added random stuff which hasn't beend added because yeah

114 files changed, 304 insertions, 0 deletions

diff --git a/set3/task17.c b/set3/task17.c
new file mode 100644
index 0000000..d2bb7e0
--- /dev/null
+++ b/set3/task17.c
@@ -0,0 +1,59 @@
+#include "../lib/lib.h"
+#include "../lib/lib2.h"
+#include "../lib/lib3.h"
+#include <time.h>
+
+/**
+  * First we try to break the last byte of a block.
+  * Do this by trying every byte
+  *
+  * Good description of the attack:
+  * https://blog.cloudflare.com/padding-oracles-and-the-decline-of-cbc-mode-ciphersuites/
+  */
+
+#define BLOCKSIZE 16
+int main()
+{
+	// intialize
+	srand(time(NULL));
+	generate_random_bytes(key, 16);
+	generate_random_bytes(iv, 16);
+
+	int length = 0, i;
+	char *encrypted = challenge17_encrypt(&length);
+
+	// detecting the length of the padding (need at least two blocks)
+	int nr_blocks = length / BLOCKSIZE;
+	nr_blocks--;
+
+	printf("length: %i, blocks: %i\n", length, nr_blocks);
+
+	char *tmp = malloc(length);
+	char *decrypted = malloc(length);;
+	memset(decrypted, 0xAA, length);
+	// try to break the last byte of the first block
+	char j;	
+	int k;
+	for(k=nr_blocks-1;k>=0;k--) {
+		memcpy(tmp, encrypted, length);
+		printf("k is %i\n", k);
+		for(j=1;j<=BLOCKSIZE;j++) {
+			// created the right padding for the last j bytes
+			for(i=1;i<j;i++)
+				tmp[(k*BLOCKSIZE)+BLOCKSIZE-i] = decrypted[((k+1)*BLOCKSIZE)+BLOCKSIZE-i] ^ encrypted[(k*BLOCKSIZE)+BLOCKSIZE-i] ^ j;
+
+			for(i=0;i<256;i++) {
+				// cbc bit flipping
+				tmp[(k*BLOCKSIZE)+BLOCKSIZE-j] = i;
+				// retursn 1 if paddign is valid
+				if(cbc_padding_oracle(&tmp[k*BLOCKSIZE], 2*BLOCKSIZE)) {
+					// 0x01 for the last padding byte, next step it is 0x02
+					decrypted[((k+1)*BLOCKSIZE)+BLOCKSIZE-j] = (char) (i ^ (encrypted[(k*BLOCKSIZE)+BLOCKSIZE-j]) ^ j);
+					printf("got a hit %c\n", decrypted[((k+1)*BLOCKSIZE)+BLOCKSIZE-j+1]);
+					break;
+				}
+			}
+		}
+	}
+	printf("recovered plaintext: %s\n", &decrypted[BLOCKSIZE]);
+}
diff --git a/set3/task17_0 b/set3/task17_0
new file mode 100644
index 0000000..3cde4d1
--- /dev/null
+++ b/set3/task17_0
@@ -0,0 +1 @@
+MDAwMDAwTm93IHRoYXQgdGhlIHBhcnR5IGlzIGp1bXBpbmc=
diff --git a/set3/task17_1 b/set3/task17_1
new file mode 100644
index 0000000..2ba2eaa
--- /dev/null
+++ b/set3/task17_1
@@ -0,0 +1 @@
+MDAwMDAxV2l0aCB0aGUgYmFzcyBraWNrZWQgaW4gYW5kIHRoZSBWZWdhJ3MgYXJlIHB1bXBpbic=
diff --git a/set3/task17_2 b/set3/task17_2
new file mode 100644
index 0000000..0cc5bce
--- /dev/null
+++ b/set3/task17_2
@@ -0,0 +1 @@
+MDAwMDAyUXVpY2sgdG8gdGhlIHBvaW50LCB0byB0aGUgcG9pbnQsIG5vIGZha2luZw==
diff --git a/set3/task17_3 b/set3/task17_3
new file mode 100644
index 0000000..b10f8d4
--- /dev/null
+++ b/set3/task17_3
@@ -0,0 +1 @@
+MDAwMDAzQ29va2luZyBNQydzIGxpa2UgYSBwb3VuZCBvZiBiYWNvbg==
diff --git a/set3/task17_4 b/set3/task17_4
new file mode 100644
index 0000000..4765c7d
--- /dev/null
+++ b/set3/task17_4
@@ -0,0 +1 @@
+MDAwMDA0QnVybmluZyAnZW0sIGlmIHlvdSBhaW4ndCBxdWljayBhbmQgbmltYmxl
diff --git a/set3/task17_5 b/set3/task17_5
new file mode 100644
index 0000000..5b99081
--- /dev/null
+++ b/set3/task17_5
@@ -0,0 +1 @@
+MDAwMDA1SSBnbyBjcmF6eSB3aGVuIEkgaGVhciBhIGN5bWJhbA==
diff --git a/set3/task17_6 b/set3/task17_6
new file mode 100644
index 0000000..1a5e976
--- /dev/null
+++ b/set3/task17_6
@@ -0,0 +1 @@
+MDAwMDA2QW5kIGEgaGlnaCBoYXQgd2l0aCBhIHNvdXBlZCB1cCB0ZW1wbw==
diff --git a/set3/task17_7 b/set3/task17_7
new file mode 100644
index 0000000..41f022f
--- /dev/null
+++ b/set3/task17_7
@@ -0,0 +1 @@
+MDAwMDA3SSdtIG9uIGEgcm9sbCwgaXQncyB0aW1lIHRvIGdvIHNvbG8=
diff --git a/set3/task17_8 b/set3/task17_8
new file mode 100644
index 0000000..adb9041
--- /dev/null
+++ b/set3/task17_8
@@ -0,0 +1 @@
+MDAwMDA4b2xsaW4nIGluIG15IGZpdmUgcG9pbnQgb2g=
diff --git a/set3/task17_9 b/set3/task17_9
new file mode 100644
index 0000000..8dc72a5
--- /dev/null
+++ b/set3/task17_9
@@ -0,0 +1 @@
+MDAwMDA5aXRoIG15IHJhZy10b3AgZG93biBzbyBteSBoYWlyIGNhbiBibG93
diff --git a/set3/task19.c b/set3/task19.c
new file mode 100644
index 0000000..a036f4f
--- /dev/null
+++ b/set3/task19.c
@@ -0,0 +1,35 @@
+#include "../lib/lib.h"
+#include "../lib/lib2.h"
