teavault - a header-only compile-time string encryption functionality using the tiny encryption algorithm (tea).

features

• compile-time encryption to resist static string extraction
• automatic or manual decryption at runtime
• per-use key derivation from call-site seeds and literal bytes
• scoped decrypted buffers that wipe themselves on destruction
• order scrambling that covers every encrypted block exactly once
• optional custom seeds

how it works

the encryption uses the tea algorithm with a 128-bit key. by default, tea_str and tea_str_m derive per-use seeds from the expansion site (__LINE__, __COUNTER__, __FILE__), build timestamp, TEA_STR_BUILD_SEED, and the literal bytes. you can also provide custom seed values to generate the key.

TEA_STR_BUILD_SEED defaults to 0. define it from your build system if you want a build-specific seed:

g++ -DTEA_STR_BUILD_SEED=0x9a7f31c2u ...

this is string obfuscation, not a cryptographic secret store: runtime decryption requires enough key material to exist in the binary.

example usage

#include <iostream>
#include "tea_str.hpp"

int main() {
    // automatic decryption with default key generation
    auto decrypted_str = tea_str("automatically decrypted string!");

    // manual decryption object
    auto encrypted_obj = tea_str_m("manually decrypted string");

    // custom seed key generation
    auto custom_seed_str = tea_str("custom seed example", 1234, 5678, 91011, 1213);

    std::cout << "automatic decryption: " << decrypted_str << "\n";
    std::cout << "manual decryption: " << encrypted_obj.decrypt() << "\n";
    std::cout << "custom seed decryption: " << custom_seed_str << "\n";

    return 0;
}

macro references

• tea_str(str, ...): creates encrypted string with automatic decryption

  • str: string to encrypt
  • ...: optional custom seed values
  • returns tea::decrypted_string<N>, an owning scoped buffer; use .c_str() when a raw pointer is required

• tea_str_m(str, ...): creates encrypted string object for manual decryption

  • str: string to encrypt
  • ...: optional custom seed values

key generation

the key_generator::generate() method creates a 128-bit key from:

• default macro use: expansion-site seeds, build timestamp, TEA_STR_BUILD_SEED, and the literal bytes
• custom: user-provided seed values

license

this project is licensed under the MIT license. see the LICENSE file for details.