From aaabeb704f200023aa544d70eaca9f363e8da975 Mon Sep 17 00:00:00 2001
From: rsiddharth <s@ricketyspace.net>
Date: Thu, 11 Feb 2021 23:00:49 -0500
Subject: lib: update Pkcs7PaddingUndo, AESDecryptCBC
Add error as the second return value to Pkcs7PaddingUndo and
AESDecryptCBC.
---
challenge/c10.go | 4 ++--
challenge/c15.go | 28 +++++++++++++++++++---------
challenge/c16.go | 2 +-
3 files changed, 22 insertions(+), 12 deletions(-)
(limited to 'challenge')
diff --git a/challenge/c10.go b/challenge/c10.go
index 18f2db2..0ed473b 100644
--- a/challenge/c10.go
+++ b/challenge/c10.go
@@ -97,11 +97,11 @@ func C10() {
fmt.Printf("NIST SP 800-38A F.2.1 (has padding):\n%v\n",
lib.PrettifyHexStr(lib.BytesToHexStr(cipher80038A)))
- o := lib.AESDecryptCBC(cipher80038A, key80038A, iv80038A)
+ o, _ := lib.AESDecryptCBC(cipher80038A, key80038A, iv80038A)
fmt.Printf("NIST SP 800-38A F.2.2:\n%v\n",
lib.PrettifyHexStr(lib.BytesToHexStr(o)))
- o = lib.AESDecryptCBC(cipher10, key10, iv10)
+ o, _ = lib.AESDecryptCBC(cipher10, key10, iv10)
fmt.Printf("Cryptopals Ch. 10:\n%v", lib.BytesToStr(o))
}
diff --git a/challenge/c15.go b/challenge/c15.go
index 40892ec..e974d64 100644
--- a/challenge/c15.go
+++ b/challenge/c15.go
@@ -15,7 +15,7 @@ func C15() {
padded_ice := lib.Pkcs7Padding(ice, 16)
fmt.Printf("ice padded: %v\n", padded_ice)
- unpadded_ice := lib.Pkcs7PaddingUndo(padded_ice)
+ unpadded_ice, _ := lib.Pkcs7PaddingUndo(padded_ice)
for i := 0; i < len(ice); i++ {
if ice[i] != unpadded_ice[i] {
panic("padding undo failed!")
@@ -23,18 +23,28 @@ func C15() {
}
fmt.Printf("unpadded ice: %v\n", unpadded_ice)
- // Will fail and panic
- // bad_ice := append(ice, []byte{5, 5, 5, 5}...)
- // fmt.Printf("bad ice: %v\n", bad_ice)
- // lib.Pkcs7PaddingUndo(bad_ice)
+ // Will fail.
+ bad_ice := append(ice, []byte{5, 5, 5, 5}...)
+ fmt.Printf("bad ice: %v\n", bad_ice)
+ _, err := lib.Pkcs7PaddingUndo(bad_ice)
+ if err != nil {
+ fmt.Printf("bad ice upadding failed: %s\n", err.Error())
+ }
- // Will fail and panic
- // evil_ice := append(ice, []byte{1, 2, 3, 4}...)
- // fmt.Printf("evil ice: %v\n", evil_ice)
- // lib.Pkcs7PaddingUndo(evil_ice)
+ // Will fail.
+ evil_ice := append(ice, []byte{1, 2, 3, 4}...)
+ fmt.Printf("evil ice: %v\n", evil_ice)
+ _, err = lib.Pkcs7PaddingUndo(evil_ice)
+ if err != nil {
+ fmt.Printf("evil ice upadding failed: %s\n", err.Error())
+ }
}
// Output:
// ice: [73 67 69 32 73 67 69 32 66 65 66 89]
// ice padded: [73 67 69 32 73 67 69 32 66 65 66 89 4 4 4 4]
// unpadded ice: [73 67 69 32 73 67 69 32 66 65 66 89]
+// bad ice: [73 67 69 32 73 67 69 32 66 65 66 89 5 5 5 5]
+// bad ice upadding failed: input is not pkcs#7 padded
+// evil ice: [73 67 69 32 73 67 69 32 66 65 66 89 1 2 3 4]
+// evil ice upadding failed: input is not pkcs#7 padded
diff --git a/challenge/c16.go b/challenge/c16.go
index 534d9fb..155fbaa 100644
--- a/challenge/c16.go
+++ b/challenge/c16.go
@@ -60,7 +60,7 @@ func cbcBitFlipEncrypt(s string) []byte {
}
func cbcBitFlipDecryptHasAdmin(c []byte) bool {
- b := lib.AESDecryptCBC(c, cbcBitFlipKey, cbcBitFlipIV)
+ b, _ := lib.AESDecryptCBC(c, cbcBitFlipKey, cbcBitFlipIV)
s := lib.BytesToStr(b)
// Convert to a map
--
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