SSLCERTS: update wrt SSL CA certificate store

This commit is contained in:
Ludwig Nussel 2015-03-27 08:22:39 +01:00 committed by Daniel Stenberg
parent 7b55279d1d
commit e49ab0a3b8
1 changed files with 31 additions and 21 deletions

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@ -20,8 +20,8 @@ support.
It is about trust
-----------------
This system is about trust. In your local CA cert bundle you have certs from
*trusted* Certificate Authorities that you then can use to verify that the
This system is about trust. In your local CA certificate store you have certs
from *trusted* Certificate Authorities that you then can use to verify that the
server certificates you see are valid. They're signed by one of the CAs you
trust.
@ -35,16 +35,16 @@ Certificate Verification
------------------------
libcurl performs peer SSL certificate verification by default. This is done
by using CA cert bundle that the SSL library can use to make sure the peer's
server certificate is valid.
by using a CA certificate store that the SSL library can use to make sure the
peer's server certificate is valid.
If you communicate with HTTPS, FTPS or other TLS-using servers using
certificates that are signed by CAs present in the bundle, you can be sure
certificates that are signed by CAs present in the store, you can be sure
that the remote server really is the one it claims to be.
If the remote server uses a self-signed certificate, if you don't install a CA
cert bundle, if the server uses a certificate signed by a CA that isn't
included in the bundle you use or if the remote host is an impostor
cert store, if the server uses a certificate signed by a CA that isn't
included in the store you use or if the remote host is an impostor
impersonating your favorite site, and you want to transfer files from this
server, do one of the following:
@ -59,12 +59,22 @@ server, do one of the following:
With the curl command line tool: --cacert [file]
3. Add the CA cert for your server to the existing default CA cert bundle.
The default path of the CA bundle used can be changed by running configure
with the --with-ca-bundle option pointing out the path of your choice.
3. Add the CA cert for your server to the existing default CA certificate
store. The default CA certificate store can changed at compile time with the
following configure options:
To do this, you need to get the CA cert for your server in PEM format and
then append that to your CA cert bundle.
--with-ca-bundle=FILE: use the specified file as CA certificate store. CA
certificates need to be concatenated in PEM format into this file.
--with-ca-path=PATH: use the specified path as CA certificate store. CA
certificates need to be stored as individual PEM files in this directory.
You may need to run c_rehash after adding files there.
If neither of the two options is specified, configure will try to auto-detect
a setting. It's also possible to explicitly not hardcode any default store
but rely on the built in default the crypto library may provide instead.
You can achieve that by passing both --without-ca-bundle and
--without-ca-path to the configure script.
If you use Internet Explorer, this is one way to get extract the CA cert
for a particular server:
@ -76,7 +86,7 @@ server, do one of the following:
- Convert it from crt to PEM using the openssl tool:
openssl x509 -inform DES -in yourdownloaded.crt \
-out outcert.pem -text
- Append the 'outcert.pem' to the CA cert bundle or use it stand-alone
- Add the 'outcert.pem' to the CA certificate store or use it stand-alone
as described below.
If you use the 'openssl' tool, this is one way to get extract the CA cert
@ -89,9 +99,9 @@ server, do one of the following:
- If you want to see the data in the certificate, you can do: "openssl
x509 -inform PEM -in certfile -text -out certdata" where certfile is
the cert you extracted from logfile. Look in certdata.
- If you want to trust the certificate, you can append it to your
cert bundle or use it stand-alone as described. Just remember that the
security is no better than the way you obtained the certificate.
- If you want to trust the certificate, you can add it to your CA
certificate store or use it stand-alone as described. Just remember that
the security is no better than the way you obtained the certificate.
4. If you're using the curl command line tool, you can specify your own CA
cert path by setting the environment variable `CURL_CA_BUNDLE` to the path
@ -113,9 +123,9 @@ server, do one of the following:
Neglecting to use one of the above methods when dealing with a server using a
certificate that isn't signed by one of the certificates in the installed CA
cert bundle, will cause SSL to report an error ("certificate verify failed")
during the handshake and SSL will then refuse further communication with that
server.
certificate store, will cause SSL to report an error ("certificate verify
failed") during the handshake and SSL will then refuse further communication
with that server.
Certificate Verification with NSS
---------------------------------
@ -123,8 +133,8 @@ Certificate Verification with NSS
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
enables NSS to read the OpenSSL PEM CA bundle. On openSUSE you can install
p11-kit-nss-trust which makes NSS use the system wide CA certificate store. NSS
also has a new [database format](https://wiki.mozilla.org/NSS_Shared_DB).
Starting with version 7.19.7, libcurl automatically adds the 'sql:' prefix to