Added necessary comments to 4-initialization program

programs/4-initialization/insecure/src/lib.rs

@@ -9,30 +9,34 @@ pub mod initialization_insecure {
     use super::*;
 
     pub fn initialize(ctx: Context<Initialize>) -> ProgramResult {
+        // Deserialize the user account data
         let mut user = User::try_from_slice(&ctx.accounts.user.data.borrow()).unwrap();
 
+        // Set the authority of the user
         user.authority = ctx.accounts.authority.key();
 
+        // Re-serialize the user data back into the account
         let mut storage = ctx.accounts.user.try_borrow_mut_data()?;
         user.serialize(storage.deref_mut()).unwrap();
         Ok(())
     }
 }
 
 /*
-- reinitialize
-- create and dont initialize
-- passing previously initialzed accounts from other programs
-  (e.g. token program => need to check delegate and authority)
+- reinitialize: The program can reinitialize the account, which may be a security risk.
+- create and don't initialize: The account could be created without being initialized.
+- passing previously initialized accounts from other programs (e.g., token program => need to check delegate and authority).
 */
 
 #[derive(Accounts)]
 pub struct Initialize<'info> {
+    // Unchecked user account, vulnerable to attacks like re-initialization
     user: AccountInfo<'info>,
     authority: Signer<'info>,
 }
 
 #[derive(BorshSerialize, BorshDeserialize)]
 pub struct User {
+    // Authority key of the user account
     authority: Pubkey,
 }

programs/4-initialization/recommended/src/lib.rs

@@ -7,22 +7,28 @@ pub mod reinitialization_4 {
     use super::*;
 
     pub fn init(_ctx: Context<Init>) -> ProgramResult {
+        // Placeholder message for program initialization
         msg!("GM");
         Ok(())
     }
 }
 
-
 #[derive(Accounts)]
 pub struct Init<'info> {
+    // Initializes a new user account, allocating 8 bytes for the discriminator and 32 bytes for the Pubkey
     #[account(init, payer = authority, space = 8+32)]
     user: Account<'info, User>,
+
+    // Authority is the payer of the transaction and must sign
     #[account(mut)]
     authority: Signer<'info>,
+
+    // System program for allocating the account
     system_program: Program<'info, System>,
 }
 
 #[account]
 pub struct User {
+    // Authority key of the user account
     authority: Pubkey,
 }

programs/4-initialization/secure/src/lib.rs

@@ -9,30 +9,39 @@ pub mod reinitialization_secure_recommended {
     use super::*;
 
     pub fn initialize(ctx: Context<Initialize>) -> ProgramResult {
+        // Deserialize the user account data
         let mut user = User::try_from_slice(&ctx.accounts.user.data.borrow()).unwrap();
+
+        // Check if the account has been initialized by verifying the discriminator
         if !user.discriminator {
             return Err(ProgramError::InvalidAccountData);
         }
 
+        // Set the authority and mark the account as initialized by setting discriminator to true
         user.authority = ctx.accounts.authority.key();
         user.discriminator = true;
 
+        // Re-serialize the user data back into the account
         let mut storage = ctx.accounts.user.try_borrow_mut_data()?;
         user.serialize(storage.deref_mut()).unwrap();
 
+        // Log a message indicating successful initialization
         msg!("GM");
         Ok(())
     }
 }
 
 #[derive(Accounts)]
 pub struct Initialize<'info> {
+    // User account with manual data checks for security
     user: AccountInfo<'info>,
     authority: Signer<'info>,
 }
 
 #[derive(BorshSerialize, BorshDeserialize)]
 pub struct User {
+    // Discriminator to ensure account has been initialized correctly
     discriminator: bool,
+    // Authority key of the user account
     authority: Pubkey,
 }