嘟哝嘟哝:最近接到一个任务:在客户端动态生成RSA密钥对,然后向服务器发送这个密钥对中的公钥字符串,由服务器进行公钥加密,返回加密后的信息,再由客户端使用私钥进行解密。我在网上查阅了大量的资料,但是大多是利用公钥私钥文件,或者直接接收RSA公私钥字符串进行加密解密,没有生成并转换成字符串,这里我们就介绍一下我是如何实现这个功能的,以备后用。
我今天要介绍的RSA加密属于非对称加密。对于安全性来说显然非对称加密更优于对称加密。在使用中,甲方需要同时生成公开密钥(公钥)和私有密钥(私钥),把其中的公钥发送给乙方,乙方利用传过来的私钥,对发送文本进行加密回传给甲方,甲方接收到加密后的文本后用此前生成的私钥进行解密,从而得到加密前的文本。但加密和解密花费时间长、速度慢,它不适合于对文件加密而只适用于对少量数据进行加密。
首先介绍利用终端生成公钥私钥
1、生成私钥
openssl genrsa -out rsa_private_key.pem1024
2、将原始私钥转换为pkcs8格式
openssl pkcs8 -topk8 -inform PEM -inrsa_private_key.pem -outform PEM -nocrypt
3、根据私钥生成公钥
openssl rsa -in rsa_private_key.pem -pubout-out ras_public_key.pem
RSAPEM文件格式
1. PEM私钥格式文件
-----BEGIN RSA PRIVATE KEY-----
-----END RSA PRIVATE KEY-----
2. PEM公钥格式文件
-----BEGIN PUBLIC KEY-----
-----END PUBLIC KEY-----
3. PEM RSAPublicKey公钥格式文件
-----BEGIN RSA PUBLIC KEY-----
-----END RSA PUBLIC KEY-----
回归正题:我们开始实现生成密钥字符串。在这里我们使用的是openssl框架来生成密钥对。
头文件中引入
#import <openssl/rsa.h>
#import <openssl/pem.h>
1,生成密钥对
/*产生RSA密钥*/
RSA*rsa =NULL;
rsa =RSA_new();
//产生一个模为num位的密钥对,e为公开的加密指数,一般为65537(0x10001)
rsa =RSA_generate_key(1024,0x10001,NULL,NULL);
这里需要说明一下,加密长度是1024位。加密长度是指理论上最大允许”被加密的信息“长度的限制,也就是明文的长度限制。随着这个参数的增大(比方说2048),允许的明文长度也会增加,但同时也会造成计算复杂度的极速增长。一般推荐的长度就是1024位(128字节)。
这种算法非常可靠,密钥越长,它就越难破解。根据已经披露的文献,目前被破解的最长RSA密钥是768个二进制位。也就是说,长度超过768位的密钥,还无法破解(至少没人公开宣布)。因此可以认为,1024位的RSA密钥基本安全,2048位的密钥极其安全。
由于我并没有在框架中找到方法转换出密钥字符串,所以这里用了个比较笨拙的方法,将公钥私钥保存为txt文件,然后将这个txt文件读出,读出后就是需要的字符串了。
上方加粗函数虽然已经过时,但是目前还可以用,下方加粗部分是替代方法
BIGNUM*bne =BN_new();
unsignedinte =RSA_3;
intresult =BN_set_word(bne, e);
result =RSA_generate_key_ex(rsa,1024, bne,NULL);
rsa就是得到的密钥对
//路径
NSString*documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)objectAtIndex:0];
/*提取公钥字符串*/
//最终存储的地方,所以需要创建一个路径去存储字符串
NSString*pubPath = [documentsPathstringByAppendingPathComponent:@"PubFile.txt"];
FILE* pubWrite =NULL;
pubWrite =fopen([pubPathUTF8String],"wb");
if(pubWrite ==NULL)
NSLog(@"Read Filed.");
else
{
PEM_write_RSA_PUBKEY(pubWrite,rsa);
fclose(pubWrite);
}
拿出字符串之后对字符串进行处理,这样就得到了我们需要的字符串了。
NSString*str=[NSStringstringWithContentsOfFile:pubPathencoding:NSUTF8StringEncodingerror:nil];
str = [strstringByReplacingOccurrencesOfString:@"-----BEGIN
