Botan

Botan (Japanese for peony flower) is a cryptography library released under thepermissiveSimplified BSD license.

Botan’sgoalis to be the best option for production cryptography by offering the toolsnecessary to implement a range of practical systems, such as TLSv1.3, X.509 PKI,modern AEAD ciphers, support for PKCS#11 and TPM hardware, memory-hard passwordhashing, and post quantum cryptography. All of this is covered by an extensivetest suite, including an automated system for detecting side channels. Themodular build system allows enabling or disabling features in a fine-grained way,and amalgamation builds are also supported.

It comes out of the box with C++, C, and Python APIs, and several otherlanguagebindings are available.The library is accompanied by a featurefulcommand line interface. Consult thedocumentation for more information.

Development is coordinated onGitHub andcontributions are welcome. If you need help, please open an issue onGitHub. If you think you have found asecurity issue, see thesecurity pagefor contact information.

CI statusnightly CI statusCoverage reportOSS-Fuzz statusPackaging statusOSSF ScorecardCII Best Practices statement

Releases

All releases are signed with aPGP key.See therelease notes forwhat’s new.

Botan is also available through mostdistributions such as Fedora,Debian, Arch and Homebrew.

Botan3

New minor releases of Botan3 are made quarterly, normally on the first Tuesday ofFebruary, May, August, and November.

The latest release in the Botan3 series is3.10.0(sig),released on 2025-11-06.

Botan2

Botan2 has, as of 2025-01-01, reached end of life. No further releases are expected.

The latest release in the Botan2 series is2.19.5(sig),released on 2024-07-08.

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 using ML-KEM or 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

  • Elliptic curve signature schemes ECDSA, Ed25519, Ed448, ECGDSA, ECKCDSA, SM2

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

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

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,SEED, Serpent, SHACAL2, SM4, Threefish-512, Twofish

  • Stream ciphers (X)ChaCha20, (X)Salsa20, RC4

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

  • Password hashing schemes Argon2, Scrypt, bcrypt, and PBKDF2

  • Authentication codes HMAC, CMAC, Poly1305, KMAC, GMAC

Other Useful Things

  • Full C++ PKCS #11 API wrapper

  • Interfaces for TPM v2.0 device access

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

  • RNG wrappers for system RNG, ESDM 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

  • 24-bit OpenPGP CRC