How to enable SSL

[tinyweasel]

When building squid normally you run the following:

./configure --enable-ssl --enable-ssl-crtd ...

How do I enable this in the docker container?

[ataka171]

Same question

[nathan-b]

It looks like the squid in Ubuntu's bionic repository is not built with --enable-ssl. This docker image just pulls from Ubuntu using apt.

I managed to work around it by basing the image off alpine instead.

Step 1: Clone the repo

git clone https://github.com/sameersbn/docker-squid.git
cd docker-squid

Step 2: Modify the Dockerfile:

nathan@nathanb-dev ~/src/docker-squid (git)-[master] % cat Dockerfile
FROM alpine:latest
LABEL maintainer="sameer@damagehead.com"

ENV SQUID_CACHE_DIR=/var/spool/squid \
    SQUID_LOG_DIR=/var/log/squid

RUN apk update \
 && apk add bash squid 

COPY entrypoint.sh /sbin/entrypoint.sh
RUN chmod 755 /sbin/entrypoint.sh

EXPOSE 3128/tcp
ENTRYPOINT ["/sbin/entrypoint.sh"]

Note that you get squid4 instead of squid3, as I don't do the version selection that this repository's dockerfile does.

Step 3: Modify the entrypoint script
The two chown lines should use the squid user and group.

Step 4: Build the image

nathan@nathanb-dev ~/src/docker-squid (git)-[master] % docker build -t mysquid --no-cache .

Step 5: Run the image

nathan@nathanb-dev ~ % docker run --rm -it --name squid -p 3128:3128 -p 3129:3129 -v /home/nathan/tmp/squid.conf:/etc/squid/squid.conf -v /home/nathan/tmp/squidlogs:/var/log/squid -v /tmp/test/certificate.pem:/etc/squid/certificate.pem localsquid:latest

Hope this helps!

[rthunoli]

Why one more port 3129? is it for https ?

[nathan-b]

@rthunoli yes, exactly. My config allows me to connect either over plaintext on port 3128 or TLS on port 3129.

[nathan-b]

If you want to run my container that I built using the recipe I give above, I put it on Dockerhub: https://hub.docker.com/repository/docker/sysdignathan/secure-squid

[nathan-b]

nathan@nathanb-dev ~/tmp % cat squid.conf
http_port 3128
https_port 3129 cert=/etc/squid/proxy.pem

dns_v4_first on

acl localnet src 10.0.0.0/8     # RFC1918 possible internal network
acl localnet src 172.16.0.0/12  # RFC1918 possible internal network
acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
acl localnet src fc00::/7       # RFC 4193 local private network range
acl localnet src fe80::/10      # RFC 4291 link-local (directly plugged) machines

acl CONNECT method CONNECT

http_access allow localnet
http_access allow localhost

Here's a minimal config that allows connections from inside the local network only on either plaintext (3128) or encrypted (3129).

[taras-vibes]

How do you add certificates?
E.g:
https_port 3129 bump ssl-bump \ cert=/etc/squid/squid-ca-cert-key.pem \ generate-host-certificates=on dynamic_cert_mem_cache_size=16MB

[nathan-b]

@taras-vibes you see on line 2 of the config I posted that there's cert=/etc/squid/proxy.pem? You just have to mount the certificate into the container at that path as part of the docker run command. For example:

docker run --rm -it --name squid -p 3128:3128 -p 3129:3129 -v /home/nathan/proxy/squid.conf:/etc/squid/squid.conf -v /home/nathan/proxy/squidlogs:/var/log/squid -v /home/nathan/proxy/cert.chain.pem:/etc/squid/proxy.pem sysdignathan/secure-squid:latest

The last -v mounts the local cert into the container at the right location for squid to find and use it.

[taras-vibes]

Hey @nathan-b thanks for your response:
Yes, I do have files in /etc/squid:
ls /etc/squid/squid-ca-cert-key.pem /etc/squid/squid-ca-cert-key.pem
When I curl it:
curl --proxy-insecure --proxy https://localhost:3129 https://skarnet.org/software/s6/
I see logs in /var/log/squid/access.log:
1711558523.802 119 192.168.65.1 TCP_MISS/200 20284 GET http://www.google.com/ - HIER_DIRECT/142.250.190.68 text/html 1711558526.013 134 192.168.65.1 TCP_MISS/200 20195 GET http://www.google.com/ - HIER_DIRECT/142.250.190.68 text/html 1711560575.965 1563 192.168.65.1 TCP_TUNNEL/200 22989 CONNECT skarnet.org:443 - HIER_DIRECT/95.142.172.232 - 1711560578.331 855 192.168.65.1 TCP_TUNNEL/200 22989 CONNECT skarnet.org:443 - HIER_DIRECT/95.142.172.232 -

It keeps missing on google, but I guess that is expected.
What is TCP_TUNNEL/200 ? Does that mean it has been cached successfully on Secure 3129 port?

[nathan-b]

@taras-vibes yes, you can read the squid docs to understand the format of the logs, but essentially it means that a TCP tunnel has been successfully established between your system (192.168.65.1) and the destination (95.142.172.232)