Hello,
After many hours of debug I found out the reason why Adobe Acrobat Reader freezes on the routine that checks the Certificates (showing a download bar for http://ocsp.digicert.com/MFEwTzBNMEswSTAJBgUrDgMCGgUABBQ50otx%2Fh0Ztl%2Bz8SiPI7wEWVxDlQQUTiJUIBiV5uNu5g%2F6%2BrkS7QYXjzkCEAn5bsKVVV8kdJ6vHl3O1J0%3D): reason is related with SQUID in transparent mode.
Looking at SQUID logs I noticed these lines were logged while Adobe Acrobat was freezing:
1727283458.399 30773 192.168.x.y NONE_NONE_ABORTED/000 0 GET http://ocsp.digicert.com/MFEwTzBNMEswSTAJBgUrDgMCGgUABBQ50otx%2Fh0Ztl%2Bz8SiPI7wEWVxDlQQUTiJUIBiV5uNu5g%2F6%2BrkS7QYXjzkCEAn5bsKVVV8kdJ6vHl3O1J0%3D - HIER_NONE/- -
1727283458.399 15789 192.168.x.y NONE_NONE_ABORTED/000 0 GET http://crl3.digicert.com/DigiCertGlobalRootG2.crl - HIER_NONE/- -
1727283583.747 31960 192.168.x.y NONE_NONE_ABORTED/000 0 GET http://crl3.digicert.com/DigiCertTrustedG4CodeSigningRSA4096SHA3842021CA1.crl - HIER_NONE/- -
1727283615.786 7 192.168.x.y TCP_MISS/304 358 GET http://crl3.digicert.com/DigiCertAssuredIDRootCA.crl - ORIGINAL_DST/192.229.221.95 -
1727283615.808 4 192.168.x.y TCP_MISS/304 358 GET http://crl3.digicert.com/DigiCertGlobalRootCA.crl - ORIGINAL_DST/192.229.221.95 -
1727283621.566 5 192.168.x.y TCP_MISS/304 359 GET http://crl3.digicert.com/Omniroot2025.crl - ORIGINAL_DST/192.229.221.95 -
1727283621.591 4 192.168.x.y TCP_MISS/304 358 GET http://crl3.digicert.com/DigiCertGlobalRootG3.crl - ORIGINAL_DST/192.229.221.95 -
1727283621.615 4 192.168.x.y TCP_MISS/304 358 GET http://crl3.digicert.com/DigiCertTrustedRootG4.crl - ORIGINAL_DST/192.229.221.95 -
1727283723.757 31975 192.168.x.y NONE_NONE_ABORTED/000 0 GET http://crl3.digicert.com/DigiCertTrustedG4CodeSigningRSA4096SHA3842021CA1.crl - HIER_NONE/- -
1727284056.003 31951 192.168.x.y NONE_NONE_ABORTED/000 0 GET http://crl3.digicert.com/DigiCertTrustedG4CodeSigningRSA4096SHA3842021CA1.crl - HIER_NONE/- -
1727284063.674 7641 192.168.x.y TCP_MISS/304 358 GET http://crl3.digicert.com/DigiCertGlobalRootCA.crl - ORIGINAL_DST/192.229.221.95 -
With SQUID turned off Adobe Acrobat no longer freezes.
I added the proxy bypass for 192.229.221.95 but still Adobe Acrobat freezes while trying to reach ocsp.digicert.com.
iptables -t nat -A CUSTOMPREROUTING -d 192.229.221.95 -j RETURN
iptables -t nat -L CUSTOMPREROUTING
Chain CUSTOMPREROUTING (1 references)
target prot opt source destination
RETURN all -- anywhere 192.229.221.95
Any other suggestion to solve this case where Digicert OCSP site and Digicert CRL site seems to have a problem with SQUID in transparent mode? (NONE_NONE_ABORTED/000, TCP_MISS/304)
Worth to be mentioned: if I turn off SQUID then Adobe Acrobat works fine!
Thank you!
Late edit: Squid Log Files | Squid Web Cache wiki (squid-cache.org)