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-rw-r--r--challenge/c12.go30
-rw-r--r--challenge/c14.go31
-rw-r--r--lib/oracle.go36
3 files changed, 45 insertions, 52 deletions
diff --git a/challenge/c12.go b/challenge/c12.go
index b76f28a..0308bd4 100644
--- a/challenge/c12.go
+++ b/challenge/c12.go
@@ -11,6 +11,18 @@ import (
func C12() {
sheep := byte(65)
+ unknown := `Um9sbGluJyBpbiBteSA1LjAKV2l0aCBteSByYWctdG9wIGRvd24gc28gbXkg
+aGFpciBjYW4gYmxvdwpUaGUgZ2lybGllcyBvbiBzdGFuZGJ5IHdhdmluZyBq
+dXN0IHRvIHNheSBoaQpEaWQgeW91IHN0b3A/IE5vLCBJIGp1c3QgZHJvdmUg
+YnkK`
+ key, err := lib.RandomBytes(16)
+ if err != nil {
+ fmt.Printf("key generatation error: %v", err)
+ }
+ encrypt := func(in []byte) []byte {
+ return lib.AESEncryptECB(append(in, lib.Base64ToBytes(unknown)...), key)
+ }
+
freshSheepBytes := func(n int) []byte {
in := make([]byte, n)
for i := 0; i < n; i++ {
@@ -22,11 +34,11 @@ func C12() {
in := make([]byte, 0)
in = append(in, sheep)
- is := len(lib.OracleAESEncryptECB(in)) // initial size
- bs := 0 // block size
+ is := len(encrypt(in)) // initial size
+ bs := 0 // block size
for {
in = append(in, sheep)
- bs = len(lib.OracleAESEncryptECB(in))
+ bs = len(encrypt(in))
if bs != is {
return (bs - is)
}
@@ -34,13 +46,13 @@ func C12() {
}
findUnknownStringCharacteristics := func(blocksize int) (int, int) {
in := make([]byte, 0)
- c_sz := len(lib.OracleAESEncryptECB(in)) // Cipher size
- nblocks := c_sz / blocksize // number of blocks
+ c_sz := len(encrypt(in)) // Cipher size
+ nblocks := c_sz / blocksize // number of blocks
// Figure out ize of unknown string.
for {
in = append(in, sheep)
- bs := len(lib.OracleAESEncryptECB(in))
+ bs := len(encrypt(in))
if bs != c_sz {
return nblocks, (c_sz - len(in))
}
@@ -49,7 +61,7 @@ func C12() {
}
isOracleUsingECB := func() bool {
in := lib.StrToBytes("OliverMkTukudzi OliverMkTukudzi OliverMkTukudzi")
- oo := lib.OracleAESEncryptECB(in)
+ oo := encrypt(in)
if lib.CipherUsesECB(oo) != nil {
return true
}
@@ -61,7 +73,7 @@ func C12() {
// `in` (n-1)th block that is known
// `ds` deciphered unknown string
decipherUnknownStringIter := func(blocksize, block, n int, in, ds []byte) ([]byte, []byte) {
- oo := lib.OracleAESEncryptECB(in[0:(blocksize - n)])
+ oo := encrypt(in[0:(blocksize - n)])
s := 16 * (block - 1)
e := s + 16
@@ -75,7 +87,7 @@ func C12() {
// Try all combinations.
for i := 0; i < 256; i++ {
in[15] = byte(i)
- oo = lib.OracleAESEncryptECB(in)
+ oo = encrypt(in)
if lib.BlocksEqual(nbl, oo[0:16]) {
ds = append(ds, in[15])
diff --git a/challenge/c14.go b/challenge/c14.go
index 552c2df..b35f2cd 100644
--- a/challenge/c14.go
+++ b/challenge/c14.go
@@ -11,6 +11,23 @@ import (
func C14() {
sheep := byte(65)
+ unknown := `Um9sbGluJyBpbiBteSA1LjAKV2l0aCBteSByYWctdG9wIGRvd24gc28gbXkg
+aGFpciBjYW4gYmxvdwpUaGUgZ2lybGllcyBvbiBzdGFuZGJ5IHdhdmluZyBq
+dXN0IHRvIHNheSBoaQpEaWQgeW91IHN0b3A/IE5vLCBJIGp1c3QgZHJvdmUg
+YnkK`
+ key, err := lib.RandomBytes(16)
+ if err != nil {
+ fmt.Printf("key generatation error: %v", err)
+ }
+ oracleRandom, err := lib.RandomBytes(int(lib.RandomInt(1, 4096)))
+ if err != nil {
+ fmt.Printf("oracle random generation error: %v", err)
+ }
+ encrypt := func(in []byte) []byte {
+ in = append(oracleRandom, in...)
