常见的几种加密方法

常见的几种加密方法和实

常见的几种加密方法：

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csdn demo下载

MD5

SHA1

RSA

AES

DES

1、MD5加密是HASH算法一种、是生成32位的数字字母混合码。 MD5主要特点是不可逆

MD5算法还具有以下性质：

1、压缩性：任意长度的数据，算出的MD5值长度都是固定的。

2、容易计算：从原数据计算出MD5值很容易。

3、抗修改性：对原数据进行任何改动，哪怕只修改1个字节，所得到的MD5值都有很大区别。

4、弱抗碰撞：已知原数据和其MD5值，想找到一个具有相同MD5值的数据（即伪造数据）是非常困难的。

5、强抗碰撞：想找到两个不同的数据，使它们具有相同的MD5值，是非常困难的。

具体代码

//输出小写

- (NSString *)lowerMD5:(NSString *)inPutText

{

//传入参数,转化成char

const char *cStr = [inPutText UTF8String];

//开辟一个16字节的空间

unsigned char result[CC_MD5_DIGEST_LENGTH];

extern unsigned char * CC_MD5(const void *data, CC_LONG len, unsigned char *md)官方封装好的加密方法

把str字符串转换成了32位的16进制数列（这个过程不可逆转）存储到了md这个空间中

CC_MD5(cStr, (CC_LONG)strlen(cStr), result);

return [[NSString stringWithFormat:@"%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",

result[0], result[1], result[2], result[3],

result[4], result[5], result[6], result[7],

result[8], result[9], result[10], result[11],

result[12], result[13], result[14], result[15]

] lowercaseString]; //大小写注意

}

//输出大写

- (NSString *)upperMD5:(NSString *)inPutText

{

//传入参数,转化成char

const char *cStr = [inPutText UTF8String];

//开辟一个16字节的空间

unsigned char result[CC_MD5_DIGEST_LENGTH];

extern unsigned char * CC_MD5(const void *data, CC_LONG len, unsigned char *md)官方封装好的加密方法

把str字符串转换成了32位的16进制数列（这个过程不可逆转）存储到了md这个空间中

CC_MD5(cStr, (CC_LONG)strlen(cStr), result);

return [[NSString stringWithFormat:@"%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",

result[0], result[1], result[2], result[3],

result[4], result[5], result[6], result[7],

result[8], result[9], result[10], result[11],

result[12], result[13], result[14], result[15]

] uppercaseString]; //大小写注意

}

调用：代码实现

NSLog(@"小写：%@",[self lowerMD5:@"123456"]);

NSLog(@"大写：%@",[self upperMD5:@"123456"]);

为了让MD5码更加安全，我们现在都采用加盐，盐要越长越乱，得到的MD5码就很难查到。

static NSString * salt =@"asdfghjklpoiuytrewqzxcvbnm";

NSLog(@"加盐小写：%@",[self lowerMD5:[@"123456" stringByAppendingString:salt]]);

NSLog(@"加盐大写：%@",[self upperMD5:[@"123456" stringByAppendingString:salt]]);

输出结果

2018-11-27 15:27:12.012590+0800 Encryption[12828:3995427]

小写：e10adc3949ba59abbe56e057f20f883e 2018-11-27 15:27:12.012774+0800

Encryption[12828:3995427] 大写：E10ADC3949BA59ABBE56E057F20F883E

2018-11-27 15:27:12.012901+0800 Encryption[12828:3995427]

加盐小写：71d1bda9346fab4eea309f4ed74b8f80 2018-11-27 15:27:12.013108+0800

Encryption[12828:3995427] 加盐大写：71D1BDA9346FAB4EEA309F4ED74B8F80

2、SHA1 算法是哈希算法的一种

代码实现：

//sha1

- (NSString *)sha1:(NSString *)input

{

const char *cstr = [input cStringUsingEncoding:NSUTF8StringEncoding];

NSData *data = [NSData dataWithBytes:cstr length:input.length];

//使用对应的 CC_SHA1_DIGEST_LENGTH,CC_SHA224_DIGEST_LENGTH,CC_SHA256_DIGEST_LENGTH,CC_SHA384_DIGEST_LENGTH,CC_SHA512_DIGEST_LENGTH的长度分别是20,28,32,48,64。；看你们需求选择对应的长度

uint8_t digest[CC_SHA1_DIGEST_LENGTH];

