GUI

On my Windows machine, I can login with GUI Data Loader 44.0.0 without providing a username and password, by choosing "OAuth" and "Production" environment and clicking "Log in":

On the little popup that appears, I click the bottom link "utiliser un domaine personnalisé" which is the French translation for "Use custom domain":

I enter the custom domain name, and see the https://xxxxx.my.salesforce.com URL displaying below the field:

And I am logged in without any issue or password entry –> "Login successful".

CLI

Now for command-line login, I can't get the same behavior. On the same Windows machine, I have tried several configurations but found none that lets me get rid of user name and password entry.

• process-conf.xml with correct values provided in sfdc.username and sfdc.password (encrypted) works perfectly
• process-conf.xml with no value provided in sfdc.username end systematically in error:

2020-04-08 15:38:22,614 ERROR [myProcess] client.ClientBase getConnectorConfig (ClientBase.java:112) - Empty salesforce.com username specified.  Please make sure that parameter sfdc.username is set to correct username.

• process-conf.xml with sfdc.username provided but nothing in sfdc.password always ends in invalid login error, whatever other values I can put in the config file:

2020-04-08 15:37:28,943 ERROR [myProcess] client.PartnerClient runOperation (PartnerClient.java:350) - Error while calling web service operation: login, error was:
[LoginFault [ApiFault  exceptionCode='INVALID_LOGIN'
 exceptionMessage='Invalid username, password, security token; or user locked out.'
 extendedErrorDetails='{[0]}'
]
]

Well, you have the big picture. Details follow.

Command line

java -cp "C:\Program Files (x86)\salesforce.com\Data Loader\dataloader-44.0.0-uber.jar" -Dsalesforce.config.dir=<my conf dir> com.salesforce.dataloader.process.ProcessRunner process.name=myProcess

I have a 100% confidence that there is no problem in touching the right configuration files, here they are:

config.properties

#Loader Config
#Thu Sep 10 09:37:47 PDT 2009
sfdc.endpoint=https\://login.salesforce.com
loader.hideWelcome=true

sfdc.oauth.environment=Production
sfdc.oauth.environments=Production,Sandbox
sfdc.oauth.Production.bulk.clientid=DataLoaderBulkUI/
sfdc.oauth.Production.partner.clientid=DataLoaderPartnerUI/
sfdc.oauth.Production.server=https://login.salesforce.com/
sfdc.oauth.Production.redirecturi=https://login.salesforce.com/services/oauth2/success
sfdc.oauth.Sandbox.bulk.clientid=DataLoaderBulkUI/
sfdc.oauth.Sandbox.partner.clientid=DataLoaderPartnerUI/
sfdc.oauth.Sandbox.server=https://test.salesforce.com/
sfdc.oauth.Sandbox.redirecturi=https://test.salesforce.com/services/oauth2/success

process-conf.xml

<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <bean id="myProcess"
          class="com.salesforce.dataloader.process.ProcessRunner"
          singleton="false">
        <description>Demonstration sample for StackExchange</description>
        <property name="name" value="myProcess"/>
        <property name="configOverrideMap">
            <map>
                <entry key="sfdc.username" value="myUser"/>
                <entry key="sfdc.password" value="89f5be1b76f7e2d7bc58d8f68bb574e02a57f06b9ab9994a1811a05a0934f9aa"/>
                <entry key="process.encryptionKeyFile" value="C:\testdl\key.key"/>

                <entry key="sfdc.timeoutSecs" value="540"/>
                <entry key="sfdc.loadBatchSize" value="200"/>
                <entry key="sfdc.entity" value="InfoQualif__c"/>
                <entry key="process.operation" value="update"/>
                <entry key="process.mappingFile" value="C:\testdl\update_icf.sdl"/>
                <entry key="process.outputError" value="C:\testdl\icftest_error.csv"/>
                <entry key="process.outputSuccess" value="C:\testdl\icftest_success.csv"/>
                <entry key="dataAccess.name" value="C:\testdl\icftest.csv" />
                <entry key="dataAccess.type" value="csvRead" />
            </map>
        </property>
    </bean>
</beans>

This sample works fine, as there is a user/password in it. the challenge is to find the keys that would allow me to remove user and password.

Update

The web browser used by GUI to ask me the custom domain is IE, as you can see here:

Even after clearing all cookies from IE (see below), I still can successfully log in with just entering my custom domain. No user name or password needed.