (intLength
> 1)
{

*objPointer++ = _base64EncodingTable[((objRawData[0]
& 0x03)
<< 4)
+ (objRawData[1]
>> 4)];

*objPointer++ = _base64EncodingTable[(objRawData[1]
& 0x0f)
<< 2];

*objPointer++ = '=';

} else {

*objPointer++ = _base64EncodingTable[(objRawData[0]
& 0x03)
<< 4];

*objPointer++ = '=';

*objPointer++ = '=';

}

}

//
Terminate the string-based result

*objPointer = '\0';

NSString *rstStr
= [NSString stringWithCString:strResult encoding:NSASCIIStringEncoding];

free(objPointer);

return rstStr;

}

3、AES

-(NSData*)
EncryptAES: (NSString *)
key {

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;

}

4、RSA

- (NSData *)
encryptWithData:(NSData *)content
{

size_t plainLen
= [content length];

if (plainLen
> maxPlainLen)
{

NSLog(@"content(%ld)
is too long, must < %ld", plainLen, maxPlainLen);

return nil;

}

void *plain
= malloc(plainLen);

[content getBytes:plain

length:plainLen];

size_t cipherLen
= 128; //
currently RSA key length is set to 128 bytes

void *cipher
= malloc(cipherLen);

OSStatus returnCode
= SecKeyEncrypt(publicKey, kSecPaddingPKCS1,
plain,

plainLen, cipher, &cipherLen);

NSData *result
= nil;

if (returnCode
!= 0)
{

NSLog(@"SecKeyEncrypt
fail. Error Code: %ld", returnCode);

}

else {

result = [NSData dataWithBytes:cipher

length:cipherLen];

}

free(plain);

free(cipher);

return result;

}