IOS des ECB mode symmetric encryption and decryption

Recently busy with Android and iOS projects, write the android des ECB mode encryption and decryption (related connection: http://blog.csdn.net/vipa1888/article/details/8086037), and return to the IOS above, because I recently started to study IOS this year, so many things on iOS don't understand. After half a year's research, I finally got it done with symmetric encryption and decryption in the ECB mode of des on IOS, I encountered a very serious problem. Many hexadecimal bytes written on the Internet had problems. After my research, I found that one of them was wrong, the decrypted nsstring
Bit null. My code has fixed this issue. The source code is provided below for your reference:

First, paste the header file of the encryption class:

/// Desutil. h // Author: spring sky // QQ: 840950105 // Email: vipa1888@163.com // # import <Foundation/Foundation. h> @ interface desutil: nsobject/** DES encryption */+ (nsstring *) encryptusedes :( nsstring *) plaintext key :( nsstring *) Key; /** des decryption */+ (nsstring *) decryptusedes :( nsstring *) plaintext key :( nsstring *) Key; @ end

Encryption Class implementation class:

/// Desutil. M // Author: spring sky // QQ: 840950105 // Email: vipa1888@163.com // # import "desutil. H "# import <commoncrypto/commoncryptor. h> # import "converutil. H "@ implementation desutilstatic byte IV [] = {1, 2, 4, 5, 6, 7, 8};/* DES encryption */+ (nsstring *) encryptusedes :( nsstring *) cleartext key :( nsstring *) Key {nsstring * ciphertext = nil; nsdata * textdata = [cleartext datausingencoding: nsutf8stringencoding]; nsuinteger datalength = [cleartext length]; unsigned char buffer [1024]; memset (buffer, 0, sizeof (char); size_t numbytesencrypted = 0; cccryptorstatus cryptstatus = cccrypt (kccencrypt, encrypt, decrypt, [Key utf8string], kcckeysizedes, IV, [textdata bytes], datalength, buffer, 1024, & numbytesencrypted); If (cryptstatus = kccsuccess) {nslog (@ "DES encrypted successfully "); nsdata * Data = [nsdata datawithbytes: Buffer length :( nsuinteger) numbytesencrypted]; byte * BB = (byte *) [data bytes]; ciphertext = [converutil parsebytearray2hexstring: BB]; else {nslog (@ "DES encryption failed");} return ciphertext;}/** des decryption */+ (nsstring *) decryptusedes :( nsstring *) plaintext key :( nsstring *) key {nsstring * cleartext = nil; nsdata * textdata = [converutil parsehextobytearray: plaintext]; nsuinteger datalength = [textdata length]; unsigned char buffer [1024]; memset (buffer, 0, sizeof (char); size_t encrypted = 0; cccryptorstatus cryptstatus = cccrypt (kccdecrypt, encrypted, encrypted, [Key utf8string], kcckeysizedes, IV, [textdata bytes], datalength, buffer, 1024, & numbytesencrypted); If (cryptstatus = kccsuccess) {nslog (@ "des decrypted"); nsdata * Data = [nsdata datawithbytes: Buffer length :( nsuinteger) numbytesencrypted]; cleartext = [[nsstring alloc] initwithdata: data encoding: nsutf8stringencoding];} else {nslog (@ "des decryption failed");} return cleartext;} @ end

The following is a transcoding class, mainly hexadecimal and byte conversion header files:

//// Converutil. h // Author: spring sky // QQ: 840950105 // Email: vipa1888@163.com // # import <Foundation/Foundation. h> @ interface converutil: nsobject/** 64 encoding */+ (nsstring *) base64encoding :( nsdata *) text; /** convert byte to hexadecimal number */+ (nsstring *) parsebyte2hexstring :( byte *) bytes; /** convert byte array to hexadecimal number */+ (nsstring *) parsebytearray2hexstring :( byte []) bytes; /* convert hexadecimal data into an nsdata array */+ (nsdata *) parsehextobytearray :( nsstring *) hexstring; @ end

Implementation class:

//// Converutil. M // Author: spring sky // QQ: 840950105 // Email: vipa1888@163.com // # import "converutil. H "@ implementation converutilstatic const char encodingtable [] =" encoding +/";/** 64 encoding */+ (nsstring *) base64encoding :( nsdata *) text {If (text. length = 0) return @ ""; char * characters = malloc (text. length * 3/2); If (characters = NULL) return @ ""; in T end = text. length-3; int Index = 0; int charcount = 0; int n = 0; while (index <= END) {int d = (INT) (char *) [text bytes]) [Index]) & 0x0ff) <16) | (INT) (char *) [text bytes]) [index + 1]) & 0x0ff) <8) | (INT) (char *) [text bytes]) [index + 2]) & 0x0ff ); characters [charcount ++] = encodingtable [(d> 18) & 63]; characters [charcount ++] = encodingtable [(d> 12) & 63]; characters [charc Ount ++] = encodingtable [(d> 6) & 63]; characters [charcount ++] = encodingtable [D & 63]; index + = 3; if (N ++> = 14) {n = 0; characters [charcount ++] = '';}} if (Index = text. length-2) {int d = (INT) (char *) [text bytes]) [Index]) & 0x0ff) <16) | (INT) (char *) [text bytes]) [index + 1]) & 255) <8 ); characters [charcount ++] = encodingtable [(d> 18) & 63]; characters [charcount ++] = encod Ingtable [(d> 12) & 63]; characters [charcount ++] = encodingtable [(d> 6) & 63]; characters [charcount ++] = ';} else if (Index = text. length-1) {int d = (INT) (char *) [text bytes]) [Index]) & 0x0ff) <16; characters [charcount ++] = encodingtable [(d> 18) & 63]; characters [charcount ++] = encodingtable [(d> 12) & 63]; characters [charcount ++] = '; characters [charcount ++] =';} nsstring * Rtnstr = [[nsstring alloc] initwithbytesnocopy: characters length: charcount encoding: nsutf8stringencoding freewhendone: Yes]; return rtnstr ;} /** convert byte to hexadecimal number */+ (nsstring *) parsebyte2hexstring :( byte *) bytes {nsmutablestring * hexstr = [[nsmutablestring alloc] init]; int I = 0; If (bytes) {While (Bytes [I]! = '\ 0') {nsstring * hexbyte = [nsstring stringwithformat: @ "% x", bytes [I] & 0xff]; /// hexadecimal number if ([hexbyte length] = 1) [hexstr appendformat: @ "0% @", hexbyte]; else [hexstr appendformat: @ "% @", hexbyte]; I ++ ;}} nslog (@ "bytes hexadecimal number: % @", hexstr); Return hexstr ;} /** convert byte array to hexadecimal number */+ (nsstring *) parsebytearray2hexstring :( byte []) bytes {nsmutablestring * hexstr = [[nsmutablestring alloc] init]; int I = 0; If (BYT Es) {While (Bytes [I]! = '\ 0') {nsstring * hexbyte = [nsstring stringwithformat: @ "% x", bytes [I] & 0xff]; /// hexadecimal number if ([hexbyte length] = 1) [hexstr appendformat: @ "0% @", hexbyte]; else [hexstr appendformat: @ "% @", hexbyte]; I ++ ;}} nslog (@ "bytes hexadecimal number: % @", hexstr); return [hexstr uppercasestring];} /* convert hexadecimal data into an nsdata array */+ (nsdata *) parsehextobytearray :( nsstring *) hexstring {Int J = 0; byte bytes [hexstring. length]; for (INT I = 0; I <[hexstring length]; I ++) {int int_ch; /// The hexadecimal number after the two hexadecimal numbers are converted. unichar hex_char1 = [hexstring characteratindex: I]; /// the first (high * 16) int int_second in the two hexadecimal numbers; If (hex_char1> = '0' & hex_char1 <= '9 ') int_fill = (hex_char1-48) * 16; // 0 ascll-48 else if (hex_char1> = 'A' & hex_char1 <= 'F') int_fill = (hex_char1-55) * 16; // A's ascll-65 else int_ch1 = (hex_char1-87) * 16; // A's ascll-97 I ++; unichar hex_char2 = [hexstring characteratindex: I]; // The second (low) int int_ch2 in the two hexadecimal numbers; if (hex_char2> = '0' & hex_char2 <= '9') int_ch2 = (hex_char2-48 ); /// 0 ascll-48 else if (hex_char2> = 'A' & hex_char1 <= 'F') int_ch2 = hex_char2-55; /// A's ascll-65 else int_ch2 = hex_char2-87; // A's ascll-97 int_ch = int_ch + int_ch2; bytes [J] = int_ch; /// put the converted number into the byte array J ++;} nsdata * newdata = [[nsdata alloc] initwithbytes: bytes length: hexstring. length/2]; nslog (@ "newdata = % @", newdata); Return newdata ;}@ end

Test results:

19:58:41. 592 [3356: 707]
Plaintext= 1 palmpay key = 12345678.

19:58:41. 599 [3356: 707] desEncrypted

19:58:41. 601 [3356: 707] bytes
Of16Number of hexadecimal: 0be9d717b1478b32

19:58:41. 603 [3356: 707]
Encrypted data:0be9d717b1478b32

19:58:41. 604 [3356: 707] newdata = <0be9d717 b1478b32>

19:58:41. 607 [3356: 707] desDecrypted

19:58:41. 608 [3356: 707]
Decrypted data:1 palmpay

My work is mainly about banking and finance, so I often use various encryption and decryption methods. If you need help, please contact me. If I can solve this problem, I will do my best!

You are welcome to reprint it, but you must retain the copyright!