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29
.clinerules/workspace_rules.md
Normal file
29
.clinerules/workspace_rules.md
Normal file
@@ -0,0 +1,29 @@
|
||||
When building, use build.sh, not make.
|
||||
|
||||
Use it as follows: build.sh -m "useful comment on changes being made"
|
||||
|
||||
When making TUI menus, try to use the first leter of the command and the key to press to execute that command. For example, if the command is "Open file" try to use a keypress of "o" upper or lower case to signal to open the file. Use this instead of number keyed menus when possible. In the command, the letter should be underlined that signifies the command.
|
||||
|
||||
## Buffer Size Guidelines
|
||||
|
||||
### Path Handling
|
||||
- Always use buffers of size 1024 or PATH_MAX (4096) for file paths
|
||||
- When concatenating paths with snprintf, ensure buffer is at least 2x the expected maximum input
|
||||
- Use safer path construction patterns that check lengths before concatenation
|
||||
|
||||
### String Formatting Safety
|
||||
- Before using snprintf with dynamic strings, validate that buffer size >= sum of all input string lengths + format characters + 1
|
||||
- Use strnlen() to check actual string lengths before formatting
|
||||
- Consider using asprintf() for dynamic allocation when exact size is unknown
|
||||
- Add length validation before snprintf calls
|
||||
|
||||
### Compiler Warning Prevention
|
||||
- Always size string buffers generously (minimum 1024 for paths, 512 for general strings)
|
||||
- Use buffer size calculations: `size >= strlen(str1) + strlen(str2) + format_overhead + 1`
|
||||
- Add runtime length checks before snprintf operations
|
||||
- Consider using safer alternatives like strlcpy/strlcat if available
|
||||
|
||||
### Code Patterns to Avoid
|
||||
- Fixed-size buffers (512 bytes) for path operations where inputs could be 255+ bytes each
|
||||
- Concatenating unchecked strings with snprintf
|
||||
- Assuming maximum path component sizes without validation
|
||||
2
.gitignore
vendored
2
.gitignore
vendored
@@ -1,5 +1,7 @@
|
||||
otp
|
||||
pads/
|
||||
Gemini.md
|
||||
TropicOfCancer-HenryMiller.txt
|
||||
|
||||
# Auto-generated version files
|
||||
src/version.h
|
||||
|
||||
194
README.md
194
README.md
@@ -1,24 +1,59 @@
|
||||
r# OTP Cipher - One Time Pad Implementation
|
||||
# OTP Cipher - One Time Pad Implementation
|
||||
|
||||
|
||||
## Introduction
|
||||
|
||||
A secure one-time pad (OTP) cipher implementation in C.
|
||||
|
||||
## Why One-Time Pads
|
||||
|
||||
Nostr and much of the web runs on public key cryptography. Public key cryptography is great, but it is vulnerable. Cryptographers know this, and they know what it takes to attack it, so what they do is just make the keys large enough such that the system is resistant to attack given computers as they are today.
|
||||
|
||||
There is one type of cryptography, however, that is invulnerable to any type of attack in our universe, and that is known as a one-time pad.
|
||||
|
||||
One-time pads rely directly on the laws of physics and what it means for a number to be truly random.
|
||||
|
||||
If you take your secret message and mix it with truly random numbers, and don't use those random numbers again, then that message is unbreakable by any computer, no matter how powerful, quantum or not, forever.
|
||||
|
||||
In fact, one-time pads are so powerful that if you have data encrypted by a one-time pad located in a distant galaxy, and that data is not kept anywhere else, then by destroying the pad used for encryption in your galaxy, the data is wiped from the universe and can never be recovered.
|
||||
|
||||
## Advantages and Limitations
|
||||
|
||||
### Limitations
|
||||
|
||||
1. The pad must be shared between the parties wanting to use it.
|
||||
2. The pad must be as long or longer than what you want to encrypt, and it can't be used a second time.
|
||||
|
||||
### Modern Advantages
|
||||
|
||||
While in the past, pad length might have been a problem, readily available USB drives in the terabytes make size less of a problem for many uses.
|
||||
|
||||
We are also becoming very accustomed to YubiKey authenticators in the USB ports of our computers. A small USB drive in our devices can now easily contain a key of greater length than all the text messages we would expect to send over a lifetime.
