Add a test to verify the ClientHello version is the same in a reneg
[openssl.git] / test / drbgtest.c
index 2363b5025caf788e86c588bec2daffbb6e58a1b2..d69456b4ee31d3bfa1a6ca4f865af53c8590b5dc 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2017 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
 #include <openssl/evp.h>
 #include <openssl/aes.h>
 #include "../crypto/rand/rand_lcl.h"
+#include "../crypto/include/internal/rand_int.h"
+
+#if defined(_WIN32)
+# include <windows.h>
+#endif
 
 #include "testutil.h"
 #include "drbgtest.h"
@@ -26,16 +31,16 @@ typedef struct drbg_selftest_data_st {
     unsigned int flags;
 
     /* KAT data for no PR */
-    const unsigned char *ent;
-    size_t entlen;
+    const unsigned char *entropy;
+    size_t entropylen;
     const unsigned char *nonce;
     size_t noncelen;
     const unsigned char *pers;
     size_t perslen;
     const unsigned char *adin;
     size_t adinlen;
-    const unsigned char *entreseed;
-    size_t entreseedlen;
+    const unsigned char *entropyreseed;
+    size_t entropyreseedlen;
     const unsigned char *adinreseed;
     size_t adinreseedlen;
     const unsigned char *adin2;
@@ -46,20 +51,20 @@ typedef struct drbg_selftest_data_st {
     size_t kat2len;
 
     /* KAT data for PR */
-    const unsigned char *ent_pr;
-    size_t entlen_pr;
+    const unsigned char *entropy_pr;
+    size_t entropylen_pr;
     const unsigned char *nonce_pr;
     size_t noncelen_pr;
     const unsigned char *pers_pr;
     size_t perslen_pr;
     const unsigned char *adin_pr;
     size_t adinlen_pr;
-    const unsigned char *entpr_pr;
-    size_t entprlen_pr;
+    const unsigned char *entropypr_pr;
+    size_t entropyprlen_pr;
     const unsigned char *ading_pr;
     size_t adinglen_pr;
-    const unsigned char *entg_pr;
-    size_t entglen_pr;
+    const unsigned char *entropyg_pr;
+    size_t entropyglen_pr;
     const unsigned char *kat_pr;
     size_t katlen_pr;
     const unsigned char *kat2_pr;
@@ -88,16 +93,19 @@ typedef struct drbg_selftest_data_st {
     pr##_pr_returnedbits, sizeof(pr##_pr_returnedbits) \
     }
 
-#define make_drbg_test_data_df(nid, pr, p) \
-    make_drbg_test_data(nid, RAND_DRBG_FLAG_CTR_USE_DF, pr, p)
+#define make_drbg_test_data_use_df(nid, pr, p) \
+    make_drbg_test_data(nid, 0, pr, p)
+
+#define make_drbg_test_data_no_df(nid, pr, p)                      \
+    make_drbg_test_data(nid, RAND_DRBG_FLAG_CTR_NO_DF, pr, p)
 
 static DRBG_SELFTEST_DATA drbg_test[] = {
-    make_drbg_test_data   (NID_aes_128_ctr, 0, aes_128_no_df, 0),
-    make_drbg_test_data   (NID_aes_192_ctr, 0, aes_192_no_df, 0),
-    make_drbg_test_data   (NID_aes_256_ctr, 0, aes_256_no_df, 1),
-    make_drbg_test_data_df(NID_aes_128_ctr,    aes_128_use_df, 0),
-    make_drbg_test_data_df(NID_aes_192_ctr,    aes_192_use_df, 0),
-    make_drbg_test_data_df(NID_aes_256_ctr,    aes_256_use_df, 1),
+    make_drbg_test_data_no_df (NID_aes_128_ctr, aes_128_no_df,  0),
+    make_drbg_test_data_no_df (NID_aes_192_ctr, aes_192_no_df,  0),
+    make_drbg_test_data_no_df (NID_aes_256_ctr, aes_256_no_df,  1),
+    make_drbg_test_data_use_df(NID_aes_128_ctr, aes_128_use_df, 0),
+    make_drbg_test_data_use_df(NID_aes_192_ctr, aes_192_use_df, 0),
+    make_drbg_test_data_use_df(NID_aes_256_ctr, aes_256_use_df, 1),
 };
 
