Implementation of the HKDF mode for hash algorithms. More...
#include <HKDF.h>
Inheritance diagram for HKDF< T >:
Public Member Functions | |
| HKDF () | |
| Constructs a new HKDF object for the hash algorithm T. | |
| ~HKDF () | |
| Destroys a HKDF instance and all sensitive data within it. | |
 Public Member Functions inherited from HKDFCommon | |
| virtual | ~HKDFCommon () |
| Destroys this HKDF instance. | |
| void | setKey (const void *key, size_t keyLen, const void *salt=0, size_t saltLen=0) |
| Sets the key and salt for a HKDF session. More... | |
| void | extract (void *out, size_t outLen, const void *info=0, size_t infoLen=0) |
| Extracts data from a HKDF session. More... | |
| void | clear () |
| Clears sensitive information from this HKDF instance. | |
Additional Inherited Members | |
| Protected Member Functions inherited from HKDFCommon | |
| HKDFCommon () | |
| Constructs a new HKDF instance. More... | |
| void | setHashAlgorithm (Hash *hashAlg, uint8_t *buffer) |
| Sets the hash algorithm to use for HKDF operations. More... | |
Detailed Description
template<typename T>
class HKDF< T >
Implementation of the HKDF mode for hash algorithms.
HKDF expands a key to a larger amount of material that can be used for cryptographic operations. It is based around a hash algorithm.
The template parameter T must be a concrete subclass of Hash indicating the specific hash algorithm to use.
The following example expands a 32-byte / 256-bit key into 128 bytes / 1024 bits of key material for use in a cryptographic session:
uint8_t key[32] = {...};
uint8_t output[128];
HKDF<SHA256> hkdf;
hkdf.setKey(key, sizeof(key));
hkdf.extract(output, sizeof(output));
Usually the key will be salted, which can be passed to the setKey() function:
hkdf.setKey(key, sizeof(key), salt, sizeof(salt));
It is also possible to acheive the same effect with a single function call using the hkdf() templated function:
hkdf<SHA256>(output, sizeof(output), key, sizeof(key),
salt, sizeof(salt), info, sizeof(info));
The documentation for this class was generated from the following files:
