Set 2 Challenge 10: Implement CBC mode

7.txt

@@ -0,0 +1,64 @@
+CRIwqt4+szDbqkNY+I0qbDe3LQz0wiw0SuxBQtAM5TDdMbjCMD/venUDW9BL
+PEXODbk6a48oMbAY6DDZsuLbc0uR9cp9hQ0QQGATyyCESq2NSsvhx5zKlLtz
+dsnfK5ED5srKjK7Fz4Q38/ttd+stL/9WnDzlJvAo7WBsjI5YJc2gmAYayNfm
+CW2lhZE/ZLG0CBD2aPw0W417QYb4cAIOW92jYRiJ4PTsBBHDe8o4JwqaUac6
+rqdi833kbyAOV/Y2RMbN0oDb9Rq8uRHvbrqQJaJieaswEtMkgUt3P5Ttgeh7
+J+hE6TR0uHot8WzHyAKNbUWHoi/5zcRCUipvVOYLoBZXlNu4qnwoCZRSBgvC
+wTdz3Cbsp/P2wXB8tiz6l9rL2bLhBt13Qxyhhu0H0+JKj6soSeX5ZD1Rpilp
+9ncR1tHW8+uurQKyXN4xKeGjaKLOejr2xDIw+aWF7GszU4qJhXBnXTIUUNUf
+RlwEpS6FZcsMzemQF30ezSJHfpW7DVHzwiLyeiTJRKoVUwo43PXupnJXDmUy
+sCa2nQz/iEwyor6kPekLv1csm1Pa2LZmbA9Ujzz8zb/gFXtQqBAN4zA8/wt0
+VfoOsEZwcsaLOWUPtF/Ry3VhlKwXE7gGH/bbShAIKQqMqqUkEucZ3HPHAVp7
+ZCn3Ox6+c5QJ3Uv8V7L7SprofPFN6F+kfDM4zAc59do5twgDoClCbxxG0L19
+TBGHiYP3CygeY1HLMrX6KqypJfFJW5O9wNIF0qfOC2lWFgwayOwq41xdFSCW
+0/EBSc7cJw3N06WThrW5LimAOt5L9c7Ik4YIxu0K9JZwAxfcU4ShYu6euYmW
+LP98+qvRnIrXkePugS9TSOJOHzKUoOcb1/KYd9NZFHEcp58Df6rXFiz9DSq8
+0rR5Kfs+M+Vuq5Z6zY98/SP0A6URIr9NFu+Cs9/gf+q4TRwsOzRMjMQzJL8f
+7TXPEHH2+qEcpDKz/5pE0cvrgHr63XKu4XbzLCOBz0DoFAw3vkuxGwJq4Cpx
+kt+eCtxSKUzNtXMn/mbPqPl4NZNJ8yzMqTFSODS4bYTBaN/uQYcOAF3NBYFd
+5x9TzIAoW6ai13a8h/s9i5FlVRJDe2cetQhArrIVBquF0L0mUXMWNPFKkaQE
+BsxpMCYh7pp7YlyCNode12k5jY1/lc8jQLQJ+EJHdCdM5t3emRzkPgND4a7O
+NhoIkUUS2R1oEV1toDj9iDzGVFwOvWyt4GzA9XdxT333JU/n8m+N6hs23MBc
+Z086kp9rJGVxZ5f80jRz3ZcjU6zWjR9ucRyjbsuVn1t4EJEm6A7KaHm13m0v
+wN/O4KYTiiY3aO3siayjNrrNBpn1OeLv9UUneLSCdxcUqjRvOrdA5NYv25Hb
+4wkFCIhC/Y2ze/kNyis6FrXtStcjKC1w9Kg8O25VXB1Fmpu+4nzpbNdJ9LXa
+hF7wjOPXN6dixVKpzwTYjEFDSMaMhaTOTCaqJig97624wv79URbCgsyzwaC7
+YXRtbTstbFuEFBee3uW7B3xXw72mymM2BS2uPQ5NIwmacbhta8aCRQEGqIZ0
+78YrrOlZIjar3lbTCo5o6nbbDq9bvilirWG/SgWINuc3pWl5CscRcgQQNp7o
+LBgrSkQkv9AjZYcvisnr89TxjoxBO0Y93jgp4T14LnVwWQVx3l3d6S1wlsci
+dVeaM24E/JtS8k9XAvgSoKCjyiqsawBMzScXCIRCk6nqX8ZaJU3rZ0LeOMTU
+w6MC4dC+aY9SrCvNQub19mBdtJUwOBOqGdfd5IoqQkaL6DfOkmpnsCs5PuLb
+GZBVhah5L87IY7r6TB1V7KboXH8PZIYc1zlemMZGU0o7+etxZWHgpdeX6JbJ