PUBLIC KEY-----"withString:@""];
str = [strstringByReplacingOccurrencesOfString:@"-----END
PUBLIC KEY-----"withString:@""];
str = [strstringByReplacingOccurrencesOfString:@"\n"withString:@""];
/*提取私钥字符串*/
NSString*priPath =
[documentsPathstringByAppendingPathComponent:@"PriFile.txt"];
FILE*priWtire =NULL;
priWtire =fopen([priPathUTF8String],"wb");
EVP_PKEY*pkey =NULL;
if(priWtire ==NULL) {
NSLog(@"Read
Filed.");
}else{
//函数使用PKCS#8标准保存EVP_PKEY里面的私钥到文件或者BIO中,并采用PKCS#5
//v2.0的标准加密私钥。enc参数定义了使用的加密算法。跟其他PEM的IO函数不一样的是,本函数的加密是基于PKCS#8层次上的,而不是基于PEM信息字段的,所以这两个函数也是单独实现的函数,而不是宏定义函数。如果enc参数为NULL,那么就不会执行加密操作,只是使用PKCS#8私钥 信息结构。成功执行返回大于0的数,否则返回0。
pkey =EVP_PKEY_new();
EVP_PKEY_assign_RSA(pkey, rsa);
PEM_write_PKCS8PrivateKey(priWtire, pkey,NULL,NULL,0,0,NULL);
fclose(priWtire);
}
NSString*priStr=[NSStringstringWithContentsOfFile:priPathencoding:NSUTF8StringEncodingerror:nil];
priStr = [priStrstringByReplacingOccurrencesOfString:@"-----BEGIN
PRIVATE KEY-----"withString:@""];
priStr = [priStrstringByReplacingOccurrencesOfString:@"-----END
PRIVATE KEY-----"withString:@""];
priStr = [priStrstringByReplacingOccurrencesOfString:@"\n"withString:@""];
得到私钥字符串。
以下是问题记录:
1.利用PEM_write_RSA_PUBKEY函数保存密钥后,无法获得密钥,原因是我在设置文件的时候,参考网上的资料,写成了文件名称,获取的时候也是利用框架中的函数获取到的RSA,还是没有转换成字符串。所以我将设置文件的地方,写入了文件路径,然后我再用自己的方式读取这个txt文件,这样就得到了我想要的字符串了。
2.保存密钥的时候,开始的时候得到的公钥私钥都是不能正确加密解密的,原因是我在保存密钥文件的时候,选错了文件的格式,这里有两个函数很容易让人混淆:
PEM_write_RSAPublicKey(<#FILE *fp#>,<#const RSA *x#>)
由这个函数得到的文件是PRM RSAPublicKey公钥格式文件,而我们需要的文件是PEM公钥格式文件,所以要看好函数指定的文件格式。利用PEM_write_RSA_PUBKEY函数。
PEM_write_RSAPrivateKey(<#FILE *fp#>, <#RSA *x#>, <#constEVP_CIPHER *enc#>, <#unsigned char *kstr#>, <#int klen#>,<#pem_password_cb *cb#>, <#void *u#>)
通过这个函数我们虽然可以得到私钥文件,但是却是PKCS1格式的,但是我需要的是PKCS8格式的。所以需要改用这个函数PEM_write_PKCS8PrivateKey。
选择了正确的文件格式,生成的公钥私钥就可以使用了。
这篇博文中有关于文件格式的大体介绍
http://blog.csdn.net/tuhuolong/article/details/42778945
这篇文章并没有对原理进行剖析,只是说明了一下使用方法,而且使用方法不是很好,我想框架中应该也有可以实现的方法,但是目前还没有找到,如果有哪位朋友找到了,一定要记得私信告诉我,谢谢。
不知道怎么传文件 贴一份源码吧 (源码中包括生成动态key 以及加密解密可能会有多余的方法,因为是在别人的源码基础上修改的)
需要引入:
libcrypto.a
libssl.a
以及openssl框架(我直接从支付宝的框架里搞来的)
//
//RYTRSAEncryptor.h
//SMSCodeTest
//Created by timmy on 16/10/19.