CC_SHA1(data.bytes, (unsigned int)data.length, digest);

NSMutableString *output = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH * 2];

for(int i=0; i<CC_SHA1_DIGEST_LENGTH; i++) {

[output appendFormat:@"%02x", digest[i]];

}

NSLog(@"sha----->%@",output);

return output;

}

调用代码实现 [self sha1:@"123456"];

运行结果：

2018-11-27 15:27:12.013237+0800 Encryption[12828:3995427]

sha----7c4a8d09ca3762af61e59520943dc26494f8941b

3、RSA 非对称加密算法 (公钥私钥生成步骤点击)

非对称加密算法需要两个密钥：公开密钥（publickey）和私有密钥（privatekey）

公开密钥与私有密钥是一对，用公开密钥对数据进行加密，只有用对应的私有密钥才能解密；

特点：

非对称密码体制的特点：算法强度复杂、安全性依赖于算法与密钥但是由于其算法复杂，而使得加密解密速度没有对称加密解密的速度快

对称密码体制中只有一种密钥，并且是非公开的，如果要解密就得让对方知道密钥。所以保证其安全性就是保证密钥的安全，而非对称密钥体制有两种密钥，其中一个是公开的，这样就可以不需要像对称密码那样传输对方的密钥了

具体代码：

// return base64 encoded string

+ (NSString *)encryptString:(NSString *)str publicKey:(NSString *)pubKey;

// return raw data

+ (NSData *)encryptData:(NSData *)data publicKey:(NSString *)pubKey;

// return base64 encoded string

+ (NSString *)encryptString:(NSString *)str privateKey:(NSString *)privKey;

// return raw data

+ (NSData *)encryptData:(NSData *)data privateKey:(NSString *)privKey;

// decrypt base64 encoded string, convert result to string(not base64 encoded)

+ (NSString *)decryptString:(NSString *)str publicKey:(NSString *)pubKey;

+ (NSData *)decryptData:(NSData *)data publicKey:(NSString *)pubKey;

+ (NSString *)decryptString:(NSString *)str privateKey:(NSString *)privKey;

+ (NSData *)decryptData:(NSData *)data privateKey:(NSString *)privKey;

实现

static NSString *base64_encode_data(NSData *data){

data = [data base64EncodedDataWithOptions:0];

NSString *ret = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

return ret;

}

static NSData *base64_decode(NSString *str){

NSData *data = [[NSData alloc] initWithBase64EncodedString:str options:NSDataBase64DecodingIgnoreUnknownCharacters];

return data;

}

+ (NSData *)stripPublicKeyHeader:(NSData *)d_key{

// Skip ASN.1 public key header

if (d_key == nil) return(nil);

unsigned long len = [d_key length];

if (!len) return(nil);

unsigned char *c_key = (unsigned char *)[d_key bytes];

unsigned int idx = 0;

if (c_key[idx++] != 0x30) return(nil);

if (c_key[idx] > 0x80) idx += c_key[idx] - 0x80 + 1;

else idx++;

// PKCS #1 rsaEncryption szOID_RSA_RSA

static unsigned char seqiod[] =

{ 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01,

0x01, 0x05, 0x00 };

if (memcmp(&c_key[idx], seqiod, 15)) return(nil);

idx += 15;

if (c_key[idx++] != 0x03) return(nil);

if (c_key[idx] > 0x80) idx += c_key[idx] - 0x80 + 1;

else idx++;

if (c_key[idx++] != '\0') return(nil);

// Now make a new NSData from this buffer

return([NSData dataWithBytes:&c_key[idx] length:len - idx]);

}

+ (NSData *)stripPrivateKeyHeader:(NSData *)d_key{

// Skip ASN.1 private key header

if (d_key == nil) return(nil);

unsigned long len = [d_key length];

if (!len) return(nil);

unsigned char *c_key = (unsigned char *)[d_key bytes];

unsigned int idx = 22; //magic byte at offset 22

if (0x04 != c_key[idx++]) return nil;

unsigned int c_len = c_key[idx++];

int det = c_len & 0x80;

if (!det) {

c_len = c_len & 0x7f;

