ps, yes, line 29 is a mistake and should read: char new_filename[strlen(
filename ) + 5];
But even with that fix i get the same results
On Fri, Aug 16, 2013 at 2:27 AM, Ztatik Light <ztatik.li...@gmail.com>wrote:
> maybe not - still confused
>
>
> On Fri, Aug 16, 2013 at 2:21 AM, Ztatik Light <ztatik.li...@gmail.com>wrote:
>
>> strange i think it has something to do with me using "rb" and "wb"
>> instead of "r" and "w"...
>>
>>
>> On Fri, Aug 16, 2013 at 2:14 AM, Ztatik Light <ztatik.li...@gmail.com>wrote:
>>
>>> So, I'm having a really weird issue... i'm trying simple file
>>> encryption/decryption with BIO_*, but if the encrypted file is in a
>>> subdirectory.. i get garbage data,
>>>
>>> I'll post the code i'm using, with a brief elaboration on how i'm using
>>> it and what behaviour i'm getting:
>>>
>>> ///////////////////////////////
>>>
>>> /*
>>>>
>>>> Example of ssl read and write to a file
>>>>
>>>>
>>>>> gcc ssl_write_read.c -lssl
>>>>
>>>> ./a.out
>>>>
>>>>
>>>>>
>>>>> */
>>>>
>>>>
>>>>>
>>>>>
>>>>> #include <openssl/bio.h>
>>>>
>>>> #include <openssl/err.h>
>>>>
>>>> #include <openssl/rand.h>
>>>>
>>>> #include <openssl/ssl.h>
>>>>
>>>> #include <openssl/x509v3.h>
>>>>
>>>>
>>>>> int read_whole_file( char* filename, char** data ){
>>>>
>>>> FILE* file = fopen( filename, "rb" );
>>>>
>>>> fseek( file, 0, SEEK_END );
>>>>
>>>> long fileSize = ftell( file );
>>>>
>>>> rewind( file );
>>>>
>>>> *data = malloc( fileSize );
>>>>
>>>> fread( *data, fileSize, 1, file );
>>>>
>>>> fclose( file );
>>>>
>>>> return fileSize;
>>>>
>>>> }
>>>>
>>>> void encrypt_file( char* filename ){
>>>>
>>>> char new_filename[strlen( filename + 4 )];
>>>>
>>>> strcpy( new_filename, filename );
>>>>
>>>> strcat( new_filename, ".enc" );
>>>>
>>>> char* data;
>>>>
>>>> int fileSize = read_whole_file( filename, &data );
>>>>
>>>> write_data( new_filename, data, fileSize, (unsigned char*)"mykey" );
>>>>
>>>> free( data );
>>>>
>>>> }
>>>>
>>>>
>>>>> int write_data(const char *filename, char *out, int len, unsigned char
>>>>> *key)
>>>>
>>>> {
>>>>
>>>> int total, written;
>>>>
>>>> BIO *cipher, *buffer, *file;
>>>>
>>>>
>>>>
>>>> /* Create a buffered file BIO for writing */
>>>>
>>>> file = BIO_new_file(filename, "wb");
>>>>
>>>> if (!file)
>>>>
>>>> return 0;
>>>>
>>>>
>>>>
>>>> /* Create a buffering filter BIO to buffer writes to the file */
>>>>
>>>> buffer = BIO_new(BIO_f_buffer( ));
>>>>
>>>>
>>>>
>>>> /* Create a base64 encoding filter BIO */
>>>>
>>>> // b64 = BIO_new(BIO_f_base64( ));
>>>>
>>>>
>>>>
>>>> /* Create the cipher filter BIO and set the key. The last parameter
>>>>> of
>>>>
>>>> BIO_set_cipher is 1 for encryption and 0 for decryption */
>>>>
>>>> cipher = BIO_new(BIO_f_cipher( ));
>>>>
>>>> BIO_set_cipher(cipher, EVP_des_ede3_cbc( ), key, NULL, 1);
>>>>
>>>>
>>>>
>>>> /* Assemble the BIO chain to be in the order cipher-b64-buffer-file */
>>>>
>>>> // BIO_push(cipher, b64);
>>>>
>>>> // BIO_push(b64, buffer);
>>>>
>>>> BIO_push(cipher,buffer);
>>>>
>>>> BIO_push(buffer, file);
>>>>
>>>>
>>>>> /* This loop writes the data to the file. It checks for errors as
>>>>> if the
>>>>
>>>> underlying file were non-blocking */
>>>>
>>>> for (total = 0; total < len; total += written)
>>>>
>>>> {
>>>>
>>>> if ((written = BIO_write(cipher, out + total, len - total)) <= 0)
>>>>
>>>> {
>>>>
