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| <html> |
| |
| <head> |
| <meta http-equiv="Content-Language" content="en-us"> |
| <link rel="stylesheet" type="text/css" href="../stylesheets/style.css"> |
| <title>Checksum Task</title> |
| </head> |
| |
| <body> |
| |
| <h2><a name="checksum">Checksum</a></h2> |
| <h3>Description</h3> |
| <p> |
| Generates checksum for files. This task can also be used to |
| perform checksum verifications. |
| </p> |
| |
| <p>Note that many popular message digest functions - including MD5 and |
| SHA-1 - have been broken recently. If you are going to use the task |
| to create checksums used in an environment where security is |
| important, please take some time to investigate the algorithms offered |
| by your JCE provider. Note also that some JCE providers like the one |
| by <a href="http://www.bouncycastle.org/">The Legion of the Bouncy |
| Castle</a>, the <a href="http://www.gnu.org/software/gnu-crypto/">GNU |
| project</a> or <a |
| href="http://jce.iaik.tugraz.at/products/01_jce/index.php">the |
| Technical University Graz</a> offer more digest algorithms than those |
| built-in into your JDK.</p> |
| |
| <p> |
| Warning: the case of the extension is that of the algorithm used. |
| If you ask for "SHA1", you get a .SHA1 extension; if you ask for "sha1", you |
| get a file ending in .sha1. The Java Crypto Engines are case-insensitive |
| in matching algorithms, so choose a name to match your desired output extension, |
| or set the <tt>fileext</tt> attribute. |
| </p> |
| |
| <h3>Parameters</h3> |
| <table border="1" cellpadding="2" cellspacing="0"> |
| <tr> |
| <td valign="top"><b>Attribute</b></td> |
| <td valign="top"><b>Description</b></td> |
| <td align="center" valign="top"><b>Required</b></td> |
| </tr> |
| <tr> |
| <td valign="top">file</td> |
| <td valign="top">The file to generate checksum for.</td> |
| <td valign="top" align="center">One of either <var>file</var> or |
| at least one nested (filesystem-only) resource collection.</td> |
| </tr> |
| <tr> |
| <td valign="top">todir</td> |
| <td valign="top">The root directory where checksums should be written.</td> |
| <td valign="top" align="center">No. If not specified, checksum files |
| will be written to the same directory as the files themselves. |
| <em>since Ant 1.6</em> |
| </td> |
| </tr> |
| <tr> |
| <td valign="top">algorithm</td> |
| <td valign="top">Specifies the algorithm to be used to |
| compute the checksum. Defaults to "MD5". |
| Other popular algorithms like "SHA" may be used |
| as well. |
| </td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">provider</td> |
| <td valign="top">Specifies the provider of the algorithm.</td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">fileext</td> |
| <td valign="top">The generated checksum file's name will be the |
| original filename with the fileext added to it. |
| Defaults to a "." and the algorithm name being used. |
| </td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">property</td> |
| <td valign="top">This attribute can mean two different things, it |
| depends on the presence of the verifyproperty attribute.<br> |
| <b>If you don't set the verifyproperty attribute</b>, property |
| specifies the name of the property to be set with the generated |
| checksum value.<br> |
| <b>If you set the verifyproperty attribute</b>, property specifies |
| the checksum you expect to be generated (the checksum itself, not |
| a name of a property containing the checksum).<br> |
| This cannot be specified when fileext is being used or when the |
| number of files for which checksums is to be generated is greater |
| than 1. |
| </td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">pattern</td> |
| <td valign="top">Specifies the pattern to use as a pattern |
| suitable for <a |
| href="http://java.sun.com/j2se/1.4.2/docs/api/java/text/MessageFormat.html">MessageFormat</a> |
| where <code>{0}</code> is replaced with the checksum and |
| <code>{1}</code> with the file name.</td> |
| <td valign="top" align="center">No - default is "{0}".</td> |
| </tr> |
| <tr> |
| <td valign="top">format</td> |
| <td valign="top">Specifies the pattern to use as one of a |
| well-known format. Supported values are |
| <table border="1"> |
| <tr> |
| <th>name</th> |
| <th>pattern</th> |
| <th>description</th> |
| </tr> |
| <tr> |
| <td>CHECKSUM </td> |
| <td><tt>{0}</tt></td> |
| <td>only the checksum itself </td> |
| </tr> |
| <tr> |
| <td>MD5SUM </td> |
| <td><tt>{0} *{1}</tt></td> |
| <td>the format of GNU textutils md5sum</td> |
