Extensions Docs Server: Doc conversion script

chrome/common/extensions/docs/server2/templates/articles/crx.html

+<h1>CRX Package Format</h1>
+
+
+<p>
+CRX files are ZIP files with a special header and the <code>.crx</code> file
+extension.
+</p>
+
+<h2>Package header</h2>
+
+<p>
+The header contains the author's public key and the extension's signature. 
+The signature is generated from the ZIP file using SHA-1 with the
+author's private key. The header requires a little-endian byte ordering with 
+4-byte alignment. The following table describes the fields of
+the <code>.crx</code> header in order:
+</p>
+
+<table>
+  <tr>
+    <th>Field</th><th>Type</th><th>Length</th><th>Value</th><th>Description</th>
+  </tr>
+  <tr>
+    <td><em>magic number</em></td><td>char[]</td><td>32 bits</td><td>Cr24</td>
+    <td>
+      Chrome requires this constant at the beginning of every <code>.crx</code>
+      package.
+    </td>
+  </tr>
+  <tr>
+    <td><em>version</em></td><td>unsigned&nbsp;int</td><td>32 bits</td><td>2</td>
+    <td>The version of the <code>*.crx</code> file format used (currently 2).</td> 
+  </tr>
+  <tr>
+    <td><em>public key length</em></td><td>unsigned&nbsp;int</td><td>32 bits</td>
+    <td><i>pubkey.length</i></td>
+    <td>
+      The length of the RSA public key in <em>bytes</em>.
+    </td>
+  </tr>
+  <tr>
+    <td><em>signature length</em></td><td>unsigned&nbsp;int</td><td>32 bits</td>
+    <td><i>sig.length</i></td>
+    <td>
+      The length of the signature in <em>bytes</em>.
+    </td>
+  </tr>
+  <tr>
+    <td><em>public key</em></td><td>byte[]</td><td><i>pubkey.length</i></i></td>
+    <td><i>pubkey.contents</i></td>
+    <td>
+      The contents of the author's RSA public key, formatted as an X509 
+      SubjectPublicKeyInfo block.
+    </td>
+  </tr>
+  <tr>
+    <td><em>signature</em></td><td>byte[]</td><td><i>sig.length</i></td>
+    <td><i>sig.contents</i></td>
+    <td>
+      The signature of the ZIP content using the author's private key. The
+      signature is created using the RSA algorithm with the SHA-1 hash function.
+    </td>
+  </tr>
+</table>
+
+<h2>Extension contents</h2>
+
+<p>
+The extension's ZIP file is appended to the <code>*.crx</code> package after the
+header. This should be the same ZIP file that the signature in the header
+was generated from.
+</p>
+
+<h2>Example</h2>
+
+<p>
+The following is an example hex dump from the beginning of a <code>.crx</code> 
+file.
+</p>
+
+<pre>
+43 72 32 34   # "Cr24" -- the magic number
+02 00 00 00   # 2 -- the crx format version number
+A2 00 00 00   # 162 -- length of public key in bytes
+80 00 00 00   # 128 -- length of signature in bytes
+...........   # the contents of the public key
+...........   # the contents of the signature
+...........   # the contents of the zip file
+
+</pre>
+
+<h2 id="scripts">Packaging scripts</h2>
+<p>
+Members of the community have written the following scripts to package 
+<code>.crx</code> files.
+</p>
+
+<h3 id="ruby">Ruby</h3>
+<blockquote>
+<a href="http://github.com/Constellation/crxmake">github: crxmake</a>
+</blockquote>
+
+<h3>Bash</h3>
+<pre>
+#!/bin/bash -e
+#
+# Purpose: Pack a Chromium extension directory into crx format
+
+if test $# -ne 2; then
+  echo "Usage: crxmake.sh &lt;extension dir&gt; &lt;pem path&gt;"
+  exit 1
+fi
+
+dir=$1
+key=$2
+name=$(basename "$dir")
+crx="$name.crx"
+pub="$name.pub"
+sig="$name.sig"
+zip="$name.zip"
+trap 'rm -f "$pub" "$sig" "$zip"' EXIT
+
+# zip up the crx dir
+cwd=$(pwd -P)
+(cd "$dir" && zip -qr -9 -X "$cwd/$zip" .)
+
+# signature
+openssl sha1 -sha1 -binary -sign "$key" < "$zip" > "$sig"
+
+# public key
+openssl rsa -pubout -outform DER < "$key" > "$pub" 2>/dev/null
+
+byte_swap () {
+  # Take "abcdefgh" and return it as "ghefcdab"
+  echo "${1:6:2}${1:4:2}${1:2:2}${1:0:2}"
+}
+
+crmagic_hex="4372 3234" # Cr24
+version_hex="0200 0000" # 2
+pub_len_hex=$(byte_swap $(printf '%08x\n' $(ls -l "$pub" | awk '{print $5}')))
+sig_len_hex=$(byte_swap $(printf '%08x\n' $(ls -l "$sig" | awk '{print $5}')))
+(
+  echo "$crmagic_hex $version_hex $pub_len_hex $sig_len_hex" | xxd -r -p
+  cat "$pub" "$sig" "$zip"
+) > "$crx"
+echo "Wrote $crx"
+</pre>