//Copyright © 2016年 timmy. All rights reserved.
//
#import <Foundation/Foundation.h>
#import <openssl/rsa.h>
@interface RYTRSAEncryptor : NSObject
+ (void)keyWith:(void(^)(NSString *pubKey, NSString *priKey))block;
/**
*加密方法
*
*@param str需要加密的字符串
*@param pubKey公钥字符串
*/
+ (NSString *)encryptString:(NSString *)str publicKey:(NSString *)pubKey;
+ (SecKeyRef)addPublicKey:(NSString *)key;
/**
*解密方法
*
*@param str需要解密的字符串
*@param privKey私钥字符串
*/
+ (NSString *)decryptString:(NSString *)str privateKey:(NSString *)privKey;
+ (SecKeyRef)addPrivateKey:(NSString *)key;
@end
//RYTRSAEncryptor.m
//SMSCodeTest
//Created by timmy on 16/10/19.
//Copyright © 2016年 timmy. All rights reserved.
#import "RYTRSAEncryptor.h"
#import <Security/Security.h>
#import <openssl/rsa.h>
#import <openssl/pem.h>
#import "RYTBase64.h"
@implementation RYTRSAEncryptor
staticNSString *base64_encode_data(NSData *data){
data = [data base64EncodedDataWithOptions:0];
NSString *ret = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
returnret;
}
staticNSData *base64_decode(NSString *str){
NSData *data = [[NSData alloc] initWithBase64EncodedString:str options:NSDataBase64DecodingIgnoreUnknownCharacters];
returndata;
}
#pragma mark -生成密钥
/* START: creat keys */
+ (void)keyWith:(void(^)(NSString *pubKey, NSString *priKey))block {
/* 产生RSA密钥 */
RSA *rsa =NULL;
rsa = RSA_new();
//产生一个模为num位的密钥对,e为公开的加密指数,一般为65537(0x10001)
rsa = RSA_generate_key(1024,0x10001,NULL,NULL);
// 路径
NSString *documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES) objectAtIndex:0];
/* 提取公钥字符串 */
// 最终存储的地方,所以需要创建一个路径去存储字符串
NSString *pubPath = [documentsPath stringByAppendingPathComponent:@"PubFile.txt"];
FILE* pubWrite =NULL;
pubWrite = fopen([pubPath UTF8String],"wb");
if(pubWrite ==NULL)
NSLog(@"Read Filed.");
else
{
PEM_write_RSA_PUBKEY(pubWrite,rsa);
fclose(pubWrite);
}
NSString *str=[NSString stringWithContentsOfFile:pubPath encoding:NSUTF8StringEncoding error:nil];
str = [str stringByReplacingOccurrencesOfString:@"-----BEGIN PUBLIC KEY-----"withString:@""];
str = [str stringByReplacingOccurrencesOfString:@"-----END PUBLIC KEY-----"withString:@""];
str = [str stringByReplacingOccurrencesOfString:@"\n"withString:@""];
/*提取私钥字符串*/
NSString *priPath = [documentsPath stringByAppendingPathComponent:@"PriFile.txt"];
FILE *priWtire =NULL;
priWtire = fopen([priPath UTF8String],"wb");
EVP_PKEY *pkey =NULL;
if(priWtire ==NULL) {
NSLog(@"Read Filed.");
}else{
//函数使用PKCS#8标准保存EVP_PKEY里面的私钥到文件或者BIO中,并采用PKCS#5
//v2.0的标准加密私钥。enc参数定义了使用的加密算法。跟其他PEM的IO函数不一样的是,本函数的加密是基于PKCS#8层次上的,而不是基于PEM信息字段的,所以这两个函数也是单独实现的函数,而不是宏定义函数。如果enc参数为NULL,那么就不会执行加密操作,只是使用PKCS#8私钥 信息结构。成功执行返回大于0 的数,否则返回0。
pkey = EVP_PKEY_new();
EVP_PKEY_assign_RSA(pkey, rsa);
PEM_write_PKCS8PrivateKey(priWtire, pkey,NULL,NULL,0,0,NULL);
fclose(priWtire);
}
NSString *priStr=[NSString stringWithContentsOfFile:priPath encoding:NSUTF8StringEncoding error:nil];
priStr = [priStr stringByReplacingOccurrencesOfString:@"-----BEGIN PRIVATE KEY-----"withString:@""];
priStr = [priStr stringByReplacingOccurrencesOfString:@"-----END PRIVATE KEY-----"withString:@""];
priStr = [priStr stringByReplacingOccurrencesOfString:@"\n"withString:@""];
block(str,priStr);
}