} else {

int byteCount = c_len & 0x7f;

if (byteCount + idx > len) {

//rsa length field longer than buffer

return nil;

}

unsigned int accum = 0;

unsigned char *ptr = &c_key[idx];

idx += byteCount;

while (byteCount) {

accum = (accum << 8) + *ptr;

ptr++;

byteCount--;

}

c_len = accum;

}

// Now make a new NSData from this buffer

return [d_key subdataWithRange:NSMakeRange(idx, c_len)];

}

+ (SecKeyRef)addPublicKey:(NSString *)key{

NSRange spos = [key rangeOfString:@"-----BEGIN PUBLIC KEY-----"];

NSRange epos = [key rangeOfString:@"-----END PUBLIC KEY-----"];

if(spos.location != NSNotFound && epos.location != NSNotFound){

NSUInteger s = spos.location + spos.length;

NSUInteger e = epos.location;

NSRange range = NSMakeRange(s, e-s);

key = [key substringWithRange:range];

}

key = [key stringByReplacingOccurrencesOfString:@"\r" withString:@""];

key = [key stringByReplacingOccurrencesOfString:@"\n" withString:@""];

key = [key stringByReplacingOccurrencesOfString:@"\t" withString:@""];

key = [key stringByReplacingOccurrencesOfString:@" " withString:@""];

// This will be base64 encoded, decode it.

NSData *data = base64_decode(key);

data = [LHRSA stripPublicKeyHeader:data];

if(!data){

return nil;

}

//a tag to read/write keychain storage

NSString *tag = @"RSAUtil_PubKey";

NSData *d_tag = [NSData dataWithBytes:[tag UTF8String] length:[tag length]];

// Delete any old lingering key with the same tag

NSMutableDictionary *publicKey = [[NSMutableDictionary alloc] init];

[publicKey setObject:(__bridge id) kSecClassKey forKey:(__bridge id)kSecClass];

[publicKey setObject:(__bridge id) kSecAttrKeyTypeRSA forKey:(__bridge id)kSecAttrKeyType];

[publicKey setObject:d_tag forKey:(__bridge id)kSecAttrApplicationTag];

SecItemDelete((__bridge CFDictionaryRef)publicKey);

// Add persistent version of the key to system keychain

[publicKey setObject:data forKey:(__bridge id)kSecValueData];

[publicKey setObject:(__bridge id) kSecAttrKeyClassPublic forKey:(__bridge id)

kSecAttrKeyClass];

[publicKey setObject:[NSNumber numberWithBool:YES] forKey:(__bridge id)

kSecReturnPersistentRef];

CFTypeRef persistKey = nil;

OSStatus status = SecItemAdd((__bridge CFDictionaryRef)publicKey, &persistKey);

if (persistKey != nil){

CFRelease(persistKey);

}

if ((status != noErr) && (status != errSecDuplicateItem)) {

return nil;

}

[publicKey removeObjectForKey:(__bridge id)kSecValueData];

[publicKey removeObjectForKey:(__bridge id)kSecReturnPersistentRef];

[publicKey setObject:[NSNumber numberWithBool:YES] forKey:(__bridge id)kSecReturnRef];

[publicKey setObject:(__bridge id) kSecAttrKeyTypeRSA forKey:(__bridge id)kSecAttrKeyType];

// Now fetch the SecKeyRef version of the key

SecKeyRef keyRef = nil;

status = SecItemCopyMatching((__bridge CFDictionaryRef)publicKey, (CFTypeRef *)&keyRef);

if(status != noErr){

return nil;

}

return keyRef;

}

+ (SecKeyRef)addPrivateKey:(NSString *)key{

NSRange spos;

NSRange epos;

spos = [key rangeOfString:@"-----BEGIN RSA PRIVATE KEY-----"];

if(spos.length > 0){

epos = [key rangeOfString:@"-----END RSA PRIVATE KEY-----"];

}else{

spos = [key rangeOfString:@"-----BEGIN PRIVATE KEY-----"];

epos = [key rangeOfString:@"-----END PRIVATE KEY-----"];

}

if(spos.location != NSNotFound && epos.location != NSNotFound){

NSUInteger s = spos.location + spos.length;

NSUInteger e = epos.location;

NSRange range = NSMakeRange(s, e-s);

key = [key substringWithRange:range];

}

key = [key stringByReplacingOccurrencesOfString:@"\r" withString:@""];

key = [key stringByReplacingOccurrencesOfString:@"\n" withString:@""];

key = [key stringByReplacingOccurrencesOfString:@"\t" withString:@""];

key = [key stringByReplacingOccurrencesOfString:@" " withString:@""];

// This will be base64 encoded, decode it.

