cURL not working (Error #77) for SSL connections o

Question

Just recently my server has stopped working for curl requests to https:// addresses for my web server. Having dug around a little it appears that it's a problem with the user the webserver is running.

If I SSH onto the server as root & call

curl -I -v https://google.com

... I get the following response...

* About to connect() to google.com port 443 (#0)
*   Trying 173.194.67.113... connected
* Connected to google.com (173.194.67.113) port 443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
*   CAfile: /etc/pki/tls/certs/ca-bundle.crt
  CApath: none
* SSL connection using SSL_RSA_WITH_RC4_128_SHA
* Server certificate:
*       subject: CN=*.google.com,O=Google Inc,L=Mountain View,ST=California,C=US
*       start date: May 22 15:50:20 2013 GMT
*       expire date: Oct 31 23:59:59 2013 GMT
*       common name: *.google.com
*       issuer: CN=Google Internet Authority,O=Google Inc,C=US
> HEAD / HTTP/1.1
> User-Agent: curl/7.19.7 (x86_64-redhat-linux-gnu) libcurl/7.19.7 NSS/3.14.0.0 zlib/1.2.3 libidn/1.18 libssh2/1.4.2
> Host: google.com
> Accept: */*

However, if I log in as any of the cPanel accounts (also used when running via the web server) I get the following...

* About to connect() to google.com port 443 (#0)
*   Trying 173.194.67.101... connected
* Connected to google.com (173.194.67.101) port 443 (#0)
* Initializing NSS with certpath: none
* NSS error -5978
* Closing connection #0
* Problem with the SSL CA cert (path? access rights?)
curl: (77) Problem with the SSL CA cert (path? access rights?)

I've not been able to find a definitive answer to the problem, & my hosting company are refusing to help as it's "Out of support" even though it was working fine last week!

I did find mention on http://curl.haxx.se/docs/sslcerts.html that

"If libcurl was built with NSS support, then depending on the OS distribution, it is probably required to take some additional steps to use the system-wide CA cert db. RedHat ships with an additional module, libnsspem.so, which enables NSS to read the OpenSSL PEM CA bundle. This library is missing in OpenSuSE, and without it, NSS can only work with its own internal formats. NSS also has a new database format: https://wiki.mozilla.org/NSS_Shared_DB"

... but I can find no information on how I get this working system-wide on my CentOS server.

Info

curl 7.19.7 (x86_64-redhat-linux-gnu) libcurl/7.19.7 NSS/3.14.0.0 zlib/1.2.3 libidn/1.18 libssh2/1.4.2
Protocols: tftp ftp telnet dict ldap ldaps http file https ftps scp sftp 
Features: GSS-Negotiate IDN IPv6 Largefile NTLM SSL libz 

Can anyone shed some light on why this might have suddenly changed, or better still how to fix it?

Thanks

Answer 1

I just had a similar problem with Error#77 on CentOS7. I was missing the softlink /etc/pki/tls/certs/ca-bundle.crt that is installed with the ca-certificates RPM.

'curl' was attempting to open this path to get the Certificate Authorities. I discovered with:

strace curl https://example.com

and saw clearly that the open failed on that link.

My fix was:

yum reinstall ca-certificates

That should setup everything again. If you have private CAs for Corporate or self-signed use make sure they are in /etc/pki/ca-trust/source/anchors so that they are re-added.

Answer 2

Check that you have the correct rights set on CA certificates bundle. Usually, that means read access for everyone to CA files in the /etc/ssl/certs directory, for instance /etc/ssl/certs/ca-certificates.crt.

You can see what files have been configured for you curl version with the

curl-config --configure

command :

$ curl-config --configure
 '--prefix=/usr' 
 '--mandir=/usr/share/man' 
 '--disable-dependency-tracking' 
 '--disable-ldap' 
 '--disable-ldaps' 
 '--enable-ipv6' 
 '--enable-manual' 
 '--enable-versioned-symbols' 
 '--enable-threaded-resolver' 
 '--without-libidn' 
 '--with-random=/dev/urandom' 
 '--with-ca-bundle=/etc/ssl/certs/ca-certificates.crt' 
 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fstack-protector --param=ssp-buffer-size=4' 'LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro' 
 'CPPFLAGS=-D_FORTIFY_SOURCE=2'

Here you need read access to /etc/ssl/certs/ca-certificates.crt

$ curl-config --configure
 '--build' 'i486-linux-gnu' 
 '--prefix=/usr' 
 '--mandir=/usr/share/man' 
 '--disable-dependency-tracking' 
 '--enable-ipv6' 
 '--with-lber-lib=lber' 
 '--enable-manual' 
 '--enable-versioned-symbols' 
 '--with-gssapi=/usr' 
 '--with-ca-path=/etc/ssl/certs' 
 'build_alias=i486-linux-gnu' 
 'CFLAGS=-g -O2' 
 'LDFLAGS=' 
 'CPPFLAGS='

And the same here.