Hello,
I'm setting up my ocs  but I have issues with the agent on Windows. On the logs, I see
COM SERVER => Sending HTTP Post request to URL <https://myhost.ad.local/ocsinventory>
WARNING *** COM SERVER => Failed to send HTTP Post request <SSL connect error>
COM SERVER => Cleaning cURL library
ERROR *** AGENT => Failed to send Prolog <SSL connect error>
The file cacert.pem I use for the Agent has been downloaded from the Linux server /etc/pki/tls/certs/ocsng.pem and has been renamed to cacert.pem
Linux CentOS 7
Apache configuration
/etc/httpd/conf/httpd.conf
ServerRoot "/etc/httpd"
Listen 80
Include conf.modules.d/*.conf
User apache
Group apache
<Files ".ht*">
    Require all denied
</Files>
ErrorLog "logs/error_log"
LogLevel warn
#LogLevel debug
EnableSendfile on
# Load config files in the "/etc/httpd/conf.d" directory, if any.
IncludeOptional conf.d/*.conf
TraceEnable off
ServerSignature Off
ServerTokens ProductOnly
<VirtualHost *:80>
ServerName myhost.ad.local
DocumentRoot "/var/www/html"
RedirectPermanent "/" "https://192.168.51.15/"
</VirtualHost>
<IfModule dir_module>
DirectoryIndex index.html index.php
</IfModule>
/etc/httpd/conf.d/ssl.conf
Listen 443 https
SSLPassPhraseDialog exec:/usr/libexec/httpd-ssl-pass-dialog
SSLSessionCache         shmcb:/run/httpd/sslcache(512000)
SSLSessionCacheTimeout  300
SSLRandomSeed startup file:/dev/urandom  256
SSLRandomSeed connect builtin
SSLCryptoDevice builtin
<VirtualHost *:443>
DocumentRoot "/var/www/html"
ServerName myhost.ad.local
ErrorLog logs/ssl_error_log
TransferLog logs/ssl_access_log
LogLevel warn
SSLEngine on
SSLProtocol -all +TLSv1.2
SSLCipherSuite HIGH:!aNULL:!MD5
SSLCertificateFile /etc/pki/tls/certs/ocsng.pem
SSLCertificateKeyFile /etc/pki/tls/private/ocsng.key
#securing root directory
<Directory "/">
        Options None
        Order deny,allow
        Deny from all
        AllowOverride None
</Directory>
<Directory "/var/www">
    AllowOverride None
    Require all granted
</Directory>
# Further relax access to the default document root:
<Directory "/var/www/html">
    Options Indexes FollowSymLinks
    AllowOverride None
    Require all granted
</Directory>
<Directory "/var/www/cgi-bin">
    AllowOverride None
    Options None
    Require all granted
</Directory>
<Directory "/var/www/cgi-bin">
    SSLOptions +StdEnvVars
</Directory>
Alias /download /var/lib/ocsinventory-reports/download
<Directory /var/lib/ocsinventory-reports/download>
        Options Indexes FollowSymLinks MultiViews
        AllowOverride None
        Order allow,deny
        allow from all
</Directory>
</VirtualHost>
/etc/httpd/conf.d/ocsinventory-reports.conf
################################################################################
#
# OCS Inventory NG Administration Server
#
# Copyleft 2008 OCS Inventory NG Team
# Web: http://www.ocsinventory-ng.org
#
# This code is open source and may be copied and modified as long as the source
# code is always made freely available.
# Please refer to the General Public Licence http://www.gnu.org/ or Licence.txt
################################################################################
#
# ANY CHANGE ON THIS FILE REQUIRES APACHE RESTART TO TAKE EFFECT
#
################################################################################
# Administration console public pages
#
# Alias used to put Administration Server static page (typically PHP) outside
# Apache document root directory
#
Alias /ocsreports /var/www/html/ocsreports
<Directory /var/www/html/ocsreports>
    # By default, users can use console from everywhere
    Order deny,allow
    Allow from all
    Options Indexes FollowSymLinks
    DirectoryIndex index.php
    AllowOverride Options
    # Uncomment following to force use of HTTPS in Administration Server
    SSLRequireSSL
    # PHP tuning (not working on all distribution, use php.ini instead)
    AddType application/x-httpd-php .php
    php_flag file_uploads           on
    # Some PHP tuning for deployement feature up to 8 MB
    # post_max_size must be greater than upload_max_filesize
    # because of HTTP headers
    php_value post_max_size         101m
    php_value upload_max_filesize   100m
    # You may have to uncomment following on errors
    #php_value max_execution_time -1
    #php_value max_input_time -1
    #!! Mandatory !! : set magic_quotes_gpc to off (to make ocsreports works correctly)
    php_flag magic_quotes_gpc      off
    # Uncomment following to allow HTTP body request up to 4 MB
    # instead default 512 KB
    #LimitRequestBody 4194304
    # Uncomment following if you need to specify a mysql socket
    #php_value mysql.default_socket "path/to/mysql/unix/socket"
</Directory>
################################################################################
# Deployment packages download area
#
# Alias to put Deployement package files outside Apache document root directory
#
Alias /download /var/lib/ocsinventory-reports/download
<Directory "/var/lib/ocsinventory-reports/download">
        deny from all
</Directory>
################################################################################
# Snmp communities area
#
# Alias to put Snmp custom Mibs files outside Apache document root directory
#
Alias /snmp /var/lib/ocsinventory-reports/snmp