关于SM4

booniez2020/11/12移动端 iOS安全

这几天看国密相关的资料,看到比较简洁的 SM4 封装代码,因此记录一下。Author By kingly

国密的资料比较少,不需要引入 openssl 的包文件,相对来说比较轻巧。

sm4.c

/*
 * SM4 Encryption alogrithm (SMS4 algorithm)
 * GM/T 0002-2012 Chinese National Standard ref:http://www.oscca.gov.cn/ 
 */

// Test vector 1
// plain: 01 23 45 67 89 ab cd ef fe dc ba 98 76 54 32 10
// key:   01 23 45 67 89 ab cd ef fe dc ba 98 76 54 32 10
// 	   round key and temp computing result:
// 	   rk[ 0] = f12186f9 X[ 0] = 27fad345
// 		   rk[ 1] = 41662b61 X[ 1] = a18b4cb2
// 		   rk[ 2] = 5a6ab19a X[ 2] = 11c1e22a
// 		   rk[ 3] = 7ba92077 X[ 3] = cc13e2ee
// 		   rk[ 4] = 367360f4 X[ 4] = f87c5bd5
// 		   rk[ 5] = 776a0c61 X[ 5] = 33220757
// 		   rk[ 6] = b6bb89b3 X[ 6] = 77f4c297
// 		   rk[ 7] = 24763151 X[ 7] = 7a96f2eb
// 		   rk[ 8] = a520307c X[ 8] = 27dac07f
// 		   rk[ 9] = b7584dbd X[ 9] = 42dd0f19
// 		   rk[10] = c30753ed X[10] = b8a5da02
// 		   rk[11] = 7ee55b57 X[11] = 907127fa
// 		   rk[12] = 6988608c X[12] = 8b952b83
// 		   rk[13] = 30d895b7 X[13] = d42b7c59
// 		   rk[14] = 44ba14af X[14] = 2ffc5831
// 		   rk[15] = 104495a1 X[15] = f69e6888
// 		   rk[16] = d120b428 X[16] = af2432c4
// 		   rk[17] = 73b55fa3 X[17] = ed1ec85e
// 		   rk[18] = cc874966 X[18] = 55a3ba22
// 		   rk[19] = 92244439 X[19] = 124b18aa
// 		   rk[20] = e89e641f X[20] = 6ae7725f
// 		   rk[21] = 98ca015a X[21] = f4cba1f9
// 		   rk[22] = c7159060 X[22] = 1dcdfa10
// 		   rk[23] = 99e1fd2e X[23] = 2ff60603
// 		   rk[24] = b79bd80c X[24] = eff24fdc
// 		   rk[25] = 1d2115b0 X[25] = 6fe46b75
// 		   rk[26] = 0e228aeb X[26] = 893450ad
// 		   rk[27] = f1780c81 X[27] = 7b938f4c
// 		   rk[28] = 428d3654 X[28] = 536e4246
// 		   rk[29] = 62293496 X[29] = 86b3e94f
// 		   rk[30] = 01cf72e5 X[30] = d206965e
// 		   rk[31] = 9124a012 X[31] = 681edf34
// cypher: 68 1e df 34 d2 06 96 5e 86 b3 e9 4f 53 6e 42 46
// 		
// test vector 2
// the same key and plain 1000000 times coumpting 
// plain:  01 23 45 67 89 ab cd ef fe dc ba 98 76 54 32 10
// key:    01 23 45 67 89 ab cd ef fe dc ba 98 76 54 32 10
// cypher: 59 52 98 c7 c6 fd 27 1f 04 02 f8 04 c3 3d 3f 66

#include "sm4.h"
#include <string.h>
#include <stdio.h>

/*
 * 32-bit integer manipulation macros (big endian)
 */
#ifndef GET_ULONG_BE
#define GET_ULONG_BE(n,b,i)                             \
{                                                       \
    (n) = ( (unsigned long) (b)[(i)    ] << 24 )        \
        | ( (unsigned long) (b)[(i) + 1] << 16 )        \
        | ( (unsigned long) (b)[(i) + 2] <<  8 )        \
        | ( (unsigned long) (b)[(i) + 3]       );       \
}
#endif

#ifndef PUT_ULONG_BE
#define PUT_ULONG_BE(n,b,i)                             \
{                                                       \
    (b)[(i)    ] = (unsigned char) ( (n) >> 24 );       \
    (b)[(i) + 1] = (unsigned char) ( (n) >> 16 );       \
    (b)[(i) + 2] = (unsigned char) ( (n) >>  8 );       \
    (b)[(i) + 3] = (unsigned char) ( (n)       );       \
}
#endif

