<concept id="GUID-1293DE8C-E803-4ADF-9FA8-862519337331" xml:lang="en"><title>Software installer</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>End users can install new software from a variety of sources:

through e-mail, Internet downloads, multimedia messaging service (MMS)

and WAP push messages, infrared and Bluetooth connections, PC Suite,

and removable memory cards. The diversity of software vendors and

delivery channels requires a sophisticated system for managing installed

software.</p>

<p>The Symbian <i>Software Installer</i> uses <i>digital signatures</i> and <i>certificates</i> to authenticate that the application being

installed on a mobile device is from a known vendor. The signature

can be obtained through the <xref href="https://www.symbiansigned.com/app/page" scope="external">Symbian Signed</xref> process, and the default certificates installed in the mobile device

act as root certificates. During installation the signature is validated

against the certificates. If they match, the application is installed

and the requested <xref href="GUID-6971B0A2-F79B-4E05-8AF3-BB1FC1932A22.dita">capabilities</xref> are stored in the executable, assuming that the

root certificate can grant the capabilities. Only <i>user capabilities</i> can be granted to unsigned or self-signed applications, and these

are always confirmed by the user. </p>

<p>The end users have an option to cancel the installation if they

detect that the vendor of the software package and certificate authority

are not trustworthy. This is especially important when installing

security-related components (for example, VPN clients, firewalls and

virus scanners) or other business-related software.</p>

<p>The Software Installer ensures that no two applications have

the same <xref href="GUID-3B6E25F7-C1A8-461F-97F7-421DB559BC98.dita#GUID-3B6E25F7-C1A8-461F-97F7-421DB559BC98/GUID-EEC50FC0-46D5-4ED7-AD95-67430D5EC652">SID</xref> value on a particular target device. The Software Installer

has the <codeph>TCB</codeph> capability to read and modify content

in the <xref href="GUID-B9414AE8-820E-4CA5-A9C4-29560CD6F2EF.dita"><codeph>\sys</codeph> </xref> folder and all its subfolders, which means

that you can write to third-party application executables in the <codeph>\sys\bin</codeph> folder when they are installed through the Software

Installer.</p>

<p>For more information on the Software Installer, see <xref href="GUID-8E160B29-18C4-574B-9259-9A8E958CDA91.dita">Secure Software Install

Tools</xref>.</p>

<fig id="GUID-98820420-7C7A-46EC-9DE4-EA3F5FFD39A8"><title>Installation process for signed packages</title><image href="GUID-85291DF3-C134-4231-938A-C20DD122AB7D_d0e14147_href.png"/></fig>

<p>The Software Installer recognizes different devices, which allows

you to define the platforms and devices to which the software can

be installed.</p>

<p>If you receive an error message when using the Software Installer,

see <xref href="http://developer.symbian.org/wiki/index.php/Troubleshooting_Installation_Errors.dita">Troubleshooting Installation Errors</xref> at the Symbian Foundation.</p>