2024-10-21 Strive Marish Leadman TypeCDR (Cryptogr

RSA is deceptively simple (and fun) | nicole@web

https://www.ntietz.com/blog/rsa-deceptively-simple/

nc challenge.ctf.games 31130 -vv
DNS fwd/rev mismatch: challenge.ctf.games != 143.148.193.35.bc.googleusercontent.com
challenge.ctf.games [35.193.148.143] 31130 (?) open
p: 0xe09cb5a80eafab2019838142da91dcea0ba059769274f477828f720992ae527ed4c5c05145e2f1455d3e082cf498c173ca530bfd4d438974d61db254f08fda2b
q: 0xcc6f6a8ffff4292b77c75b410da2f2c128a4b33e146204c556e3d78eb00d560ecaf73568b0582959b6b93a363f2580cd4f3745a473624b132cb4403dd2b8508b
d: 0x72523c7b6e9961bf08449c21cc1be096774e322fc0956f8d27ffa8143ac65860081a85dedd037d9a081b3c19c879afdb8c51f769695ddc294b19d4659b44f93485ac1b2a60c27d9908f57a5367e70a9392ef354ec49b55baaf27d1bca1c0b659225c17aac2164b7525b4a1a6cdc2452a5e9f40ed20545dff7820b9c4881c0ae9
e: 0x10001
n: 0xb35ea233eae5bbec7f8ce750d0daf31524ca03b070cd3dfa621d64ea87a88c8f6ab7d3bbea190bc9f456a99a3766af185b60a001c515e3a17700f0d579f1321cceb2c5e86e6d19ed7e6e5e05b122b8cfe68325eb5e7efa738937156798497de231899ce9bd8ee4e7b9421cd083050a3446ea6747f606ca32774b03e6a730e559

0x8891d81e261a1e1eb3bd158da174b637154226b5da2e90e79e36b327d75a5de53a05c90d70b2b0197278cca354fae1acde56926c55fdc57e7c9e1ff675f677ba8a61e05028f3efc9491ccd96da8357c5873a916e54c905885bda9d851b2e3f4c1ca4f2b62ae94eb913584b03aefa9e2fc761b46ad4fc9f3566a42929edd5911a
 sent 0, rcvd 1063

#Import crypto
from Crypto.Util.number import long_to_bytes

# Given values
p = 0xe09cb5a80eafab2019838142da91dcea0ba059769274f477828f720992ae527ed4c5c05145e2f1455d3e082cf498c173ca530bfd4d438974d61db254f08fda2b
q = 0xcc6f6a8ffff4292b77c75b410da2f2c128a4b33e146204c556e3d78eb00d560ecaf73568b0582959b6b93a363f2580cd4f3745a473624b132cb4403dd2b8508b
d = 0x72523c7b6e9961bf08449c21cc1be096774e322fc0956f8d27ffa8143ac65860081a85dedd037d9a081b3c19c879afdb8c51f769695ddc294b19d4659b44f93485ac1b2a60c27d9908f57a5367e70a9392ef354ec49b55baaf27d1bca1c0b659225c17aac2164b7525b4a1a6cdc2452a5e9f40ed20545dff7820b9c4881c0ae9
e = 0x10001
n = 0xb35ea233eae5bbec7f8ce750d0daf31524ca03b070cd3dfa621d64ea87a88c8f6ab7d3bbea190bc9f456a99a3766af185b60a001c515e3a17700f0d579f1321cceb2c5e86e6d19ed7e6e5e05b122b8cfe68325eb5e7efa738937156798497de231899ce9bd8ee4e7b9421cd083050a3446ea6747f606ca32774b03e6a730e559

# Ciphertext to decode (as hex)
c = 0x8891d81e261a1e1eb3bd158da174b637154226b5da2e90e79e36b327d75a5de53a05c90d70b2b0197278cca354fae1acde56926c55fdc57e7c9e1ff675f677ba8a61e05028f3efc9491ccd96da8357c5873a916e54c905885bda9d851b2e3f4c1ca4f2b62ae94eb913584b03aefa9e2fc761b46ad4fc9f3566a42929edd5911a

# Decryption formula: m = c^d % n
m = pow(c, d, n)

# Convert to readable format (string)
message = long_to_bytes(m)
print(message)

flag{cf614b15ac1dd461a2e48afdfe21b8e8}