/*
 *rotate shift left marco definition
 *
 */
#define  SHL(x,n) (((x) & 0xFFFFFFFF) << n)
#define ROTL(x,n) (SHL((x),n) | ((x) >> (32 - n)))

#define SWAP(a,b) { unsigned long t = a; a = b; b = t; t = 0; }

/*
 * Expanded SM4 S-boxes
 * Sbox table: 8bits input convert to 8 bits output
 */
 
static const unsigned char SboxTable[16][16] = 
{
{0xd6,0x90,0xe9,0xfe,0xcc,0xe1,0x3d,0xb7,0x16,0xb6,0x14,0xc2,0x28,0xfb,0x2c,0x05},
{0x2b,0x67,0x9a,0x76,0x2a,0xbe,0x04,0xc3,0xaa,0x44,0x13,0x26,0x49,0x86,0x06,0x99},
{0x9c,0x42,0x50,0xf4,0x91,0xef,0x98,0x7a,0x33,0x54,0x0b,0x43,0xed,0xcf,0xac,0x62},
{0xe4,0xb3,0x1c,0xa9,0xc9,0x08,0xe8,0x95,0x80,0xdf,0x94,0xfa,0x75,0x8f,0x3f,0xa6},
{0x47,0x07,0xa7,0xfc,0xf3,0x73,0x17,0xba,0x83,0x59,0x3c,0x19,0xe6,0x85,0x4f,0xa8},
{0x68,0x6b,0x81,0xb2,0x71,0x64,0xda,0x8b,0xf8,0xeb,0x0f,0x4b,0x70,0x56,0x9d,0x35},
{0x1e,0x24,0x0e,0x5e,0x63,0x58,0xd1,0xa2,0x25,0x22,0x7c,0x3b,0x01,0x21,0x78,0x87},
{0xd4,0x00,0x46,0x57,0x9f,0xd3,0x27,0x52,0x4c,0x36,0x02,0xe7,0xa0,0xc4,0xc8,0x9e},
{0xea,0xbf,0x8a,0xd2,0x40,0xc7,0x38,0xb5,0xa3,0xf7,0xf2,0xce,0xf9,0x61,0x15,0xa1},
{0xe0,0xae,0x5d,0xa4,0x9b,0x34,0x1a,0x55,0xad,0x93,0x32,0x30,0xf5,0x8c,0xb1,0xe3},
{0x1d,0xf6,0xe2,0x2e,0x82,0x66,0xca,0x60,0xc0,0x29,0x23,0xab,0x0d,0x53,0x4e,0x6f},
{0xd5,0xdb,0x37,0x45,0xde,0xfd,0x8e,0x2f,0x03,0xff,0x6a,0x72,0x6d,0x6c,0x5b,0x51},
{0x8d,0x1b,0xaf,0x92,0xbb,0xdd,0xbc,0x7f,0x11,0xd9,0x5c,0x41,0x1f,0x10,0x5a,0xd8},
{0x0a,0xc1,0x31,0x88,0xa5,0xcd,0x7b,0xbd,0x2d,0x74,0xd0,0x12,0xb8,0xe5,0xb4,0xb0},
{0x89,0x69,0x97,0x4a,0x0c,0x96,0x77,0x7e,0x65,0xb9,0xf1,0x09,0xc5,0x6e,0xc6,0x84},
{0x18,0xf0,0x7d,0xec,0x3a,0xdc,0x4d,0x20,0x79,0xee,0x5f,0x3e,0xd7,0xcb,0x39,0x48}
};

/* System parameter */
static const unsigned long FK[4] = {0xa3b1bac6,0x56aa3350,0x677d9197,0xb27022dc};

/* fixed parameter */
static const unsigned long CK[32] =
{
0x00070e15,0x1c232a31,0x383f464d,0x545b6269,
0x70777e85,0x8c939aa1,0xa8afb6bd,0xc4cbd2d9,
0xe0e7eef5,0xfc030a11,0x181f262d,0x343b4249,
0x50575e65,0x6c737a81,0x888f969d,0xa4abb2b9,
0xc0c7ced5,0xdce3eaf1,0xf8ff060d,0x141b2229,
0x30373e45,0x4c535a61,0x686f767d,0x848b9299,
0xa0a7aeb5,0xbcc3cad1,0xd8dfe6ed,0xf4fb0209,
0x10171e25,0x2c333a41,0x484f565d,0x646b7279
};


