added submission for hcarroll

hcarroll-assign1/caesar-cipher.txt

@@ -0,0 +1 @@
+SBWKRQ

hcarroll-assign1/caesar-plain.txt

@@ -0,0 +1 @@
+PYTHON

hcarroll-assign1/crypto.py

@@ -0,0 +1,299 @@
+"""
+Assignment 1: Cryptography
+Course: CS 92SI
+Name: Harper Carroll
+Date: 10/9/15
+
+An interactive ciphering and deciphering program. Allows the user to encipher or decipher
+either a string or a file using one of three methods: a caesar cipher, a de Vigenere cipher,
+and a railfence cipher (well, it should... not really with my implementation because I didn't have time).
+Then, the user can receive the encrypted or decrypted message via a printed string or a
+file.
+
+"""
+
+alphabet_upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+alphabet_lower = "abcdefghijklmnopqrstuvwxyz"
+
+def encrypt_caesar(plaintext):
+    """
+    Encrypts plaintext using a Caesar cipher of a shift of 3.
+    """
+    ciphertext = ""
+    for letter in plaintext:
+        if (letter in alphabet_lower):
+            newLetter = alphabet_lower.index(letter) + 3
+            newLetter = newLetter % 26
+            ciphertext += alphabet_lower[newLetter]
+        else:
+            newLetter = alphabet_upper.index(letter) + 3
+            newLetter = newLetter % 26
+            ciphertext += alphabet_upper[newLetter]
+
+    print("Encrypting " + plaintext + " using Caesar cipher...")
+    return ciphertext;
+
+def decrypt_caesar(ciphertext):
+    """
+    Decrypts a ciphertext using a Caesar cipher of a shift of 3.
+    """
+    plaintext = ""
+    for letter in ciphertext:
+        if (letter in alphabet_lower):
+            newLetter = alphabet_lower.index(letter) - 3
+            if (newLetter < 0):
+                newLetter = 26 + newLetter;
+            else:
+                newLetter = newLetter % 26
+            plaintext += alphabet_lower[newLetter]
+        else:
+            newLetter = alphabet_upper.index(letter) - 3
+            if (newLetter < 0):
+                newLetter = 26 + newLetter;
+            else:
+                newLetter = newLetter % 26
+            plaintext += alphabet_upper[newLetter]
+    print("Decrypting " + ciphertext + " using Caesar cipher...")
+    return plaintext;
+
+def encrypt_vigenere(plaintext, keyword):
+    """
+    Encrypts plaintext using a Vigenere cipher with a keyword.
+    """
+    ciphertext = ""
+    for index, letter in enumerate(plaintext):
+        if (index > (len(keyword) - 1)):
+            index = index % len(keyword)
+        if (letter in alphabet_lower):
+            newLetter = alphabet_lower.index(letter) + alphabet_upper.index(keyword[index])
+            newLetter = newLetter % 26
+            ciphertext += alphabet_lower[newLetter]
+        else:
+            newLetter = alphabet_upper.index(letter) + alphabet_upper.index(keyword[index])
+            newLetter = newLetter % 26
+            ciphertext += alphabet_upper[newLetter]
+
+    print("Encrypting " + plaintext + " using Vigenere cipher with key " + keyword + "...")
+    return ciphertext;
+
+
+def decrypt_vigenere(ciphertext, keyword):
+    """
+    Decrypts ciphertext using a Vigenere cipher with a keyword.
+    """
+    plaintext = ""
+    for index, letter in enumerate(ciphertext):
+        if (index > (len(keyword) - 1)):
+            index = index % len(keyword)
+        if (letter in alphabet_lower):
+            newLetter = alphabet_lower.index(letter) - alphabet_upper.index(keyword[index])
+            if (newLetter < 0):
+                newLetter = 26 + newLetter;
+            else:
+                newLetter = newLetter % 26
+            plaintext += alphabet_lower[newLetter]
+        else:
+            newLetter = alphabet_upper.index(letter) - alphabet_upper.index(keyword[index])
+            if (newLetter < 0):
+                newLetter = 26 + newLetter;
+            else:
+                newLetter = newLetter % 26
+            plaintext += alphabet_upper[newLetter]
+
+    print("Decrypting " + ciphertext + " using Vigenere cipher with key " + keyword + "...")
+    return plaintext;
+
+def encrypt_railfence(plaintext, num_rails):
+    """
+    Encrypts plaintext using a railfence cipher.
+    """
+    l = []
+    for letter in plaintext:
+        l.append(letter)
+    used_indices = []
+    distance = 2 * (num_rails - 1)
+    currentRailIndices = []
+    currentRailIndices.append([])
+    currentRailIndices.append([])
+    indices = list(range(0, len(plaintext)))
+    rail = 1
+    while (rail <= num_rails):
+        for i in indices[(rail-1)::distance]:
+            if (i not in used_indices):
+                used_indices.append(i)
+                currentRailIndices.append(i)
+        for j in indices[(2*(rail-1))::distance]:
+            if (j not in used_indices):
+                used_indices.append(j)
+                currentRailIndices[rail-1].append(j)
+        currentRailIndices[rail-1] = sorted(currentRailIndices[rail-1])
+        rail += 1
+
+    ciphertext = ""
+    for i in range(num_rails):
+        for j in range((len(plaintext)/3 + len(plaintext%3))):
+            ciphertext += plaintext[currentRailIndices[i][j]]
+
+    print("Encrypting " + plaintext + " using Railfence cipher with " + str(num_rails) + " rails...")
+    return ciphertext
+
+def decrypt_railfence(ciphertext, num_rails):
+    """
+    Encrypts plaintext using a railfence cipher.
+    Add more implementation details here.
+    """
+    pass  # Your implementation here
+
+
+def read_from_file(filename):
+    """
+    Reads and returns content from a file.
+    Add more implementation details here.
+    """
+    with open(filename, 'r') as f:
