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Copyright (C) 2016 Guido Berhoerster <guido+sencrypt@berhoerster.name>

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<refentry xmlns="http://docbook.org/ns/docbook" xml:lang="en">
  <info>
    <author>
      <personname>
        <firstname>Guido</firstname>
        <surname>Berhoerster</surname>
      </personname>
      <email>guido+sencrypt@berhoerster.name</email>
      <personblurb/>
    </author>
    <date>3 September, 2016</date>
  </info>
  <refmeta>
    <refentrytitle>sencrypt</refentrytitle>
    <manvolnum>1</manvolnum>
    <refmiscinfo class="source"/>
    <refmiscinfo class="version"/>
    <refmiscinfo class="manual">User Commands</refmiscinfo>
  </refmeta>
  <refnamediv>
    <refname>sencrypt</refname>
    <refname>sdecrypt</refname>
    <refpurpose>encrypt and decrypt data</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <cmdsynopsis>
      <command>sencrypt</command>
      <arg choice="req">
        <option>-l</option>
      </arg>
    </cmdsynopsis>
    <cmdsynopsis>
      <command>sencrypt</command>
      <arg choice="opt">
        <option>-v</option>
      </arg>
      <arg choice="req">
        <option>-a</option>
        <replaceable>algorithm</replaceable>
      </arg>
      <arg choice="opt">
        <option>-k</option>
        <replaceable>key_file</replaceable>
      </arg>
      <arg choice="opt">
        <option>-i</option>
        <replaceable>input_file</replaceable>
      </arg>
      <arg choice="opt">
        <option>-o</option>
        <replaceable>output_file</replaceable>
      </arg>
    </cmdsynopsis>
    <cmdsynopsis>
      <command>sdecrypt</command>
      <arg choice="req">
        <option>-l</option>
      </arg>
    </cmdsynopsis>
    <cmdsynopsis>
      <command>sdecrypt</command>
      <arg choice="opt">
        <option>-v</option>
      </arg>
      <arg choice="req">
        <option>-a</option>
        <replaceable>algorithm</replaceable>
      </arg>
      <arg choice="opt">
        <option>-k</option>
        <replaceable>key_file</replaceable>
      </arg>
      <arg choice="opt">
        <option>-i</option>
        <replaceable>input_file</replaceable>
      </arg>
      <arg choice="opt">
        <option>-o</option>
        <replaceable>output_file</replaceable>
      </arg>
    </cmdsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>Description</title>
    <para>The <command>sencrypt</command> utility encrypts data and the
    <command>sdecrypt</command> utility decrypts data using the specified
    algorithm. A key file must be a regular file and have the exact size of the
    desired key length, its content will be used verbatim as the key. If no key
    file is specified <command>sencrypt</command> or
    <command>sdecrypt</command> will ask for a passphrase and use that together
    with a salt to derive a key using the PBKDF2 key derivation function. If no
    input file is specfified, the input will be read from stdin. If no output
    file is specfied, the output will be written to stdout. The input and
    output file may be identical, in which case the content of the input file
    is replaced with the output after successful encryption or decryption. The
    algorithm used for encrypting data is not saved and needs to be explicitly
    specified when decrypting data.</para>
    <para><command>sencrypt</command> and <command>sdecrypt</command> are
    portable and compatible reimplementations of the <command>encrypt</command>
    and <command>decrypt</command> utilities in Solaris/Illumos-based operating
    systems.</para>
  </refsect1>
  <refsect1>
    <title>Options</title>
    <para>The following options are supported:</para>
    <variablelist>
      <varlistentry>
        <term>
          <option>-l</option>
        </term>
        <listitem>
          <para>List the available algorithms and supported key lengths and
          exit.</para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>
          <option>-a</option>
          <replaceable>algorithm</replaceable>
        </term>
        <listitem>
          <para>Use the specified algorithm. See
          <xref linkend="algorithms"/> for a list of supported
          algorithms.</para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>
          <option>-k</option>
          <replaceable>key_file</replaceable>
        </term>
        <listitem>
          <para>Read key data from specified key file. Key size requirements
          depend on the selected algorithm.</para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>
          <option>-i</option>
          <replaceable>input_file</replaceable>
        </term>
        <listitem>
          <para>Read the input from the specified file.</para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>
          <option>-o</option>
          <replaceable>output_file</replaceable>
        </term>
        <listitem>
          <para>Write the output to the specified file.</para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>
          <option>-v</option>
        </term>
        <listitem>
          <para>Ignored for compatibility with <command>encrypt</command> and
          <command>decrypt</command>.</para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>
  <refsect1 xml:id="algorithms">
    <title>Algorithms</title>
    <para>The following algorithms and key lengths are supported:
      <simplelist type="vert" columns="2">
        <member>aes</member>
        <member>arcfour</member>
        <member>des</member>
        <member>3des</member>
      </simplelist></para>
      <para>The arcfour, des, and 3des algorithms are considered insecure and should
      not longer be used to encrypt new files. Using them will print a warning
      message.</para>
  </refsect1>
  <refsect1>
    <title>Examples</title>
    <example>
      <title>Encrypt a file with the AES algorithm</title>
      <para>The following example encrypts a file with the AES algorithm:</para>
      <screen>
$ sencrypt -a aes -i secret.txt -o secret.aes
      </screen>
    </example>
    <example>
      <title>Decrypt a file in-place</title>
      <para>The following example decrypts a file in-place:</para>
      <screen>
$ sdecrypt -a 3des -i data.bin -o data.bin
      </screen>
    </example>
    <example>
      <title>Encrypt a file using a key file</title>
      <para>The following example generates a key file with 512 bits of random
      data and uses it to encrypt a file:</para>
      <screen>
$ dd if=/dev/urandom of=key.bin bs=64 count=1
$ sencrypt -a arcfour -k key.bin -i secret.txt -o secret.rc4
      </screen>
    </example>
    <example>
      <title>Pipe data trough encrypt in order to make a remote encrypted
      backup</title>
      <para>The following example creates an archive in the tar format,
      encrypts it and sends it to a remote location via
      <abbrev>SSH</abbrev>:</para>
      <screen>
$ pax -w -x ustar /home | sencrypt -a aes -k backup-key.bin |\
    ssh backuphost 'cat > home.tar'
      </screen>
    </example>
  </refsect1>
  <refsect1>
    <title>Exit Status</title>
    <para>The following exit values are returned:</para>
    <variablelist>
      <varlistentry>
        <term>0</term>
        <listitem>
          <para>Command successfully executed.</para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term>&gt; 0</term>
        <listitem>
          <para>An error has occured.</para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>
</refentry>