Subject: | Old versions of OpenSSL cannot handle CA files with multiple certificates |
It appears to be the case that old versions of OpenSSL (known broken
0.9.8g, known fixed 0.9.8o) do not properly handle certificate authority
files that contain multiple certificate authorities. Here is an example
(no Perl involved, but it illustrates the bug):
ezyang@dr-wily:~$ head Public/cacert.pem
##
## lib/Mozilla/CA/cacert.pem -- Bundle of CA Root Certificates
##
## Certificate data from Mozilla as of: Thu Apr 7 03:47:06 2011
##
## This is a bundle of X.509 certificates of public Certificate Authorities
## (CA). These were automatically extracted from Mozilla's root certificates
## file (certdata.txt). This file can be found in the mozilla source tree:
## '/mozilla/security/nss/lib/ckfw/builtins/certdata.txt'
##
ezyang@dr-wily:~$ grep Entrust Public/cacert.pem
Entrust.net Secure Server CA
Entrust.net Premium 2048 Secure Server CA
Entrust Root Certification Authority
ezyang@dr-wily:~$ curl --version
curl 7.18.2 (i486-pc-linux-gnu) libcurl/7.18.2 OpenSSL/0.9.8g
zlib/1.2.3.3 libidn/1.8 libssh2/0.18
Protocols: tftp ftp telnet dict ldap ldaps http file https ftps scp sftp
Features: GSS-Negotiate IDN IPv6 Largefile NTLM SSL libz
ezyang@dr-wily:~$ curl --cacert Public/cacert.pem --capath /dev/null
https://graph.facebook.com
curl: (60) SSL certificate problem, verify that the CA cert is OK. Details:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate
verify failed
More details here: http://curl.haxx.se/docs/sslcerts.html
curl performs SSL certificate verification by default, using a "bundle"
of Certificate Authority (CA) public keys (CA certs). The default
bundle is named curl-ca-bundle.crt; you can specify an alternate file
using the --cacert option.
If this HTTPS server uses a certificate signed by a CA represented in
the bundle, the certificate verification probably failed due to a
problem with the certificate (it might be expired, or the name might
not match the domain name in the URL).
If you'd like to turn off curl's verification of the certificate, use
the -k (or --insecure) option.
ezyang@dr-wily:~$ cat test.pem
Show quoted text
-----BEGIN CERTIFICATE-----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=
-----END CERTIFICATE-----
ezyang@dr-wily:~$ curl --cacert test.pem --capath /dev/null
https://graph.facebook.com
ezyang@dr-wily:~$ grep MIIE2DCCBEGgAwIBAgIE Public/cacert.pem
MIIE2DCCBEGgAwIBAgIEN0rSQzANBgkqhkiG9w0BAQUFADCBwzELMAkGA1UEBhMCVVMxFDASBgNV
The upshot is that if you're using new versions of libwww-perl that do
certificate authority checking, and you have old versions of OpenSSL,
you will get spurious failed certificate validation errors.
This is a definitive problem for distributions like Debian Lenny, which
are still using old versions of the OpenSSL library which have this bug.
It would be lovely if Mozilla::CA could work around this problem by
having a certificate directory rather than file.