| </tr> |
| <tr> |
| <td>SVF </td> |
| <td><tt>MD5 ({1}) = {0}</tt></td> |
| <td>the format of BSDs md5 command </td> |
| </tr> |
| </table> |
| </td> |
| <td valign="top" align="center">No - default is "CHECKSUM".</td> |
| </tr> |
| <tr> |
| <td valign="top">totalproperty</td> |
| <td valign="top">If specified, this attribute specifies the name of |
| the property that will hold a checksum of all the checksums and |
| file paths. The individual checksums and the relative paths to the files |
| within the resource collections in which they are defined will be used to |
| compute this checksum. (The file separators in the paths will be |
| converted to '/' before computation to ensure platform portability). |
| <em>since Ant 1.6</em> |
| </td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">forceoverwrite</td> |
| <td valign="top">Overwrite existing files even if the destination |
| files are newer. Defaults to "no".</td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">verifyproperty</td> |
| <td valign="top">Specifies the name of the property to be set |
| with "true" or "false" depending upon whether |
| the generated checksum matches the existing checksum. When |
| this is set, the generated checksum is not written to a file or |
| property, but rather, the content of the file or property is used to |
| check against the generated checksum. |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">readbuffersize</td> |
| <td valign="top">The size of the buffer (in bytes) to use when |
| reading a file. Defaults to "8192" - you may get a |
| better performance on big files if you increase this value.</td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| </table> |
| <h3>Parameters specified as nested elements</h3> |
| |
| <h4>resource collection</h4> |
| <p> |
| <a href="../CoreTypes/resources.html#collection">Resource collections</a> are |
| used to select files for which checksums should be generated. |
| </p> |
| |
| <h3>Examples</h3> |
| <p><b>Example 1</b></p> |
| <blockquote><pre><checksum file="foo.bar"/></pre></blockquote> |
| Generates a MD5 checksum for foo.bar and stores the checksum in the destination file |
| foo.bar.MD5. foo.bar.MD5 is overwritten only if foo.bar is newer than itself. |
| |
| <p><b>Example 2</b></p> |
| <blockquote><pre><checksum file="foo.bar" forceOverwrite="yes"/></pre></blockquote> |
| Generates a MD5 checksum for foo.bar and stores the checksum in foo.bar.MD5. |
| If foo.bar.MD5 already exists, it is overwritten. |
| |
| <p><b>Example 3</b></p> |
| <blockquote><pre><checksum file="foo.bar" property="foobarMD5"/></pre></blockquote> |
| Generates a MD5 checksum for foo.bar and stores it in the Project Property foobarMD5. |
| |
| <p><b>Example 4</b></p> |
| <blockquote><pre><checksum file="foo.bar" verifyProperty="isMD5ok"/></pre></blockquote> |
| Generates a MD5 checksum for foo.bar, compares it against foo.bar.MD5 and sets |
| isMD5ok to either true or false, depending upon the result. |
| |
| <p><b>Example 5</b></p> |
| <blockquote><pre><checksum file="foo.bar" algorithm="SHA" fileext="asc"/></pre></blockquote> |
| Generates a SHA checksum for foo.bar and stores the checksum in the destination file |
| foo.bar.asc. foo.bar.asc is overwritten only if foo.bar is newer than itself. |
| |
| <p><b>Example 6</b></p> |
| <blockquote><pre> |
| <checksum file="foo.bar" property="${md5}" verifyProperty="isEqual"/> |
| </pre></blockquote> |
| Generates a MD5 checksum for foo.bar, compares it against the value of the property |
| md5, and sets isEqual to either true or false, depending upon the result. |
| |
| <p><b>Example 7</b></p> |
| <blockquote><pre> |
| <checksum> |
| <fileset dir="."> |
| <include name="foo*"/> |
| </fileset> |
| </checksum> |
| </pre></blockquote> |
| Works just like Example 1, but generates a .MD5 file for every file that begins with the name foo. |
| |
| <p><b>Example 8</b></p> |
| <blockquote><pre> |
| <condition property="isChecksumEqual"> |
| <checksum> |
| <fileset dir="."> |
| <include name="foo.bar"/> |
| </fileset> |
| </checksum> |
| </condition> |
| </pre></blockquote> |
| Works like Example 4, but only sets isChecksumEqual to true, if the |
| checksum matches - it will never be set to false. This example |
| demonstrates use with the Condition task. |
| |
| |
| <h3>Note:</h3> |
| When working with more than one file, if condition and/or verifyproperty is used, |
| the result will be true only if the checksums matched correctly for all files being |
| considered. |
| |
| |
| |
| </body> |
| </html> |
| |