>>>> if (BIO_should_retry(cipher))
>>>>
>>>> {
>>>>
>>>> written = 0;
>>>>
>>>> continue;
>>>>
>>>> }
>>>>
>>>> break;
>>>>
>>>> }
>>>>
>>>> }
>>>>
>>>>
>>>>
>>>> /* Ensure all of our data is pushed all the way to the file */
>>>>
>>>> BIO_flush(cipher);
>>>>
>>>>
>>>>
>>>> BIO_free_all(cipher);
>>>>
>>>> }
>>>>
>>>>
>>>>> BIO* decrypt_open( const char *filename, unsigned char *key ){
>>>>
>>>> int total, written;
>>>>
>>>> BIO *cipher, *buffer, *file;
>>>>
>>>> //char *b = malloc(len);
>>>>
>>>>
>>>>
>>>> /* Create a buffered file BIO for reading */
>>>>
>>>> file = BIO_new_file(filename, "rb");
>>>>
>>>> if (!file)
>>>>
>>>> return 0;
>>>>
>>>>
>>>>
>>>> /* Create a buffering filter BIO to buffer writes to the file */
>>>>
>>>> buffer = BIO_new(BIO_f_buffer( ));
>>>>
>>>>
>>>>
>>>> /* Create a base64 encoding filter BIO */
>>>>
>>>> // b64 = BIO_new(BIO_f_base64( ));
>>>>
>>>>
>>>>
>>>> /* Create the cipher filter BIO and set the key. The last parameter
>>>>> of
>>>>
>>>> BIO_set_cipher is 1 for encryption and 0 for decryption */
>>>>
>>>> cipher = BIO_new(BIO_f_cipher( ));
>>>>
>>>> BIO_set_cipher(cipher, EVP_des_ede3_cbc( ), key, NULL, 0);
>>>>
>>>>
>>>>
>>>> /* Assemble the BIO chain to be in the order cipher-b64-buffer-file */
>>>>
>>>> // BIO_push(cipher, b64);
>>>>
>>>> // BIO_push(b64, buffer);
>>>>
>>>> BIO_push(cipher,buffer);
>>>>
>>>> BIO_push(buffer, file);
>>>>
>>>> return cipher;
>>>>
>>>> }
>>>>
>>>> char* decrypt_read( BIO* cipher, int len, char* b ){
>>>>
>>>> int total, written;
>>>>
>>>>
>>>>> // char b[len + 1];
>>>>
>>>> for (total = 0; total < len; total += written)
>>>>
>>>> {
>>>>
>>>> if ((written = BIO_read(cipher, b, len - total)) <= 0)
>>>>
>>>> {
>>>>
>>>> if (BIO_should_retry(cipher))
>>>>
>>>> {
>>>>
>>>> written = 0;
>>>>
>>>> continue;
>>>>
>>>> }
>>>>
>>>> break;
>>>>
>>>> }
>>>>
>>>> }
>>>>
>>>>
>>>>
>>>> b[total] = '\0';
>>>>
>>>>
>>>>
>>>> return b;
>>>>
>>>> }
>>>>
>>>>
>>>>> int main(void)
>>>>
>>>> {
>>>>
>>>> //chdir("subdirectory");
>>>>
>>>> char *file_="test.txt";
>>>>
>>>> char* data = "howdy\n";
>>>>
>>>> write_data( file_, data, strlen(data), "mykey");
>>>>
>>>>
>>>>> BIO* cipher = decrypt_open( file_, (unsigned char*)"mykey" );
>>>>
>>>> char b[999999];
>>>>
>>>> decrypt_read( cipher, 999999, b );
>>>>
>>>> BIO_flush( cipher );
>>>>
>>>> BIO_free_all( cipher );
>>>>
>>>> printf(">%s\n",b);
>>>>
>>>>
>>>>> //char* test="plain.txt";
>>>>
>>>> //encrypt_file(test);
>>>>
>>>>
>>>>> }
>>>>
>>>>
>>> ///////////////////////////////////////////////////////////
>>>
>>> 1. So, first run creates and writes encrypted file "test.txt" and then
>>> decrypts and prints out the contents, "howdy",
>>>
>>> 2. Now, comment out line 141 // write_data( ... re-run to verify
>>> "howdy", works fine
>>>
>>> 3. make directory "temp", move "test.txt" into "temp" and change line
>>> 139 to reflect that: char *file_="temp/test.txt";.. re-run - I get no
>>> results ??
>>>
>>> 4. Even more weird: change line 139 back to just "test.txt", and replace
>>> file_ on line 143 with "temp/test.txt" ... so it reads: BIO* cipher =
>>> decrypt_open( "temp/test.txt", (unsigned char*)"mykey" ); // re-run... now
>>> it works again all of a sudden. BUT - if you comment out line 139 // char
>>> *file_="test.txt";.... then it doesn't work again? Even though *file_ isn't
>>> being used???
>>>
>>
>>
>
