Python Binding¶
New in version 1.11.14.
The Python binding is based on the ffi module of botan and the ctypes module of the Python standard library.
Versioning¶
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botan.version_major()¶ Returns the major number of the library version (currently, 1)
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botan.version_minor()¶ Returns the minor number of the library version (currently, 11)
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botan.version_patch()¶ Returns the patch number of the library version (currently, 14)
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botan.version_string()¶ Returns a free form version string for the library
Random Number Generators¶
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class
botan.rng(rng_type = 'system')¶ - Type ‘user’ also allowed (userspace HKDF RNG seeded from system rng). The system RNG is very cheap to create, as just a single file handle or CSP handle is kept open, from first use until shutdown, no matter how many ‘system’ rng instances are created. Thus it is easy to use the RNG in a one-off way, with botan.rng().get(32).
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get(length)¶ Return some bits
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reseed(bits = 256)¶ Meaningless on system RNG, on userspace RNG causes a reseed/rekey
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Hash Functions¶
Message Authentication Codes¶
Ciphers¶
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class
botan.cipher(object, algo, encrypt = True)¶ The algorithm is spcified as a string (eg ‘AES-128/GCM’, ‘Serpent/OCB(12)’, ‘Threefish-512/EAX’).
Set the second param to False for decryption
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tag_length()¶ Returns the tag length (0 for unauthenticated modes)
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default_nonce_length()¶ Returns default nonce length
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update_granularity()¶ Returns update block size. Call to update() must provide input of exactly this many bytes
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is_authenticated()¶ Returns True if this is an AEAD mode
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valid_nonce_length(nonce_len)¶ Returns True if nonce_len is a valid nonce len for this mode
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clear()¶ Resets all state
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set_key(key)¶ Set the key
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start(nonce)¶ Start processing a message using nonce
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update(txt)¶ Consumes input text and returns output. Input text must be of update_granularity() length. Alternately, always call finish with the entire message, avoiding calls to update entirely
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finish(txt = None)¶ Finish processing (with an optional final input). May throw if message authentication checks fail, in which case all plaintext previously processed must be discarded. You may call finish() with the entire message
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Bcrypt¶
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botan.bcrypt(passwd, rng, work_factor = 10)¶ Provided the password and an RNG object, returns a bcrypt string
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botan.check_bcrypt(passwd, bcrypt)¶ Check a bcrypt hash against the provided password, returning True iff the password matches.
PBKDF¶
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botan.pbkdf(algo, password, out_len, iterations = 100000, salt = rng().get(12))¶ Runs a PBKDF2 algo specified as a string (eg ‘PBKDF2(SHA-256)’, ‘PBKDF2(CMAC(Blowfish))’). Runs with n iterations with meaning depending on the algorithm. The salt can be provided or otherwise is randomly chosen. In any case it is returned from the call.
Returns out_len bytes of output (or potentially less depending on the algorithm and the size of the request).
Returns tuple of salt, iterations, and psk
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botan.pbkdf_timed(algo, password, out_len, ms_to_run = 300, salt = rng().get(12))¶ Runs for as many iterations as needed to consumed ms_to_run milliseconds on whatever we’re running on. Returns tuple of salt, iterations, and psk
Public Key¶
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class
botan.private_key(algo, param, rng)¶ Constructor creates a new private key. The parameter type/value depends on the algorithm. For “rsa” is is the size of the key in bits. For “ecdsa” and “ecdh” it is a group name (for instance “secp256r1”). For “ecdh” there is also a special case for group “curve25519” (which is actually a completely distinct key type with a non-standard encoding).
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get_public_key()¶
Return a public_key object
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export()¶
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