Thanks for posting this... It appears that he squid configuration allows everything https through. I was able to resolve by:

#ssl_bump terminate step3 all
ssl_bump terminate all

Using squid-3.5.20 on amazon linux 2

Hello, i run your configuration on Centos7, and have this error:

$docker logs great_hopper
2020/05/01 07:35:11| ERROR: No forward-proxy ports configured.
2020/05/01 07:35:11| ERROR: No forward-proxy ports configured.
2020/05/01 07:35:11| ERROR: No forward-proxy ports configured.
2020/05/01 07:35:11| ERROR: No forward-proxy ports configured.
2020/05/01 07:35:11| ERROR: No forward-proxy ports configured.
2020/05/01 07:35:11| Finished loading MIME types and icons.
2020/05/01 07:35:11| HTCP Disabled.
2020/05/01 07:35:11| Squid plugin modules loaded: 0
2020/05/01 07:35:11| Adaptation support is off.
2020/05/01 07:35:11| Accepting NAT intercepted HTTP Socket connections at local=0.0.0.0:3129 remote=[::] FD 13 flags=41
2020/05/01 07:35:11| Accepting NAT intercepted SSL bumped HTTPS Socket connections at local=0.0.0.0:3130 remote=[::] FD 14 flags=41
2020/05/01 07:35:12| storeLateRelease: released 0 objects

In AWS (frankfurt) i use ami-05788af9005ef9a93.
My docker-ce verstion 19.03.8

My iptables rules:

# iptables-save
# Generated by iptables-save v1.4.21 on Fri May 1 08:00:06 2020
*filter
:INPUT ACCEPT [1291:94443]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [870:435793]
:DOCKER - [0:0]
:DOCKER-ISOLATION-STAGE-1 - [0:0]
:DOCKER-ISOLATION-STAGE-2 - [0:0]
:DOCKER-USER - [0:0]
-A FORWARD -j DOCKER-USER
-A FORWARD -j DOCKER-ISOLATION-STAGE-1
-A FORWARD -o docker0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -o docker0 -j DOCKER
-A FORWARD -i docker0 ! -o docker0 -j ACCEPT
-A FORWARD -i docker0 -o docker0 -j ACCEPT
-A DOCKER-ISOLATION-STAGE-1 -i docker0 ! -o docker0 -j DOCKER-ISOLATION-STAGE-2
-A DOCKER-ISOLATION-STAGE-1 -j RETURN
-A DOCKER-ISOLATION-STAGE-2 -o docker0 -j DROP
-A DOCKER-ISOLATION-STAGE-2 -j RETURN
-A DOCKER-USER -j RETURN
COMMIT
# Completed on Fri May 1 08:00:06 2020
# Generated by iptables-save v1.4.21 on Fri May 1 08:00:06 2020
*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [8:480]
:OUTPUT ACCEPT [39:3228]
:POSTROUTING ACCEPT [39:3228]
:DOCKER - [0:0]
-A PREROUTING -s 10.0.0.0/16 -p tcp -m tcp --dport 443 -j REDIRECT --to-ports 3130
-A PREROUTING -s 10.0.0.0/16 -p tcp -m tcp --dport 80 -j REDIRECT --to-ports 3129
-A PREROUTING -m addrtype --dst-type LOCAL -j DOCKER
-A OUTPUT ! -d 127.0.0.0/8 -m addrtype --dst-type LOCAL -j DOCKER
-A POSTROUTING -s 172.17.0.0/16 ! -o docker0 -j MASQUERADE
-A DOCKER -i docker0 -j RETURN
COMMIT
# Completed on Fri May 1 08:00:06 2020

Squid config:

# cat /etc/squid/squid.conf
visible_hostname squid

#Handling HTTP requests
http_port 3129 intercept
acl allowed_http_sites dstdomain .amazonaws.com
acl allowed_http_sites dstdomain .security.ubuntu.com
http_access allow allowed_http_sites

#Handling HTTPS requests
https_port 3130 cert=/etc/squid/ssl/squid.pem ssl-bump intercept
acl SSL_port port 443
http_access allow SSL_port
acl allowed_https_sites ssl::server_name .amazonaws.com
acl allowed_https_sites ssl::server_name .badssl.com
acl allowed_https_sites ssl::server_name .security.ubuntu.com

acl step1 at_step SslBump1
acl step2 at_step SslBump2
acl step3 at_step SslBump3
ssl_bump peek step1 all
ssl_bump peek step2 allowed_https_sites
ssl_bump splice step3 allowed_https_sites
ssl_bump terminate step3 all
http_access deny all