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| -rw-r--r-- | doc/manual/rng.rst | 34 |
1 files changed, 14 insertions, 20 deletions
diff --git a/doc/manual/rng.rst b/doc/manual/rng.rst index ba838ce8e..7d586e743 100644 --- a/doc/manual/rng.rst +++ b/doc/manual/rng.rst @@ -73,26 +73,20 @@ Note well: like most other classes in Botan, it is not safe to share an instance of ``AutoSeeded_RNG`` among multiple threads without serialization. -The current version uses the HMAC_DRBG with SHA-384. The initial seed -is generated either by the system PRNG (if available) or a default set -of entropy sources. These are also used for periodic reseeding of the -RNG state. - -ANSI X9.31 -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - -This generator is deprecated and will be removed in a future release. - -``ANSI_X931_PRNG`` is the standard issue X9.31 Appendix A.2.4 PRNG, -though using AES-256 instead of 3DES as the block cipher. This PRNG -implementation has been checked against official X9.31 test vectors. - -Internally, the PRNG holds a pointer to another RNG object. This -internal PRNG generates the key and seed used by the X9.31 algorithm, -as well as the date/time vectors. Each time an X9.31 PRNG object -receives entropy, it passes it along to the PRNG it is holding, and -then pulls out some random bits to generate a new key and seed. This -PRNG considers itself seeded as soon as the internal PRNG is seeded. +The current version uses the HMAC_DRBG with SHA-384 or SHA-256. The +initial seed is generated either by the system PRNG (if available) or +a default set of entropy sources. These are also used for periodic +reseeding of the RNG state. + +TPM_RNG +^^^^^^^^^^^^^^^^^ + +This RNG type allows using the RNG exported from a TPM chip. + +PKCS11_RNG +^^^^^^^^^^^^^^^^^ + +This RNG type allows using the RNG exported from a hardware token accessed via PKCS11. Entropy Sources --------------------------------- |