/*
 * private function:
 * look up in SboxTable and get the related value.
 * args:    [in] inch: 0x00~0xFF (8 bits unsigned value).
 */
static unsigned char sm4Sbox(unsigned char inch)
{
    unsigned char *pTable = (unsigned char *)SboxTable;
    unsigned char retVal = (unsigned char)(pTable[inch]);
    return retVal;
}

/*
 * private F(Lt) function:
 * "T algorithm" == "L algorithm" + "t algorithm".
 * args:    [in] a: a is a 32 bits unsigned value;
 * return: c: c is calculated with line algorithm "L" and nonline algorithm "t"
 */
static unsigned long sm4Lt(unsigned long ka)
{
    unsigned long bb = 0;
    unsigned long c = 0;
    unsigned char a[4];
	unsigned char b[4];
    PUT_ULONG_BE(ka,a,0)
    b[0] = sm4Sbox(a[0]);
    b[1] = sm4Sbox(a[1]);
    b[2] = sm4Sbox(a[2]);
    b[3] = sm4Sbox(a[3]);
	GET_ULONG_BE(bb,b,0)
    c =bb^(ROTL(bb, 2))^(ROTL(bb, 10))^(ROTL(bb, 18))^(ROTL(bb, 24));
    return c;
}

/*
 * private F function:
 * Calculating and getting encryption/decryption contents.
 * args:    [in] x0: original contents;
 * args:    [in] x1: original contents;
 * args:    [in] x2: original contents;
 * args:    [in] x3: original contents;
 * args:    [in] rk: encryption/decryption key;
 * return the contents of encryption/decryption contents.
 */
static unsigned long sm4F(unsigned long x0, unsigned long x1, unsigned long x2, unsigned long x3, unsigned long rk)
{
    return (x0^sm4Lt(x1^x2^x3^rk));
}


/* private function:
 * Calculating round encryption key.
 * args:    [in] a: a is a 32 bits unsigned value;
 * return: sk[i]: i{0,1,2,3,...31}.
 */
static unsigned long sm4CalciRK(unsigned long ka)
{
    unsigned long bb = 0;
    unsigned long rk = 0;
    unsigned char a[4];
    unsigned char b[4];
    PUT_ULONG_BE(ka,a,0)
    b[0] = sm4Sbox(a[0]);
    b[1] = sm4Sbox(a[1]);
    b[2] = sm4Sbox(a[2]);
    b[3] = sm4Sbox(a[3]);
	GET_ULONG_BE(bb,b,0)
    rk = bb^(ROTL(bb, 13))^(ROTL(bb, 23));
    return rk;
}

static void sm4_setkey( unsigned long SK[32], unsigned char key[16] )
{
    unsigned long MK[4];
    unsigned long k[36];
    unsigned long i = 0;

    GET_ULONG_BE( MK[0], key, 0 );
    GET_ULONG_BE( MK[1], key, 4 );
    GET_ULONG_BE( MK[2], key, 8 );
    GET_ULONG_BE( MK[3], key, 12 );
    k[0] = MK[0]^FK[0];
    k[1] = MK[1]^FK[1];
    k[2] = MK[2]^FK[2];
    k[3] = MK[3]^FK[3];
    for(; i<32; i++)
    {
        k[i+4] = k[i] ^ (sm4CalciRK(k[i+1]^k[i+2]^k[i+3]^CK[i]));
        SK[i] = k[i+4];
	}

}

/*
 * SM4 standard one round processing
 *
 */
static void sm4_one_round( unsigned long sk[32],
                    unsigned char input[16],
                    unsigned char output[16] )
{
    unsigned long i = 0;
    unsigned long ulbuf[36];

    memset(ulbuf, 0, sizeof(ulbuf));
    GET_ULONG_BE( ulbuf[0], input, 0 )
    GET_ULONG_BE( ulbuf[1], input, 4 )
    GET_ULONG_BE( ulbuf[2], input, 8 )
    GET_ULONG_BE( ulbuf[3], input, 12 )
    while(i<32)
    {
        ulbuf[i+4] = sm4F(ulbuf[i], ulbuf[i+1], ulbuf[i+2], ulbuf[i+3], sk[i]);
// #ifdef _DEBUG
//        	printf("rk(%02d) = 0x%08x,  X(%02d) = 0x%08x \n",i,sk[i], i, ulbuf[i+4] );
// #endif
	    i++;
    }
	PUT_ULONG_BE(ulbuf[35],output,0);
	PUT_ULONG_BE(ulbuf[34],output,4);
	PUT_ULONG_BE(ulbuf[33],output,8);
	PUT_ULONG_BE(ulbuf[32],output,12);
}

