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POAndroid AES in C
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copied!<p>I wanna encrypt my files on PC(Windows 7, 64bit) and decrypt 'em on Android.<br> <br> I use this algo to encrypt files.<br> <a href="http://gladman.plushost.co.uk/oldsite/AES/aes-byte-29-08-08.zip" rel="nofollow">http://gladman.plushost.co.uk/oldsite/AES/aes-byte-29-08-08.zip</a><br> <br> I encrypt my files on PC, push them to SDcard.<br> Unfortunately when I try to decrypt them on Android,<br> the result is different,<br> files are completely unreadable...!<br> <br> What's wrong with my code?<br></p> <pre><code>jbyteArray Java_com_example_hellojni_HelloJni_decrypt(JNIEnv* env, jobject thiz, jstring fileName) { ...... /* read the file into the buffer */ size_t result = fread (buffer_in, 1, file_size, fin); if (result!=file_size) { fputs("Reading error", stderr); exit(3); } /* end if */ fclose(fin); /* decrypt file */ aes_context ctx[1]; aes_set_key(key, 16, ctx); long i; for (i=0; i<num_block; i++) { long begin = i*16; char *block = copyBlock(buffer_in, file_size, begin, 16), /* copy buffer_in[begin] ~ buffer_in[begin+16-1] to block[] */ *tmp = (char*)malloc(sizeof(char)*16); aes_decrypt(block, tmp, ctx); fillBuffer(buffer_out, out_size, tmp, begin, 16); /* copy tmp[] to buffer_out[begin] ~ buffer_out[begin+16-1] */ free(tmp); free(block); } /* end for */ ...... } /* end Java_com_example_hellojni_HelloJni_decrypt() */ </code></pre> <p>I know the discrepancy happens in aes.c:</p> <pre><code>return_type aes_set_key( const unsigned char key[], length_type keylen, aes_context ctx[1] ) { ...... for( cc = keylen, rc = 1; cc < hi; cc += 4 ) { uint_8t tt, t0, t1, t2, t3; /* difference begins here */ t0 = ctx->ksch[cc - 4]; t1 = ctx->ksch[cc - 3]; t2 = ctx->ksch[cc - 2]; t3 = ctx->ksch[cc - 1]; ....... } /* end for */ return 0; } /* end aes_set_key() */ </code></pre> <p>but why?!<br> <br> Help needed badly!</p>

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