+Is3ilAzYqw/Hz65no7eUxcDg1aOaxemuPqnYRGhW6PvjZbwAtfQPlofhB0jT
+Ht5bRlzF17rn9q/6wzlc1ssp2xmeFzXoxffpELABV6+yj3gfQ/bxIB9NWjdZ
+K08RX9rjm9CcBlRQeTZrD67SYQWqRpT5t7zcVDnx1s7ZffLBWm/vXLfPzMaQ
+YEJ4EfoduSutjshXvR+VQRPs2TWcF7OsaE4csedKUGFuo9DYfFIHFDNg+1Py
+rlWJ0J/X0PduAuCZ+uQSsM/ex/vfXp6Z39ngq4exUXoPtAIqafrDMd8SuAty
+EZhyY9V9Lp2qNQDbl6JI39bDz+6pDmjJ2jlnpMCezRK89cG11IqiUWvIPxHj
+oiT1guH1uk4sQ2Pc1J4zjJNsZgoJDcPBbfss4kAqUJvQyFbzWshhtVeAv3dm
+gwUENIhNK/erjpgw2BIRayzYw001jAIF5c7rYg38o6x3YdAtU3d3QpuwG5xD
+fODxzfL3yEKQr48C/KqxI87uGwyg6H5gc2AcLU9JYt5QoDFoC7PFxcE3RVqc
+7/Um9Js9X9UyriEjftWt86/tEyG7F9tWGxGNEZo3MOydwX/7jtwoxQE5ybFj
+WndqLp8DV3naLQsh/Fz8JnTYHvOR72vuiw/x5D5PFuXV0aSVvmw5Wnb09q/B
+owS14WzoHH6ekaWbh78xlypn/L/M+nIIEX1Ol3TaVOqIxvXZ2sjm86xRz0Ed
+oHFfupSekdBULCqptxpFpBshZFvauUH8Ez7wA7wjL65GVlZ0f74U7MJVu9Sw
+sZdgsLmnsQvr5n2ojNNBEv+qKG2wpUYTmWRaRc5EClUNfhzh8iDdHIsl6edO
+ewORRrNiBay1NCzlfz1cj6VlYYQUM9bDEyqrwO400XQNpoFOxo4fxUdd+AHm
+CBhHbyCR81/C6LQTG2JQBvjykG4pmoqnYPxDyeiCEG+JFHmP1IL+jggdjWhL
+WQatslrWxuESEl3PEsrAkMF7gt0dBLgnWsc1cmzntG1rlXVi/Hs2TAU3RxEm
+MSWDFubSivLWSqZj/XfGWwVpP6fsnsfxpY3d3h/fTxDu7U8GddaFRQhJ+0ZO
+dx6nRJUW3u6xnhH3mYVRk88EMtpEpKrSIWfXphgDUPZ0f4agRzehkn9vtzCm
+NjFnQb0/shnqTh4Mo/8oommbsBTUKPYS7/1oQCi12QABjJDt+LyUan+4iwvC
+i0k0IUIHvk21381vC0ixYDZxzY64+xx/RNID+iplgzq9PDZgjc8L7jMg+2+m
+rxPS56e71m5E2zufZ4d+nFjIg+dHD/ShNPzVpXizRVUERztLuak8Asah3/yv
+wOrH1mKEMMGC1/6qfvZUgFLJH5V0Ep0n2K/Fbs0VljENIN8cjkCKdG8aBnef
+EhITdV7CVjXcivQ6efkbOQCfkfcwWpaBFC8tD/zebXFE+JshW16D4EWXMnSm
+/9HcGwHvtlAj04rwrZ5tRvAgf1IR83kqqiTvqfENcj7ddCFwtNZrQK7EJhgB
+5Tr1tBFcb9InPRtS3KYteYHl3HWR9t8E2YGE8IGrS1sQibxaK/C0kKbqIrKp
+npwtoOLsZPNbPw6K2jpko9NeZAx7PYFmamR4D50KtzgELQcaEsi5aCztMg7f
+p1mK6ijyMKIRKwNKIYHagRRVLNgQLg/WTKzGVbWwq6kQaQyArwQCUXo4uRty
+zGMaKbTG4dns1OFB1g7NCiPb6s1lv0/lHFAF6HwoYV/FPSL/pirxyDSBb/FR
+RA3PIfmvGfMUGFVWlyS7+O73l5oIJHxuaJrR4EenzAu4Avpa5d+VuiYbM10a
+LaVegVPvFn4pCP4U/Nbbw4OTCFX2HKmWEiVBB0O3J9xwXWpxN1Vr5CDi75Fq
+NhxYCjgSJzWOUD34Y1dAfcj57VINmQVEWyc8Tch8vg9MnHGCOfOjRqp0VGyA
+S15AVD2QS1V6fhRimJSVyT6QuGb8tKRsl2N+a2Xze36vgMhw7XK7zh//jC2H

