+{
+ const RAND_METHOD *meth = RAND_get_rand_method();
+ if (meth && meth->status)
+ return meth->status();
+ return 0;
+}
+
+#ifdef OPENSSL_FIPS
+
+/*
+ * FIPS DRBG initialisation code. This sets up the DRBG for use by the rest
+ * of OpenSSL.
+ */
+
+/*
+ * Entropy gatherer: use standard OpenSSL PRNG to seed (this will gather
+ * entropy internally through RAND_poll().
+ */
+
+static size_t drbg_get_entropy(DRBG_CTX *ctx, unsigned char **pout,
+ int entropy, size_t min_len, size_t max_len)
+{
+ /* Round up request to multiple of block size */
+ min_len = ((min_len + 19) / 20) * 20;
+ *pout = OPENSSL_malloc(min_len);
+ if (!*pout)
+ return 0;
+ if (ssleay_rand_bytes(*pout, min_len, 0, 0) <= 0) {
+ OPENSSL_free(*pout);
+ *pout = NULL;
+ return 0;
+ }
+ return min_len;
+}
+
+static void drbg_free_entropy(DRBG_CTX *ctx, unsigned char *out, size_t olen)
+{
+ if (out) {
+ OPENSSL_cleanse(out, olen);
+ OPENSSL_free(out);
+ }
+}
+
+/*
+ * Set "additional input" when generating random data. This uses the current
+ * PID, a time value and a counter.
+ */
+
+static size_t drbg_get_adin(DRBG_CTX *ctx, unsigned char **pout)
+{
+ /* Use of static variables is OK as this happens under a lock */
+ static unsigned char buf[16];
+ static unsigned long counter;
+ FIPS_get_timevec(buf, &counter);
+ *pout = buf;
+ return sizeof(buf);
+}
+
+/*
+ * RAND_add() and RAND_seed() pass through to OpenSSL PRNG so it is
+ * correctly seeded by RAND_poll().
+ */
+
+static int drbg_rand_add(DRBG_CTX *ctx, const void *in, int inlen,
+ double entropy)
+{
+ RAND_SSLeay()->add(in, inlen, entropy);
+ return 1;
+}
+
+static int drbg_rand_seed(DRBG_CTX *ctx, const void *in, int inlen)
+{
+ RAND_SSLeay()->seed(in, inlen);
+ return 1;
+}
+
+# ifndef OPENSSL_DRBG_DEFAULT_TYPE
+# define OPENSSL_DRBG_DEFAULT_TYPE NID_aes_256_ctr
+# endif
+# ifndef OPENSSL_DRBG_DEFAULT_FLAGS
+# define OPENSSL_DRBG_DEFAULT_FLAGS DRBG_FLAG_CTR_USE_DF
+# endif
+
+static int fips_drbg_type = OPENSSL_DRBG_DEFAULT_TYPE;
+static int fips_drbg_flags = OPENSSL_DRBG_DEFAULT_FLAGS;
+
+void RAND_set_fips_drbg_type(int type, int flags)
+{
+ fips_drbg_type = type;
+ fips_drbg_flags = flags;
+}
+
+int RAND_init_fips(void)
+{
+ DRBG_CTX *dctx;
+ size_t plen;
+ unsigned char pers[32], *p;
+# ifndef OPENSSL_ALLOW_DUAL_EC_DRBG
+ if (fips_drbg_type >> 16) {
+ RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_DUAL_EC_DRBG_DISABLED);
+ return 0;
+ }
+# endif
+
+ dctx = FIPS_get_default_drbg();
+ if (FIPS_drbg_init(dctx, fips_drbg_type, fips_drbg_flags) <= 0) {
+ RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INITIALISING_DRBG);
+ return 0;
+ }
+
+ FIPS_drbg_set_callbacks(dctx,
+ drbg_get_entropy, drbg_free_entropy, 20,
+ drbg_get_entropy, drbg_free_entropy);
+ FIPS_drbg_set_rand_callbacks(dctx, drbg_get_adin, 0,
+ drbg_rand_seed, drbg_rand_add);
+ /* Personalisation string: a string followed by date time vector */
+ strcpy((char *)pers, "OpenSSL DRBG2.0");
+ plen = drbg_get_adin(dctx, &p);
+ memcpy(pers + 16, p, plen);
+
+ if (FIPS_drbg_instantiate(dctx, pers, sizeof(pers)) <= 0) {
+ RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INSTANTIATING_DRBG);
+ return 0;
+ }
+ FIPS_rand_set_method(FIPS_drbg_method());
+ return 1;
+}
+
+#endif