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Chapter 2. Authentication and Security
2.1. TLS/SSL Certification
The Red Hat Virtualization API requires Hypertext Transfer Protocol Secure (HTTPS) footnote:[See RFC 2818: HTTP Over TLS for secure interaction with client software, such as the SDK and CLI components. This involves obtaining the CA certificate used by the server and importing it into the certificate store of your client.
2.1.1. Obtaining the CA Certificate
You can obtain the CA certificate from the Red Hat Virtualization Manager and transfer it to the client machine using one of these methods:
- Method 1
The preferred method for obtaining the CA certificate is to use the
openssl s_client
command line tool to perform a real TLS handshake with the server, and then extract the certificates that it presents.Run the
openssl s_client
command as in the following example:$ openssl s_client \ -connect myengine.example.com:443 \ -showcerts \ < /dev/null
Example output
CONNECTED(00000003) depth=1 C = US, O = Example Inc., CN = myengine.example.com.23416 verify error:num=19:self signed certificate in certificate chain --- Certificate chain 0 s:/C=US/O=Example Inc./CN=myengine.example.com i:/C=US/O=Example Inc./CN=myengine.example.com.23416 -----BEGIN CERTIFICATE----- MIIEaTCCA1GgAwIBAgICEAQwDQYJKoZIhvcNAQEFBQAwSTELMAkGA1UEBhMCVVMx FTATBgNVBAoTDEV4YW1wbGUgSW5jLjEjMCEGA1UEAxMaZW5naW5lNDEuZXhhbXBs SVlJe7e5FTEtHJGTAeWWM6dGbsFhip5VXM0gfqg= -----END CERTIFICATE----- 1 s:/C=US/O=Example Inc./CN=myengine.example.com.23416 i:/C=US/O=Example Inc./CN=myengine.example.com.23416 -----BEGIN CERTIFICATE----- MIIDxjCCAq6gAwIBAgICEAAwDQYJKoZIhvcNAQEFBQAwSTELMAkGA1UEBhMCVVMx FTATBgNVBAoTDEV4YW1wbGUgSW5jLjEjMCEGA1UEAxMaZW5naW5lNDEuZXhhbXBs Pkyg1rQHR6ebGQ== -----END CERTIFICATE-----
The text between the
-----BEGIN CERTIFICATE-----
and-----END CERTIFICATE-----
lines shows the certificates presented by the server.The first certificate is the certificate of the server itself. The second certificate is the certificate of the CA.
Copy the CA certificate, including the
-----BEGIN CERTIFICATE-----
and-----END CERTIFICATE-----
lines, to theca.crt
file as in the following example:-----BEGIN CERTIFICATE----- MIIDxjCCAq6gAwIBAgICEAAwDQYJKoZIhvcNAQEFBQAwSTELMAkGA1UEBhMCVVMx FTATBgNVBAoTDEV4YW1wbGUgSW5jLjEjMCEGA1UEAxMaZW5naW5lNDEuZXhhbXBs Pkyg1rQHR6ebGQ== -----END CERTIFICATE-----
ImportantThis is the most reliable method to obtain the CA certificate used by the server. The rest of the methods described here will work in most cases, but they will not obtain the correct CA certificate if the certificate has been manually replaced by the server administrator.
- Method 2
If you cannot use
openssl s_client
to obtain the certificate, you can use a command line tool, for examplecurl
orwget
, to download the CA certificate from the Red Hat Virtualization Manager.curl
andwget
are available on multiple platforms.If using
curl
:$ curl \ --output ca.crt \ 'http://myengine.example.com/ovirt-engine/services/pki-resource?resource=ca-certificate&format=X509-PEM-CA'
If using
wget
:$ wget \ --output-document ca.crt \ 'http://myengine.example.com/ovirt-engine/services/pki-resource?resource=ca-certificate&format=X509-PEM-CA'
- Method 3
Use a web browser to navigate to the certificate located at `https://myengine.example.com/ovirt-engine/services/pki-resource?resource=ca-certificate&format=X509-PEM-CA`.
Depending on the chosen browser, the certificate is downloaded or imported into the browser’s keystore:
-
If the browser downloads the certificate, save the file as
ca.crt
. -
If the browser imports the certificate, export it using the browser’s certificate management options and save it as
ca.crt
.
-
If the browser downloads the certificate, save the file as
- Method 4
Log in to the Red Hat Virtualization Manager, export the certificate from the truststore, and copy it to your client machine.
-
Log in to the Red Hat Virtualization Manager machine as
root
. Export the certificate from the truststore using the Java
keytool
management utility:# keytool \ -keystore /etc/pki/ovirt-engine/.truststore \ -storepass mypass \ -exportcert \ -alias cacert \ -rfc \ -file ca.crt
This creates a certificate file called
ca.crt
.Copy the certificate to the client machine using the
scp
command:$ scp ca.crt myuser@myclient.example.com:/home/myuser/.
Each of these methods results in a certificate file named
ca.crt
on your client machine. You must then import this file into the certificate store of the client.
-
Log in to the Red Hat Virtualization Manager machine as
2.1.2. Importing a Certificate to a Client
Importing a certificate to a client relies on how the client stores and interprets certificates. See your client documentation for more information on importing a certificate.
2.2. Authentication
Any user with a Red Hat Virtualization Manager account has access to the API. All requests must be authenticated using either OAuth or basic authentication, as described below.
