hmacSha1算法

(NSString ) hmacSha1:(NSString)key text:(NSString*)text
{
const char *cKey = [key cStringUsingEncoding:NSUTF8StringEncoding];
const char *cData = [text cStringUsingEncoding:NSUTF8StringEncoding];

uint8_t cHMAC[CC_SHA1_DIGEST_LENGTH];

CCHmac(kCCHmacAlgSHA1, cKey, strlen(cKey), cData, strlen(cData), cHMAC);

//NSData *HMAC = [[NSData alloc] initWithBytes:cHMAC length:CC_SHA1_DIGEST_LENGTH];
NSString hash;
NSMutableString output = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH * 2];
for(int i = 0; i < CC_SHA1_DIGEST_LENGTH; i++)
[output appendFormat:@"%02x", cHMAC[i]];
hash = output;

return hash;
}