Update

.github/workflows/docker-compose.yml

@@ -0,0 +1,54 @@
+name: Docker Image CI
+
+on:
+  push:
+    branches: [ "main" ]
+
+jobs:
+
+  build:
+
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Get changed files
+      id: changed-files
+      uses: tj-actions/changed-files@v37
+
+    - name: List changed
+      run: |
+        for file in ${{ steps.changed-files.outputs.all_changed_files }}; do
+          echo "$file was changed"
+        done
+    
+    - name: Log in to registry
+        # This is where you will update the personal access token to GITHUB_TOKEN
+      run: echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u $ --password-stdin
+
+
+    - name: Build and push the Docker image
+      run: |
+        declare -a built_images=()
+        for file in ${{ steps.changed-files.outputs.all_changed_files }}; do
+          if [[ "$file" =~ ^(Pwn|Web)/[a-zA-Z0-9_-]+/deployment/.+ ]]; then
+            IMAGE_NAME=$(echo -n $file | cut -d "/" -f2)
+            NORM_IMAGE_NAME=$(echo $IMAGE_NAME | tr A-Z a-z | tr - _)
+            CATEGORY=$(echo -n $file | cut -d "/" -f1)
+            if [[ " ${built_images[*]} " != *" $IMAGE_NAME "* ]]; then
+              echo "building and pushing: $CATEGORY/$IMAGE_NAME/deployment/"
+              docker build $CATEGORY/$IMAGE_NAME/deployment/ --tag $NORM_IMAGE_NAME
+              built_images+=("$NORM_IMAGE_NAME")
+              IMAGE_ID=ghcr.io/guzzwho/$NORM_IMAGE_NAME 
+              echo "pushing to $IMAGE_ID"
+              VERSION=latest
+              docker tag $NORM_IMAGE_NAME $IMAGE_ID:$VERSION
+              docker push $IMAGE_ID:$VERSION
+            else echo "already built $NORM_IMAGE_NAME"
+            fi
+          fi
+        done

Crypto/Primapocalypse/Handout/Primapocalypse/Primapocalypse.py

@@ -0,0 +1,21 @@
+from Crypto.Util.number import getPrime, bytes_to_long as b2l
+from sympy import nextprime
+
+flag = b2l(b"inctfj{?????}")
+
+L = [getPrime(2048)]
+for i in range(3):
+    L.append(nextprime(L[-1]))
+
+e = 0x10001
+
+cipher = flag
+for i in range(3):
+    a, b = L[i], L[i + 1]
+    N = a * b
+    cipher = pow(cipher, e, N)
+
+with open('output.txt', 'w') as output_file:
+    output_file.write(f"cipher: {hex(cipher)}\n")
+    output_file.write(f"e: {hex(e)}\n")
+    output_file.write(f"leak: {hex(L[0]*L[3])}, {hex(L[1]*L[2])}\n")

Crypto/Primapocalypse/Handout/Primapocalypse/output.txt

@@ -0,0 +1,3 @@
+cipher: 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
+e: 0x10001
+leak: 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, 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

Crypto/Primapocalypse/README.md

@@ -0,0 +1,27 @@
+# Primapocalypse  
+
+### Challenge Description
+I was a bit lazy to generate 4 primes but at least the bit length is large right...?
+
+**Challenge File**
++ [Primary Link](./Handout/chall.zip)
++ [Mirror Link]()
+
+**MD5 Hash**: 31bab32c4988a357aa8668f75affeef0
+
+### Short Writeup
++ This RSA challenge involves generating a 2048 bit prime as well as the next three primes after that one.  
++ The flag goes through 3 rounds of RSA encryption with N being the product of the first and the second prime and in the next round N is the product of the second and third prime and so on.
++ The ciphertext, e and the product of the first and last prime as well as the product of the 2nd and 3rd prime is written to a file.
+
+Solving this challenge involves factoring the two products given with the fermat's factoring algorithm (since the primes are close together).
+Since primes are generated in a successive manner, the factored values must be sorted and then the decryption can be done by considering the last two values first.  
+
+### Flag
+
+inctfj{n0t_4_t0u4h_p51me_1s_i7}
+
+### Author
+
+**Ankith**
+**Devanandan**

