Update crypto_challenge_1/makechallenge.sh, crypto_challenge_1/flag.txt,...

Update crypto_challenge_1/makechallenge.sh, crypto_challenge_1/flag.txt, crypto_challenge_1/challenge.txt, crypto_challenge_1/solution.txt files

crypto_challenge_1/challenge.txt

+PFem1muWtjYXhiQ26kcrZkK3BiMttNA1UxO8c/11mjNTZ/8VADfmRDJG4ubc1vODByceNaXGpaWDpBoHEVfrJK8DRBX+Fask5DZfFZxzXBeY1hRWi2c4FqSDZTNMM2QUEDetJYQzsbZ606HXDqA=

crypto_challenge_1/flag.txt

+umichctf{2KS17W3vQsDdnm8rSlZJpuB0QQBcQ7qmeva833AsR3k=}

crypto_challenge_1/makechallenge.sh

+# Make challenge
+# Create a flag file, then a file of random bytes of the same length
+flag="umichctf{"$(openssl rand -base64 32)"}"
+echo $flag > flag.txt
+filesize=$(wc -c < flag.txt)
+openssl rand -out src-file_rand.bin $filesize
+
+# Do a hex dump of the random file, a hex dump of the flag file (in reverse)
+# and combine into one file
+xxd -p -c1 src-file_rand.bin > tmp1
+xxd -p -c1 flag.txt | rev > tmp2
+paste -d "\n" tmp1 tmp2 > tmp3
+
+# Base64 it for upload as a challenge
+xxd -r -p tmp3 | base64 > challenge.txt
+
+# Clean up
+rm tmp1 tmp2 tmp3 src-file_rand.bin
+
+# Check solution
+base64 --decode challenge.txt > challenge-txt.bin
+xxd -p -c 2 challenge-txt.bin | cut -b 3-4 | rev | xxd -r -p > solution.txt
+
+rm challenge-txt.bin
+
+if ! cmp -s "flag.txt" "solution.txt"; then
+	echo "Something went wrong - the flag file and solution do not match!"
+fi

crypto_challenge_1/solution.txt

+umichctf{2KS17W3vQsDdnm8rSlZJpuB0QQBcQ7qmeva833AsR3k=}