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Refactor rand

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* Removed dependency from internal headers in rand.h. xmpp_rand
  interface can be public in the future;
* xmpp_rand functions accept xmpp_rand_t object instead of xmpp_ctx_t.
This commit is contained in:
Dmitry Podgorny
2016-04-29 14:18:43 +00:00
parent 063f4deb22
commit b5d9b33b6f
5 changed files with 68 additions and 43 deletions
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54
src/rand.c
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@@ -16,13 +16,19 @@
* Hash function is SHA1.
*/
#include <assert.h>
#include <string.h>
#include <time.h>
/** @defgroup Random Pseudo-random number generator
*/
#include "common.h"
#include "ostypes.h"
#include <assert.h>
#include <string.h> /* memeset */
#include <time.h> /* clock, time */
#include "common.h" /* xmpp_alloc, xmpp_free */
#include "ostypes.h" /* uint8_t, uint32_t, size_t */
#include "sha1.h"
#include "snprintf.h" /* xmpp_snprintf */
#include "rand.h" /* xmpp_rand_t */
#define outlen SHA1_DIGEST_SIZE
#define seedlen (440 / 8)
@@ -214,30 +220,31 @@ do { \
} \
} while (0)
static void xmpp_rand_reseed(xmpp_ctx_t *ctx)
static void xmpp_rand_reseed(xmpp_rand_t *rand)
{
uint8_t entropy[ENTROPY_MAX];
uint8_t *ptr = entropy;
const uint8_t *last = entropy + sizeof(entropy);
size_t len;
xmpp_rand_t *rand = ctx->rand;
/* entropy:
* 1. time(2)
* 2. clock(3) if != -1
* 3. xmpp_ctx_t address to make unique seed within one process
* 3. xmpp_rand_t address to make unique seed within one process
* 4. counter to make unique seed within one context
* 5. local ports of every connection in list (getsockname)
* 6. other non-constant info that can be retieved from socket
* 5. stack address
* 6. local ports of every connection in list (getsockname)
* 7. other non-constant info that can be retieved from socket
*
* rand(3) can't be used as it isn't thread-safe.
* XXX 5 and 6 not implemented yet.
* XXX 6 and 7 are not implemented yet.
*/
ENTROPY_ACCUMULATE(ptr, last, time_t, time(NULL));
ENTROPY_ACCUMULATE(ptr, last, clock_t, clock());
ENTROPY_ACCUMULATE(ptr, last, void *, ctx);
ENTROPY_ACCUMULATE(ptr, last, void *, rand);
ENTROPY_ACCUMULATE(ptr, last, unsigned, ++rand->reseed_count);
ENTROPY_ACCUMULATE(ptr, last, void *, &entropy);
len = ptr - entropy;
if (rand->inited) {
@@ -262,35 +269,34 @@ void xmpp_rand_free(xmpp_ctx_t *ctx, xmpp_rand_t *rand)
xmpp_free(ctx, rand);
}
void xmpp_rand_bytes(xmpp_ctx_t *ctx, uint8_t *output, size_t len)
void xmpp_rand_bytes(xmpp_rand_t *rand, unsigned char *output, size_t len)
{
int rc;
xmpp_rand_t *rand = ctx->rand;
rc = Hash_DRBG_Generate(&rand->ctx, output, len);
rc = Hash_DRBG_Generate(&rand->ctx, (uint8_t *)output, len);
if (rc == RESEED_NEEDED) {
xmpp_rand_reseed(ctx);
rc = Hash_DRBG_Generate(&rand->ctx, output, len);
xmpp_rand_reseed(rand);
rc = Hash_DRBG_Generate(&rand->ctx, (uint8_t *)output, len);
assert(rc == 0);
}
}
int xmpp_rand(xmpp_ctx_t *ctx)
int xmpp_rand(xmpp_rand_t *rand)
{
int result;
xmpp_rand_bytes(ctx, (uint8_t *)&result, sizeof(result));
xmpp_rand_bytes(rand, (unsigned char *)&result, sizeof(result));
return result;
}
void xmpp_rand_nonce(xmpp_ctx_t *ctx, char *output, size_t len)
void xmpp_rand_nonce(xmpp_rand_t *rand, char *output, size_t len)
{
size_t i;
size_t rand_len = len / 2;
#ifndef _MSC_VER
uint8_t rand_buf[rand_len];
unsigned char rand_buf[rand_len];
#else
uint8_t* rand_buf = (uint8_t*)_alloca(rand_len);
unsigned char *rand_buf = (unsigned char *)_alloca(rand_len);
#endif
/* current implementation returns printable HEX representation of
@@ -299,9 +305,9 @@ void xmpp_rand_nonce(xmpp_ctx_t *ctx, char *output, size_t len)
* as result can fail.
*/
xmpp_rand_bytes(ctx, rand_buf, rand_len);
xmpp_rand_bytes(rand, rand_buf, rand_len);
for (i = 0; i < rand_len; ++i) {
xmpp_snprintf(output + i * 2, len, "%02x", (unsigned char)rand_buf[i]);
xmpp_snprintf(output + i * 2, len, "%02x", rand_buf[i]);
len -= 2;
}
}