AES C# File Encryption - stream writes only 16 bytes -

-

here piece of code, should encrypt file , write cryptograph new file. code similiar example found @ microsoft msdn webpage.

byte[] inputbuffer = new byte[inputfilestream.length]; byte[] outputbuffer = new byte[inputfilestream.length];  inputfilestream.read(inputbuffer, 0, (int)inputfilestream.length);  icryptotransform encryptor = aesinstance.createencryptor(aesinstance.key, aesinstance.iv);               using (memorystream memorystream = new memorystream())             {                  using (cryptostream stream = new cryptostream(memorystream, encryptor, cryptostreammode.write))                 {                     using (streamwriter encrypted = new streamwriter(stream))                     {                          encrypted.write(inputbuffer);                      }                      outputbuffer = memorystream.toarray();                      outputfilestream.write(outputbuffer, 0, (int)outputbuffer.length);                   }              }  outputfilestream.close(); inputfilestream.close();`

the problem input buffer reads bytes file correct, output buffer seems have 16 bytes of data. result output file has 16 bytes, if input file large. mistake? problem exists on various modes, ecb, cbc, etc.

i believe when use

encrypted.write(inputbuffer);

you not giving writer size of buffer write.


Comments

Post a Comment

Popular posts from this blog

java - Jmockit String final length method mocking Issue -

-
using jmockit 1.2 jar, trying mock string's length method getting unexpected invocation exception: failed: test java.lang.illegalstateexception: missing invocation mocked type @ point; please make sure such invocations appear after declaration of suitable mock field or parameter @ stringdemo.testa$1.<init>(testa.java:17) @ stringdemo.testa.test(testa.java:13) i using testng: @test public void test() throws exception { new expectations() { @mocked("length") string astring; { astring.length(); result = 2; } }; system.out.println(a.showa("test")); } } actual class a: public class { public static int showa(string str){ int a= str.length(); return a; } } this wrong way of recording expected results. shouldn't mock , record string's length() method, record showa() instead. here solution @suppresswarnings("unused...
Read more

What is the difference between data design and data model(ERD) -

-
i have google question , find answer in day. know, data design many many table have list column,and mark pk , fk. why er-diagram have find this? data design process of designing database. main output of data design detailed logical data model of database. some people data design includes of needed logical , physical design choices , physical storage parameters needed generate design in data definition language. technically, database analysis, database analysts (dbas) trained do. while person can both data design , database analysis, these 2 different tasks. data design models data. database analysis takes model , applies 1 or more database engines (relational, hierarchical, nosql). a logical data model 1 of main outputs of data design. data model represented entity relationship diagram, or er diagram.
Read more

ios - Can NSManagedObject conform to NSCoding -

-
i need transfer single object across device. right converting nsmanagedobject dictionary , archiving , sending nsdata. upon receiving unarchiving it. transfer nsmanagedobject archiving , unarchiving instead of creating intermediate data object. @interface test : nsmanagedobject<nscoding> @property (nonatomic, retain) nsstring * title; @end @implementation test @dynamic title; - (id)initwithcoder:(nscoder *)coder { self = [super init]; if (self) { self.title = [coder decodeobjectforkey:@"title"]; //<crash } return self; } - (void)encodewithcoder:(nscoder *)coder { [coder encodeobject:self.title forkey:@"title"]; } @end nsdata *archivedobjects = [nskeyedarchiver archiveddatawithrootobject:testobj]; nsdata *objectsdata = archivedobjects; if ([objectsdata length] > 0) { nsarray *objects = [nskeyedunarchiver unarchiveobjectwithdata:objectsdata]; } the problem above code is. crashes @ self.title in initwithcoder sa...
Read more