A comprehensive cryptographic library written in C providing implementations of common cryptographic algorithms including block ciphers, hash functions, and public key cryptography.

• AES (Advanced Encryption Standard) - 128/192/256-bit keys
• DES/3DES (Data Encryption Standard)
• SEED - Korean block cipher standard
• ARIA - Korean block cipher standard (128/192/256-bit)
• Blowfish - Variable key length cipher
• RC4 - Stream cipher

• MD2/MD4/MD5 - Message Digest algorithms
• SHA-1 - Secure Hash Algorithm 1
• SHA-2 - SHA-224, SHA-256, SHA-384, SHA-512, SHA-512/224, SHA-512/256
• HAS-160 - Korean hash standard

• RSA - Key generation, encryption/decryption, digital signatures
• ASN.1 - DER encoding/decoding for key import/export

• ECB (Electronic Codebook)
• CBC (Cipher Block Chaining)
• CFB (Cipher Feedback)
• OFB (Output Feedback)
• CTR (Counter)

• None
• Zero padding
• PKCS#7

RaCrypt supports multiple platforms with optimized implementations:

• Windows (MSVC x86/x64)
• Linux/Unix (GCC x86/x86_64)
• ARM64 (with NEON/crypto extensions)
• MinGW cross-compilation

The library includes platform-specific assembly optimizations:

• x86_64: MASM assembly for AES, SHA-1, SHA-2
• x86: MASM assembly for AES, SHA-1, SHA-2
• GCC/MinGW: C intrinsics fallback
• ARM64: NEON and crypto extensions

• CMake 3.10 or higher
• C compiler (MSVC, GCC, or MinGW)
• For MSVC: Visual Studio with MASM support

# Generate build files
cmake -B build

# Build the library and test executable
cmake --build build

# Or use specific configuration
cmake --build build --config Release

Pre-configured Visual Studio project files are available:

• msvc2022/racrypt.sln - Hand-maintained projects

• racrypt - Static library
• racrypt_test - Test executable with comprehensive test suite

#include <racrypt.h>

// AES encryption example
struct RaAesCtx ctx;
uint8_t key[RA_KEY_LEN_AES_128] = {0}; // 128-bit key
uint8_t input[] = "The quick brown fox jumps over the lazy dog";
// The length is a multiple of RA_BLOCK_LEN_AES(16) longer than the input length
uint8_t encrypted[64];      
uint8_t decrypted[64];

// Initialize AES-128 in CBC mode
RaAesInit(&ctx, key, RA_AES_128, RA_BLOCK_MODE_CBC);

// Encrypt with PKCS7 padding
int encLen = RaAesEncryptFinal(&ctx, input, sizeof(input), encrypted, RA_BLOCK_PADDING_PKCS7);

// Decrypt
int decLen = RaAesDecryptFinal(&ctx, encrypted, encLen, decrypted, RA_BLOCK_PADDING_PKCS7);

The library includes a comprehensive test suite (racrypt_test) that validates:

• Algorithm correctness with known test vectors
• Cross-platform compatibility
• Performance benchmarks (1GB throughput tests)
• RSA key generation and cryptographic operations
• Random data encryption/decryption stress tests

Run tests:

# After building
./build/racrypt_test              # Linux/Unix

The library is optimized for high performance:

• Hardware-accelerated implementations where available
• Assembly optimizations for x86/x64 platforms
• ARM64 NEON/crypto extensions support

• src/cipher/ - Block cipher implementations
• src/digest/ - Hash function implementations
• src/pk/ - Public key cryptography (RSA, ASN.1)
• src/com/ - Common utilities (big numbers, GCD, prime generation)
• src/include/ - Public API headers

All public key operations use the built-in big number library:

• Automatic word size adaptation (32/64-bit)
• Montgomery multiplication for modular exponentiation
• Prime number generation with Miller-Rabin testing

Copyright 2017, Keonwoo Kim. Licensed under the BSD 2-clause license.

When contributing:

1. Maintain cross-platform compatibility
2. Add test vectors for new algorithms
3. Update both C and assembly implementations
4. Verify endianness compatibility