 static int app_data_index;
@@ -106,22 +114,23 @@ static int app_data_index;
  * Test context data, attached as EXDATA to the RAND_DRBG
  */
 typedef struct test_ctx_st {
-    const unsigned char *ent;
-    size_t entlen;
-    int entcnt;
+    const unsigned char *entropy;
+    size_t entropylen;
+    int entropycnt;
     const unsigned char *nonce;
     size_t noncelen;
     int noncecnt;
 } TEST_CTX;
 
 static size_t kat_entropy(RAND_DRBG *drbg, unsigned char **pout,
-                          int entropy, size_t min_len, size_t max_len)
+                          int entropy, size_t min_len, size_t max_len,
+                          int prediction_resistance)
 {
     TEST_CTX *t = (TEST_CTX *)RAND_DRBG_get_ex_data(drbg, app_data_index);
 
-    t->entcnt++;
-    *pout = (unsigned char *)t->ent;
-    return t->entlen;
+    t->entropycnt++;
+    *pout = (unsigned char *)t->entropy;
+    return t->entropylen;
 }
 
 static size_t kat_nonce(RAND_DRBG *drbg, unsigned char **pout,
@@ -164,8 +173,8 @@ static int single_kat(DRBG_SELFTEST_DATA *td)
         goto err;
     }
     memset(&t, 0, sizeof(t));
-    t.ent = td->ent;
-    t.entlen = td->entlen;
+    t.entropy = td->entropy;
+    t.entropylen = td->entropylen;
     t.nonce = td->nonce;
     t.noncelen = td->noncelen;
     RAND_DRBG_set_ex_data(drbg, app_data_index, &t);
@@ -177,9 +186,9 @@ static int single_kat(DRBG_SELFTEST_DATA *td)
         failures++;
 
     /* Reseed DRBG with test entropy and additional input */
-    t.ent = td->entreseed;
-    t.entlen = td->entreseedlen;
-    if (!TEST_true(RAND_DRBG_reseed(drbg, td->adinreseed, td->adinreseedlen)
+    t.entropy = td->entropyreseed;
+    t.entropylen = td->entropyreseedlen;
+    if (!TEST_true(RAND_DRBG_reseed(drbg, td->adinreseed, td->adinreseedlen, 0)
             || !TEST_true(RAND_DRBG_generate(drbg, buff, td->kat2len, 0,
                                              td->adin2, td->adin2len))
             || !TEST_mem_eq(td->kat2, td->kat2len, buff, td->kat2len)))
@@ -195,11 +204,11 @@ static int single_kat(DRBG_SELFTEST_DATA *td)
                                                   kat_nonce, NULL)))
         failures++;
     RAND_DRBG_set_ex_data(drbg, app_data_index, &t);
-    t.ent = td->ent_pr;
-    t.entlen = td->entlen_pr;
+    t.entropy = td->entropy_pr;
+    t.entropylen = td->entropylen_pr;
     t.nonce = td->nonce_pr;
     t.noncelen = td->noncelen_pr;
-    t.entcnt = 0;
+    t.entropycnt = 0;
     t.noncecnt = 0;
     if (!TEST_true(RAND_DRBG_instantiate(drbg, td->pers_pr, td->perslen_pr)))
         failures++;
@@ -208,8 +217,8 @@ static int single_kat(DRBG_SELFTEST_DATA *td)
      * Now generate with PR: we need to supply entropy as this will
      * perform a reseed operation.
      */
-    t.ent = td->entpr_pr;
-    t.entlen = td->entprlen_pr;
+    t.entropy = td->entropypr_pr;
+    t.entropylen = td->entropyprlen_pr;
     if (!TEST_true(RAND_DRBG_generate(drbg, buff, td->katlen_pr, 1,
                                       td->adin_pr, td->adinlen_pr))
             || !TEST_mem_eq(td->kat_pr, td->katlen_pr, buff, td->katlen_pr))
@@ -218,8 +227,8 @@ static int single_kat(DRBG_SELFTEST_DATA *td)
     /*
      * Now generate again with PR: supply new entropy again.
      */
-    t.ent = td->entg_pr;
-    t.entlen = td->entglen_pr;
+    t.entropy = td->entropyg_pr;
+    t.entropylen = td->entropyglen_pr;
 