Crypto/Primapocalypse/admin/exploit/output.txt

@@ -0,0 +1,3 @@
+cipher: 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
+e: 0x10001
+leak: 0x7a759c247b8e820c9b40915addfac71388587db324a55159754f4cad25c32dc7c5b847547777f7affdba42f6fc6b88f4e872893c92d5802248ffe1474f5f93656e1d312f58433adb92ca71af52f410053183c6c6ffd4509fc626e44839c97f2739496832cc7883a416ca48585987e1b0c27e582e60b71339013c6892fdf8b41ce6bbd6737452052e63d35fcbde793814c7ce1816490c8acac7809bcaab4caabda599b2e3b9306018fac24121fb119217432582cb938027f931bf953cd3ed6fa9feeed7ea1f584c8bcb6ad9573f51ffe2cfeb0ad734debb91d720b1b6efbdf784d6dedff6a885b122f8be4ee95075ea17e2377aff79c124c2245a6709564819bf0531d339d0694e1cfcc0effa528729c01fc99322da2f49ff2cca9fd3ac75dac4c96a5839959199df0c838b29bbbffec6622a26ce5aa265fd0b185b6d93848d021e22d5d4e5579cee16056d246a99e76d74e2e09286113987e84d487ed3d245e80acfca91d58201c57408dffa5505d0c3c5e33e18923dde17d0759b081d26552929e8b413262d422677d351fa580cc9049c43edbb371ecb67156d71f2a7ce737216a2c08c89171463c5138f4b0d3ac4e10d8c43f2a52de669ff22a239d10578edd1f62d5b04e148cea88e9036001dddd3bf7a1ec2f7c8ef125582934065579c270da91a8076f3a476a27f5455f1e8664ebe620b483da7d83c0883474d5588e54b, 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

Crypto/Primapocalypse/admin/exploit/solver.py

@@ -0,0 +1,38 @@
+from gmpy2 import isqrt
+from gmpy2 import is_square
+from Crypto.Util.number import long_to_bytes
+
+with open('output.txt', 'r') as output_file:
+    cipher = int(output_file.readline().lstrip("cipher: "), 16)
+    e = int(output_file.readline().lstrip("e: "), 16)
+    leak = output_file.readline().lstrip("leak: ")
+
+N1, N2 = leak.split(", ")
+N1 = int(N1, 16)
+N2 = int(N2, 16)
+
+def factor(n):
+    a = isqrt(n)
+    b2 = a**2 - n
+
+    while not is_square(b2):
+        b2 += 2*a + 1
+        a += 1
+
+    p = int(a - isqrt(b2))
+    q = int(a + isqrt(b2))
+
+    assert p * q == n
+    return p, q
+
+L = sorted(factor(N2) + factor(N1), reverse=True)
+e = 0x10001
+
+for i in range(3):
+    p, q = L[i], L[i+1]
+    N = p*q
+    phi = (p-1)*(q-1)
+    d = pow(e,-1, phi)
+    cipher = pow(cipher, d, N)
+
+print(long_to_bytes(cipher).decode())

Crypto/Primapocalypse/admin/src/challenge.py

@@ -0,0 +1,21 @@
+from Crypto.Util.number import getPrime, bytes_to_long as b2l
+from sympy import nextprime
+
+flag = b2l(b"inctfj{n0t_4_t0u4h_p51me_1s_i7}")
+
+L = [getPrime(2048)]
+for i in range(3):
+    L.append(nextprime(L[-1]))
+
+e = 0x10001
+
+cipher = flag
+for i in range(3):
+    a, b = L[i], L[i + 1]
+    N = a * b
+    cipher = pow(cipher, e, N)
+
+with open('output.txt', 'w') as output_file:
+    output_file.write(f"cipher: {hex(cipher)}\n")
+    output_file.write(f"e: {hex(e)}\n")
+    output_file.write(f"leak: {hex(L[0]*L[3])}, {hex(L[1]*L[2])}\n")

Crypto/Primapocalypse/admin/src/output.txt

@@ -0,0 +1,3 @@
+cipher: 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
+e: 0x10001
+leak: 0x7a759c247b8e820c9b40915addfac71388587db324a55159754f4cad25c32dc7c5b847547777f7affdba42f6fc6b88f4e872893c92d5802248ffe1474f5f93656e1d312f58433adb92ca71af52f410053183c6c6ffd4509fc626e44839c97f2739496832cc7883a416ca48585987e1b0c27e582e60b71339013c6892fdf8b41ce6bbd6737452052e63d35fcbde793814c7ce1816490c8acac7809bcaab4caabda599b2e3b9306018fac24121fb119217432582cb938027f931bf953cd3ed6fa9feeed7ea1f584c8bcb6ad9573f51ffe2cfeb0ad734debb91d720b1b6efbdf784d6dedff6a885b122f8be4ee95075ea17e2377aff79c124c2245a6709564819bf0531d339d0694e1cfcc0effa528729c01fc99322da2f49ff2cca9fd3ac75dac4c96a5839959199df0c838b29bbbffec6622a26ce5aa265fd0b185b6d93848d021e22d5d4e5579cee16056d246a99e76d74e2e09286113987e84d487ed3d245e80acfca91d58201c57408dffa5505d0c3c5e33e18923dde17d0759b081d26552929e8b413262d422677d351fa580cc9049c43edbb371ecb67156d71f2a7ce737216a2c08c89171463c5138f4b0d3ac4e10d8c43f2a52de669ff22a239d10578edd1f62d5b04e148cea88e9036001dddd3bf7a1ec2f7c8ef125582934065579c270da91a8076f3a476a27f5455f1e8664ebe620b483da7d83c0883474d5588e54b, 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