+#include "../lib/lib3.h"
+#include <time.h>
+
+#define CHALLENGE19_FILE_NR 40
+int main()
+{
+	int i;
+	char **file = malloc(sizeof(char *)*CHALLENGE19_FILE_NR);
+	int length_file[CHALLENGE19_FILE_NR];
+	int length[CHALLENGE19_FILE_NR];
+	char **plaintext= malloc(sizeof(char *)*CHALLENGE19_FILE_NR);
+	char **ciphertext= malloc(sizeof(char *)*CHALLENGE19_FILE_NR);
+	char filename[] = "./task19_data/task19_00";
+
+	char nonce[16];
+	generate_random_bytes(key, 16);
+	generate_random_bytes(nonce, 16);
+
+	for(i=0;i<CHALLENGE19_FILE_NR;i++) {
+		filename[strlen(filename)-1] = ((i % 10)+ '0');
+		filename[strlen(filename)-2] = ((i / 10) + '0');
+		length_file[i] = read_base64_file(filename, &file[i]);
+		plaintext[i] = malloc(length_file[i]);
+		length[i] = decode_base64(file[i], plaintext[i]);
+		printf("%s\n", plaintext[i]);
+		ciphertext[i] = malloc(length[i]);
+		aes_ctr(plaintext[i], length[i], ciphertext[i], key, nonce);
+	}
+
+	// let the cracking begin
+
+
+}
diff --git a/set3/task19_data/task19_00 b/set3/task19_data/task19_00
new file mode 100644
index 0000000..ded873a
--- /dev/null
+++ b/set3/task19_data/task19_00
@@ -0,0 +1 @@
+SSBoYXZlIG1ldCB0aGVtIGF0IGNsb3NlIG9mIGRheQ==
diff --git a/set3/task19_data/task19_01 b/set3/task19_data/task19_01
new file mode 100644
index 0000000..2ef0ae1
--- /dev/null
+++ b/set3/task19_data/task19_01
@@ -0,0 +1 @@
+Q29taW5nIHdpdGggdml2aWQgZmFjZXM=
diff --git a/set3/task19_data/task19_02 b/set3/task19_data/task19_02
new file mode 100644
index 0000000..a9b546e
--- /dev/null
+++ b/set3/task19_data/task19_02
@@ -0,0 +1 @@
+RnJvbSBjb3VudGVyIG9yIGRlc2sgYW1vbmcgZ3JleQ==
diff --git a/set3/task19_data/task19_03 b/set3/task19_data/task19_03
new file mode 100644
index 0000000..2ea23fa
--- /dev/null
+++ b/set3/task19_data/task19_03
@@ -0,0 +1 @@
+RWlnaHRlZW50aC1jZW50dXJ5IGhvdXNlcy4=
diff --git a/set3/task19_data/task19_04 b/set3/task19_data/task19_04
new file mode 100644
index 0000000..7ea2a43
--- /dev/null
+++ b/set3/task19_data/task19_04
@@ -0,0 +1 @@
+SSBoYXZlIHBhc3NlZCB3aXRoIGEgbm9kIG9mIHRoZSBoZWFk
diff --git a/set3/task19_data/task19_05 b/set3/task19_data/task19_05
new file mode 100644
index 0000000..ba3f268
--- /dev/null
+++ b/set3/task19_data/task19_05
@@ -0,0 +1 @@
+T3IgcG9saXRlIG1lYW5pbmdsZXNzIHdvcmRzLA==
diff --git a/set3/task19_data/task19_06 b/set3/task19_data/task19_06
new file mode 100644
index 0000000..a5e1a79
--- /dev/null
+++ b/set3/task19_data/task19_06
@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_07 b/set3/task19_data/task19_07
new file mode 100644
index 0000000..6b43132
--- /dev/null
+++ b/set3/task19_data/task19_07
@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_08 b/set3/task19_data/task19_08
new file mode 100644
index 0000000..8cc6a9a
--- /dev/null
+++ b/set3/task19_data/task19_08
@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_09 b/set3/task19_data/task19_09
new file mode 100644
index 0000000..b2c7bd8
--- /dev/null
+++ b/set3/task19_data/task19_09
@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_10 b/set3/task19_data/task19_10
new file mode 100644
index 0000000..734f4d8
--- /dev/null
+++ b/set3/task19_data/task19_10
@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_11 b/set3/task19_data/task19_11
new file mode 100644
index 0000000..a1f04b4
--- /dev/null
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@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_12 b/set3/task19_data/task19_12
new file mode 100644
index 0000000..864a764
--- /dev/null
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@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_13 b/set3/task19_data/task19_13
new file mode 100644
index 0000000..23a2eb1
--- /dev/null
+++ b/set3/task19_data/task19_13
@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_14 b/set3/task19_data/task19_14
new file mode 100644
index 0000000..5865e2c
--- /dev/null
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@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_15 b/set3/task19_data/task19_15
new file mode 100644
index 0000000..cc8e0a4
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diff --git a/set3/task19_data/task19_16 b/set3/task19_data/task19_16