data/s2c10.txt

@@ -0,0 +1,64 @@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project.clj

@@ -46,4 +46,5 @@ built, but you'll also understand how they're attacked.
                     "src/hale/cryptopals/set1/challenge8.clj"
                     "src/hale/cryptopals/set2.clj"
                     "src/hale/cryptopals/set2/challenge9.clj"
+                    "src/hale/cryptopals/set2/challenge10.clj"
                     "src/hale/cryptopals/utils.clj"]})

src/hale/cryptopals/set1/challenge7.clj

@@ -25,25 +25,29 @@
            [javax.crypto.spec SecretKeySpec]))
 
 
-
 (defn decrypt-aes-ecb
-  [byte-stream key]
+  [key byte-stream]
   (let [key-spec  (SecretKeySpec. (.getBytes key) "AES")
-        cipher    (Cipher/getInstance "AES/ECB/PKCS5Padding")
+        cipher    (Cipher/getInstance "AES/ECB/NoPadding")
         _         (.init cipher (int Cipher/DECRYPT_MODE) key-spec)
+        _ (println (count byte-stream))
         decrypted (.doFinal cipher (byte-array byte-stream))]
     decrypted))
 
 
-(defn decrypt-aes-ecb-base64 [b64 key]
-  (decrypt-aes-ecb (base64/base64-decode b64) key))
+(defn decrypt-aes-ecb-base64 [key b64]
+  (decrypt-aes-ecb key (base64/base64-decode b64)))
 
 (def decrypt-aes-ecb-base64-to-str
   "Decrypt AES in ECB mode"
   (comp utils/bytes-to-str decrypt-aes-ecb-base64))
 
