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Diffstat (limited to 'doc/kdf.txt')
| -rw-r--r-- | doc/kdf.txt | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/doc/kdf.txt b/doc/kdf.txt index feb458108..da916dcb3 100644 --- a/doc/kdf.txt +++ b/doc/kdf.txt @@ -4,4 +4,34 @@ Key Derivation Functions ======================================== -Todo +Key derivation functions are used to turn some amount of shared secret +material into uniform random keys suitable for use with symmetric +algorithms. An example of an input which is useful for a KDF is a +shared secret created using Diffie-Hellman key agreement. + +.. cpp:class:: KDF + + .. cpp:function:: SecureVector<byte> derive_key( \ + size_t key_len, const MemoryRegion<byte>& secret, \ + const std::string& salt = "") const + + .. cpp:function:: SecureVector<byte> derive_key( \ + size_t key_len, const MemoryRegion<byte>& secret, \ + const MemoryRegion<byte>& salt) const + + .. cpp:function:: SecureVector<byte> derive_key( \ + size_t key_len, const MemoryRegion<byte>& secret, \ + const byte* salt, size_t salt_len) const + + .. cpp:function:: SecureVector<byte> derive_key( \ + size_t key_len, const byte* secret, size_t secret_len, \ + const std::string& salt) const + + All variations on the same theme. Deterministically creates a + uniform random value from *secret* and *salt*. Typically *salt* is + a lable or identifier, such as a session id. + +You can create a :cpp:class:`KDF` using + +.. cpp:function:: KDF* get_kdf(const std::string& algo_spec) + |