+ in = append(in, lib.Base64ToBytes(unknown)...)
+ return lib.AESEncryptECB(in, key)
+ }
freshSheepBytes := func(n int) []byte {
in := make([]byte, n)
for i := 0; i < n; i++ {
@@ -22,11 +39,11 @@ func C14() {
in := make([]byte, 0)
in = append(in, sheep)
- is := len(lib.OracleAESVarEncryptECB(in)) // initial size
+ is := len(encrypt(in)) // initial size
bs := 0
for {
in = append(in, sheep)
- bs = len(lib.OracleAESVarEncryptECB(in))
+ bs = len(encrypt(in))
if bs != is {
return (bs - is)
}
@@ -41,7 +58,7 @@ func C14() {
found := false
for {
in := append(v, tsb...)
- c := lib.OracleAESVarEncryptECB(in)
+ c := encrypt(in)
index, found = lib.HasConsecutiveMatchingBlocks(c, blocksize)
if found {
break
@@ -63,7 +80,7 @@ func C14() {
findUnknownStringNumBlocksLength := func(rpl, blocksize int) (int, int) {
padding := blocksize - (rpl % blocksize)
in := make([]byte, padding)
- c_sz := len(lib.OracleAESVarEncryptECB(in)) // Cipher size
+ c_sz := len(encrypt(in)) // Cipher size
nblocks := c_sz / blocksize // total number of blocks
rblocks := (rpl + padding) / blocksize // number of blocks of random prefix
@@ -71,7 +88,7 @@ func C14() {
// Figure out size of unknown string.
for {
in = append(in, sheep)
- bs := len(lib.OracleAESVarEncryptECB(in))
+ bs := len(encrypt(in))
if bs != c_sz {
return ublocks, (c_sz - len(in) - rpl)
}
@@ -85,7 +102,7 @@ func C14() {
// `in` (n-1)th block that is known
// `ds` deciphered unknown string
decipherOneByte := func(nrpb, rpo, blocksize, block, n int, in, ds []byte) ([]byte, []byte) {
- oo := lib.OracleAESVarEncryptECB(in[0:(len(in) - n)])
+ oo := encrypt(in[0:(len(in) - n)])
s := (nrpb * blocksize) + 16*(block-1)
e := s + 16
@@ -99,7 +116,7 @@ func C14() {
// Try all combinations.
for i := 0; i < 256; i++ {
in[len(in)-1] = byte(i)
- oo = lib.OracleAESVarEncryptECB(in)
+ oo = encrypt(in)
if lib.BlocksEqual(nbl,
oo[(nrpb*blocksize):(nrpb*blocksize)+16]) {
diff --git a/lib/oracle.go b/lib/oracle.go
deleted file mode 100644
index 8a449a1..0000000
--- a/lib/oracle.go
+++ /dev/null
@@ -1,36 +0,0 @@
-// Copyright © 2020 rsiddharth <s@ricketyspace.net>
-// SPDX-License-Identifier: ISC
-
-package lib
-
-var oracleUnknown string = `Um9sbGluJyBpbiBteSA1LjAKV2l0aCBteSByYWctdG9wIGRvd24gc28gbXkg
-aGFpciBjYW4gYmxvdwpUaGUgZ2lybGllcyBvbiBzdGFuZGJ5IHdhdmluZyBq
-dXN0IHRvIHNheSBoaQpEaWQgeW91IHN0b3A/IE5vLCBJIGp1c3QgZHJvdmUg
-YnkK`
-
-var oracleKey []byte
-var oracleRandom []byte
-
-func init() {
- var err error
-
- oracleKey, err = RandomBytes(16)
- if err != nil {
- panic(err)
- }
-
- oracleRandom, err = RandomBytes(int(RandomInt(1, 4096)))
- if err != nil {
- panic(err)
- }
-}
-
-func OracleAESEncryptECB(in []byte) []byte {
- return AESEncryptECB(append(in, Base64ToBytes(oracleUnknown)...), oracleKey)
-}
-
-func OracleAESVarEncryptECB(in []byte) []byte {
- in = append(oracleRandom, in...)
- in = append(in, Base64ToBytes(oracleUnknown)...)
- return AESEncryptECB(in, oracleKey)
-}
siddharth ravikumar snafu