diff options
Diffstat (limited to 'challenge')
| -rw-r--r-- | challenge/c25.go | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/challenge/c25.go b/challenge/c25.go new file mode 100644 index 0000000..6c698fc --- /dev/null +++ b/challenge/c25.go @@ -0,0 +1,234 @@ +// Copyright © 2021 rsiddharth <s@ricketyspace.net> +// SPDX-License-Identifier: ISC + +package challenge + +import ( + "fmt" + + "ricketyspace.net/cryptopals/lib" +) + +func C25() { + // + plain := lib.AESDecryptECB( + lib.Base64ToBytes(`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`), + lib.StrToBytes("YELLOW SUBMARINE")) + + // Generate Nonce for AES counter function. + nonce := uint64(lib.RandomInt(0, 10)) + + // Generate random key. + key, err := lib.RandomBytes(16) + if err != nil { + fmt.Printf("Error generating key %v", err) + return + } + + // Function for editing AES CTR cipher. + editCipher := func(cipher, key []byte, offset int, newtxt []byte) []byte { + if len(key) != 16 { + return cipher // key must be 16 bytes. + } + if offset+len(newtxt) > len(cipher) { + return cipher // Cannot edit. + } + + // Get counter function. + ctrFunc := lib.AESGenCTRFunc(nonce) + + // Get output block for the cipher. + ob := make([]byte, 0) + for { + ob = append(ob, lib.AESCipher(ctrFunc(), key)...) + if len(ob) >= len(cipher) { + break + } + } + + // Make a copy of the cipher. + cipherc := make([]byte, len(cipher)) + copy(cipherc, cipher) + + // Edit. + c := lib.FixedXORBytes(newtxt, ob[offset:offset+len(newtxt)]) + for i, j := offset, 0; j < len(newtxt); i, j = i+1, j+1 { + cipherc[i] = c[j] + } + return cipherc + } + + // API Function for editing AES CTR cipher. + apiEditCipher := func(cipher []byte, offset int, newtxt []byte) []byte { + return editCipher(cipher, key, offset, newtxt) + } + + // Cracks cipher using API function + crack := func(cipher []byte) []byte { + as := lib.FillBytes('A', len(cipher)) // 'A's. + ec := apiEditCipher(cipher, 0, as) // Edited cipher. + + // Get output block. + ob := lib.FixedXORBytes(as, ec) + + // Crack cipher. + p := lib.FixedXORBytes(cipher, ob) + + return p + } + + // Get AES CTR cipher from plain text. + cipher, err := lib.AESEncryptCTR(plain, key, lib.AESGenCTRFunc(nonce)) + if err != nil { + fmt.Printf("Error encrypting plain: %v", err) + return + } + + // Crack plain text using API function. + p := crack(cipher) + fmt.Printf("%v", lib.BytesToStr(p)) +} + +// Output: +// I'm back and I'm ringin' the bell +// A rockin' on the mike while the fly girls yell +// In ecstasy in the back of me +// Well that's my DJ Deshay cuttin' all them Z's +// Hittin' hard and the girlies goin' crazy +// Vanilla's on the mike, man I'm not lazy. +// +// I'm lettin' my drug kick in +// It controls my mouth and I begin +// To just let it flow, let my concepts go +// My posse's to the side yellin', Go Vanilla Go! +// +// Smooth 'cause that's the way I will be +// And if you don't give a damn, then +// Why you starin' at me +// So get off 'cause I control the stage +// There's no dissin' allowed +// I'm in my own phase +// The girlies sa y they love me and that is ok +// And I can dance better than any kid n' play +// +// Stage 2 -- Yea the one ya' wanna listen to +// It's off my head so let the beat play through +// So I can funk it up and make it sound good +// 1-2-3 Yo -- Knock on some wood +// For good luck, I like my rhymes atrocious +// Supercalafragilisticexpialidocious +// I'm an effect and that you can bet +// I can take a fly girl and make her wet. +// +// I'm like Samson -- Samson to Delilah +// There's no denyin', You can try to hang +// But you'll keep tryin' to get my style +// Over and over, practice makes perfect +// But not if you're a loafer. +// +// You'll get nowhere, no place, no time, no girls +// Soon -- Oh my God, homebody, you probably eat +// Spaghetti with a spoon! Come on and say it! +// +// VIP. Vanilla Ice yep, yep, I'm comin' hard like a rhino +// Intoxicating so you stagger like a wino +// So punks stop trying and girl stop cryin' +// Vanilla Ice is sellin' and you people are buyin' +// 'Cause why the freaks are jockin' like Crazy Glue +// Movin' and groovin' trying to sing along +// All through the ghetto groovin' this here song +// Now you're amazed by the VIP posse. +// +// Steppin' so hard like a German Nazi +// Startled by the bases hittin' ground +// There's no trippin' on mine, I'm just gettin' down +// Sparkamatic, I'm hangin' tight like a fanatic +// You trapped me once and I thought that +// You might have it +// So step down and lend me your ear +// '89 in my time! You, '90 is my year. +// +// You're weakenin' fast, YO! and I can tell it +// Your body's gettin' hot, so, so I can smell it +// So don't be mad and don't be sad +// 'Cause the lyrics belong to ICE, You can call me Dad +// You're pitchin' a fit, so step back and endure +// Let the witch doctor, Ice, do the dance to cure +// So come up close and don't be square +// You wanna battle me -- Anytime, anywhere +// +// You thought that I was weak, Boy, you're dead wrong +// So come on, everybody and sing this song +// +// Say -- Play that funky music Say, go white boy, go white boy go +// play that funky music Go white boy, go white boy, go +// Lay down and boogie and play that funky music till you die. +// +// Play that funky music Come on, Come on, let me hear +// Play that funky music white boy you say it, say it +// Play that funky music A little louder now +// Play that funky music, white boy Come on, Come on, Come on +// Play that funky music |