Comments for Martin Matula's Blog http://blog.alutam.com Thu, 18 Feb 2010 17:11:58 +0000 http://wordpress.org/?v=2.9.1 hourly 1 Comment on Reading Password-Protected ZIP Files in Java by endyk http://blog.alutam.com/2009/10/31/reading-password-protected-zip-files-in-java/comment-page-1/#comment-140 endyk Thu, 18 Feb 2010 17:11:58 +0000 http://blog.alutam.com/?p=102#comment-140 hello sir, i h'd successed in decrypting, but, may i know how the code for creating zip file with password in java thankyou much... :) hello sir,
i h’d successed in decrypting,
but, may i know how the code for creating zip file with password in java
thankyou much… :)

]]> Comment on Reading Password-Protected ZIP Files in Java by endyk http://blog.alutam.com/2009/10/31/reading-password-protected-zip-files-in-java/comment-page-1/#comment-139 endyk Thu, 18 Feb 2010 09:30:13 +0000 http://blog.alutam.com/?p=102#comment-139 hi, thankyou, i'll try this one hi, thankyou, i’ll try this one

]]> Comment on Reading Password-Protected ZIP Files in Java by Martin http://blog.alutam.com/2009/10/31/reading-password-protected-zip-files-in-java/comment-page-1/#comment-138 Martin Wed, 03 Feb 2010 00:07:16 +0000 http://blog.alutam.com/?p=102#comment-138 Hi, the ZIP spec. says: "After the header is decrypted, the last 1 or 2 bytes in Buffer should be the high-order word/byte of the CRC for the file being decrypted, stored in Intel low-byte/high-byte order. Versions of PKZIP prior to 2.0 used a 2 byte CRC check; a 1 byte CRC check is used on versions after 2.0. This can be used to test if the password supplied is correct or not." In the code from my blog, you could do this check at the end of the HEADER case branch. To compare the header bytes with the CRC of the file, you would have to add another branch for reading the CRC as well - CRC of the file are 4 bytes just before the COMPRESSED_SIZE section of the zip file. Hi,
the ZIP spec. says:
“After the header is decrypted, the last 1 or 2 bytes in Buffer
should be the high-order word/byte of the CRC for the file being
decrypted, stored in Intel low-byte/high-byte order. Versions of
PKZIP prior to 2.0 used a 2 byte CRC check; a 1 byte CRC check is
used on versions after 2.0. This can be used to test if the password
supplied is correct or not.”

In the code from my blog, you could do this check at the end of the HEADER case branch. To compare the header bytes with the CRC of the file, you would have to add another branch for reading the CRC as well – CRC of the file are 4 bytes just before the COMPRESSED_SIZE section of the zip file.

]]> Comment on Reading Password-Protected ZIP Files in Java by Martin http://blog.alutam.com/2009/10/31/reading-password-protected-zip-files-in-java/comment-page-1/#comment-137 Martin Tue, 02 Feb 2010 23:52:43 +0000 http://blog.alutam.com/?p=102#comment-137 Do you mean ZipEncryptOutputStream, that would password protect the zip? No, that one I did not do. I did not need it and ZipOutputStream does things the way that makes it a little bit harder to implement similarly simple output stream for encryption. Do you mean ZipEncryptOutputStream, that would password protect the zip? No, that one I did not do. I did not need it and ZipOutputStream does things the way that makes it a little bit harder to implement similarly simple output stream for encryption.

]]> Comment on Reading Password-Protected ZIP Files in Java by Martin http://blog.alutam.com/2009/10/31/reading-password-protected-zip-files-in-java/comment-page-1/#comment-136 Martin Tue, 02 Feb 2010 23:49:15 +0000 http://blog.alutam.com/?p=102#comment-136 Heather, this class cannot handle the AES256 encryption - just the basic pkware encryption that was used in earlier versions of ZIP files. Heather, this class cannot handle the AES256 encryption – just the basic pkware encryption that was used in earlier versions of ZIP files.

]]> Comment on Reading Password-Protected ZIP Files in Java by Tyler Durden http://blog.alutam.com/2009/10/31/reading-password-protected-zip-files-in-java/comment-page-1/#comment-135 Tyler Durden Fri, 29 Jan 2010 11:59:19 +0000 http://blog.alutam.com/?p=102#comment-135 Is there an ZipDecryptOutputStream class too? Is there an ZipDecryptOutputStream class too?

]]> Comment on Reading Password-Protected ZIP Files in Java by Eloïse P. http://blog.alutam.com/2009/10/31/reading-password-protected-zip-files-in-java/comment-page-1/#comment-134 Eloïse P. Thu, 28 Jan 2010 13:10:38 +0000 http://blog.alutam.com/?p=102#comment-134 How do I know if the password is correct? Sorry for my English! Thanks :) How do I know if the password is correct?
Sorry for my English!
Thanks :)

]]> Comment on JavaFX Password Field by rodrigo salado anaya http://blog.alutam.com/2009/09/12/javafx-password-field/comment-page-1/#comment-133 rodrigo salado anaya Tue, 26 Jan 2010 17:33:39 +0000 http://blog.alutam.com/?p=76#comment-133 perfecto... muy bueno y bonito , me gusto mucho :) gracias... yo are el mio basándome en el tuyo gracias... perfecto… muy bueno y bonito , me gusto mucho :) gracias… yo are el mio basándome en el tuyo gracias…

]]> Comment on Reading Password-Protected ZIP Files in Java by Heather http://blog.alutam.com/2009/10/31/reading-password-protected-zip-files-in-java/comment-page-1/#comment-132 Heather Wed, 20 Jan 2010 18:21:35 +0000 http://blog.alutam.com/?p=102#comment-132 This is great and a time saver. however, I'm getting an invalid compression method when the ZipInputStream is trying to read my file. It's using pkzip format and AES256 bit encryption. It seems like I shouldn't need to change anything, but I don't know. If anyone could help or offer input? :) This is great and a time saver. however, I’m getting an invalid compression method when the ZipInputStream is trying to read my file. It’s using pkzip format and AES256 bit encryption. It seems like I shouldn’t need to change anything, but I don’t know. If anyone could help or offer input? :)

]]> Comment on Reading Password-Protected ZIP Files in Java by Vincenzo http://blog.alutam.com/2009/10/31/reading-password-protected-zip-files-in-java/comment-page-1/#comment-131 Vincenzo Wed, 13 Jan 2010 17:11:07 +0000 http://blog.alutam.com/?p=102#comment-131 What zip softwares do still use pkware encryption??? What zip softwares do still use pkware encryption???

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