ios - Checksum and XOR in Swift -

i worte these methods in objective-c. they're checksum , xor nsdata

- (void)xor:(nsmutabledata *)inputdata withkey:(nsdata *)key {     unsigned char* inputbytedata = (unsigned char*)[inputdata mutablebytes];     unsigned char* keybytedata   = (unsigned char*)[key bytes];     (int = 0; < [inputdata length]; i++)     {         inputbytedata[i] = inputbytedata[i] ^ keybytedata[i % [key length]];     } }  - (byte)checksum:(nsmutabledata *)data withlength:(byte)datalength {     byte * databyte = (byte *)malloc(datalength);     memcpy(databyte, [data bytes], datalength);      byte result = 0;     int count = 0;     while (datalength>0) {         result += databyte[count];         datalength--;         count++;     };     result = result&0xff;     return result&0xff; } 

however, i'm not familiar bitwise operators, in swift, these unsafemutablepointer<void>... things.

can me converting ? (basically, need checksum , xor functions)
1 more things, should put in nsdata/nsmutabledata extension ?

thank you.

unsafebufferpointer/unsafemutablebufferpointer might need now. i've tried translating code swift below. (but code not tested well.)

func xor(inputdata: nsmutabledata, withkey key: nsdata) {     let b = unsafemutablebufferpointer<uint8>(start:         unsafemutablepointer(inputdata.mutablebytes), count: inputdata.length)      let k = unsafebufferpointer<uint8>(start:         unsafepointer(key.bytes), count: key.length)      in 0..<inputdata.length {         b[i] ^= k[i % key.length]     } }  func checksum(data: nsdata) -> int {     let b = unsafebufferpointer<uint8>(start:         unsafepointer(data.bytes), count: data.length)      var sum = 0     in 0..<data.length {         sum += int(b[i])     }     return sum & 0xff }