#pragma mark -使用公钥字符串加密
/* START: Encryption with RSA public key */
//使用公钥字符串加密(PKCS8格式)
+ (NSString *)encryptString:(NSString *)str publicKey:(NSString *)pubKey{
NSData *data = [selfencryptData:[str dataUsingEncoding:NSUTF8StringEncoding] publicKey:pubKey];
NSString *ret = base64_encode_data(data);
returnret;
}
+ (NSData *)encryptData:(NSData *)data publicKey:(NSString *)pubKey{
if(!data || !pubKey){
returnnil;
}
SecKeyRef keyRef = [selfaddPublicKey:pubKey];
if(!keyRef){
returnnil;
}
return[selfencryptData:data withKeyRef:keyRef];
}
//构建公钥(PKCS8格式)
+ (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:@""];
//key经过base64编码 解码
NSData *data = base64_decode(key);
data = [selfstripPublicKeyHeader:data];
if(!data){
returnnil;
}
//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:(__bridgeid) kSecClassKey forKey:(__bridgeid)kSecClass];
[publicKey setObject:(__bridgeid) kSecAttrKeyTypeRSA forKey:(__bridgeid)kSecAttrKeyType];
[publicKey setObject:d_tag forKey:(__bridgeid)kSecAttrApplicationTag];
SecItemDelete((__bridgeCFDictionaryRef)publicKey);
// Add persistent version of the key to system keychain
[publicKey setObject:data forKey:(__bridgeid)kSecValueData];
[publicKey setObject:(__bridgeid) kSecAttrKeyClassPublic forKey:(__bridgeid)
kSecAttrKeyClass];
[publicKey setObject:[NSNumber numberWithBool:YES] forKey:(__bridgeid)
kSecReturnPersistentRef];
CFTypeRef persistKey =nil;
OSStatus status = SecItemAdd((__bridgeCFDictionaryRef)publicKey, &persistKey);
if(persistKey !=nil){
CFRelease(persistKey);
}
if((status != noErr) && (status != errSecDuplicateItem)) {
returnnil;
}
[publicKey removeObjectForKey:(__bridgeid)kSecValueData];
[publicKey removeObjectForKey:(__bridgeid)kSecReturnPersistentRef];
[publicKey setObject:[NSNumber numberWithBool:YES] forKey:(__bridgeid)kSecReturnRef];
[publicKey setObject:(__bridgeid) kSecAttrKeyTypeRSA forKey:(__bridgeid)kSecAttrKeyType];
// Now fetch the SecKeyRef version of the key
SecKeyRef keyRef =nil;
status = SecItemCopyMatching((__bridgeCFDictionaryRef)publicKey, (CFTypeRef *)&keyRef);
if(status != noErr){
returnnil;
}
returnkeyRef;
}
+ (NSData *)stripPublicKeyHeader:(NSData *)d_key{
// Skip ASN.1 public key header
if(d_key ==nil)return(nil);
unsignedlonglen = [d_key length];
if(!len)return(nil);
unsignedchar*c_key = (unsignedchar*)[d_key bytes];
unsignedintidx=0;
if(c_key[idx++] !=0x30)return(nil);
if(c_key[idx] >0x80) idx += c_key[idx] -0x80+1;
elseidx++;
// PKCS #1 rsaEncryption szOID_RSA_RSA
staticunsignedcharseqiod[] =
{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;
elseidx++;
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 *)encryptData:(NSData *)data withKeyRef:(SecKeyRef) keyRef{
constuint8_t *srcbuf = (constuint8_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(intidx=0; idx
//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 = 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);
returnret;
}
/* END: Encryption with RSA public key */
#pragma mark -使用私钥字符串解密
/* START: Decryption with RSA private key */
//使用私钥字符串解密
+ (NSString *)decryptString:(NSString *)str privateKey:(NSString *)privKey{
if(!str)returnnil;
NSData *data = [[NSData alloc] initWithBase64EncodedString:str options:NSDataBase64DecodingIgnoreUnknownCharacters];