Crypto/README.md

@@ -0,0 +1,9 @@
+# Crypto
+
+
+|   Challenge    | Author | Difficulty |
+| ----------- | ----------- | ----------- |
+|bragcrid|Parvathy|Easy|
+|Primapocalypse|Ankith, Devanand|Medium|
+|Sums_n_Diffs|Ankith, Devanand|Medium|
+|beginner|Sans|Hard|

Crypto/Sums_n_Diffs/Handout/Sums_n_Diffs/Sums_n_Diffs.py

@@ -0,0 +1,30 @@
+flag = "inctfj{?????}"
+flag = list(flag.encode())
+
+def product(arr):
+    product = 1
+    for num in arr:
+        product *= num
+    return product
+
+def generatePs(arr):
+    Ps = []
+    for i in range(len(arr)):
+        Ps.append(product(arr[:i] + arr[i+1:]))
+    return Ps
+
+def generateDs(Ps, P):
+    Ds = []
+    for i in range(len(Ps)):
+        Ds.append(P - Ps[i])
+    return Ds
+
+P = product(flag)
+Ps = generatePs(flag)
+Ds = generateDs(Ps, P)
+
+out = [hex(Ps[i] * Ds[i]) for i in range(len(flag))]
+
+with open('output.txt', 'w') as output_file:
+    output_file.write(f"P: {hex(P)}\n")
+    output_file.write(f"Out: {out}\n")