NSData *data = base64_decode(key);

data = [LHRSA stripPrivateKeyHeader:data];

if(!data){

return nil;

}

//a tag to read/write keychain storage

NSString *tag = @"RSAUtil_PrivKey";

NSData *d_tag = [NSData dataWithBytes:[tag UTF8String] length:[tag length]];

// Delete any old lingering key with the same tag

NSMutableDictionary *privateKey = [[NSMutableDictionary alloc] init];

[privateKey setObject:(__bridge id) kSecClassKey forKey:(__bridge id)kSecClass];

[privateKey setObject:(__bridge id) kSecAttrKeyTypeRSA forKey:(__bridge id)kSecAttrKeyType];

[privateKey setObject:d_tag forKey:(__bridge id)kSecAttrApplicationTag];

SecItemDelete((__bridge CFDictionaryRef)privateKey);

// Add persistent version of the key to system keychain

[privateKey setObject:data forKey:(__bridge id)kSecValueData];

[privateKey setObject:(__bridge id) kSecAttrKeyClassPrivate forKey:(__bridge id)

kSecAttrKeyClass];

[privateKey setObject:[NSNumber numberWithBool:YES] forKey:(__bridge id)

kSecReturnPersistentRef];

CFTypeRef persistKey = nil;

OSStatus status = SecItemAdd((__bridge CFDictionaryRef)privateKey, &persistKey);

if (persistKey != nil){

CFRelease(persistKey);

}

if ((status != noErr) && (status != errSecDuplicateItem)) {

return nil;

}

[privateKey removeObjectForKey:(__bridge id)kSecValueData];

[privateKey removeObjectForKey:(__bridge id)kSecReturnPersistentRef];

[privateKey setObject:[NSNumber numberWithBool:YES] forKey:(__bridge id)kSecReturnRef];

[privateKey setObject:(__bridge id) kSecAttrKeyTypeRSA forKey:(__bridge id)kSecAttrKeyType];

// Now fetch the SecKeyRef version of the key

SecKeyRef keyRef = nil;

status = SecItemCopyMatching((__bridge CFDictionaryRef)privateKey, (CFTypeRef *)&keyRef);

if(status != noErr){

return nil;

}

return keyRef;

}

/* START: Encryption & Decryption with RSA private key */

+ (NSData *)encryptData:(NSData *)data withKeyRef:(SecKeyRef) keyRef isSign:(BOOL)isSign {

const uint8_t *srcbuf = (const uint8_t *)[data bytes];

size_t srclen = (size_t)data.length;

size_t block_size = SecKeyGetBlockSize(keyRef) * sizeof(uint8_t);

void *outbuf = malloc(block_size);

size_t src_block_size = block_size - 11;

NSMutableData *ret = [[NSMutableData alloc] init];

for(int idx=0; idx<srclen; idx+=src_block_size){

//NSLog(@"%d/%d block_size: %d", idx, (int)srclen, (int)block_size);

size_t data_len = srclen - idx;

if(data_len > src_block_size){

data_len = src_block_size;

}

size_t outlen = block_size;

OSStatus status = noErr;

if (isSign) {

status = SecKeyRawSign(keyRef,

kSecPaddingPKCS1,

srcbuf + idx,

data_len,

outbuf,

&outlen

);

} else {

status = SecKeyEncrypt(keyRef,

kSecPaddingPKCS1,

srcbuf + idx,

data_len,

outbuf,

&outlen

);

}

if (status != 0) {

NSLog(@"SecKeyEncrypt fail. Error Code: %d", status);

ret = nil;

break;

}else{

[ret appendBytes:outbuf length:outlen];

}

free(outbuf);

CFRelease(keyRef);

return ret;

