ios - Objective C encryption code not working like Android AES 256, md5 encryption -

i encrypting text send server using "aes256/pkcs5padding/ecb" encryption. following code android works encrypted data decrypted in nodejs server.

public static string encryptaes_java_node(string content, string key) {                 byte[] input;               string query = null;               try {                      input = content.getbytes("utf-8");                        messagedigest md = messagedigest.getinstance("md5");                      byte[] thedigest = md.digest(key.getbytes("utf-8"));                      secretkeyspec skc = new secretkeyspec(thedigest,                                   "aes/ecb/pkcs5padding");                      cipher cipher = cipher.getinstance("aes/ecb/pkcs5padding");                      cipher.init(cipher.encrypt_mode, skc);                        byte[] ciphertext = newbyte[cipher.getoutputsize(input.length)];                      int ctlength = cipher.update(input, 0, input.length, ciphertext, 0);                      ctlength += cipher.dofinal(ciphertext, ctlength);                        query = base64.encodetostring(ciphertext, base64.default);                                    } catch (unsupportedencodingexception e) {                      // todo auto-generated catch block                      e.printstacktrace();               } catch (nosuchalgorithmexception e) {                      // todo auto-generated catch block                      e.printstacktrace();               } catch (nosuchpaddingexception e) {                      // todo auto-generated catch block                      e.printstacktrace();               } catch (invalidkeyexception e) {                      // todo auto-generated catch block                      e.printstacktrace();               } catch (illegalblocksizeexception e) {                      // todo auto-generated catch block                      e.printstacktrace();               } catch (shortbufferexception e) {                      // todo auto-generated catch block                      e.printstacktrace();               } catch (badpaddingexception e) {                      // todo auto-generated catch block                      e.printstacktrace();               }               return query;          } 

here code in objc

(nsstring *)encrypttext:(nsstring *)rawtext withkey:(nsstring *)key {     // 'key' should 32 bytes aes256, null-padded otherwise     char keyptr[kcckeysizeaes256+1]; // room terminator (unused)     bzero(keyptr, sizeof(keyptr)); // fill zeroes (for padding)       nsdata *rawdata = [rawtext datausingencoding:nsutf8stringencoding];      //convert hash     nsstring *md5key = [self md5string:key];      // fetch key data     [md5key getcstring:keyptr maxlength:sizeof(keyptr) encoding:nsutf8stringencoding];      nsuinteger datalength = [rawdata length];      //see doc: block ciphers, output size less or     //equal input size plus size of 1 block.     //that's why need add size of 1 block here     size_t buffersize = datalength + kccblocksizeaes128;     void *buffer = malloc(buffersize);      size_t numbytesencrypted = 0;     cccryptorstatus cryptstatus = cccrypt(kccencrypt, kccalgorithmaes128, kccoptionpkcs7padding + kccoptionecbmode,                                           keyptr, kcckeysizeaes256,                                           null /* initialization vector (optional) */,                                           [rawdata bytes], datalength, /* input */                                           buffer, buffersize, /* output */                                           &numbytesencrypted);     if (cryptstatus == kccsuccess) {         //the returned nsdata takes ownership of buffer , free on deallocation         nsdata *tempdata  = [nsdata datawithbytesnocopy:buffer length:numbytesencrypted];         nsstring* encrypted64 = [tempdata base64encodedstringwithoptions:0];//even have tried base 64 encding other options available         return encrypted64;     }      free(buffer); //free buffer;     return nil; } 

am making mistake while converting key md5 done in android?

adding code decryption in nodejs service reference.

var decipher = crypto.createdecipher('aes-128-ecb', encryption_key);              chunks = []             chunks.push( decipher.update( new buffer(fullbuffer, "base64").tostring("binary")) );             chunks.push( decipher.final('binary') );             var txt = chunks.join("");             txt = new buffer(txt, "binary").tostring("utf-8");  // encryption_key = key, fullbuffer input , txt output 

md5 produces 16-byte result.

the java see key , use aes128 uses 16-byte key. better explicitly specify key size in java version using: "aes/ecb/nopadding (128)".

the ios version explicitly specifying aes256 uses 32-byte key , null pad 16-byts 32-bytes.

in ios version change encryption aes16: kcckeysizeaes128.

there security issues:

1. using md5 create key string not secure, current practice use key derivation function such pbkdf2 iteration count , random salt passed pre-pended encrypted data.

2. ecb mode not secure, better use cbc mode random iv , pre-pend iv encrypted data.

   but if security not important md5 , ecb fine.