NCTF2023wp

misc

Jump For Signin

没啥好说的，运行.exe文件，进入游戏，发现跳一下会从天空掉二维码下来，我这种方法可能比较原始，就直接拿着手机对着扫得到flag。

Jump For Flag

这题刚开始做挺迷茫的，我以为是要根据方块生成的位置，把二维码拼出来，后面我去搜了一下这个exe文件关键词unity,找到一篇浅谈CTF中的unity游戏逆向 | (mrwq.github.io),我用dnspy查看了jump for flag\game\JumpForFlag_Data\Managed下的Assembly-CSharp.dll文件，是从上面这篇文章得到的信息，然后找到了生成二维码方块的代码

然后我把这段代码直接复制到jump for signin这题的文件中替换掉原有的二维码，然后就能扫二维码得到flag

Crypto

Sign

这题考的是NTRU，格密码，用了大佬的脚本[MAR DASCTF明御攻防赛] 个人（or团队）writeup - 知乎 (zhihu.com)，然后稍微改改，得到

N=509
p=3
q=512
d=3

Q.<x> = Zmod(q)[]
P.<y> = Zmod(p)[]
R.<y> = ZZ['y']

def modCoeffs(f,pp):
    clist=f.list()
    clist = [Integer(t) for t in clist]
    p2=pp/2
    for i in range(len(clist)):
        clist[i] = clist[i]%pp
        if clist[i]>p2:
            clist[i]-=pp
    return R(clist)