}

+ (NSString *)encryptString:(NSString *)str privateKey:(NSString *)privKey{

NSData *data = [LHRSA encryptData:[str dataUsingEncoding:NSUTF8StringEncoding] privateKey:privKey];

NSString *ret = base64_encode_data(data);

return ret;

}

+ (NSData *)encryptData:(NSData *)data privateKey:(NSString *)privKey{

if(!data || !privKey){

return nil;

}

SecKeyRef keyRef = [LHRSA addPrivateKey:privKey];

if(!keyRef){

return nil;

}

return [LHRSA encryptData:data withKeyRef:keyRef isSign:YES];

}

+ (NSData *)decryptData:(NSData *)data withKeyRef:(SecKeyRef) keyRef{

const uint8_t *srcbuf = (const uint8_t *)[data bytes];

size_t srclen = (size_t)data.length;

size_t block_size = SecKeyGetBlockSize(keyRef) * sizeof(uint8_t);

UInt8 *outbuf = malloc(block_size);

size_t src_block_size = block_size;

NSMutableData *ret = [[NSMutableData alloc] init];

for(int idx=0; idx<srclen; idx+=src_block_size){

//NSLog(@"%d/%d block_size: %d", idx, (int)srclen, (int)block_size);

size_t data_len = srclen - idx;

if(data_len > src_block_size){

data_len = src_block_size;

}

size_t outlen = block_size;

OSStatus status = noErr;

status = SecKeyDecrypt(keyRef,

kSecPaddingNone,

srcbuf + idx,

data_len,

outbuf,

&outlen

);

if (status != 0) {

NSLog(@"SecKeyEncrypt fail. Error Code: %d", status);

ret = nil;

break;

}else{

//the actual decrypted data is in the middle, locate it!

int idxFirstZero = -1;

int idxNextZero = (int)outlen;

for ( int i = 0; i < outlen; i++ ) {

if ( outbuf[i] == 0 ) {

if ( idxFirstZero < 0 ) {

idxFirstZero = i;

} else {

idxNextZero = i;

break;

}

[ret appendBytes:&outbuf[idxFirstZero+1] length:idxNextZero-idxFirstZero-1];

}

free(outbuf);

CFRelease(keyRef);

return ret;

}

+ (NSString *)decryptString:(NSString *)str privateKey:(NSString *)privKey{

NSData *data = [[NSData alloc] initWithBase64EncodedString:str options:NSDataBase64DecodingIgnoreUnknownCharacters];

data = [LHRSA decryptData:data privateKey:privKey];

NSString *ret = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

return ret;

}

+ (NSData *)decryptData:(NSData *)data privateKey:(NSString *)privKey{

if(!data || !privKey){

return nil;

}

SecKeyRef keyRef = [LHRSA addPrivateKey:privKey];

if(!keyRef){

return nil;

}

return [LHRSA decryptData:data withKeyRef:keyRef];

}

/* END: Encryption & Decryption with RSA private key */

/* START: Encryption & Decryption with RSA public key */

+ (NSString *)encryptString:(NSString *)str publicKey:(NSString *)pubKey{

NSData *data = [LHRSA encryptData:[str dataUsingEncoding:NSUTF8StringEncoding] publicKey:pubKey];

NSString *ret = base64_encode_data(data);

return ret;

}

+ (NSData *)encryptData:(NSData *)data publicKey:(NSString *)pubKey{

if(!data || !pubKey){

return nil;

}

SecKeyRef keyRef = [LHRSA addPublicKey:pubKey];

if(!keyRef){

return nil;

}

return [LHRSA encryptData:data withKeyRef:keyRef isSign:NO];

}

+ (NSString *)decryptString:(NSString *)str publicKey:(NSString *)pubKey{

NSData *data = [[NSData alloc] initWithBase64EncodedString:str options:NSDataBase64DecodingIgnoreUnknownCharacters];

data = [LHRSA decryptData:data publicKey:pubKey];

NSString *ret = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

return ret;

}

+ (NSData *)decryptData:(NSData *)data publicKey:(NSString *)pubKey{

if(!data || !pubKey){

return nil;

}

SecKeyRef keyRef = [LHRSA addPublicKey:pubKey];

if(!keyRef){

return nil;

}

return [LHRSA decryptData:data withKeyRef:keyRef];