|
||||
|
||||
### Multi-Device Coordination
|
||||
|
||||
One of the problems to address is the fact that to use an OTP across several devices means that they have to coordinate to know when they are encrypting new plaintext and where to start in the key. Reusing the same section of the pad, while not necessarily fatal, degrades the encryption from its status as "Information Theoretically Secure".
|
||||
|
||||
To address this problem, we can use Nostr to share among devices the place in the pad that was last left off.
|
||||
|
||||
### Additional Benefits
|
||||
|
||||
One-time pads can be trivially encrypted and decrypted using pencil and paper, making them accessible even without electronic devices.
|
||||
|
||||
|
||||
|
||||
A secure one-time pad (OTP) cipher implementation in C with automatic versioning system.
|
||||
|
||||
## Features
|
||||
|
||||
- **Perfect Security**: Implements true one-time pad encryption with information-theoretic security
|
||||
- **Text & File Encryption**: Supports both inline text and file encryption
|
||||
- **Multiple Output Formats**: Binary (.otp) and ASCII armored (.otp.asc) file formats
|
||||
- **Keyboard Entropy**: Optional keyboard entropy collection for enhanced randomness
|
||||
- **Short Command Flags**: Convenient single-character flags for all operations
|
||||
- **Automatic Versioning**: Built-in semantic versioning with automatic patch increment
|
||||
- **Multiple Build Options**: Standard and static linking builds
|
||||
- **Cross-Platform**: Works on Linux and other UNIX-like systems
|
||||
|
||||
## Version Information
|
||||
|
||||
This project uses an automatic versioning system that:
|
||||
- Automatically increments the patch version on each build
|
||||
- Embeds build timestamp, git commit hash, and branch information
|
||||
- Creates git tags for version tracking
|
||||
- Generates version header files with detailed build metadata
|
||||
|
||||
Current version can be viewed with: `./otp --help` or by running the interactive mode.
|
||||
|
||||
## Building
|
||||
|
||||
@@ -28,7 +63,7 @@ Current version can be viewed with: `./otp --help` or by running the interactive
|
||||
- Git (for version tracking)
|
||||
- Make
|
||||
|
||||
**Note: OpenSSL is no longer required! This implementation is now completely self-contained.**
|
||||
|
||||
|
||||
### Build Commands
|
||||
|
||||
@@ -148,45 +183,122 @@ otp/
|
||||
└── VERSION # Plain text version (generated)
|
||||
```
|
||||
|
||||
## Examples
|
||||
## File Formats
|
||||
|
||||
### .otp File Format (Binary)
|
||||
|
||||
Binary encrypted files use a structured header format:
|
||||
|
||||
```
|
||||
Offset | Size | Field | Description
|
||||
-------|------|-------------------|----------------------------------
|
||||
0 | 4 | Magic | "OTP\0" - File type identifier
|
||||
4 | 2 | Version | Format version (currently 1)
|
||||
6 | 32 | Pad Checksum | Binary pad checksum (32 bytes)
|
||||
38 | 8 | Pad Offset | Offset in pad file (uint64_t)
|
||||
46 | 4 | File Mode | Original file permissions (uint32_t)
|
||||
50 | 8 | File Size | Original file size (uint64_t)
|
||||
58 | var | Encrypted Data | XOR-encrypted file contents
|
||||
```
|
||||
|
||||
### .otp.asc File Format (ASCII Armored)
|
||||
|
||||
ASCII armored files use the same format as encrypted text messages:
