From 5dfc803487e9defebc0dd8716f346b419460fd43 Mon Sep 17 00:00:00 2001
From: Pavan Sriram Kannuri <86733057+SportingDot1024@users.noreply.github.com>
Date: Mon, 9 Oct 2023 23:17:45 +0530
Subject: [PATCH 1/6] Added/Blockchain RSA Algorithm

---
 blockchain/rivest_shamir_adleman.py | 123 ++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+)
 create mode 100644 blockchain/rivest_shamir_adleman.py

diff --git a/blockchain/rivest_shamir_adleman.py b/blockchain/rivest_shamir_adleman.py
new file mode 100644
index 000000000000..c4774cacaa40
--- /dev/null
+++ b/blockchain/rivest_shamir_adleman.py
@@ -0,0 +1,123 @@
+"""
+RSA Encryption and Decryption using the `cryptography` library.
+
+This script demonstrates RSA encryption and decryption using the
+`cryptography` library. The `cryptography` library is a package
+which provides cryptographic recipes and primitives to Python
+developers. It aims to support all currently supported versions
+of Python.
+
+The RSA algorithm is an asymmetric encryption algorithm, meaning
+that it uses two keys: one public and one private. The public key
+can be shared with everyone, while the private key must be kept
+secret. In RSA, this asymmetry is based on the practical difficulty
+of the factorization of the product of two large prime numbers, the
+"factoring problem". The public key consists of the modulus n and
+the public (or encryption) exponent e. The private key consists of
+the modulus n and the private (or decryption) exponent d, which must
+be kept secret. RSA is often used to encrypt session keys, which are
+symmetric keys used to encrypt data in a symmetric encryption scheme.
+This avoids the need to distribute a symmetric key to each party
+wanting to encrypt data.
+
+References:
+- RSA Algorithm: https://en.wikipedia.org/wiki/RSA_(cryptosystem)
+- cryptography library: https://cryptography.io/
+
+"""
+
+from doctest import testmod
+
+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives import hashes
+from cryptography.hazmat.primitives.asymmetric import padding, rsa
+
+
+def generate_key_pair():
+    """
+    Generate RSA key pair.
+
+    Returns:
+        private_key: Private key for decryption.
+        public_key: Public key for encryption.
+
+    >>> private_key, public_key = generate_key_pair()
+    >>> isinstance(private_key, rsa.RSAPrivateKey)
+    True
+    >>> isinstance(public_key, rsa.RSAPublicKey)
+    True
+    """
+
+    private_key = rsa.generate_private_key(
+        public_exponent=65537, key_size=2048, backend=default_backend()
+    )
+
+    public_key = private_key.public_key()
+
+    return private_key, public_key
+
+
+def encrypt(message, public_key):
+    """
+    Encrypt a message using RSA.
+
+    Args:
+        message (str): Message to be encrypted.
+        public_key: Public key for encryption.
+
+    Returns:
+        bytes: Encrypted ciphertext.
+
+    >>> private_key, public_key = generate_key_pair()
+    >>> message = "Hello, this is a message to be encrypted!"
+    >>> ciphertext = encrypt(message, public_key)
+    >>> decrypted_message = decrypt(ciphertext, private_key)
+    >>> decrypted_message == message
+    True
+    """
+
+    ciphertext = public_key.encrypt(
+        message.encode(),
+        padding.OAEP(
+            mgf=padding.MGF1(algorithm=hashes.SHA256()),
+            algorithm=hashes.SHA256(),
+            label=None,
+        ),
+    )
+    return ciphertext
+
+
+def decrypt(ciphertext, private_key):
+    """
+    Decrypt a ciphertext using RSA.
+
+    Args:
+        ciphertext (bytes): Encrypted ciphertext.
+        private_key: Private key for decryption.
+
+    Returns:
+        str: Decrypted plaintext.
+
+    >>> private_key, public_key = generate_key_pair()
+    >>> message = "Hello, this is a message to be encrypted!"
+    >>> ciphertext = encrypt(message, public_key)
+    >>> decrypted_message = decrypt(ciphertext, private_key)
+    >>> decrypted_message == message
+    True
+    """
+
+    plaintext = private_key.decrypt(
+        ciphertext,
+        padding.OAEP(
+            mgf=padding.MGF1(algorithm=hashes.SHA256()),
+            algorithm=hashes.SHA256(),
+            label=None,
+        ),
+    )
+    return plaintext.decode()
+
+
+if __name__ == "__main__":
+    testmod(name="generate_key_pair", verbose=True)
+    testmod(name="encrypt", verbose=True)
+    testmod(name="decrypt", verbose=True)

From d4b57f3b5621042e50c96c73d554faa7ba612808 Mon Sep 17 00:00:00 2001
From: Pavan Sriram Kannuri <86733057+SportingDot1024@users.noreply.github.com>
Date: Tue, 10 Oct 2023 00:05:37 +0530
Subject: [PATCH 2/6] Update rivest_shamir_adleman.py

---
 blockchain/rivest_shamir_adleman.py | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/blockchain/rivest_shamir_adleman.py b/blockchain/rivest_shamir_adleman.py
index c4774cacaa40..77c79f8a5ce1 100644
--- a/blockchain/rivest_shamir_adleman.py
+++ b/blockchain/rivest_shamir_adleman.py
@@ -32,8 +32,9 @@
 from cryptography.hazmat.primitives import hashes
 from cryptography.hazmat.primitives.asymmetric import padding, rsa
 
+from typing import Tuple, Union
 
-def generate_key_pair():
+def generate_key_pair() -> Tuple[rsa.RSAPrivateKey, rsa.RSAPublicKey]:
     """
     Generate RSA key pair.
 