/*
 * SM4 key schedule (128-bit, encryption)
 */
void sm4_setkey_enc( sm4_context *ctx, unsigned char key[16] )
{
    ctx->mode = SM4_ENCRYPT;
	sm4_setkey( ctx->sk, key );
}

/*
 * SM4 key schedule (128-bit, decryption)
 */
void sm4_setkey_dec( sm4_context *ctx, unsigned char key[16] )
{
    int i;
	ctx->mode = SM4_ENCRYPT;
    sm4_setkey( ctx->sk, key );
    for( i = 0; i < 16; i ++ )
    {
        SWAP( ctx->sk[ i ], ctx->sk[ 31-i] );
    }
}


/*
 * SM4-ECB block encryption/decryption
 */

void sm4_crypt_ecb( sm4_context *ctx,
				   int mode,
				   int length,
				   unsigned char *input,
                   unsigned char *output)
{
    while( length > 0 )
    {
        sm4_one_round( ctx->sk, input, output );
        input  += 16;
        output += 16;
        length -= 16;
    }

}

/*
 * SM4-CBC buffer encryption/decryption
 */
void sm4_crypt_cbc( sm4_context *ctx,
                    int mode,
                    int length,
                    unsigned char iv[16],
                    unsigned char *input,
                    unsigned char *output )
{
    int i;
    unsigned char temp[16];

    if( mode == SM4_ENCRYPT )
    {
        while( length > 0 )
        {
            for( i = 0; i < 16; i++ )
                output[i] = (unsigned char)( input[i] ^ iv[i] );

            sm4_one_round( ctx->sk, output, output );
            memcpy( iv, output, 16 );

            input  += 16;
            output += 16;
            length -= 16;
        }
    }
    else /* SM4_DECRYPT */
    {
        while( length > 0 )
        {
            memcpy( temp, input, 16 );
            sm4_one_round( ctx->sk, input, output );

            for( i = 0; i < 16; i++ )
                output[i] = (unsigned char)( output[i] ^ iv[i] );

            memcpy( iv, temp, 16 );

            input  += 16;
            output += 16;
            length -= 16;
        }
    }
}

sm4.h

/**
 * \file sm4.h
 */
#ifndef XYSSL_SM4_H
#define XYSSL_SM4_H

#define SM4_ENCRYPT     1
#define SM4_DECRYPT     0

/**
 * \brief          SM4 context structure
 */
typedef struct
{
    int mode;                   /*!<  encrypt/decrypt   */
    unsigned long sk[32];       /*!<  SM4 subkeys       */
}
sm4_context;


#ifdef __cplusplus
extern "C" {
#endif

/**
 * \brief          SM4 key schedule (128-bit, encryption)
 *
 * \param ctx      SM4 context to be initialized
 * \param key      16-byte secret key
 */
void sm4_setkey_enc( sm4_context *ctx, unsigned char key[16] );

/**
 * \brief          SM4 key schedule (128-bit, decryption)
 *
 * \param ctx      SM4 context to be initialized
 * \param key      16-byte secret key
 */
void sm4_setkey_dec( sm4_context *ctx, unsigned char key[16] );

/**
 * \brief          SM4-ECB block encryption/decryption
 * \param ctx      SM4 context
 * \param mode     SM4_ENCRYPT or SM4_DECRYPT
 * \param length   length of the input data
 * \param input    input block
 * \param output   output block
 */
void sm4_crypt_ecb( sm4_context *ctx,
				     int mode,
					 int length,
                     unsigned char *input,
                     unsigned char *output);

/**
 * \brief          SM4-CBC buffer encryption/decryption
 * \param ctx      SM4 context
 * \param mode     SM4_ENCRYPT or SM4_DECRYPT
 * \param length   length of the input data
 * \param iv       initialization vector (updated after use)
 * \param input    buffer holding the input data
 * \param output   buffer holding the output data
 */
void sm4_crypt_cbc( sm4_context *ctx,
                     int mode,
                     int length,
                     unsigned char iv[16],
                     unsigned char *input,
                     unsigned char *output );