     if (!TEST_true(RAND_DRBG_generate(drbg, buff, td->kat2len_pr, 1,
                                       td->ading_pr, td->adinglen_pr))
@@ -243,11 +252,11 @@ static int init(RAND_DRBG *drbg, DRBG_SELFTEST_DATA *td, TEST_CTX *t)
                                                   kat_nonce, NULL)))
         return 0;
     RAND_DRBG_set_ex_data(drbg, app_data_index, t);
-    t->ent = td->ent;
-    t->entlen = td->entlen;
+    t->entropy = td->entropy;
+    t->entropylen = td->entropylen;
     t->nonce = td->nonce;
     t->noncelen = td->noncelen;
-    t->entcnt = 0;
+    t->entropycnt = 0;
     t->noncecnt = 0;
     return 1;
 }
@@ -274,7 +283,7 @@ static int error_check(DRBG_SELFTEST_DATA *td)
     RAND_DRBG *drbg = NULL;
     TEST_CTX t;
     unsigned char buff[1024];
-    unsigned int reseed_counter_tmp;
+    unsigned int generate_counter_tmp;
     int ret = 0;
 
     if (!TEST_ptr(drbg = RAND_DRBG_new(0, 0, NULL)))
@@ -286,7 +295,7 @@ static int error_check(DRBG_SELFTEST_DATA *td)
 
     /* Test detection of too large personlisation string */
     if (!init(drbg, td, &t)
-            || RAND_DRBG_instantiate(drbg, td->pers, drbg->max_pers + 1) > 0)
+            || RAND_DRBG_instantiate(drbg, td->pers, drbg->max_perslen + 1) > 0)
         goto err;
 
     /*
@@ -294,7 +303,7 @@ static int error_check(DRBG_SELFTEST_DATA *td)
      */
 
     /* Test entropy source failure detecion: i.e. returns no data */
-    t.entlen = 0;
+    t.entropylen = 0;
     if (TEST_int_le(RAND_DRBG_instantiate(drbg, td->pers, td->perslen), 0))
         goto err;
 
@@ -305,14 +314,14 @@ static int error_check(DRBG_SELFTEST_DATA *td)
         goto err;
 
     /* Test insufficient entropy */
-    t.entlen = drbg->min_entropy - 1;
+    t.entropylen = drbg->min_entropylen - 1;
     if (!init(drbg, td, &t)
             || RAND_DRBG_instantiate(drbg, td->pers, td->perslen) > 0
             || !uninstantiate(drbg))
         goto err;
 
     /* Test too much entropy */
-    t.entlen = drbg->max_entropy + 1;
+    t.entropylen = drbg->max_entropylen + 1;
     if (!init(drbg, td, &t)
             || RAND_DRBG_instantiate(drbg, td->pers, td->perslen) > 0
             || !uninstantiate(drbg))
@@ -323,8 +332,8 @@ static int error_check(DRBG_SELFTEST_DATA *td)
      */
 
     /* Test too small nonce */
-    if (drbg->min_nonce) {
-        t.noncelen = drbg->min_nonce - 1;
+    if (drbg->min_noncelen) {
+        t.noncelen = drbg->min_noncelen - 1;
         if (!init(drbg, td, &t)
                 || RAND_DRBG_instantiate(drbg, td->pers, td->perslen) > 0
                 || !uninstantiate(drbg))
@@ -332,8 +341,8 @@ static int error_check(DRBG_SELFTEST_DATA *td)
     }
 
     /* Test too large nonce */
-    if (drbg->max_nonce) {
-        t.noncelen = drbg->max_nonce + 1;
+    if (drbg->max_noncelen) {
+        t.noncelen = drbg->max_noncelen + 1;
         if (!init(drbg, td, &t)
                 || RAND_DRBG_instantiate(drbg, td->pers, td->perslen) > 0
                 || !uninstantiate(drbg))
@@ -353,14 +362,14 @@ static int error_check(DRBG_SELFTEST_DATA *td)
 
     /* Try too large additional input */
     if (!TEST_false(RAND_DRBG_generate(drbg, buff, td->exlen, 0,
-                                       td->adin, drbg->max_adin + 1)))
+                                       td->adin, drbg->max_adinlen + 1)))
         goto err;
 
     /*
      * Check prediction resistance request fails if entropy source
      * failure.
      */
-    t.entlen = 0;
+    t.entropylen = 0;
     if (TEST_false(RAND_DRBG_generate(drbg, buff, td->exlen, 1,
                                       td->adin, td->adinlen))
             || !uninstantiate(drbg))
@@ -369,15 +378,15 @@ static int error_check(DRBG_SELFTEST_DATA *td)
     /* Instantiate again with valid data */
     if (!instantiate(drbg, td, &t))
         goto err;
-    reseed_counter_tmp = drbg->reseed_counter;
-    drbg->reseed_counter = drbg->reseed_interval;
+    generate_counter_tmp = drbg->generate_counter;
+    drbg->generate_counter = drbg->reseed_interval;
 
