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

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 instances

Original: 170987350 Password: 170

The specific implementation code for the AES encryption and decryption algorithm for OBJECTIVE-C is as follows: 1. Expand NSData, add AES256 encryption method

//Nsdata+aes256.h//#import <Foundation/Foundation.h>#import <CommonCrypto/CommonDigest.h>#import <CommonCrypto/CommonCryptor.h> @Interface NSData (AES256)-(NSData *) Aes256_encrypt: (NSString *) key;-(NSData *) Aes256_decrypt: (NSString *) key; @end//Nsdata+aes256.m//#import "Nsdata+aes256.h" @implementation NSData (AES256)-(NSData *) Aes256_encrypt: (NSString *) keyEncryption 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 *) Aes256_decrypt: (NSString *) keyDecrypt 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); Span class= "indent" > if (cryptstatus = kccsuccess) { return [nsdata datawithbytesnocopy:buffer length:numbytesdecrypted]; Span class= "indent" >} free (buffer); return nil;} @end

2. Expand NSString, add AES256 encryption method, need to import nsdata+aes256.h

//NSString +aes256.h// #Import <foundation/foundation.h>#Import <commoncrypto/commondigest.h>#Import <CommonCrypto/CommonCryptor.h> #Import"Nsdata+aes256.h" @interface nsstring (AES256)-(NSString *) Aes256_encrypt: (NSString *) key;-(NSString *) aes256_ Decrypt: (NSString *) key; @end//NSString +aes256.h@implementation NSString (AES256)-(NSString *) Aes256_encrypt: (NSString *) key{ Constchar *cstr = [self cstringusingencoding:nsutf8stringencoding];NSData *data = [NSData datawithbytes:cstr length:self.length]; Encrypt the dataNSData *result = [data Aes256_encrypt:key]; Convert to 2 binary string If (Result && result.length >0) { Byte *datas = (byte*) [result bytes]; nsmutablestring *output = [nsmutablestring stringWithCapacity:result.length *2]; Forint i =0; i < result.length; i++) { [Output appendformat:@"%02x", Datas[i]]; } return output;} return nil;} -(NSString *) Aes256_decrypt: (NSString *) key{ Convert to 2 binary dataNsmutabledata *data = [Nsmutabledata dataWithCapacity:self.length/2];UnsignedChar Whole_byte; Char byte_chars[3] = {' A ',' A ',' N '}; int i; for (i=0; i < [self length]/2; i++) { byte_chars[0] = [self characteratindex:i*2]; Byte_chars[1] = [self characteratindex:i*2+1]; Whole_byte = Strtol (Byte_chars, NULL, 16); [data appendbytes:&whole_byte Length:1]; //decrypt data nsdata* result = [Data aes256_ Decrypt:key]; if (result && result.length > 0) { return [[NSString alloc] Initwithdata:result encoding: Nsutf8stringencoding]autorelease]; } return nil;} @end

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