openssl/crypto/rand/rand_meth.c
Pauli 7d615e2178 rand_drbg: remove RAND_DRBG.
The RAND_DRBG API did not fit well into the new provider concept as
implemented by EVP_RAND and EVP_RAND_CTX. The main reason is that the
RAND_DRBG API is a mixture of 'front end' and 'back end' API calls
and some of its API calls are rather low-level. This holds in particular
for the callback mechanism (RAND_DRBG_set_callbacks()) and the RAND_DRBG
type changing mechanism (RAND_DRBG_set()).

Adding a compatibility layer to continue supporting the RAND_DRBG API as
a legacy API for a regular deprecation period turned out to come at the
price of complicating the new provider API unnecessarily. Since the
RAND_DRBG API exists only since version 1.1.1, it was decided by the OMC
to drop it entirely.

Other related changes:

Use RNG instead of DRBG in EVP_RAND documentation.  The documentation was
using DRBG in places where it should have been RNG or CSRNG.

Move the RAND_DRBG(7) documentation to EVP_RAND(7).

Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/12509)
2020-08-07 14:16:47 +10:00

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1.5 KiB
C

/*
* Copyright 2011-2020 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <openssl/evp.h>
#include <openssl/rand.h>
#include "rand_local.h"
/* Implements the default OpenSSL RAND_add() method */
static int drbg_add(const void *buf, int num, double randomness)
{
EVP_RAND_CTX *drbg = RAND_get0_primary(NULL);
if (drbg == NULL || num <= 0)
return 0;
return EVP_RAND_reseed(drbg, 0, NULL, 0, buf, num);
}
/* Implements the default OpenSSL RAND_seed() method */
static int drbg_seed(const void *buf, int num)
{
return drbg_add(buf, num, num);
}
/* Implements the default OpenSSL RAND_status() method */
static int drbg_status(void)
{
EVP_RAND_CTX *drbg = RAND_get0_primary(NULL);
if (drbg == NULL)
return 0;
return EVP_RAND_state(drbg) == EVP_RAND_STATE_READY ? 1 : 0;
}
/* Implements the default OpenSSL RAND_bytes() method */
static int drbg_bytes(unsigned char *out, int count)
{
EVP_RAND_CTX *drbg = RAND_get0_public(NULL);
if (drbg == NULL)
return 0;
return EVP_RAND_generate(drbg, out, count, 0, 0, NULL, 0);
}
RAND_METHOD rand_meth = {
drbg_seed,
drbg_bytes,
NULL,
drbg_add,
drbg_bytes,
drbg_status
};
RAND_METHOD *RAND_OpenSSL(void)
{
#ifndef FIPS_MODULE
return &rand_meth;
#else
return NULL;
#endif
}