Botan: Crypto and TLS for Modern C++

Botan (Japanese for peony flower) is a C++ cryptography library released under the permissive Simplified BSD license.

Botan’s goal is to be the best option for cryptography in C++ by offering the tools necessary to implement a range of practical systems, such as TLS protocol, X.509 certificates, modern AEAD ciphers, PKCS#11 and TPM hardware support, password hashing, and post quantum crypto schemes. A Python binding is included, and several other language bindings are available. The library is accompanied by a featureful command line interface.

See the documentation for more information about included features.

Development is coordinated on GitHub and contributions are welcome. If you need help, please open an issue on GitHub.

If you think you have found a security issue, see the security page for contact information.

CI status nightly CI status Coverage report OSS-Fuzz status Packaging status OSSF Scorecard CII Best Practices statement

Releases

The latest release from the Botan3 release series is 3.6.1 (sig), released on 2024-10-26.

The latest release from the Botan2 release series is 2.19.5 (sig), released on 2024-07-08. Be aware that Botan2 is currently scheduled to reach end of life at the end of 2024.

All releases are signed with a PGP key. See the release notes for what is new. Botan is also available through most distributions such as Fedora, Debian, Arch and Homebrew.

Find Enclosed

Transport Layer Security (TLS) Protocol

  • TLS v1.2/v1.3, and DTLS v1.2

  • Supported extensions include session tickets, SNI, ALPN, OCSP stapling, encrypt-then-mac CBC, and extended master secret.

  • Supports authentication using certificates or preshared keys (PSK)

  • Supports record encryption with modern AEAD modes as well as legacy CBC ciphersuites.

  • TLS 1.3 supports hybrid post-quantum key exchange with ML-KEM/Kyber and FrodoKEM

Public Key Infrastructure

  • X.509v3 certificates and CRL creation and handling

  • PKIX certificate path validation, including name constraints.

  • OCSP request creation and response handling

  • PKCS #10 certificate request generation and processing

  • Access to Windows, macOS and Unix system certificate stores

  • SQL database backed certificate store

Public Key Cryptography

  • RSA signatures and encryption

  • DH, ECDH, X25519 and X448 key agreement

  • Signature schemes ECDSA, DSA, Ed25519, Ed448, ECGDSA, ECKCDSA, SM2, GOST 34.10

  • Post-quantum signature schemes ML-DSA (Dilithium), SLH-DSA (SPHINCS+), HSS/LMS, XMSS

  • Post-quantum key encapsulation schemes ML-KEM (Kyber), FrodoKEM, McEliece

  • ElGamal encryption

  • Padding schemes OAEP, PSS, PKCS #1 v1.5, X9.31

Ciphers, hashes, MACs, and checksums

  • Authenticated cipher modes EAX, OCB, GCM, SIV, CCM, (X)ChaCha20Poly1305

  • Cipher modes CTR, CBC, XTS, CFB, OFB

  • Block ciphers AES, ARIA, Blowfish, Camellia, CAST-128, DES/3DES, IDEA, Lion, SEED, Serpent, SHACAL2, SM4, Threefish-512, Twofish

  • Stream ciphers (X)ChaCha20, (X)Salsa20, SHAKE-128, RC4

  • Hash functions SHA-1, SHA-2, SHA-3, MD5, RIPEMD-160, BLAKE2b/BLAKE2s, Skein-512, SM3, Streebog, Whirlpool

  • eXtendable Output Functions (XOFs) SHAKE-128, SHAKE-256

  • Password hashing schemes PBKDF2, Argon2, Scrypt, bcrypt

  • Authentication codes HMAC, CMAC, Poly1305, KMAC, SipHash, GMAC, X9.19 DES-MAC

  • Non-cryptographic checksums Adler32, CRC24, CRC32

Other Useful Things

  • Full C++ PKCS #11 API wrapper

  • Interfaces for TPM v1.2 and v2.0 device access

  • Simple compression API wrapping zlib, bzip2, and lzma libraries

  • RNG wrappers for system RNG and hardware RNGs

  • HMAC_DRBG and entropy collection system for userspace RNGs

  • SRP-6a password authenticated key exchange

  • Key derivation functions including HKDF, KDF2, SP 800-108, SP 800-56A, SP 800-56C

  • HOTP and TOTP algorithms

  • Format preserving encryption scheme FE1

  • Threshold secret sharing

  • Roughtime client

  • Zfec compatible forward error correction encoding

  • Encoding schemes including hex, base32, base64 and base58

  • NIST key wrapping

  • Boost.Asio compatible TLS client stream