+        content = f.read()
+    f.close()
+    return content;
+
+def write_to_file(filename, content):
+    """
+    Writes content to a file.
+    Add more implementation details here.
+    """
+    with open(filename, 'w+') as f:
+        f.write(content)
+    f.close()
+    return f;
+
+
+def run_suite():
+    """
+    Runs a single iteration of the cryptography suite.
+
+    Asks the user for input text from a string or file, whether to encrypt
+    or decrypt, what tool to use, and where to show the output.
+    """
+    print("*Input*")
+    input_combination = ""
+    file_or_string = input("(F)ile or (S)tring? ")
+    string = ""
+    content = ""
+    while (file_or_string.upper()[0] not in ['S', 'F']):
+        print ("Invalid response.")
+        file_or_string = input("(F)ile or (S)tring? ")
+    if (file_or_string.upper()[0] == 'F'):
+        filename = input("Filename: ")
+        roughContent = read_from_file(filename)
+        for letter in roughContent: #eliminates all non-alphabetical characters
+            if (letter.isalpha()):
+                content += letter
+    elif (file_or_string.upper()[0] == 'S'):
+         roughString = input("Enter the string to transform: ")
+         string = ""
+         for letter in roughString: #eliminates all non-alphabetical characters
+            if (letter.isalpha()):
+                string += letter
+
+    input_combination += file_or_string.upper()[0]
+
+    print("*Transform*")
+    encrypt_or_decrypt = input("(E)ncrypt or (D)ecrypt? ")
+    while (encrypt_or_decrypt.upper()[0] not in ['E', 'D']):
+        print ("Invalid response.")
+        file_or_string = input("(E)ncrypt or (D)ecrypt?")
+    input_combination += encrypt_or_decrypt.upper()[0]
+
+    tool = input("(C)aesar, (V)igenere, or (R)ailfence? ")
+    while (tool.upper()[0] not in ['C', 'V', 'R']):
+        print ("Invalid response.")
+        tool = input("(C)aesar, (V)igenere, or (R)ailfence?")
+    input_combination += tool.upper()[0]
+    transformed = ""
+
+    if (input_combination[0] == 'F'): #if file
+        if (input_combination[1] == 'E'): #encrypt
+            if (input_combination[2] == 'C'): #caesar
+                transformed = encrypt_caesar(content)
+            elif (input_combination[2] == 'V'): #de vigenere
+                keyword = input("Keyword? ")
+                keyword = keyword.upper()
+                transformed = encrypt_vigenere(content, keyword)
+            else: #if railfence
+                num_rails = int(input("Number of rails? "))
+                transformed = encrypt_railfence(content, num_rails)
+        else: #decrypt
+            if (input_combination[2] =='C'):
+                transformed = decrypt_caesar(content)
+            elif (input_combination[2] == 'V'): #de vigenere
+                keyword = input("Keyword? ")
+                keyword = keyword.upper()
+                transformed = decrypt_vigenere(content, keyword)
+            else: #if railfence
+                num_rails = int(input("Number of rails? "))
+                transformed = decrypt_railfence(content, num_rails)
+
+    else: #if string
+        if (input_combination[1] == 'E'): #encrypt
+            if (input_combination[2] == 'C'): #caesar
+                transformed = encrypt_caesar(string)
+            elif (input_combination[2] == 'V'): #de vigenere
+                keyword = input("Keyword? ")
+                keyword = keyword.upper()
+                transformed = encrypt_vigenere(string, keyword)
+            else: #if railfence
+                num_rails = int(input("Number of rails? "))
+                transformed = encrypt_railfence(string, num_rails)
+        else: #decrypt
+            if (input_combination[2] =='C'):
+                transformed = decrypt_caesar(string)
+            elif (input_combination[2] == 'V'): #de vigenere
+                keyword = input("Keyword? ")
+                keyword = keyword.upper()
+                transformed = decrypt_vigenere(string, keyword)
+            else: #if railfence
+                num_rails = int(input("Number of rails? "))
+                transformed = decrypt_railfence(string, num_rails)
+    print("")
+
+
+
+    print("*Output*")
+    file_or_string = input("(F)ile or (S)tring? ")
+    while (file_or_string.upper()[0] not in ['S', 'F']):
+        print ("Invalid response.")
+        file_or_string = input("(F)ile or (S)tring? ")
+    if (file_or_string.upper()[0] == 'F'):
+        filename = input("Filename? ")
+        print("Writing transformed text to " + filename + "...")
+        file_of_content = write_to_file(filename, content)
+    elif (file_or_string.upper()[0] == 'S'):
+        print("The transformed text is: " + transformed)
+
+
+# Do not modify code beneath this point.
+def should_continue():
+    """
+    Asks the user whether they would like to continue.
+    Responses that begin with a `Y` return True. (case-insensitively)
+    Responses that begin with a `N` return False. (case-insensitively)
+    All other responses (including '') cause a reprompt.
+    """
+    choice = input("Again (Y/N)? ").upper()
+    while not choice or choice[0] not in ['Y', 'N']:
+        choice = input("Please enter either 'Y' or 'N'. Again (Y/N)? ").upper()
+    return choice[0] == 'Y'
+
+
+def main():
+    """Harness for the Cryptography Suite"""
+    print("Welcome to the Cryptography Suite!")
+    run_suite()
+    while should_continue():
+        run_suite()
+    print("Goodbye!")
+
+
+if __name__ == '__main__':
+    """This block is run if and only if the Python script is invoked from the
+    command line."""
+    main()