|
||||
|
||||
```
|
||||
-----BEGIN OTP MESSAGE-----
|
||||
Version: v0.2.15
|
||||
Pad-ChkSum: <64-character-hex-checksum>
|
||||
Pad-Offset: <decimal-offset-value>
|
||||
|
||||
<base64-encoded-encrypted-data>
|
||||
-----END OTP MESSAGE-----
|
||||
```
|
||||
|
||||
**Note:** ASCII armored files do not preserve original file permissions metadata.
|
||||
|
||||
## Usage Examples
|
||||
|
||||
### Short Command Flags
|
||||
```bash
|
||||
# Quick commands using short flags
|
||||
./otp -g 1GB # Generate 1GB pad
|
||||
./otp -l # List available pads
|
||||
./otp -e 1a2b "Hello world" # Encrypt text inline
|
||||
./otp -d "-----BEGIN OTP..." # Decrypt message inline
|
||||
|
||||
# File operations
|
||||
./otp -f document.pdf 1a2b # Encrypt file (binary)
|
||||
./otp -f document.pdf 1a2b -a # Encrypt file (ASCII)
|
||||
./otp -f document.pdf 1a2b -o secret.otp # Custom output name
|
||||
```
|
||||
|
||||
### Text Encryption
|
||||
```bash
|
||||
# Interactive text encryption
|
||||
./otp encrypt 1a2b3c
|
||||
Enter text to encrypt: This is my secret message
|
||||
# Outputs ASCII armored message
|
||||
|
||||
# Inline text encryption
|
||||
./otp -e 1a2b3c "This is my secret message"
|
||||
# Outputs ASCII armored message immediately
|
||||
```
|
||||
|
||||
### File Encryption
|
||||
```bash
|
||||
# Binary format (preserves metadata)
|
||||
./otp -f sensitive.doc a1b2c3
|
||||
|
||||
# ASCII armored format (text-safe)
|
||||
./otp -f sensitive.doc a1b2c3 -a
|
||||
|
||||
# Custom output filename
|
||||
./otp -f sensitive.doc a1b2c3 -o encrypted_document.otp
|
||||
```
|
||||
|
||||
### Decryption
|
||||
```bash
|
||||
# Auto-detect format and pad from message/file
|
||||
./otp -d encrypted.otp.asc
|
||||
./otp -d "-----BEGIN OTP MESSAGE-----..."
|
||||
|
||||
# Interactive mode
|
||||
./otp decrypt
|
||||
# Prompts for encrypted message input
|
||||
```
|
||||
|
||||
### Build and Version Tracking
|
||||
```bash
|
||||
$ ./build.sh build
|
||||
[INFO] Incrementing version...
|
||||
[INFO] Current version: v0.1.4
|
||||
[INFO] New version: v0.1.5
|
||||
[SUCCESS] Created new version tag: v0.1.5
|
||||
[INFO] Current version: v0.2.14
|
||||
[INFO] New version: v0.2.15
|
||||
[SUCCESS] Created new version tag: v0.2.15
|
||||
[SUCCESS] Build completed successfully
|
||||
|
||||
$ ./otp
|
||||
=== OTP Cipher v0.1.5 ===
|
||||
|
||||
=== Main Menu ===
|
||||
1. Generate new pad
|
||||
2. Encrypt message
|
||||
3. Decrypt message
|
||||
4. List available pads
|
||||
5. Show pad information
|
||||
6. Exit
|
||||
|
||||
$ ./otp --help
|
||||
OTP Cipher - One Time Pad Implementation v0.1.5
|
||||
Built on 2025-08-10 at 08:17:47 from commit 9edfa5f on branch master
|
||||
Usage:
|
||||
./otp - Interactive mode
|
||||
...
|
||||
OTP Cipher - One Time Pad Implementation v0.2.15
|
||||
Built on 2025-08-10 at 14:07:58 from commit ae0afcf on branch master
|
||||
```
|
||||
|
||||
### Version History
|
||||
### Advanced Features
|
||||
```bash
|
||||
$ git tag --list
|
||||
v0.1.0
|
||||
v0.1.1
|
||||
v0.1.2
|
||||
v0.1.3
|
||||
v0.1.4
|
||||
v0.1.5
|
||||
# Generate pad with keyboard entropy
|
||||
./otp generate 5GB
|
||||
# Follow prompts for keyboard entropy collection
|
||||
|
||||
# Check pad usage
|
||||
./otp -l
|
||||
Available pads:
|
||||
No. ChkSum (first 16 chars) Size Used % Used
|
||||
--- ------------------- ---------- ---------- ------
|
||||
1 97d9d82b5414a943 1.00GB 156B 0.0%
|
||||
2 0c8e19fde996e683 1000B 248B 24.8%
|
||||
|
||||
# Show detailed pad information
|
||||
./otp
|
||||
# Select "S" for show pad info, enter checksum or prefix
|
||||
```
|
||||
|
||||
## License
|
||||
@@ -199,5 +311,3 @@ When contributing:
|
||||
1. The version will automatically increment on builds
|
||||
2. For major features, consider manually creating minor version tags
|
||||
3. Generated version files (`src/version.*`, `VERSION`) should not be committed
|
||||
# Test change
|
||||
# Testing -m flag
|
||||
|
||||
19
TODO.md
Normal file
19
TODO.md
Normal file
@@ -0,0 +1,19 @@
|
||||
# TODO
|
||||
|
||||
|
||||
## Change technique for adding keyboard entropy.
|
||||
|
||||
|
||||
## There is the problem of the location of the pad revealing metadata about how many messages have been sent in the past, or at least the size of the messsages.
