squid配置https遇到的问题

关于HTTPS通讯，在验证过程中有问题
首先说个架构，client-----------------squid代理-----------------webserver
我需要在整个过程中都使用HTTPS通讯，我在squid和webserver都部署好了服务器证书，并且在我squid上也已经部署了CA证书。而验证过程是client发生请求到我squid上，验证我squid上部署的证书是否受信任，然后再由我squid去到webserver上验证我webserver的证书是否受信任。现在client能够验证我squid上的服务器证书是受信任的，但在我squid到webserver去验证的时候会有问题，从我squid的cache.log中会有如下的报错信息：
Jul  7 14:43:49 x.x.x.x squid[785]: Using private key in /usr/local/squid/cap/success.352.cn.key
Jul  7 14:43:49 x.x.x.x squid[785]: Error error setting CA certificate locations: error:02001002:system library:fopen:No such file or directory
Jul  7 14:43:50 x.x.x.x squid[785]: continuing anyway...
Jul  7 14:43:50 x.x.x.x squid[785]: Initialising SSL.
Jul  7 14:43:50 x.x.x.x squid[785]: NOTICE: Peer certificates are not verified for validity!
Jul  7 14:43:50 x.x.x.x squid[785]: Initialising SSL.
Jul  7 14:43:50 x.x.x.x squid[785]: Error error setting CA certificate locations: error:02001002:system library:fopen:No such file or directory
Jul  7 14:43:50 x.x.x.x squid[785]: continuing anyway...
Jul  7 14:43:50 x.x.x.x squid[785]: Cache dir '/cache1' size remains unchanged at 102400000 KB
Jul  7 14:43:50 x.x.x.x squid[785]: Cache dir '/cache2' size remains unchanged at 102400000 KB
Jul  7 14:43:50 x.x.x.x squid[785]: Logformat for 'combined' is '%>a %ui %un [%tl] "%rm %ru HTTP/%rv" %Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh'
Jul  7 14:43:50 x.x.x.x squid[785]: accessLogParseLogFormat: got definition '%>a %ui %un [%tl] "%rm %ru HTTP/%rv" %Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh'
Jul  7 14:43:50 x.x.x.x squid[785]: WARNING: use of 'override-lastmod' in 'refresh_pattern' violates HTTP
Jul  7 14:43:50 x.x.x.x squid[785]: Initialising SSL.
Jul  7 14:43:50 x.x.x.x squid[785]: Error error setting CA certificate locations: error:02001002:system library:fopen:No such file or directory

而在访问使用https的域名htttps://www.exzanpm.com/时，有如下报错：
Jul  7 15:02:23 x.x.x.x  squid[785]: SSL unknown certificate error 20 in /CN=www.exzanpm.com
Jul  7 15:02:23 x.x.x.x  squid[785]: fwdNegotiateSSL: Error negotiating SSL connection on FD 35: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed (1/-1/0)
Jul  7 15:02:23 x.x.x.x  squid[785]: TCP connection to webserverhost (webserverhost:443) failed

这到底是哪里有问题呢？？不知道各位有没有建议？

Jul  7 14:43:49 x.x.x.x squid[785]: Error error setting CA certificate locations: error:02001002:system library:fopen:No such file or directory
要么是路径不对～～～要么就是权限不对·～～～

CA证书的路径检查了 没有错，权限的话我都给了744了，还是报同样的错！！