SHA1哈希计算

SHA1哈希计算

标签（空格分隔）： iOS

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用融云做即时通讯时，用到的哈希计算，记录一下

#pragma mark SHA1哈希计算
- (NSString*) sha1:(NSString *)hashString
{
    const char *cstr = [hashString cStringUsingEncoding:NSUTF8StringEncoding];
    NSData *data = [NSData dataWithBytes:cstr length:hashString.length];

    uint8_t digest[CC_SHA1_DIGEST_LENGTH];

    CC_SHA1(data.bytes, (CC_LONG)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]];

    return output;
}