国庆匆忙做了几题简单的，希望有空能补上。

Forensics Warmup 1 - Points: 50

Can you unzip this file for me and retreive the flag?

解压得到图片

picoCTF{welcome_to_forensics}

Forensics Warmup 2 - Points: 50

Hmm for some reason I can’t open this PNG? Any ideas?

其实是jpg文件

picoCTF{extensions_are_a_lie}

General Warmup 1 - Points: 50

If I told you your grade was 0x41 in hexadecimal, what would it be in ASCII?

picoCTF{A}

General Warmup 2 - Points: 50

Can you convert the number 27 (base 10) to binary (base 2)?

picoCTF{11011}

General Warmup 3 - Points: 50

What is 0x3D (base 16) in decimal (base 10).

picoCTF{61}

Resources - Points: 50

We put together a bunch of resources to help you out on our website! If you go over there, you might even find a flag! https://picoctf.com/resources (link)

picoCTF{xiexie_ni_lai_zheli}

Reversing Warmup 1

Throughout your journey you will have to run many programs. Can you navigate to /problems/reversing-warmup-1_4_6b2499250c4624337a1948ac374c4934 on the shell server and run this program to retreive the flag?

picoCTF{welc0m3_t0_r3VeRs1nG}

Reversing Warmup 2

Can you decode the following string dGg0dF93NHNfczFtcEwz from base64 format to ASCII?

picoCTF{th4t_w4s_s1mpL3}

Crypto Warmup 1

Crpyto can often be done by hand, here’s a message you got from a friend, llkjmlmpadkkc with the key of thisisalilkey. Can you use this table to solve it?.

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    A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
   +----------------------------------------------------
A | A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
B | B C D E F G H I J K L M N O P Q R S T U V W X Y Z A
C | C D E F G H I J K L M N O P Q R S T U V W X Y Z A B
D | D E F G H I J K L M N O P Q R S T U V W X Y Z A B C
E | E F G H I J K L M N O P Q R S T U V W X Y Z A B C D
F | F G H I J K L M N O P Q R S T U V W X Y Z A B C D E
G | G H I J K L M N O P Q R S T U V W X Y Z A B C D E F
H | H I J K L M N O P Q R S T U V W X Y Z A B C D E F G
I | I J K L M N O P Q R S T U V W X Y Z A B C D E F G H
J | J K L M N O P Q R S T U V W X Y Z A B C D E F G H I
K | K L M N O P Q R S T U V W X Y Z A B C D E F G H I J
L | L M N O P Q R S T U V W X Y Z A B C D E F G H I J K
M | M N O P Q R S T U V W X Y Z A B C D E F G H I J K L
N | N O P Q R S T U V W X Y Z A B C D E F G H I J K L M
O | O P Q R S T U V W X Y Z A B C D E F G H I J K L M N
P | P Q R S T U V W X Y Z A B C D E F G H I J K L M N O
Q | Q R S T U V W X Y Z A B C D E F G H I J K L M N O P
R | R S T U V W X Y Z A B C D E F G H I J K L M N O P Q
S | S T U V W X Y Z A B C D E F G H I J K L M N O P Q R
T | T U V W X Y Z A B C D E F G H I J K L M N O P Q R S
U | U V W X Y Z A B C D E F G H I J K L M N O P Q R S T
V | V W X Y Z A B C D E F G H I J K L M N O P Q R S T U
W | W X Y Z A B C D E F G H I J K L M N O P Q R S T U V
X | X Y Z A B C D E F G H I J K L M N O P Q R S T U V W
Y | Y Z A B C D E F G H I J K L M N O P Q R S T U V W X
Z | Z A B C D E F G H I J K L M N O P Q R S T U V W X Y

picoCTF{SECRETMESSAGE}

Crypto Warmup 2

Cryptography doesn’t have to be complicated, have you ever heard of something called rot13? cvpbPGS{guvf_vf_pelcgb!}

picoCTF{this_is_crypto!}

grep 1 - Points: 75

Can you find the flag in file? This would be really obnoxious to look through by hand, see if you can find a faster way. You can also find the file in /problems/grep-1_3_8d9cff3d178c231ab735dfef3267a1c2 on the shell server.

