Control-M Managed File Transfer jobs using a connection to Amazon S3 server fails due to untrusted certificate, with an error similar to the following in the logs: Unable to execute HTTP request: certificate_unknown(46)

When connecting to an S3 compatible service, the connection profile test fails to connect.

The <agent>/ctm/proclog/ctmaft.log file shows an error like:
 

2021-01-27 15:15:50,605 ERROR [qtp2083999882-22] (S3Wrapper:214) - Error connecting with account's AWS credentials
com.amazonaws.SdkClientException: Unable to execute HTTP request: certificate_unknown(46)

For Google Cloud it shows 
Error: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target 

Import the CA certificate to the Control-M Managed File Transfer (MFT)'s JRE truststore, which is:
<ctm_agent>/ctm/cm/AFT/JRE_LINK/lib/security/cacerts using the following steps:

1. Copy the S3 server CA file or the Google cloud one, or any that the connection profile is trying to connect, to a temporary location on the computer where Control-M Managed File Transfer is installed. Note that it can be easily exported using a browser.

2. Navigate to the following location:
<ctm_agent>/ctm/cm/AFT/JRE_LINK/bin/

replace <ctm_agent> with the full path to the Agent.

3. Import the certificate for the CA by running:
Linux: ./keytool -importcert -alias <server_alias> -file <server_certificate_file> -keystore ../lib/security/cacerts -storepass changeit -trustcacerts
Windows: keytool -importcert -alias <server_alias> -file <server_certificate_file> -keystore ..\lib\security\cacerts -storepass changeit -trustcacerts

replace <server_certificate_file> with the filename where you placed the certificate in step 1
replace <server_alias> with any unique name for this server

4. Restart the Control-M/Agent processes.