iOS hmac(哈希)256带密钥的加密方法

找了很多地方都没有找到ios关于哈希带密钥的加密方法,最终还是在朋友的帮助下搞定的。


-(NSString*) hmacForSecret:(NSString*)secret data:(NSString*)data {

    

    const char *cKey  = [secret cStringUsingEncoding:NSASCIIStringEncoding];

    const char *cData = [data cStringUsingEncoding:NSUTF8StringEncoding];

    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 base64EncodedString];

    

    return hash;

}

再创建一个NSData的category类名字自己随意取

.h文件代码

void *NewBase64Decode(const char *inputBuffer, size_t length, size_t *outputLength);

char *NewBase64Encode(const void *inputBuffer, size_t length, bool separateLines, size_t *outputLength);


@interface NSData (base64EncodedString)


+ (NSData *)dataFromBase64String:(NSString *)aString;

- (NSString *)base64EncodedString;


.m文件代码

static unsigned char base64EncodeLookup[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

#define xx 65


static unsigned char base64DecodeLookup[256] =

{

    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx,

    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx,

    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, 62, xx, xx, xx, 63,

    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, xx, xx, xx, xx, xx, xx,

    xx012 34567 89, 10, 11, 12, 13, 14,

    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, xx, xx, xx, xx, xx,

    xx, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,

    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, xx, xx, xx, xx, xx,

    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx,

    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx,

    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx,

    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx,

    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx,

    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx,

    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx,

    xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx,

};


#define BINARY_UNIT_SIZE 3

#define BASE64_UNIT_SIZE 4


void *NewBase64Decode(const char *inputBuffer, size_t length, size_t *outputLength)

{

    if (length == -1)

    {

        length = strlen(inputBuffer);

    }

    

    size_t outputBufferSize = (length / BASE64_UNIT_SIZE) * BINARY_UNIT_SIZE;

    unsigned char *outputBuffer = (unsigned char *)malloc(outputBufferSize);

    

    size_t i = 0;

    size_t j = 0;

    while (i < length)

    {


        unsigned char accumulated[BASE64_UNIT_SIZE];

        size_t accumulateIndex = 0;

        while (i < length)

        {

            unsigned char decode = base64DecodeLookup[inputBuffer[i++]];

            if (decode != xx)

            {

                accumulated[accumulateIndex] = decode;

                accumulateIndex++;

                

                if (accumulateIndex == BASE64_UNIT_SIZE)

                {

                    break;

                }

            }

        }

        

        //

        // Store the 6 bits from each of the 4 characters as 3 bytes

        //

        outputBuffer[j] = (accumulated[0] << 2) | (accumulated[1] >> 4);

        outputBuffer[j + 1] = (accumulated[1] << 4) | (accumulated[2] >> 2);

        outputBuffer[j + 2] = (accumulated[2] << 6) | accumulated[3];

        j += accumulateIndex - 1;

    }

    

    if (outputLength)

    {

        *outputLength = j;

    }

    return outputBuffer;

}


char *NewBase64Encode(

                      const void *buffer,

                      size_t length,

                      bool separateLines,

                      size_t *outputLength)

{

    const unsigned char *inputBuffer = (const unsigned char *)buffer;

    

#define MAX_NUM_PADDING_CHARS 2

#define OUTPUT_LINE_LENGTH 64

#define INPUT_LINE_LENGTH ((OUTPUT_LINE_LENGTH / BASE64_UNIT_SIZE) * BINARY_UNIT_SIZE)

#define CR_LF_SIZE 2


    size_t outputBufferSize =

    ((length / BINARY_UNIT_SIZE)

     + ((length % BINARY_UNIT_SIZE) ? 1 : 0))

    * BASE64_UNIT_SIZE;

    if (separateLines)

    {

        outputBufferSize +=

        (outputBufferSize / OUTPUT_LINE_LENGTH) * CR_LF_SIZE;

    }


    outputBufferSize += 1;


    char *outputBuffer = (char *)malloc(outputBufferSize);

    if (!outputBuffer)

    {

        return NULL;

    }

    

    size_t i = 0;

    size_t j = 0;

    const size_t lineLength = separateLines ? INPUT_LINE_LENGTH : length;

    size_t lineEnd = lineLength;

    

    while (true)

    {

        if (lineEnd > length)

        {

            lineEnd = length;

        }

        

        for (; i + BINARY_UNIT_SIZE - 1 < lineEnd; i += BINARY_UNIT_SIZE)

        {

            outputBuffer[j++] = base64EncodeLookup[(inputBuffer[i] & 0xFC) >> 2];

            outputBuffer[j++] = base64EncodeLookup[((inputBuffer[i] & 0x03) << 4)

                                                   | ((inputBuffer[i + 1] & 0xF0) >> 4)];

            outputBuffer[j++] = base64EncodeLookup[((inputBuffer[i + 1] & 0x0F) << 2)

                                                   | ((inputBuffer[i + 2] & 0xC0) >> 6)];

            outputBuffer[j++] = base64EncodeLookup[inputBuffer[i + 2] & 0x3F];

        }

        

        if (lineEnd == length)

        {

            break;

        }

        outputBuffer[j++] = '\r';

        outputBuffer[j++] = '\n';

        lineEnd += lineLength;

    }

    

    if (i + 1 < length)

    {

        outputBuffer[j++] = base64EncodeLookup[(inputBuffer[i] & 0xFC) >> 2];

        outputBuffer[j++] = base64EncodeLookup[((inputBuffer[i] & 0x03) << 4)

                                               | ((inputBuffer[i + 1] & 0xF0) >> 4)];

        outputBuffer[j++] = base64EncodeLookup[(inputBuffer[i + 1] & 0x0F) << 2];

        outputBuffer[j++] = '=';

    }

    else if (i < length)

    {

        outputBuffer[j++] = base64EncodeLookup[(inputBuffer[i] & 0xFC) >> 2];

        outputBuffer[j++] = base64EncodeLookup[(inputBuffer[i] & 0x03) << 4];

        outputBuffer[j++] = '=';

        outputBuffer[j++] = '=';

    }

    outputBuffer[j] = 0;


    if (outputLength)

    {

        *outputLength = j;

    }

    return outputBuffer;

}


@implementation NSData (base64EncodedString)



+ (NSData *)dataFromBase64String:(NSString *)aString {

    

    NSData *data = [aString dataUsingEncoding:NSASCIIStringEncoding];

    size_t outputLength;

    void *outputBuffer = NewBase64Decode([data bytes], [data length], &outputLength);

    NSData *result = [NSData dataWithBytes:outputBuffer length:outputLength];

    free(outputBuffer);

    return result;

}



- (NSString *)base64EncodedString {

    

    size_t outputLength;

    char *outputBuffer = NewBase64Encode([self bytes], [self length], true, &outputLength);

    

    NSString *result = [[NSString alloc] initWithBytes:outputBuffer length:outputLength encoding:NSASCIIStringEncoding];

    free(outputBuffer);

    return result;

}






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转载自blog.csdn.net/shuzhi57/article/details/51209669