Botan: Crypto and TLS for C++11

Botan (Japanese for peony) is a cryptography library written in C++11 and 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/DTLS, X.509 certificates, modern AEAD ciphers, PKCS#11 and TPM hardware support, password hashing, and post quantum crypto schemes. Botan also has a C89 API specifically designed to be easy to call from other languages. A Python binding using ctypes is included, and several other language bindings are available. Find the full feature list below.

Development is coordinated on GitHub and contributions are welcome (read doc/contributing.rst for more info).

If you need help with a problem, please open an issue on GitHub or email the botan-devel mailing list.

New releases are announced on the botan-announce mailing list.

If you think you have found a security bug in Botan please contact Jack Lloyd by emailing His PGP public key with fingerprint 4E60C73551AF2188DF0A5A6278E9804357123B60 can can be found in doc/pgpkey.txt in the distribution,, and some public PGP key servers.

For all the details on building the library, read the users manual, but basically:

$ ./
$ make
$ ./botan-test
$ make install

Botan can also be built into a single-file amalgamation for easy inclusion into external build systems, see the manual for details.

Travis CI status AppVeyor CI status Kullo CI status Code coverage report Coverity results Sonarcloud analysis CII Best Practices statement

Release Downloads

See the release notes and security advisories

All releases are signed with a PGP key:

pub   2048R/EFBADFBC 2004-10-30
      Key fingerprint = 621D AF64 11E1 851C 4CF9  A2E1 6211 EBF1 EFBA DFBC
uid                  Botan Distribution Key

Some distributions such as Arch, Fedora and Debian include packages for Botan. However these are often out of date; using the latest source release is recommended.

Current Stable Release

Version 2 requires a C++11 compiler; GCC 4.8 and later, Clang 3.8 and later, and MSVC 2015/2017 are regularly tested. New releases of Botan 2 are made on a quarterly basis.

The latest 2.x release is 2.7.0 (sig) released on 2018-07-02

Old Release

The 1.10 branch is the last version of the library written in C++98. It is no longer supported except for critical security updates (with all support ending in December 2018), and the developers do not recommend its use anymore.

The latest 1.10 release is 1.10.17 (sig) released on 2017-10-02

Find Enclosed

Transport Layer Security (TLS) Protocol

  • TLS v1.0, v1.1, and v1.2. The broken SSLv3 protocol is no longer supported.
  • DTLS v1.0 and v1.2 are adaptations of TLS to datagram operation.
  • Extensions include session tickets, SNI, ALPN, OCSP staple requests (client side only right now), encrypt-then-mac CBC, and extended master secret.
  • Supports authentication using preshared keys (PSK) or passwords (SRP)
  • Supports record encryption with ChaCha20Poly1305, AES/OCB, AES/GCM, AES/CCM, Camellia/GCM as well as legacy CBC ciphersuites.
  • Key exchange using CECPQ1, ECDH, FFDHE, or RSA

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
  • SQL database backed certificate store

Public Key Cryptography

  • RSA signatures and encryption
  • DH and ECDH key agreement
  • Signature schemes ECDSA, DSA, Ed25519, ECGDSA, ECKCDSA, SM2, and GOST 34.10-2001
  • Post-quantum signature scheme XMSS
  • Post-quantum key agreement schemes McEliece and NewHope
  • 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, and ChaCha20Poly1305
  • Cipher modes CTR, CBC, XTS, CFB, and OFB
  • Block ciphers AES, ARIA, Blowfish, Camellia, CAST-128, CAST-256, DES/3DES, GOST 28147, IDEA, KASUMI, Lion, MISTY1, Noekeon, SEED, Serpent, SHACAL2, SM4, Threefish-512, Twofish, XTEA
  • Stream ciphers ChaCha20, Salsa20/XSalsa20, SHAKE-128, and RC4
  • Hash functions SHA-1, SHA-2, SHA-3, RIPEMD-160, Skein-512, BLAKE2b, SM3, Tiger, Whirlpool, GOST 34.11, MD5, MD4
  • Hash function combiners Parallel and Comb4P
  • Authentication codes HMAC, CMAC, Poly1305, SipHash, GMAC, CBC-MAC, X9.19 DES-MAC
  • Non-cryptographic checksums Adler32, CRC24, and CRC32

Other Useful Things

  • Full C++ PKCS #11 API wrapper
  • Interfaces for TPM v1.2 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
  • Password based key derivation functions PBKDF2 and Scrypt
  • Password hashing function bcrypt and passhash9 (custom PBKDF scheme)
  • 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
  • NIST key wrapping