Implementation of AES encryption and decryption algorithm for iOS development objective-c

Original: http://www.lidaren.com/archives/1470

Advanced Encryption Standard (encryption Standard,aes), also known as Rijndael encryption method. The following implementation code adds a category for NSData and NSString, respectively. Can be called directly when used.

It should be noted that AES is not a hash algorithm, encrypted and decrypted results, and not necessarily the same as the original, please pay attention to the results of the calculation. such as decoding the length of the original text, formatting rules. ng Instance Original: 170987350 password:objective-c The specific implementation code of AES encryption and decryption algorithm is as follows: 1. Expand NSData, add AES256 encryption method  

1 //2 //nsdata+aes256.h3 //4  5 #import<Foundation/Foundation.h>6 #import<CommonCrypto/CommonDigest.h>7 #import<CommonCrypto/CommonCryptor.h>8  9 @interfaceNSData (AES256)Ten-(NSData *) Aes256_encrypt: (NSString *) key; One-(NSData *) Aes256_decrypt: (NSString *) key; A @end -   -   the // - //NSDATA+AES256.M - // - #import "nsdata+aes256.h" +   - @implementationNSData (AES256) +   A-(NSData *) Aes256_encrypt: (NSString *) key//Encrypt at { -   Charkeyptr[kcckeysizeaes256+1]; -Bzero (Keyptr,sizeof(keyptr)); -[Key getcstring:keyptr MaxLength:sizeof(KEYPTR) encoding:nsutf8stringencoding]; -Nsuinteger datalength =[self length]; -size_t buffersize = datalength +kCCBlockSizeAES128; in   void*buffer =malloc (buffersize); -size_t numbytesencrypted =0; toCccryptorstatus Cryptstatus =Cccrypt (Kccencrypt, kCCAlgorithmAES128, +kccoptionpkcs7padding |Kccoptionecbmode, - keyptr, kCCBlockSizeAES128, the NULL, * [Self bytes], datalength, $ buffer, buffersize,Panax Notoginseng&numbytesencrypted); -   if(Cryptstatus = =kccsuccess) { the     return[NSData Datawithbytesnocopy:buffer length:numbytesencrypted]; +   } A Free (buffer); the   returnNil; + } -   $   $-(NSData *) Aes256_decrypt: (NSString *) key//decryption - { -   Charkeyptr[kcckeysizeaes256+1]; theBzero (Keyptr,sizeof(keyptr)); -[Key getcstring:keyptr MaxLength:sizeof(KEYPTR) encoding:nsutf8stringencoding];WuyiNsuinteger datalength =[self length]; thesize_t buffersize = datalength +kCCBlockSizeAES128; -   void*buffer =malloc (buffersize); Wusize_t numbytesdecrypted =0; -Cccryptorstatus Cryptstatus =Cccrypt (Kccdecrypt, kCCAlgorithmAES128, Aboutkccoptionpkcs7padding |Kccoptionecbmode, $ keyptr, kCCBlockSizeAES128, - NULL, - [Self bytes], datalength, - buffer, buffersize, A&numbytesdecrypted); +   if(Cryptstatus = =kccsuccess) { the     return[NSData Datawithbytesnocopy:buffer length:numbytesdecrypted]; -   $   } the Free (buffer); the   returnNil; the } the @end - 2Expand NSString, add AES256 encryption method, need to import nsdata+AES256.h in  the   the // About //NSString +aes256.h the // the   the #import<Foundation/Foundation.h> + #import<CommonCrypto/CommonDigest.h> - #import<CommonCrypto/CommonCryptor.h> the  Bayi #import "nsdata+aes256.h" the   the @interfacensstring (AES256) -   --(NSString *) Aes256_encrypt: (NSString *) key; the-(NSString *) Aes256_decrypt: (NSString *) key; the   the @end the   -   the // the //NSString +aes256.h the //94   the @implementationnsstring (AES256) the   the-(NSString *) Aes256_encrypt: (NSString *) Key98 { About   Const Char*cstr =[self cstringusingencoding:nsutf8stringencoding]; -NSData *data =[NSData datawithbytes:cstr length:self.length];101   //Encrypt the data102NSData *result =[Data Aes256_encrypt:key];103  104   //Convert to 2 binary string the   if(Result && result.length >0) {106  107Byte *datas = (byte*) [result bytes];108nsmutablestring *output = [nsmutablestring stringWithCapacity:result.length *2];109      for(inti =0; i < result.length; i++){ the[Output AppendFormat:@"%02x", Datas[i]];111     } the     returnoutput;113   } the   returnNil; the } the  117-(NSString *) Aes256_decrypt: (NSString *) Key118 {   119   //Convert to 2 binary data -Nsmutabledata *data = [Nsmutabledata dataWithCapacity:self.length/2];121UnsignedCharWhole_byte;122   Charbyte_chars[3] = {' /',' /',' /'};123   inti;124    for(i=0; i < [self length]/2; i++) { thebyte_chars[0] = [Self characteratindex:i*2];126byte_chars[1] = [Self characteratindex:i*2+1];127Whole_byte = Strtol (Byte_chars, NULL, -); -[Data appendbytes:&whole_byte Length:1];129   } the  131   //Decrypt the data thensdata* result =[Data Aes256_decrypt:key];133   if(Result && result.length >0) {134     return[[NSString alloc] Initwithdata:result encoding:nsutf8stringencoding];135   }136   returnNil;137 }138 @end

Implementation of AES encryption and decryption algorithm for iOS development objective-c