-(t/deftest decrypt-aes-in-ecb-mode
+;; TODO: why does this return ^D^D^D^D at the end? the same is NOT returned by openssl:
+;;
+;; openssl enc -d -a -aes-128-ecb -in 7.txt -v -K $(echo -n "YELLOW SUBMARINE" | hexdump -v -e '/1 "%02X"') -out 7.solution.txt
+;;
+(t/deftest test-decrypt-aes-ecb
   (let [key "YELLOW SUBMARINE"
         ciphertext (slurp "data/s1c7.txt")
         plaintext (slurp "data/s1c7.solution.txt")]
-    (t/is (= (decrypt-aes-ecb-base64-to-str ciphertext key) plaintext))))
+    (t/is (= plaintext (decrypt-aes-ecb-base64-to-str key ciphertext)))))

src/hale/cryptopals/set2/challenge10.clj

@@ -0,0 +1,81 @@
+;;
+;; # Implement CBC mode
+;;
+;; CBC mode is a block cipher mode that allows us to encrypt irregularly-sized
+;; messages, despite the fact that a block cipher natively only transforms
+;; individual blocks.
+;;
+;; In CBC mode, each ciphertext block is added to the next plaintext block
+;; before the next call to the cipher core.
+;;
+;; The first plaintext block, which has no associated previous ciphertext block,
+;; is added to a "fake 0th ciphertext block" called the initialization vector,
+;; or IV.
+;;
+;; Implement CBC mode by hand by taking the ECB function you wrote earlier,
+;; making it encrypt instead of decrypt (verify this by decrypting whatever you
+;; encrypt to test), and using your XOR function from the previous exercise to
+;; combine them.
+;;
+;; The file here is intelligible (somewhat) when CBC decrypted against "YELLOW
+;; SUBMARINE" with an IV of all ASCII 0 (\x00\x00\x00 &c)
+;;
+;; <hr />
+(ns hale.cryptopals.set2.challenge10
+  (:require [hale.cryptopals.utils :as utils]
+            [hale.cryptopals.set1.challenge1 :as base64]
+            [hale.cryptopals.set1.challenge7 :refer [decrypt-aes-ecb-base64-to-str]]
+            [clojure.test :as t])
+  (:import [javax.crypto Cipher]
+           [javax.crypto.spec SecretKeySpec]))
+
+
+
+(defn encrypt-aes-ecb
+  [key bs]
+  (let [key-spec  (SecretKeySpec. (.getBytes key) "AES")
+        cipher    (Cipher/getInstance "AES/ECB/NoPadding")
+        _         (.init cipher (int Cipher/ENCRYPT_MODE) key-spec)
+        encrypted (.doFinal cipher (byte-array bs))]
+    encrypted))
+
+(defn encrypt-aes-ecb-str-to-base64
+  [key str]
+  (->> str
+       utils/str-to-bytes
+       ((partial encrypt-aes-ecb key))
+       base64/base64-encode))
+
+;; (let [key       "ICEICEBABY123456"
+;;       plaintext "YELLOW SUBMARINE"
+;;       encrypted (encrypt-aes-ecb-str-to-base64 key plaintext)
+;;       _ (println encrypted)
+;;       _ (println (count encrypted))
+;;       decrypted (decrypt-aes-ecb-base64-to-str key encrypted)
+;;       ])
+
+;; (decrypt-aes-ecb-base64-to-str encrypted key)
+
+(t/deftest encrypt-aes-in-ecb-mode
+  (let [key "YELLOW SUBMARINE"
+        ciphertext (slurp "data/s1c7.txt")
+        plaintext (slurp "data/s1c7.solution.txt")]
+    (t/is (= (encrypt-aes-ecb-str-to-base64 key plaintext) ciphertext))))
+
+
+
+;; I found this image on Wikipedia helpful for understanding how CBC encryption works:
+;;
+;; <img src="https://pghale.com/images/cryptopals/CBC_encryption.svg.png" width="100%" />
+;;
+;; So we need a function that takes an IV + plaintext and returns ciphertext.
+
+
+(defn encrypt-aes-ecb
+  "bs   -- bytestream input plaintext
+   iv   -- initialization vector
+   blocks -- number of bytes per block"
+  [bs iv blocks])
+
+
+(def input (base64/base64-decode (slurp "data/s2c10.txt")))