@@ -57,19 +58,19 @@ def generate_key_pair():
     return private_key, public_key
 
 
-def encrypt(message, public_key):
+def encrypt(message: str, public_key: rsa.RSAPublicKey) -> bytes:
     """
     Encrypt a message using RSA.
 
     Args:
         message (str): Message to be encrypted.
-        public_key: Public key for encryption.
+        public_key (rsa.RSAPublicKey): Public key for encryption.
 
     Returns:
         bytes: Encrypted ciphertext.
 
     >>> private_key, public_key = generate_key_pair()
-    >>> message = "Hello, this is a message to be encrypted!"
+    >>> message = "Hello, this is a message to be encrypted!" 
     >>> ciphertext = encrypt(message, public_key)
     >>> decrypted_message = decrypt(ciphertext, private_key)
     >>> decrypted_message == message
@@ -87,13 +88,13 @@ def encrypt(message, public_key):
     return ciphertext
 
 
-def decrypt(ciphertext, private_key):
+def decrypt(ciphertext: bytes, private_key: rsa.RSAPrivateKey) -> str:
     """
     Decrypt a ciphertext using RSA.
 
     Args:
         ciphertext (bytes): Encrypted ciphertext.
-        private_key: Private key for decryption.
+        private_key (rsa.RSAPrivateKey): Private key for decryption.
 
     Returns:
         str: Decrypted plaintext.

From d29ad7f69e4c46bc580e12ee69a31c3b87e95fcb Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Mon, 9 Oct 2023 18:36:11 +0000
Subject: [PATCH 3/6] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 blockchain/rivest_shamir_adleman.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/blockchain/rivest_shamir_adleman.py b/blockchain/rivest_shamir_adleman.py
index 77c79f8a5ce1..fc77f528c2cb 100644
--- a/blockchain/rivest_shamir_adleman.py
+++ b/blockchain/rivest_shamir_adleman.py
@@ -34,6 +34,7 @@
 
 from typing import Tuple, Union
 
+
 def generate_key_pair() -> Tuple[rsa.RSAPrivateKey, rsa.RSAPublicKey]:
     """
     Generate RSA key pair.
@@ -70,7 +71,7 @@ def encrypt(message: str, public_key: rsa.RSAPublicKey) -> bytes:
         bytes: Encrypted ciphertext.
 
     >>> private_key, public_key = generate_key_pair()
-    >>> message = "Hello, this is a message to be encrypted!" 
+    >>> message = "Hello, this is a message to be encrypted!"
     >>> ciphertext = encrypt(message, public_key)
     >>> decrypted_message = decrypt(ciphertext, private_key)
     >>> decrypted_message == message

From 49cba92eddef88f1262c6e0875a18c1b064cc4a7 Mon Sep 17 00:00:00 2001
From: Pavan Sriram Kannuri <86733057+SportingDot1024@users.noreply.github.com>
Date: Tue, 10 Oct 2023 00:18:51 +0530
Subject: [PATCH 4/6] Update rivest_shamir_adleman.py

---
 blockchain/rivest_shamir_adleman.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/blockchain/rivest_shamir_adleman.py b/blockchain/rivest_shamir_adleman.py
index fc77f528c2cb..e69b18fa1e1a 100644
--- a/blockchain/rivest_shamir_adleman.py
+++ b/blockchain/rivest_shamir_adleman.py
@@ -32,10 +32,8 @@
 from cryptography.hazmat.primitives import hashes
 from cryptography.hazmat.primitives.asymmetric import padding, rsa
 
-from typing import Tuple, Union
 
-
-def generate_key_pair() -> Tuple[rsa.RSAPrivateKey, rsa.RSAPublicKey]:
+def generate_key_pair() -> tuple[rsa.RSAPrivateKey, rsa.RSAPublicKey]:
     """
     Generate RSA key pair.
 

From ca007895c45a19b4256f7b790bf8cfc7fa1240e8 Mon Sep 17 00:00:00 2001
From: Pavan Sriram Kannuri <86733057+SportingDot1024@users.noreply.github.com>
Date: Tue, 10 Oct 2023 00:33:30 +0530
Subject: [PATCH 5/6] Update requirements.txt

---
 requirements.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/requirements.txt b/requirements.txt
index 25dba6f5a250..d13bd24c1092 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -22,3 +22,4 @@ texttable
 tweepy
 xgboost
 yulewalker
+cryptography

From 39e34de30643f729157d9b1f93974c904824560a Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Mon, 9 Oct 2023 19:04:03 +0000
Subject: [PATCH 6/6] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 requirements.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/requirements.txt b/requirements.txt
index d13bd24c1092..7dea95f120fa 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,5 @@
 beautifulsoup4
+cryptography
 fake_useragent
 imageio
 keras
@@ -22,4 +23,3 @@ texttable
 tweepy
 xgboost
 yulewalker
-cryptography