#ifdef __cplusplus
}
#endif

#endif /* sm4.h */

paddingBytes.c

#include "paddingBytes.h"
#include <stdlib.h>
#include <string.h>


/**
 为要加密的原文进行填充字节

 @param input unsigned char  要加密的字符串
 @param stringLength unsigned long  输入参数:要加密的字符串的长度
 */
void paddingForEncryption(unsigned char **input, unsigned long stringLength)
{
    unsigned long length = stringLength;
    if (!*input || length <= 0)
    {
        return;
    }
    
    int mod = 16 - length % 16;
    length = length + mod;
    unsigned char *modChar = (unsigned char*)malloc(sizeof(unsigned char) * (mod + 1));
    memset(modChar, 0, mod + 1);
    memset(modChar, mod, mod);
    
    unsigned char *newChar = (unsigned char*)malloc(sizeof(unsigned char) * (length + 1));
    memset(newChar, 0, length + 1);
    unsigned char *pNewChar = newChar;
    
    unsigned char *pInput = *input;
    
    while (*pInput)
    {
        *pNewChar = *pInput;
        ++pNewChar;
        ++pInput;
    }
    
    unsigned char *pModChar = modChar;
    while (*pModChar)
    {
        *pNewChar = *pModChar;
        ++pNewChar;
        ++pModChar;
    }
    
    pInput = NULL;
    pNewChar = NULL;
    pModChar = NULL;
    free(modChar);
    free(*input);
    *input = newChar;
}

/**
 为已解密的消息去掉填充的字节

 @param input unsigned char  要解密的字符串
 @param stringLength unsigned long 输出参数:字符串的实际长度
 */
void unpaddingForDecryption(unsigned char **input, unsigned long *stringLength)
{
    if (!*input)
    {
        return;
    }
    
    size_t length = 0;
    unsigned char *pInput = *input;
    while (*pInput)
    {
        ++length;
        ++pInput;
    }
    
    //将pInput指向最后一个字节
    --pInput;
    
    //将后面mod个字节置为0
    int mod = *pInput;
    *stringLength = length - mod;
    
    while (mod)
    {
        *pInput = 0;
        --mod;
        --pInput;
    }
}

paddingBytes.h

#ifndef paddingBytes_h
#define paddingBytes_h

#include <stdio.h>

/**
 *
 *  对要加密的字符串进行补足字节
 *
 *  @param input        要加密的字符串
 *  @param stringLength 输入参数:要加密的字符串的长度
 */
void paddingForEncryption(unsigned char **input, unsigned long stringLength);


/**
 *
 *  补足字节的反操作
 *
 *  @param input        要解密的字符串
 *  @param stringLength 输出参数:字符串的实际长度
 */
void unpaddingForDecryption(unsigned char **input, unsigned long *stringLength);

#endif /* paddingBytes_h */

NSString+KYSM4.h

#import <Foundation/Foundation.h>

@interface NSString (KYSM4)

/**
 *  使用密钥和初始化向量生成CBC模式的SM4加解密对象
 *
 *  @param secretKey 密钥
 *  @param iv        初始化向量
 *
 *  @return SM4加密字符串
 */
- (nullable NSString *)encryptionWithSM4Key:(nonnull NSString *)secretKey iv:(nonnull NSString *)iv;

/**
 在CBC模式下,利用给定的密钥,初始化向量,对字符串解密

 @param secretKey 密钥
 @param iv 初始化向量
 @return SM4解密字符串
 */
- (nullable NSString *)decryptionWithSM4Key:(nonnull NSString *)secretKey iv:(nonnull NSString *)iv;
/**
 *  使用密钥生成ECB模式的SM4加解密对象
 *
 *  @param secretKey 密钥
 *
 *  @return SM4加解密对象
 */
- (nullable NSString *)encryptionWithSM4Key:(nonnull NSString *)secretKey;

/**
 *  在ECB模式下,利用给定的密钥,对字符串解密
 *
 *  @param secretKey 密钥
 *
 *  @return SM4解密字符串
 */
- (nullable NSString *)decryptionWithSM4Key:(nonnull NSString *)secretKey;

@end

NSString+KYSM4.m

#import "NSString+KYSM4.h"
#import "sm4.h"
#import "paddingBytes.h"


@implementation NSString (KYSM4)


/**
 *  使用密钥和初始化向量生成CBC模式的SM4加解密对象
 *
 *  @param secretKey 密钥
 *  @param iv        初始化向量
 *
 *  @return SM4加密字符串
 */
- (nullable NSString *)encryptionWithSM4Key:(nonnull NSString *)secretKey iv:(nonnull NSString *)iv {
    
    if ([secretKey length] != 16 || [iv length] != 16 || self == nil || [self length] == 0)
    {
#ifdef DEBUG
        NSLog(@"CBC模式 encryptionWithSM4Key方法入参有问题");
#endif
        return nil;
    }
    
    NSData *keyData = [secretKey dataUsingEncoding:NSUTF8StringEncoding];
    const char *keyChar = [secretKey cStringUsingEncoding:NSUTF8StringEncoding];
    size_t keyLength = [keyData length];
    