2.2.1. OAuth Authentication
Since version 4.0 of Red Hat Virtualization the preferred authentication mechanism is OAuth 2.0, as described in RFC 6749.
OAuth is a sophisticated protocol, with several mechanisms for obtaining authorization and access tokens. For use with the Red Hat Virtualization API, the only supported one is the Resource Owner Password Credentials Grant, as described in RFC 6749.
You must first obtain a token, sending the user name and password to the Red Hat Virtualization Manager single sign-on service:
POST /ovirt-engine/sso/oauth/token HTTP/1.1 Host: myengine.example.com Content-Type: application/x-www-form-urlencoded Accept: application/json
The request body must contain the grant_type
, scope
, username
, and password
parameters:
Name | Value |
---|---|
|
|
|
|
|
|
|
|
These parameters must be URL-encoded. For example, the @
character in the user name needs to be encoded as %40
. The resulting request body will be something like this:
grant_type=password&scope=ovirt-app-api&username=admin%40internal&password=mypassword
The scope
parameter is described as optional in the OAuth RFC, but when using it with the Red Hat Virtualization API it is mandatory, and its value must be ovirt-app-api
.
If the user name and password are valid, the Red Hat Virtualization Manager single sign-on service will respond with a JSON document similar to this one:
{ "access_token": "fqbR1ftzh8wBCviLxJcYuV5oSDI=", "token_type": "bearer", "scope": "...", ... }
For API authentication purposes, the only relevant name/value pair is the access_token
. Do not manipulate this in any way; use it exactly as provided by the SSO service.
Once the token has been obtained, it can be used to perform requests to the API by including it in the HTTP Authorization
header, and using the Bearer
scheme. For example, to get the list of virtual machines, send a request like this:
GET /ovirt-engine/api/vms HTTP/1.1 Host: myengine.example.com Accept: application/xml Authorization: Bearer fqbR1ftzh8wBCviLxJcYuV5oSDI=
The token can be used multiple times, for multiple requests, but it will eventually expire. When it expires, the server will reject the request with the 401 HTTP response code:
HTTP/1.1 401 Unauthorized
When this happens, a new token is needed, as the Red Hat Virtualization Manager single sign-on service does not currently support refreshing tokens. A new token can be requested using the same method described above.
2.2.2. Basic Authentication
Basic authentication is supported only for backwards compatibility; it is deprecated since version 4.0 of Red Hat Virtualization, and will be removed in the future.
Each request uses HTTP Basic Authentication [1] to encode the credentials. If a request does not include an appropriate Authorization
header, the server sends a 401 Authorization Required
response:
HEAD /ovirt-engine/api HTTP/1.1 Host: myengine.example.com HTTP/1.1 401 Authorization Required
Request are issued with an Authorization
header for the specified realm. Encode an appropriate Red Hat Virtualization Manager domain and user in the supplied credentials with the username@domain:password
convention.
The following table shows the process for encoding credentials in Base64.
Item | Value |
---|---|
User name |
|
Domain |
|
Password |
|
Unencoded credentials |
|
Base64 encoded credentials |
|
Provide the Base64-encoded credentials as shown:
HEAD /ovirt-engine/api HTTP/1.1 Host: myengine.example.com Authorization: Basic YWRtaW5AaW50ZXJuYWw6bXlwYXNzd29yZA== HTTP/1.1 200 OK
Basic authentication involves potentially sensitive information, such as passwords, sent as plain text. The API requires Hypertext Transfer Protocol Secure (HTTPS) for transport-level encryption of plain-text requests.
Some Base64 libraries break the result into multiple lines and terminate each line with a newline character. This breaks the header and causes a faulty request. The Authorization
header requires the encoded credentials on a single line within the header.
2.2.3. Authentication Sessions
The API also provides authentication session support. Send an initial request with authentication details, then send all subsequent requests using a session cookie to authenticate.
2.2.3.1. Requesting an Authenticated Session
Send a request with the
Authorization
andPrefer: persistent-auth
headers:HEAD /ovirt-engine/api HTTP/1.1 Host: myengine.example.com Authorization: Basic YWRtaW5AaW50ZXJuYWw6bXlwYXNzd29yZA== Prefer: persistent-auth HTTP/1.1 200 OK ...
This returns a response with the following header:
Set-Cookie: JSESSIONID=5dQja5ubr4yvI2MM2z+LZxrK; Path=/ovirt-engine/api; Secure
Take note of the
JSESSIONID=
value. In this example the value is5dQja5ubr4yvI2MM2z+LZxrK
.Send all subsequent requests with the
Prefer: persistent-auth
andCookie
headers with theJSESSIONID=
value. TheAuthorization
header is no longer needed when using an authenticated session.HEAD /ovirt-engine/api HTTP/1.1 Host: myengine.example.com Prefer: persistent-auth Cookie: JSESSIONID=5dQja5ubr4yvI2MM2z+LZxrK HTTP/1.1 200 OK ...
When the session is no longer required, perform a request to the sever without the
Prefer: persistent-auth
header.HEAD /ovirt-engine/api HTTP/1.1 Host: myengine.example.com Authorization: Basic YWRtaW5AaW50ZXJuYWw6bXlwYXNzd29yZA== HTTP/1.1 200 OK ...