data = [selfdecryptData:data privateKey:privKey];
NSString *ret = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
returnret;
}
+ (NSData *)decryptData:(NSData *)data privateKey:(NSString *)privKey{
if(!data || !privKey){
returnnil;
}
SecKeyRef keyRef = [selfaddPrivateKey:privKey];
if(!keyRef){
returnnil;
}
return[selfdecryptData:data withKeyRef:keyRef];
}
//(PKCS8格式)
+ (SecKeyRef)addPrivateKey:(NSString *)key{
NSRange spos = [key rangeOfString:@"-----BEGIN PRIVATE KEY-----"];
NSRange 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 = [selfstripPrivateKeyHeader:data];
if(!data){
returnnil;
}
//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:(__bridgeid) kSecClassKey forKey:(__bridgeid)kSecClass];
[privateKey setObject:(__bridgeid) kSecAttrKeyTypeRSA forKey:(__bridgeid)kSecAttrKeyType];
[privateKey setObject:d_tag forKey:(__bridgeid)kSecAttrApplicationTag];
SecItemDelete((__bridgeCFDictionaryRef)privateKey);
// Add persistent version of the key to system keychain
[privateKey setObject:data forKey:(__bridgeid)kSecValueData];
[privateKey setObject:(__bridgeid) kSecAttrKeyClassPrivate forKey:(__bridgeid)
kSecAttrKeyClass];
[privateKey setObject:[NSNumber numberWithBool:YES] forKey:(__bridgeid)
kSecReturnPersistentRef];
CFTypeRef persistKey =nil;
OSStatus status = SecItemAdd((__bridgeCFDictionaryRef)privateKey, &persistKey);
if(persistKey !=nil){
CFRelease(persistKey);
}
if((status != noErr) && (status != errSecDuplicateItem)) {
returnnil;
}
[privateKey removeObjectForKey:(__bridgeid)kSecValueData];
[privateKey removeObjectForKey:(__bridgeid)kSecReturnPersistentRef];
[privateKey setObject:[NSNumber numberWithBool:YES] forKey:(__bridgeid)kSecReturnRef];
[privateKey setObject:(__bridgeid) kSecAttrKeyTypeRSA forKey:(__bridgeid)kSecAttrKeyType];
// Now fetch the SecKeyRef version of the key
SecKeyRef keyRef =nil;
status = SecItemCopyMatching((__bridgeCFDictionaryRef)privateKey, (CFTypeRef *)&keyRef);
if(status != noErr){
returnnil;
}
returnkeyRef;
}
+ (NSData *)stripPrivateKeyHeader:(NSData *)d_key{
// Skip ASN.1 private key header
if(d_key ==nil)return(nil);
unsignedlonglen = [d_key length];
if(!len)return(nil);
unsignedchar*c_key = (unsignedchar*)[d_key bytes];
unsignedintidx=22;//magic byte at offset 22
if(0x04!= c_key[idx++])returnnil;
//calculate length of the key
unsignedintc_len = c_key[idx++];
intdet = c_len &0x80;
if(!det) {
c_len = c_len &0x7f;
}else{
intbyteCount = c_len &0x7f;
if(byteCount + idx > len) {
//rsa length field longer than buffer
returnnil;
}
unsignedintaccum =0;
unsignedchar*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)];
}
+ (NSData *)decryptData:(NSData *)data withKeyRef:(SecKeyRef) keyRef{
constuint8_t *srcbuf = (constuint8_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(intidx=0; idx
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,
kSecPaddingPKCS1,
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!
intidxFirstZero = -1;
intidxNextZero = (int)outlen;
for(inti =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);
returnret;
}
@end
比起码源码,还是放项目比较直接,这个是项目地址,有兴趣的同学可以看看。
https://git.oschina.net/euagore/smscodeframework.git