hcarroll-assign1/discovered.txt

@@ -0,0 +1 @@
+we are discovered!!! flee at once!!!!

hcarroll-assign1/discovered_soln.txt

@@ -0,0 +1 @@
+wearediscoveredfleeatonce

hcarroll-assign1/feedback.txt

@@ -0,0 +1,24 @@
+Name: Harper Carroll
+1) How long did this assignment take you to complete?
+Too long…. and it’s not completed.
+Probably 7 hours to do what I’ve done, but mostly because rail fence gave me such misery. Sorry I didn’t finish it! 
+I’d like to see a solution, though, so I know how I can do it in the future. I also wonder how far off my logic was; if I was close with logic but the syntax was messing me up, I think i’ll feel better.
+
+
+2) What has been the best part of the class so far?
+Learning Python! The assignment was pretty fun, actually, except for the debugging issues I ran into. I also like how it’s pass/fail - it’s low stress, so I can actually enjoy the learning and enjoy the assignments. I feel like I’m actually getting more out of the class that way.
+
+
+
+3) What can we do to make this class more enjoyable for you?
+Not sure; maybe move a TINY bit slower? It’s been pretty great so far. I like the lab.
+
+
+
+4) What types of assignments would excite you in this class?
+This one was great! I think you have the right idea in mind. However, maybe a bit shorter… railfence was very difficult for a lot of people, and took a long time.
+
+Thanks for all your help, guys! You’re awesome teachers. 
+
+
+

hcarroll-assign1/railfence-cipher.txt

@@ -0,0 +1 @@
+WECRLTEERDSOEEFEAOCAIVDEN

hcarroll-assign1/railfence-plain.txt

@@ -0,0 +1 @@
+WE ARE DISCOVERED. FLEE AT ONCE

hcarroll-assign1/secret_message.txt

@@ -0,0 +1 @@
+KHOORZRUOG

hcarroll-assign1/vigenere-cipher.txt

@@ -0,0 +1 @@
+LXFOPVEFRNHR

hcarroll-assign1/vigenere-plain.txt

@@ -0,0 +1 @@
+Attack At Dawn!