    NSData *msgData = [self dataUsingEncoding:NSUTF8StringEncoding];
    const char *msgChar = [self cStringUsingEncoding:NSUTF8StringEncoding];
    size_t msgLength = [msgData length];
    
    NSData *ivData = [iv dataUsingEncoding:NSUTF8StringEncoding];
    const char *ivChar = [iv cStringUsingEncoding:NSUTF8StringEncoding];
    size_t ivLength = [ivData length];
    
    int paddingLength = 16 - (int)msgLength % 16 + (int)msgLength;
    
    unsigned char *pKey = (unsigned char*)malloc(sizeof(unsigned char) * (keyLength + 1));
    memset(pKey, 0, keyLength + 1);
    unsigned char *pfreeKey = pKey;
    unsigned char *pMsg = (unsigned char*)malloc(sizeof(unsigned char) * (msgLength + 1));
    memset(pMsg, 0, msgLength + 1);
    
    unsigned char *pIv = (unsigned char*)malloc(sizeof(unsigned char) * (ivLength + 1));
    memset(pIv, 0, ivLength + 1);
    unsigned char *pfreeIv = pIv;
    unsigned char *output = (unsigned char*)malloc(sizeof(unsigned char) * (paddingLength + 1));
    memset(output, 0, paddingLength + 1);
    unsigned char *pfreeoutput = output;
    
    unsigned char *pKeyChar = (unsigned char *)keyChar;
    unsigned char *pMsgChar = (unsigned char *)msgChar;
    unsigned char *pIvChar = (unsigned char *)ivChar;
    unsigned char *currentKey = (unsigned char *)pKey;
    unsigned char *currentMsg = (unsigned char *)pMsg;
    unsigned char *currentIv = (unsigned char *)pIv;
    unsigned char *pOutput = output;
    
    while (*pKeyChar)
    {
        *currentKey = *pKeyChar;
        ++pKeyChar;
        ++currentKey;
    }
    pKeyChar = NULL;
    currentKey = NULL;
    
    while (*pMsgChar)
    {
        *currentMsg = *pMsgChar;
        ++pMsgChar;
        ++currentMsg;
    }
    pMsgChar = NULL;
    currentMsg = NULL;
    
    while (*pIvChar)
    {
        *currentIv = *pIvChar;
        ++pIvChar;
        ++currentIv;
    }
    pIvChar = NULL;
    currentIv = NULL;
    
    paddingForEncryption(&pMsg, msgLength);
    unsigned char *pfreeMsg = pMsg;
    
    sm4_context ctx;
    sm4_setkey_enc(&ctx, pKey);
    sm4_crypt_cbc(&ctx,1,paddingLength,(unsigned char *)pIv,(unsigned char *)pMsg,(unsigned char *)output);
    
    //base64加密
    NSData *outdata = [NSData dataWithBytes:pOutput length:paddingLength];
    NSString *base64string = [outdata base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
    
    free(pfreeKey);
    free(pfreeIv);
    free(pfreeMsg);
    free(pfreeoutput);
    pKey = NULL;
    pIv = NULL;
    pMsg = NULL;
    pOutput = NULL;
    pfreeoutput = NULL;
    pfreeMsg = NULL;
    pfreeIv = NULL;
    pfreeKey = NULL;
    
    return base64string;
}

/**
 在CBC模式下,利用给定的密钥,初始化向量,对字符串解密
 
 @param secretKey 密钥
 @param iv 初始化向量
 @return SM4解密字符串
 */
- (nullable NSString *)decryptionWithSM4Key:(nonnull NSString *)secretKey iv:(nonnull NSString *)iv {
    
    if ([secretKey length] != 16 || [iv length] != 16 || self == nil || [self length] == 0)
    {
#ifdef DEBUG
        NSLog(@"CBC模式 decryptionWithSM4Key方法入参有问题");
#endif
        return nil;
    }
    
    NSData *keyData = [secretKey dataUsingEncoding:NSUTF8StringEncoding];
    const char *keyChar = [secretKey cStringUsingEncoding:NSUTF8StringEncoding];
    size_t keyLength = [keyData length];
    
    //base64解密
    NSData *msgData = [[NSData alloc]initWithBase64EncodedString:self options:NSDataBase64DecodingIgnoreUnknownCharacters];
    size_t msgLength = [msgData length];
    
