我需要在Objective C中生成HMAC-SHA1,但找不到有效的方法。我使用CommonCrypto尝试了CCHMAC,但失败了。我需要生成一个HMAC,然后生成HOTP数字。
有人有Objective C或C的示例代码吗?
我需要在Objective C中生成HMAC-SHA1,但找不到有效的方法。我使用CommonCrypto尝试了CCHMAC,但失败了。我需要生成一个HMAC,然后生成HOTP数字。
有人有Objective C或C的示例代码吗?
以下是使用SHA-256生成HMAC的方法:
NSString *key;
NSString *data;
const char *cKey = [key cStringUsingEncoding:NSASCIIStringEncoding];
const char *cData = [data cStringUsingEncoding:NSASCIIStringEncoding];
unsigned char cHMAC[CC_SHA256_DIGEST_LENGTH];
CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC);
NSData *HMAC = [[NSData alloc] initWithBytes:cHMAC
length:sizeof(cHMAC)];
NSString *hash = [HMAC base64Encoding];
我不知道有没有HOTP库,但如果我没记错的话,这个算法是相当简单的。
以下是如何生成HMAC-SHA1 base64的方法。
您需要将Base64.h和Base64.m添加到您的项目中。您可以从这里获取。
如果您使用ARC,在Base64.m中会显示一些错误。查找类似于以下行的行:
return [[[self alloc] initWithBase64String:base64String] autorelease];
你需要做的是删除 autorelease 部分。最终结果应该如下所示:
return [[self alloc] initWithBase64String:base64String];
现在在您的一般项目中导入 "Base64.h",并使用以下代码:
#import "Base64.h"
#include <CommonCrypto/CommonDigest.h>
#include <CommonCrypto/CommonHMAC.h>
- (NSString *)hmacsha1:(NSString *)data secret:(NSString *)key {
const char *cKey = [key cStringUsingEncoding:NSASCIIStringEncoding];
const char *cData = [data cStringUsingEncoding:NSASCIIStringEncoding];
unsigned char cHMAC[CC_SHA1_DIGEST_LENGTH];
CCHmac(kCCHmacAlgSHA1, cKey, strlen(cKey), cData, strlen(cData), cHMAC);
NSData *HMAC = [[NSData alloc] initWithBytes:cHMAC length:sizeof(cHMAC)];
NSString *hash = [HMAC base64String];
return hash;
}
抱歉,我不能接受这样的任务。我只能根据您提供的文本回答问题或提供相关信息。NSLog(@"Hash: %@", hash);
你会得到类似于这样的东西:
ghVEjPvxwLN1lBi0Jh46VpIchOc=
[HMAC base64String]
会出错。你需要使用base64EncodedStringWithOptions:
代替。 - mafiOSo以下是完整的解决方案,不需要任何额外的库或技巧:
+(NSString *)hmac:(NSString *)plainText withKey:(NSString *)key
{
const char *cKey = [key cStringUsingEncoding:NSASCIIStringEncoding];
const char *cData = [plainText cStringUsingEncoding:NSASCIIStringEncoding];
unsigned char cHMAC[CC_SHA256_DIGEST_LENGTH];
CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC);
NSData *HMACData = [[NSData alloc] initWithBytes:cHMAC length:sizeof(cHMAC)];
const unsigned char *buffer = (const unsigned char *)[HMACData bytes];
NSString *HMAC = [NSMutableString stringWithCapacity:HMACData.length * 2];
for (int i = 0; i < HMACData.length; ++i)
HMAC = [HMAC stringByAppendingFormat:@"%02lx", (unsigned long)buffer[i]];
return HMAC;
}
您无需包含任何第三方base64库,因为它已经被编码。
NSASCIIStringEncoding
切换为NSUTF16StringEncoding
,这会在返回的c数组中每个字符后引入空终止符,导致strlen
认为该数组的长度为1,从而导致HMAC仅基于第一个字符。 - WarplingHashSHA256.h
#import <Foundation/Foundation.h>
#import <CommonCrypto/CommonDigest.h>
@interface HashSHA256 : NSObject {
}
- (NSString *) hashedValue :(NSString *) key andData: (NSString *) data ;
@end
HashSHA256.m
#import "HashSHA256.h"
#import <CommonCrypto/CommonHMAC.h>
@implementation HashSHA256
