stsRoleArn                = "RoleArn"
	stsWebIdentityToken       = "WebIdentityToken"
	stsWebIdentityAccessToken = "WebIdentityAccessToken" // only valid if UserInfo is enabled.
	stsDurationSeconds        = "DurationSeconds"
	stsLDAPUsername           = "LDAPUsername"
	stsLDAPPassword           = "LDAPPassword"
	stsRevokeTokenType        = "TokenRevokeType"

	// STS API action constants
	clientGrants        = "AssumeRoleWithClientGrants"

			bs, err := io.ReadAll(f)
			if err != nil {
				log.Fatalf("Error reading session policy file: %v", err)
			}
			policy = string(bs)
		}
		stsOpts.Policy = policy
	}
	if expiryDuration != 0 {
		stsOpts.DurationSeconds = int(expiryDuration.Seconds())
	}
	li, err := cr.NewSTSAssumeRole(stsEndpoint, stsOpts)
	if err != nil {
		log.Fatalf("Error initializing STS Identity: %v", err)
	}

	if exp == nil || exp.IsZero() || exp.Equal(timeSentinel) {
		return nil
	}
	dur := time.Until(*exp)
	if dur <= 0 {
		return errors.New("unsupported expiration time")
	}
	condValues["DurationSeconds"] = []string{strconv.FormatInt(int64(dur.Seconds()), 10)}
	return nil
}