new file mode 100644
index 0000000..4db1ffe
--- /dev/null
+++ b/set3/task19_data/task19_16
@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_17 b/set3/task19_data/task19_17
new file mode 100644
index 0000000..64da3a8
--- /dev/null
+++ b/set3/task19_data/task19_17
@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_18 b/set3/task19_data/task19_18
new file mode 100644
index 0000000..740bb98
--- /dev/null
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@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_19 b/set3/task19_data/task19_19
new file mode 100644
index 0000000..26b01e1
--- /dev/null
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@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_20 b/set3/task19_data/task19_20
new file mode 100644
index 0000000..15b6e63
--- /dev/null
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@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_21 b/set3/task19_data/task19_21
new file mode 100644
index 0000000..95eb336
--- /dev/null
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@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_22 b/set3/task19_data/task19_22
new file mode 100644
index 0000000..1fe7f50
--- /dev/null
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@@ -0,0 +1 @@
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diff --git a/set3/task19_data/task19_23 b/set3/task19_data/task19_23
new file mode 100644
index 0000000..f6a3b04
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new file mode 100644
index 0000000..cceb1bf
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new file mode 100644
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diff --git a/set3/task19_data/task19_26 b/set3/task19_data/task19_26
new file mode 100644
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new file mode 100644
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new file mode 100644
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new file mode 100644
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new file mode 100644
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new file mode 100644
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new file mode 100644
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new file mode 100644
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new file mode 100644
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diff --git a/set3/task19_data/task19_35 b/set3/task19_data/task19_35
new file mode 100644
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new file mode 100644
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new file mode 100644
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new file mode 100644
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new file mode 100644
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diff --git a/set3/task19_data/task19_all b/set3/task19_data/task19_all
new file mode 100644
index 0000000..affd17b
--- /dev/null
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diff --git a/set3/task20_data/20.txt b/set3/task20_data/20.txt
new file mode 100644
index 0000000..d601f0b
--- /dev/null
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new file mode 100644
index 0000000..ac2e746
--- /dev/null
+++ b/set3/task20_data/task20_00
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new file mode 100644
index 0000000..6943297
--- /dev/null
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new file mode 100644
index 0000000..14536ba
--- /dev/null
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new file mode 100644
index 0000000..1a5e846
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new file mode 100644
index 0000000..27afef9
--- /dev/null
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new file mode 100644
index 0000000..ceecbfa
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new file mode 100644
index 0000000..d62512b
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new file mode 100644
index 0000000..1b0cdc6
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new file mode 100644
index 0000000..167d125
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