fx =  [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]
gx =  [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]
hx =  [292, 374, 91, 384, 263, 330, 77, 497, 294, 141, 485, 464, 46, 478, 315, 100, 287, 1, 337, 477, 451, 387, 340, 370, 384, 19, 158, 440, 377, 177, 235, 340, 166, 359, 488, 332, 252, 443, 256, 453, 33, 282, 175, 18, 218, 208, 414, 147, 12, 468, 155, 34, 109, 390, 312, 472, 345, 176, 9, 184, 100, 414, 293, 366, 132, 128, 223, 242, 137, 223, 268, 259, 446, 57, 463, 344, 459, 115, 509, 510, 82, 42, 408, 139, 341, 351, 511, 339, 317, 139, 317, 297, 288, 58, 33, 120, 244, 194, 44, 128, 278, 130, 449, 282, 274, 376, 209, 240, 148, 426, 244, 319, 251, 438, 317, 166, 161, 37, 361, 468, 172, 116, 211, 64, 446, 162, 301, 447, 92, 325, 285, 4, 8, 160, 382, 365, 413, 150, 141, 323, 107, 225, 466, 93, 86, 219, 174, 198, 155, 88, 194, 259, 140, 36, 82, 462, 182, 496, 250, 337, 39, 435, 448, 365, 262, 146, 89, 283, 195, 395, 216, 159, 312, 53, 70, 485, 368, 130, 491, 474, 325, 4, 205, 1, 292, 330, 186, 66, 137, 291, 452, 236, 25, 114, 407, 125, 343, 2, 304, 267, 459, 432, 129, 21, 197, 51, 26, 342, 457, 163, 51, 52, 82, 229, 332, 72, 408, 242, 218, 286, 368, 503, 498, 434, 135, 311, 321, 205, 269, 318, 19, 119, 422, 425, 463, 368, 317, 99, 178, 390, 8, 127, 156, 27, 332, 437, 87, 187, 92, 115, 380, 54, 236, 287, 259, 386, 391, 94, 312, 454, 459, 340, 382, 424, 25, 318, 47, 249, 115, 20, 89, 82, 377, 328, 231, 298, 402, 336, 452, 264, 265, 83, 254, 156, 449, 34, 99, 412, 101, 183, 38, 142, 231, 181, 495, 6, 327, 278, 92, 452, 372, 12, 91, 102, 277, 98, 418, 22, 32, 493, 50, 374, 230, 479, 496, 6, 382, 300, 496, 157, 1, 221, 418, 381, 275, 391, 199, 472, 5, 222, 448, 377, 102, 468, 94, 35, 6, 6, 464, 452, 453, 354, 277, 425, 120, 501, 172, 222, 314, 362, 6, 105, 387, 77, 14, 112, 289, 358, 495, 350, 411, 378, 30, 89, 115, 171, 42, 32, 427, 125, 420, 486, 435, 151, 234, 416, 428, 425, 250, 142, 301, 245, 154, 338, 223, 292, 27, 194, 220, 34, 283, 255, 53, 5, 420, 134, 351, 216, 92, 242, 39, 454, 96, 239, 390, 182, 368, 463, 176, 187, 25, 122, 441, 54, 171, 426, 435, 318, 345, 166, 224, 258, 246, 349, 50, 400, 381, 236, 315, 439, 249, 201, 262, 95, 210, 327, 199, 205, 402, 175, 280, 337, 388, 205, 336, 52, 68, 364, 293, 462, 388, 354, 169, 163, 72, 374, 220, 355, 275, 36, 208, 198, 363, 369, 344, 61, 13, 230, 196, 190, 463, 351, 37, 276, 336, 110, 352, 56, 117, 376, 500, 373, 438, 309, 496, 400, 76, 169, 447, 434, 255, 456, 511, 414, 83, 369, 174, 291, 213, 227, 254, 186, 145, 402, 265, 13, 20, 212, 442]
e=[219, 149, 491, 115, 68, 464, 91, 223, 480, 506, 103, 373, 19, 52, 368, 467, 304, 380, 495, 372, 506, 318, 320, 263, 120, 126, 165, 271, 435, 378, 443, 261, 336, 381, 57, 360, 36, 155, 424, 458, 84, 80, 187, 261, 501, 279, 167, 13, 241, 85, 214, 133, 483, 374, 430, 401, 265, 127, 497, 405, 60, 34, 81, 422, 423, 200, 276, 424, 245, 437, 31, 193, 282, 154, 93, 13, 499, 190, 1, 304, 415, 189, 82, 472, 13, 488, 366, 364, 319, 121, 322, 120, 468, 134, 305, 228, 288, 284, 33, 430, 125, 366, 212, 207, 227, 201, 286, 377, 376, 57, 336, 379, 101, 461, 375, 101, 475, 126, 306, 73, 88, 1, 149, 378, 381, 129, 402, 341, 390, 57, 305, 139, 436, 101, 386, 460, 43, 468, 9, 449, 255, 184, 374, 466, 429, 167, 101, 247, 183, 159, 346, 45, 79, 192, 259, 32, 140, 151, 16, 214, 42, 450, 111, 7, 303, 286, 435, 491, 339, 248, 114, 185, 103, 81, 414, 100, 485, 428, 137, 13, 243, 202, 62, 208, 136, 376, 88, 158, 377, 404, 355, 194, 452, 373, 107, 290, 89, 489, 259, 462, 169, 235, 86, 214, 333, 472, 343, 487, 19, 371, 203, 234, 315, 339, 430, 133, 96, 161, 278, 13, 20, 87, 303, 466, 353, 139, 395, 131, 298, 85, 144, 244, 150, 488, 254, 284, 89, 300, 297, 288, 245, 439, 307, 222, 110, 343, 318, 202, 429, 81, 203, 468, 144, 140, 480, 370, 501, 14, 490, 278, 493, 390, 214, 108, 174, 150, 287, 197, 497, 374, 420, 298, 222, 188, 146, 298, 466, 459, 456, 16, 131, 253, 153, 481, 342, 498, 173, 12, 452, 197, 233, 18, 439, 332, 185, 48, 330, 4, 99, 105, 75, 306, 174, 492, 131, 39, 126, 491, 79, 145, 186, 493, 23, 230, 195, 118, 310, 173, 244, 80, 25, 502, 373, 457, 275, 282, 26, 206, 14, 181, 61, 391, 454, 417, 370, 70, 413, 389, 434, 400, 88, 417, 364, 458, 496, 425, 12, 280, 102, 265, 471, 43, 257, 327, 10, 334, 239, 344, 77, 298, 140, 287, 260, 194, 431, 65, 304, 302, 210, 393, 473, 463, 312, 255, 368, 476, 462, 390, 412, 266, 138, 410, 246, 101, 460, 307, 123, 4, 240, 502, 115, 147, 370, 241, 222, 495, 109, 51, 138, 354, 447, 282, 434, 280, 275, 404, 214, 68, 77, 167, 302, 95, 462, 16, 184, 213, 227, 130, 50, 405, 30, 353, 24, 143, 100, 163, 212, 388, 283, 252, 187, 247, 190, 163, 252, 169, 267, 363, 72, 399, 195, 215, 103, 60, 466, 318, 71, 193, 449, 65, 358, 443, 260, 253, 46, 5, 416, 115, 390, 15, 120, 384, 50, 122, 87, 428, 282, 464, 83, 80, 401, 8, 175, 457, 301, 63, 205, 402, 468, 368, 510, 488, 345, 103, 306, 387, 34, 119, 459, 43, 319, 264, 184, 406, 407, 358, 242, 42, 241, 34, 118, 477, 117, 325, 511, 499, 365, 192, 507]

fx = Q(fx)
gx = Q(gx)
ex = Q(e)
hx = Q(hx)

lhs = (ex * fx).mod(x^N-1)
print(lhs)
lhs = modCoeffs(lhs, q)
print(lhs)
f_list = fx.list()
print(f_list)
f_list = modCoeffs(fx, q)
fpx = P(f_list).inverse_mod(y^N-1)
print(fpx)
another_mx = P(lhs) * fpx
another_mx = another_mx.mod(y^N-1)
print(another_mx.list())