    NSData *ivData = [iv dataUsingEncoding:NSUTF8StringEncoding];
    const char *ivChar = [iv cStringUsingEncoding:NSUTF8StringEncoding];
    size_t ivLength = [ivData length];
    
    unsigned char *pKey = (unsigned char*)malloc(sizeof(unsigned char) * (keyLength + 1));
    unsigned char *pfreeKey = pKey;
    memset(pKey, 0, keyLength + 1);
    unsigned char *pMsg = (unsigned char*)malloc(sizeof(unsigned char) * (msgLength + 1));
    memset(pMsg, 0, msgLength + 1);
    unsigned char *pfreeMsg = pMsg;
    unsigned char *pIv = (unsigned char*)malloc(sizeof(unsigned char) * (ivLength + 1));
    memset(pIv, 0, ivLength + 1);
    unsigned char *pfreeIv = pIv;
    unsigned char *output = (unsigned char*)malloc(sizeof(unsigned char) * (msgLength + 1));
    memset(output, 0, msgLength + 1);
    
    
    unsigned char *pKeyChar = (unsigned char *)keyChar;
    unsigned char *pIvChar = (unsigned char *)ivChar;
    unsigned char *currentKey = (unsigned char *)pKey;
    __block unsigned char *currentMsg = (unsigned char *)pMsg;
    unsigned char *currentIv = (unsigned char *)pIv;
    unsigned char *pOutput = output;
    
    while (*pKeyChar)
    {
        *currentKey = *pKeyChar;
        ++pKeyChar;
        ++currentKey;
    }
    pKeyChar = NULL;
    currentKey = NULL;
    
    [msgData enumerateByteRangesUsingBlock:^(const void *bytes, NSRange byteRange, BOOL *stop) {
        for (NSInteger i = 0; i < byteRange.length; i++)
        {
            *currentMsg = *((unsigned char*)bytes + i);
            ++currentMsg;
        }
    }];
    currentMsg = NULL;
    
    while (*pIvChar)
    {
        *currentIv = *pIvChar;
        ++pIvChar;
        ++currentIv;
    }
    pIvChar = NULL;
    currentIv = NULL;
    
    
    sm4_context ctx;
    sm4_setkey_dec(&ctx, pKey);
    sm4_crypt_cbc(&ctx,0,(int)msgLength,(unsigned char *)pIv,(unsigned char *)pMsg,(unsigned char *)pOutput);
    
    unsigned long stringLength = 0;
    unpaddingForDecryption(&output, &stringLength);
    unsigned char *pfreeoutput = output;
    
    NSString *outString = [[NSString alloc]initWithBytes:output length:stringLength encoding:NSUTF8StringEncoding];
    
    free(pfreeKey);
    free(pfreeIv);
    free(pfreeMsg);
    free(pfreeoutput);
    pKey = NULL;
    pIv = NULL;
    pMsg = NULL;
    pOutput = NULL;
    output = NULL;
    pfreeKey = NULL;
    pfreeIv = NULL;
    pfreeMsg = NULL;
    pfreeoutput = NULL;
    
    return outString;
    
}
/**
 *  使用密钥生成ECB模式的SM4加解密对象
 *
 *  @param secretKey 密钥
 *
 *  @return SM4加解密对象
 */
- (nullable NSString *)encryptionWithSM4Key:(nonnull NSString *)secretKey {
    
    if ([secretKey length] != 16 || self == nil || [self length] == 0)
    {
#ifdef DEBUG
        NSLog(@"ECB模式 encryptionWithSM4Key方法入参有问题");
#endif
        return nil;
    }
    
    NSData *keyData = [secretKey dataUsingEncoding:NSUTF8StringEncoding];
    const char *keyChar = [secretKey cStringUsingEncoding:NSUTF8StringEncoding];
    size_t keyLength = [keyData length];
    
    NSData *msgData = [self dataUsingEncoding:NSUTF8StringEncoding];
    const char *msgChar = [self cStringUsingEncoding:NSUTF8StringEncoding];
    size_t msgLength = [msgData length];
    
    
    int paddingLength = 16 - (int)msgLength % 16 + (int)msgLength;
    
    unsigned char *pKey = (unsigned char*)malloc(sizeof(unsigned char) * (keyLength + 1));
    memset(pKey, 0, keyLength + 1);
    unsigned char *pfreeKey = pKey;
    
    unsigned char *pMsg = (unsigned char*)malloc(sizeof(unsigned char) * (msgLength + 1));
    memset(pMsg, 0, msgLength + 1);
    
    unsigned char *output = (unsigned char*)malloc(sizeof(unsigned char) * (paddingLength + 1));
    memset(output, 0, paddingLength + 1);
    unsigned char *pfreeoutput = output;
    