Crypto/Sums_n_Diffs/Handout/Sums_n_Diffs/output.txt

@@ -0,0 +1,2 @@
+P: 0x45a0329fce551659417d40ab7b4860711bb82be95b102000000
+Out: ['0x2dbab510cbc3dc98cfa31154fc18584d10369fe17b0f352c2a7547bd4dd432c6ab49ddaf46e51c2186eb47a0000000000000', '0x2bab77dda2486be1e5fafc7276dd5f300030aa53f6c35e9ccbc29a28ab3e85a03be502263fb0779805ab4add000000000000', '0x3078f81a1bac45c258aa7e97ee523dfd33e8e3cc565c1e35b59a814d3d4f1c8ac54030151d601a0b2e381d48000000000000', '0x296e4020e24081ab29514ce08123a29981d2e685dce07bf8d800bbe71c5b9106986d64649f9910be634a3536c00000000000', '0x2f0f9d368681c73c1ea4d3185b23e9e15035eebc7a60bc02155615bcf22f2990b7aa5a9c84739d0df366d0dd000000000000', '0x2d4d518d647c98ed6a13a8689436365d28d67d012502faf32592016365708155a7dcf3ecf64334c2f18dedf1000000000000', '0x271797c1e950793da20085219eaaa1487343d75b6579e894ee32920ce5b27c5dc3e48a84b69c3b67de6f5e28000000000000', '0x2a85519ed88d5be9342a62e37f97077edcbe3cbe07265ec05fff5d3c81ade1d5d1f527bdc4b02b83584d79c0000000000000', '0x2914615d12f843089e9c6c85b47cd97e13e1296bc9f2213507a6a5696e5ae94aca19765fdc1e30593bd9fc50000000000000', '0x5b6ee0fbb638d882c571670fa9dbf415b8a927a42ff6ebd78c7a3945022cd4376daf91d138f680da797d989ec00000000000', '0x2ffe220d568a2a474a9a6e5b2129d2163e6685a3e89a417bfb8ce4eeed0c15f42ea8a77e71d1bdf5d1ff3544c00000000000', '0x2a26adbbb7520d5bea9446377080f7ced8f30bb7693c63c82e078f02162284c0906510f687eb46b5abced0c1000000000000', '0x5b6ee0fbb638d882c571670fa9dbf415b8a927a42ff6ebd78c7a3945022cd4376daf91d138f680da797d989ec00000000000', '0x296e4020e24081ab29514ce08123a29981d2e685dce07bf8d800bbe71c5b9106986d64649f9910be634a3536c00000000000', '0x60ea221857d423e3cdbfab5ce6717c0a9aed229c5b34b9d4f5e9aef20c3a4770cbde0d4742412f28e9b0b8c0000000000000', '0x3078f81a1bac45c258aa7e97ee523dfd33e8e3cc565c1e35b59a814d3d4f1c8ac54030151d601a0b2e381d48000000000000', '0x327de568109b8f52a58c3039b5cc0e791773ca4061c94a7d10fca3b1aab0bc04d81a187cf2ebfa71c503b378000000000000', '0x2f0f9d368681c73c1ea4d3185b23e9e15035eebc7a60bc02155615bcf22f2990b7aa5a9c84739d0df366d0dd000000000000', '0x62e404b16d6a731808c9f473b1e460917f5247d78a2fa09c9d8c23efb10724b0605b8dd99b8d65c92823f88ddc0000000000', '0x2a26adbbb7520d5bea9446377080f7ced8f30bb7693c63c82e078f02162284c0906510f687eb46b5abced0c1000000000000', '0x2c11152330ca8d2f1475dc7d41b20cb5927e9fd3df3dd93a081c270b4c2e20ecee8727eb984535ca754a4e30000000000000', '0x2914615d12f843089e9c6c85b47cd97e13e1296bc9f2213507a6a5696e5ae94aca19765fdc1e30593bd9fc50000000000000', '0x60ea221857d423e3cdbfab5ce6717c0a9aed229c5b34b9d4f5e9aef20c3a4770cbde0d4742412f28e9b0b8c0000000000000', '0x5b6ee0fbb638d882c571670fa9dbf415b8a927a42ff6ebd78c7a3945022cd4376daf91d138f680da797d989ec00000000000', '0x327de568109b8f52a58c3039b5cc0e791773ca4061c94a7d10fca3b1aab0bc04d81a187cf2ebfa71c503b378000000000000', '0x2a26adbbb7520d5bea9446377080f7ced8f30bb7693c63c82e078f02162284c0906510f687eb46b5abced0c1000000000000', '0x2914615d12f843089e9c6c85b47cd97e13e1296bc9f2213507a6a5696e5ae94aca19765fdc1e30593bd9fc50000000000000', '0x2c788f97cec20f4f996fddc1d8b4b456242431ca6f3b01f4cb747af1dfd94071becc93711f4933c1f2fbef78c00000000000', '0x5d30a95f4c405a5db3cf41b17f3f8316e0bbe7f3f4ddf8186714ebade9b61a8b8f2dd972c46122b8c61a2b88000000000000', '0x29c9ab788e92d8471b8c676ba2b0b1ff650a1f472b1c54c369a7d49b2f281a0981e3c876e53cc6c6ef121888000000000000', '0x2678c3462aaf815c6b620a0f55a5322effdb06e67b5cef16bddaf69c90ec6a8d557fda26adc7ae198f33ce70000000000000']

Crypto/Sums_n_Diffs/README.md

@@ -0,0 +1,39 @@
+# Sums_n_Diffs
+
+### Challenge Description  
+polynomials... polynomials...
+
+**Challenge File**
++ [Primary Link](./Handout/chall.zip)
++ [Mirror Link]()
+
+**MD5 Hash**: 659500611fbaea0929833cc504b110af
+
+### Short Writeup
+
++ The ascii value of each byte in the flag is taken and the product P of all of these values is calculated.
++ Then, a list with values `Pi` where each value is the total product divided by the ascii value of the ith byte of the flag, is created.
++ Next, a list with values `Di` where each value is `P-Pi` for every ith byte of the flag, is created.
++ Finally, a list with the values `Pi * Di` is created. 
++ The value of P as well as the product list is written to a flag.
+
+This challenge can be solved using the quadratic equation.  
+We have:
+```
+Di = P-Pi
+prod = Pi * Di
+prod = Pi * (P-Pi)
+prod = Pi*P - Pi^2
+Pi^2 - Pi*P + prod = 0
+```
+Since prod and P is known, each Pi can be calculated by finding the root of the equation.  
+Calculating P/Pi gives each byte of the flag.  
+
+### Flag
+
+inctfj{qu4dr4t1c_f0rmu14_rul3s}
+
+### Authors
+
+**Ankith**
+**Devanandan**