Re: Please help about zend engine

Andreas K Santoso wrote: > Hello sir/ma'am > > My name is andre from Indonesia. I am a student of a university, and > i'm doing my thesis. I subscribe to this list to look for some help. > Oh by the way, my thesis is about PHP file encryption. So i need to > decrypt the file when it's accessed and before any further > processing. I'm surely not as smart and experienced as all of you, so > please be patient > > Mr. Malyshev told me that i have 2 options 1. Override the > zend_compile function (he said that this one seems to be the easiest > way) 2. Use the PHP stream system (http://php.net/streams) to create > filters that decrypt data on-the-fly. > > So i decided to try the second option. But still i can't understand > it well. The example i've read (http://php.net/streams) is not clear > enough for me. I mean, how to make the filter itself, and how to use > it? and can the filter automaticaly applied to every .php files? > > And can anyone tell me where i must insert my codes if i want to > override the zend_compile? I'm afraid that i don't have much time > left, so if i can't use option 2, i will use option 1 instead. > > > Sorry if my english impolite or confusing. Thank you very much for > your patience and help. Hi Andreas, For stream filters, check out the zlib and bz2 stream filters in ext/zlib/zlib_filter.c and ext/bz2/bz2_filter.c The filter can't be automatically applied without overriding zend_compile, but I still highly recommend you implement it as a stream filter. Why? You can check for encryption on file inclusion and then append the stream filter to the returned stream inside the zend_file_handle, or disable this in php.ini and decrypt on a per-file basis manually. For an example of zend_compile() interception that does something similar, look at the end of ext/phar/phar.c. In this case, phar's zend_compile override checks for filenames containing '.phar' and attempts to process them as a phar archive, creates a phar stream URL and passes that to zend_stream_open_function to return a file_handle. You could simply call zend_stream_open_function, and then read in the first few bytes of the file handle in the modified zend_file_handle * to determine if decryption is necessary, and then use code something like this to append the filter and compile the file: filter = php_stream_filter_create("my.encrypt", NULL, php_stream_is_persistent(file_handle->handle.stream.handle) TSRMLS_CC); php_stream_filter_append(&file_handle->handle.stream.handle->readfilters, encrypt_filter); return encrypt_orig_compile_file(file_handle, type TSRMLS_CC); where encrypt_orig_compile_file is the saved value of zend_compile_file. Greg