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cat file | grep "CTF"
picoCTF{grep_and_you_will_find_cdf2e7c2}

picoCTF{grep_and_you_will_find_cdf2e7c2}

net cat - Points: 75

Using netcat (nc) will be a necessity throughout your adventure. Can you connect to 2018shell1.picoctf.com at port 10854 to get the flag?

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nc 2018shell1.picoctf.com 10854
That wasn't so hard was it?

picoCTF{NEtcat_iS_a_NEcESSiTy_c97963fe}

strings - Points: 100

Can you find the flag in this file without actually running it? You can also find the file in /problems/strings_1_c7bac958dd6a4b695dc72446d8014f59 on the shell server.

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strings strings | grep CTF
YzOejwCTF3GVzbdb8PkOKp1cKvAwEUvRSOLLm1yFFETiT
picoCTF{sTrIngS_sAVeS_Time_d7c8de6c}
7Oqu9T7p8SAoQcOcQVHM46k1xpt1M6Iu2ag4dw1OFCTFRbv6

picoCTF{sTrIngS_sAVeS_Time_d7c8de6c}

pipe

During your adventure, you will likely encounter a situation where you need to process data that you receive over the network rather than through a file. Can you find a way to save the output from this program and search for the flag? Connect with 2018shell1.picoctf.com 48696.

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nc 2018shell1.picoctf.com 48696 > ctf.txt
cat ctf.txt | grep CTF
picoCTF{almost_like_mario_f617d1d7}

picoCTF{almost_like_mario_f617d1d7}

Inspect Me

Inpect this code! http://2018shell1.picoctf.com:53213 (link)

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<!-- I learned HTML! Here's part 1/3 of the flag: picoCTF{ur_4_real_1nspe -->
/* I learned CSS! Here's part 2/3 of the flag: ct0r_g4dget_402b0bd3} */
/* I learned JavaScript! Here's part 3/3 of the flag:  */

picoCTF{ur_4_real_1nspect0r_g4dget_402b0bd3}

grep 2

This one is a little bit harder. Can you find the flag in /problems/grep-2_1_ef31faa711ad74321a7467978cb0ef3a/files on the shell server? Remember, grep is your friend.

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grep picoCTF . -r      
./files9/file13:picoCTF{grep_r_and_you_will_find_4baaece4}

picoCTF{grep_r_and_you_will_find_4baaece4}

Client Side is Still Bad

I forgot my password again, but this time there doesn’t seem to be a reset, can you help me? http://2018shell1.picoctf.com:8930 (link)

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function verify() {
  checkpass = document.getElementById("pass").value;
  split = 4;
  if (checkpass.substring(split*7, split*8) == '}') {
    if (checkpass.substring(split*6, split*7) == 'ebbd') {
      if (checkpass.substring(split*5, split*6) == 'd_d0') {
       if (checkpass.substring(split*4, split*5) == 's_ba') {
        if (checkpass.substring(split*3, split*4) == 'nt_i') {
          if (checkpass.substring(split*2, split*3) == 'clie') {
            if (checkpass.substring(split, split*2) == 'CTF{') {
              if (checkpass.substring(0,split) == 'pico') {
                alert("You got the flag!")
                }
              }
            }
    
          }
        }
      }
    }
  }
  else {
    alert("Incorrect password");
  }
}

picoCTF{client_is_bad_d0ebbd}

admin panel

We captured some traffic logging into the admin panel, can you find the password?

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))yE|@@~P0].[T
wPOST /login HTTP/1.1
Host: 192.168.3.128
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:59.0) Gecko/20100101 Firefox/59.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: http://192.168.3.128/
Content-Type: application/x-www-form-urlencoded
Content-Length: 53
Connection: keep-alive
Upgrade-Insecure-Requests: 1

user=admin&password=picoCTF{n0ts3cur3_13597b43}

picoCTF{n0ts3cur3_13597b43}