}

调用

//公钥

NSString *publicKey = @"MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCVtz/hQUNiLE1prYofqLlmYtK0OupHN7wk+ZaeYVoQqk0v+1w/MIUm20BGKNjVAo9ZBH7IDWSQ25Mhh9+niizPULk+tWqvm5wWOwEy5R/dbjNmGDFCrFXC0gYAXI4uLhcVNGNWbu3mm3BVh9LmVU+d3qr1ZxILkJ+36x/VCe/vIQIDAQAB";

//私钥

NSString *privateKey = @"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";

//要加密的数据

NSString *sourceStr = @"123456";

//公钥加密

NSString *encryptStr = [LHRSA encryptString:sourceStr publicKey:publicKey];

//私钥解密

NSString *decrypeStr = [LHRSA decryptString:encryptStr privateKey:privateKey];

NSLog(@"\n加密后的数据:%@ \n 解密后的数据:%@",encryptStr,decrypeStr);

运行结果：

2018-11-27 15:27:13.099152+0800 Encryption[12828:3995427]

加密后的数据:F+I/egBsrrGlneTT4vr6b6Q9slJ5zPJBhGx85kKEsfkbkvlh1DcVOW29vaCdPQ2klwIyjVOC+FM9PoJRPa6h9RJX5h/ESEz2dD7ZAl2kEkvVr69Eg+1KYzLhAlNagHiT1bMcXRIBfO99oyrJFqLQoWlLG3jURyXwjzQ7Lwc9rmU=

解密后的数据:123456

4、AES 对称密钥加密

加密代码实现：引入 #import

+ (NSData *)AES256EncryptWithKey:(NSString *)key encryptString:(NSString *)str{

char keyPtr[kCCKeySizeAES256+1]; // room for terminator (unused)

bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)

// fetch key data

[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

NSUInteger dataLength = [str length];

size_t bufferSize = dataLength + kCCBlockSizeAES128;

void *buffer = malloc(bufferSize);

size_t numBytesEncrypted = 0;

CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,

keyPtr, kCCKeySizeAES256,

NULL /* initialization vector (optional) */,

[[str dataUsingEncoding:NSUTF8StringEncoding] bytes], dataLength, /* input */

buffer, bufferSize, /* output */

&numBytesEncrypted);

if (cryptStatus == kCCSuccess) {

//the returned NSData takes ownership of the buffer and will free it on deallocation

return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];

}

free(buffer); //free the buffer;

return nil;

}

+ (NSData *)AES256DecryptWithKey:(NSString *)key DecryptString:(NSData *)str{

// 'key' should be 32 bytes for AES256, will be null-padded otherwise

char keyPtr[kCCKeySizeAES256+1]; // room for terminator (unused)

bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)

// fetch key data

[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

NSUInteger dataLength = [str length];

size_t bufferSize = dataLength + kCCBlockSizeAES128;

void *buffer = malloc(bufferSize);

size_t numBytesDecrypted = 0;

CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,

keyPtr, kCCKeySizeAES256,

NULL /* initialization vector (optional) */,

[str bytes], dataLength, /* input */

buffer, bufferSize, /* output */

&numBytesDecrypted);

if (cryptStatus == kCCSuccess) {

//the returned NSData takes ownership of the buffer and will free it on deallocation

return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];

}

free(buffer); //free the buffer;

return nil;

}

调用代码

//用来密钥

NSString * key = @"123456";

//用来发送的原始数据

NSString * secret = @"654321";

//用密钥加密

NSData * result = [LHAES AES256EncryptWithKey:key encryptString:secret];

//输出测试

NSLog(@"AES加密 :%@",result);

//解密方法

NSData * data = [LHAES AES256DecryptWithKey:key DecryptString:result];

NSLog(@"AES解密 :%@", [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]);