    unsigned char *pKeyChar = (unsigned char *)keyChar;
    unsigned char *pMsgChar = (unsigned char *)msgChar;
    unsigned char *currentKey = (unsigned char *)pKey;
    unsigned char *currentMsg = (unsigned char *)pMsg;
    unsigned char *pOutput = output;
    
    while (*pKeyChar)
    {
        *currentKey = *pKeyChar;
        ++pKeyChar;
        ++currentKey;
    }
    
    while (*pMsgChar)
    {
        *currentMsg = *pMsgChar;
        ++pMsgChar;
        ++currentMsg;
    }
    
    
    paddingForEncryption(&pMsg, msgLength);
    unsigned char *pfreeMsg = pMsg;
    
    sm4_context ctx;
    sm4_setkey_enc(&ctx, pKey);
    sm4_crypt_ecb(&ctx,1,paddingLength,(unsigned char *)pMsg,(unsigned char *)output);
    
    //base64加密
    NSData *outdata = [NSData dataWithBytes:pOutput length:paddingLength];
    NSString *base64string = [outdata base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
    
    free(pfreeKey);
    free(pfreeMsg);
    free(pfreeoutput);
    pKey = NULL;
    pMsg = NULL;
    pOutput = NULL;
    output = NULL;
    pfreeoutput = NULL;
    pfreeMsg = NULL;
    pfreeKey = NULL;
    
    return base64string;
    
}

/**
 *  在ECB模式下,利用给定的密钥,对字符串解密
 *
 *  @param secretKey 密钥
 *
 *  @return SM4解密字符串
 */
- (nullable NSString *)decryptionWithSM4Key:(nonnull NSString *)secretKey {
    
    if ([secretKey length] != 16 || self == nil || [self length] == 0)
    {
#ifdef DEBUG
        NSLog(@"ECB模式 decryptionWithSM4Key方法入参有问题");
#endif
        return nil;
    }
    
    NSData *keyData = [secretKey dataUsingEncoding:NSUTF8StringEncoding];
    const char *keyChar = [secretKey cStringUsingEncoding:NSUTF8StringEncoding];
    size_t keyLength = [keyData length];
    
    //base64解密
    NSData *msgData = [[NSData alloc]initWithBase64EncodedString:self options:NSDataBase64DecodingIgnoreUnknownCharacters];
    size_t msgLength = [msgData length];
    
    
    unsigned char *pKey = (unsigned char*)malloc(sizeof(unsigned char) * (keyLength + 1));
    memset(pKey, 0, keyLength + 1);
    unsigned char *pfreeKey = pKey;
    
    unsigned char *pMsg = (unsigned char*)malloc(sizeof(unsigned char) * (msgLength + 1));
    memset(pMsg, 0, msgLength + 1);
    unsigned char *pfreeMsg = pMsg;
    
    unsigned char *output = (unsigned char*)malloc(sizeof(unsigned char) * (msgLength + 1));
    memset(output, 0, msgLength + 1);
    
    unsigned char *pKeyChar = (unsigned char *)keyChar;
    unsigned char *currentKey = (unsigned char *)pKey;
    __block unsigned char *currentMsg = (unsigned char *)pMsg;
    unsigned char *pOutput = output;
    
    while (*pKeyChar)
    {
        *currentKey = *pKeyChar;
        ++pKeyChar;
        ++currentKey;
    }
    
    [msgData enumerateByteRangesUsingBlock:^(const void *bytes, NSRange byteRange, BOOL *stop) {
        for (NSInteger i = 0; i < byteRange.length; i++)
        {
            *currentMsg = *((unsigned char*)bytes + i);
            ++currentMsg;
        }
    }];
    
    
    sm4_context ctx;
    sm4_setkey_dec(&ctx, pKey);
    sm4_crypt_ecb(&ctx,0,(int)msgLength,(unsigned char *)pMsg,(unsigned char *)output);
    
    unsigned long stringLength = 0;
    unpaddingForDecryption(&pOutput, &stringLength);
    unsigned char *pfreeoutput = pOutput;
    
    NSString *outString = [[NSString alloc]initWithBytes:pOutput length:stringLength encoding:NSUTF8StringEncoding];
    
    free(pfreeKey);
    free(pfreeoutput);
    free(pfreeMsg);
    pKey = NULL;
    pMsg = NULL;
    pOutput = NULL;
    output = NULL;
    pfreeMsg = NULL;
    pfreeoutput = NULL;
    pfreeKey = NULL;
    
    return outString;
    
}
@end
最后更新 7/10/2024, 5:45:07 AM
评论
  • 按正序
  • 按倒序
  • 按热度
Powered by Waline v2.15.8