|
||||
|
||||
One solution could be to start the pad at a random location, and then wrap around, so an attacker could never tell the size of the past text sent. This helps. But then you have to store the start location, which you could do within the header of the pad along with the pad?
|
||||
|
||||
Or, better yet, assume the offset is a very large size, and use the pad itself to encrypt the offset.
|
||||
|
||||
## Take a look at how the file header is being handled.
|
||||
|
||||
|
||||
## Setup for multiple USB drives
|
||||
|
||||
|
||||
|
||||
13
build.sh
13
build.sh
@@ -98,6 +98,19 @@ increment_version() {
|
||||
# Create new git tag
|
||||
if git tag "$NEW_VERSION" 2>/dev/null; then
|
||||
print_success "Created new version tag: $NEW_VERSION"
|
||||
|
||||
# Push changes and tags to remote repository
|
||||
if git push ssh://ubuntu@laantungir.net:/home/ubuntu/git_repos/otp 2>/dev/null; then
|
||||
print_success "Pushed changes to remote repository"
|
||||
else
|
||||
print_warning "Failed to push changes to remote repository"
|
||||
fi
|
||||
|
||||
if git push ssh://ubuntu@laantungir.net:/home/ubuntu/git_repos/otp --tags 2>/dev/null; then
|
||||
print_success "Pushed tags to remote repository"
|
||||
else
|
||||
print_warning "Failed to push tags to remote repository"
|
||||
fi
|
||||
else
|
||||
print_warning "Tag $NEW_VERSION already exists - using existing version"
|
||||
NEW_VERSION=$LATEST_TAG
|
||||
|
||||
1
debug.c
Normal file
1
debug.c
Normal file
@@ -0,0 +1 @@
|
||||
int main() { printf("Testing direct filename: %d\n", strncmp("97d9d82b5414a9439102f3811fb90ab1d6368a00d33229a18b306476f9d04f82.pad", "97", 2)); return 0; }
|
||||
1
files/o2.txt
Normal file
1
files/o2.txt
Normal file
@@ -0,0 +1 @@
|
||||
Hello, this is a test file for encryption!
|
||||
BIN
files/out2.otp
Normal file
BIN
files/out2.otp
Normal file
Binary file not shown.
BIN
files/output.otp
Normal file
BIN
files/output.otp
Normal file
Binary file not shown.
1
files/test_decrypt.txt
Normal file
1
files/test_decrypt.txt
Normal file
@@ -0,0 +1 @@
|
||||
Test file content for decryption
|
||||
BIN
files/test_decrypt.txt.otp
Normal file
BIN
files/test_decrypt.txt.otp
Normal file
Binary file not shown.
1
files/test_file.txt
Normal file
1
files/test_file.txt
Normal file
@@ -0,0 +1 @@
|
||||
Hello, this is a test file for encryption!
|
||||
7
files/test_file.txt.otp.asc
Normal file
7
files/test_file.txt.otp.asc
Normal file
@@ -0,0 +1,7 @@
|
||||
-----BEGIN OTP MESSAGE-----
|
||||
Version: v0.2.29
|
||||
Pad-ChkSum: d0d4a489354348b08d8c7b324814d8c50010042e9da47f2c973f32a16a09101b
|
||||
Pad-Offset: 57
|
||||
|
||||
05S8GfS0tFfczNMUz0xrieFGoPSREM4uo5QhFGoBCcOzjfTXTDMt3hRtAQ==
|
||||
-----END OTP MESSAGE-----
|
||||
BIN
files/test_files_dir.txt.otp
Normal file
BIN
files/test_files_dir.txt.otp
Normal file
Binary file not shown.
1
files/test_input.txt
Normal file
1
files/test_input.txt
Normal file
@@ -0,0 +1 @@
|
||||
This is a test file for encryption.
|
||||
8898
files/toc.txt
Executable file
8898
files/toc.txt
Executable file
File diff suppressed because it is too large
Load Diff
BIN
files/toc.txt.otp
Normal file
BIN
files/toc.txt.otp
Normal file
Binary file not shown.
8
otp.code-workspace
Normal file
8
otp.code-workspace
Normal file
@@ -0,0 +1,8 @@
|
||||
{
|
||||
"folders": [
|
||||
{
|
||||
"path": "."
|
||||
}
|
||||
],
|
||||
"settings": {}
|
||||
}
|
||||
Reference in New Issue
Block a user