运行结果

2018-11-27 15:27:13.100121+0800 Encryption[12828:3995427] AES加密

:<93d4cdab 759376b4 51565e57 85f684f6> 2018-11-27 15:27:13.100257+0800

Encryption[12828:3995427] AES解密 :654321

5、DES 加密：先将内容加密一下，然后转十六进制，传过去；DES解密：把收到的数据转二进制，decode一下，然后再解密，得到原本的数据

代码实现：引入 #import <CommonCrypto/CommonCryptor.h>

//加密

+ (NSString *) encryptUseDES2:(NSString *)content key:(NSString *)key{

NSString *ciphertext = nil;

const char *textBytes = [content UTF8String];

size_t dataLength = [content length];

uint8_t *bufferPtr = NULL;

size_t bufferPtrSize = 0;

size_t movedBytes = 0;

bufferPtrSize = (dataLength + kCCBlockSizeDES) & ~(kCCBlockSizeDES - 1);

bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));

memset((void *)bufferPtr, 0x0, bufferPtrSize);

CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithm3DES,

kCCOptionPKCS7Padding|kCCOptionECBMode,

[key UTF8String], kCCKeySize3DES,

NULL,

textBytes, dataLength,

(void *)bufferPtr, bufferPtrSize,

&movedBytes);

if (cryptStatus == kCCSuccess) {

ciphertext= [self parseByte2HexString:bufferPtr :(int)movedBytes];

}

ciphertext=[ciphertext uppercaseString];//字符变大写

return ciphertext ;

}

//加密用到的二进制转化十六进制方法：

+ (NSString *) parseByte2HexString:(Byte *) bytes :(int)len{

NSString *hexStr = @"";

if(bytes)

{

for(int i=0;i<len;i++)

{

NSString *newHexStr = [NSString stringWithFormat:@"%x",bytes[i]&0xff]; ///16进制数

if([newHexStr length] == 1)

hexStr = [NSString stringWithFormat:@"%@0%@",hexStr,newHexStr];

else

{

hexStr = [NSString stringWithFormat:@"%@%@",hexStr,newHexStr];

}

return hexStr;

}

//解密

+ (NSString *)decryptUseDES:(NSString *)content key:(NSString *)key

{

NSData* cipherData = [self convertHexStrToData:[content lowercaseString]];

unsigned char buffer[1024];

memset(buffer, 0, sizeof(char));

size_t numBytesDecrypted = 0;

CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,

kCCAlgorithm3DES,

kCCOptionPKCS7Padding|kCCOptionECBMode,

[key UTF8String],

kCCKeySize3DES,

NULL,

[cipherData bytes],

[cipherData length],

buffer,

1024,

&numBytesDecrypted);

NSString* plainText = nil;

if (cryptStatus == kCCSuccess) {

NSData* data = [NSData dataWithBytes:buffer length:(NSUInteger)numBytesDecrypted];

plainText = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

}

return plainText;

}

//解密过程用到的十六进制转换二进制：

+ (NSData *)convertHexStrToData:(NSString *)str {

if (!str || [str length] == 0) {

return nil;

}

NSMutableData *hexData = [[NSMutableData alloc] initWithCapacity:8];

NSRange range;

if ([str length] % 2 == 0) {

range = NSMakeRange(0, 2);

} else {

range = NSMakeRange(0, 1);

}

for (NSInteger i = range.location; i < [str length]; i += 2) {

unsigned int anInt;

NSString *hexCharStr = [str substringWithRange:range];

NSScanner *scanner = [[NSScanner alloc] initWithString:hexCharStr];

[scanner scanHexInt:&anInt];

NSData *entity = [[NSData alloc] initWithBytes:&anInt length:1];

[hexData appendData:entity];

range.location += range.length;

range.length = 2;

}

return hexData;

}

调用代码

//用来密钥

NSString * keyDES = @"123456";

//用来发送的原始数据

NSString * secretDES = @"654321";

NSString * resultDES = [LHDES encryptUseDES2:secretDES key:keyDES];

NSLog(@"DES加密 :%@",resultDES);

NSString * decryptResult = [LHDES decryptUseDES:resultDES key:keyDES];

NSLog(@"DES解密 :%@",decryptResult);

运行结果

2018-11-27 15:27:13.100455+0800 Encryption[12828:3995427] DES加密

:CC1A2A7516D45169 2018-11-27 15:27:13.100643+0800

Encryption[12828:3995427] DES解密 :654321

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常见的几种加密方法

2、SHA1 算法是哈希算法的一种

3、RSA 非对称加密算法 (公钥私钥生成步骤点击)

4、AES 对称密钥加密

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