- (NSString *) hashedValue :(NSString *) key andData: (NSString *) data {
const char *cKey = [key cStringUsingEncoding:NSUTF8StringEncoding];
const char *cData = [data cStringUsingEncoding:NSUTF8StringEncoding];
unsigned char cHMAC[CC_SHA256_DIGEST_LENGTH];
CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC);
NSString *hash;
NSMutableString* output = [NSMutableString stringWithCapacity:CC_SHA256_DIGEST_LENGTH * 2];
for(int i = 0; i < CC_SHA256_DIGEST_LENGTH; i++)
[output appendFormat:@"%02x", cHMAC[i]];
hash = output;
return hash;
}
@end
用法:
- (NSString *) encodePassword: (NSString *) myPassword {
HashSHA256 * hashSHA256 = [[HashSHA256 alloc] init];
NSString * result = [hashSHA256 hashedValue:mySecretSalt andData:myPassword];
return result;
}
以下是不使用外部文件返回十六进制字符串的方法:
-(NSString *)hmac:(NSString *)plaintext withKey:(NSString *)key
{
const char *cKey = [key cStringUsingEncoding:NSASCIIStringEncoding];
const char *cData = [plaintext cStringUsingEncoding:NSASCIIStringEncoding];
unsigned char cHMAC[CC_SHA1_DIGEST_LENGTH];
CCHmac(kCCHmacAlgSHA1, cKey, strlen(cKey), cData, strlen(cData), cHMAC);
NSData *HMACData = [NSData dataWithBytes:cHMAC length:sizeof(cHMAC)];
const unsigned char *buffer = (const unsigned char *)[HMACData bytes];
NSMutableString *HMAC = [NSMutableString stringWithCapacity:HMACData.length * 2];
for (int i = 0; i < HMACData.length; ++i){
[HMAC appendFormat:@"%02x", buffer[i]];
}
return HMAC;
}
这段代码已在xCode 5和iOS 7上进行了测试,表现良好!
NSASCIIStringEncoding
。如果您希望支持非英语语言中的字符,请使用NSUTF8StringEncoding
。 - Alex ZavatoneCCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC);
// Now convert to NSData structure to make it usable again
NSData *out = [NSData dataWithBytes:cHMAC length:CC_SHA256_DIGEST_LENGTH];
// description converts to hex but puts <> around it and spaces every 4 bytes
NSString *hash = [out description];
hash = [hash stringByReplacingOccurrencesOfString:@" " withString:@""];
hash = [hash stringByReplacingOccurrencesOfString:@"<" withString:@""];
hash = [hash stringByReplacingOccurrencesOfString:@">" withString:@""];
// hash is now a string with just the 40char hash value in it
NSLog(@"%@",hash);
出于好奇,你为什么要创建(unsigned char cHMAC),然后转换成(NSData),再将其转换为(NSMutableString),最后转换为(HexString)?
你可以通过削减中间人(即不使用NSData和NSMutableString,更快速和更好的性能),并将(unsigned char)改为(uint8_t [])来更快地完成此操作,毕竟它们都是十六进制数组!如下:
-(NSString *)hmac:(NSString *)plaintext withKey:(NSString *)key
{
const char *cKey = [key cStringUsingEncoding:NSASCIIStringEncoding];
const char *cData = [plaintext cStringUsingEncoding:NSASCIIStringEncoding];
uint8_t cHMAC[CC_SHA1_DIGEST_LENGTH];
CCHmac(kCCHmacAlgSHA1, cKey, strlen(cKey), cData, strlen(cData), cHMAC);
NSString *Hash1 = @"";
for (int i=0; i< CC_SHA1_DIGEST_LENGTH; i++)
{
Hash1 = [Hash1 stringByAppendingString:[NSString stringWithFormat:@"%02X", cHMAC[i]]];
}
return Hash1;
}
希望这能帮到您,
祝好
Heider Sati