     /* Generate output and check entropy has been requested for reseed */
-    t.entcnt = 0;
+    t.entropycnt = 0;
     if (!TEST_true(RAND_DRBG_generate(drbg, buff, td->exlen, 0,
                                       td->adin, td->adinlen))
-            || !TEST_int_eq(t.entcnt, 1)
-            || !TEST_int_eq(drbg->reseed_counter, reseed_counter_tmp + 1)
+            || !TEST_int_eq(t.entropycnt, 1)
+            || !TEST_int_eq(drbg->generate_counter, generate_counter_tmp + 1)
             || !uninstantiate(drbg))
         goto err;
 
@@ -385,7 +394,7 @@ static int error_check(DRBG_SELFTEST_DATA *td)
      * Check prediction resistance request fails if entropy source
      * failure.
      */
-    t.entlen = 0;
+    t.entropylen = 0;
     if (!TEST_false(RAND_DRBG_generate(drbg, buff, td->exlen, 1,
                                        td->adin, td->adinlen))
             || !uninstantiate(drbg))
@@ -394,15 +403,15 @@ static int error_check(DRBG_SELFTEST_DATA *td)
     /* Test reseed counter works */
     if (!instantiate(drbg, td, &t))
         goto err;
-    reseed_counter_tmp = drbg->reseed_counter;
-    drbg->reseed_counter = drbg->reseed_interval;
+    generate_counter_tmp = drbg->generate_counter;
+    drbg->generate_counter = drbg->reseed_interval;
 
     /* Generate output and check entropy has been requested for reseed */
-    t.entcnt = 0;
+    t.entropycnt = 0;
     if (!TEST_true(RAND_DRBG_generate(drbg, buff, td->exlen, 0,
                                       td->adin, td->adinlen))
-            || !TEST_int_eq(t.entcnt, 1)
-            || !TEST_int_eq(drbg->reseed_counter, reseed_counter_tmp + 1)
+            || !TEST_int_eq(t.entropycnt, 1)
+            || !TEST_int_eq(drbg->generate_counter, generate_counter_tmp + 1)
             || !uninstantiate(drbg))
         goto err;
 
@@ -412,33 +421,33 @@ static int error_check(DRBG_SELFTEST_DATA *td)
 
     /* Test explicit reseed with too large additional input */
     if (!init(drbg, td, &t)
-            || RAND_DRBG_reseed(drbg, td->adin, drbg->max_adin + 1) > 0)
+            || RAND_DRBG_reseed(drbg, td->adin, drbg->max_adinlen + 1, 0) > 0)
         goto err;
 
     /* Test explicit reseed with entropy source failure */
-    t.entlen = 0;
-    if (!TEST_int_le(RAND_DRBG_reseed(drbg, td->adin, td->adinlen), 0)
+    t.entropylen = 0;
+    if (!TEST_int_le(RAND_DRBG_reseed(drbg, td->adin, td->adinlen, 0), 0)
             || !uninstantiate(drbg))
         goto err;
 
     /* Test explicit reseed with too much entropy */
     if (!init(drbg, td, &t))
         goto err;
-    t.entlen = drbg->max_entropy + 1;
-    if (!TEST_int_le(RAND_DRBG_reseed(drbg, td->adin, td->adinlen), 0)
+    t.entropylen = drbg->max_entropylen + 1;
+    if (!TEST_int_le(RAND_DRBG_reseed(drbg, td->adin, td->adinlen, 0), 0)
             || !uninstantiate(drbg))
         goto err;
 
     /* Test explicit reseed with too little entropy */
     if (!init(drbg, td, &t))
         goto err;
-    t.entlen = drbg->min_entropy - 1;
-    if (!TEST_int_le(RAND_DRBG_reseed(drbg, td->adin, td->adinlen), 0)
+    t.entropylen = drbg->min_entropylen - 1;
+    if (!TEST_int_le(RAND_DRBG_reseed(drbg, td->adin, td->adinlen, 0), 0)
             || !uninstantiate(drbg))
         goto err;
 
     /* Standard says we have to check uninstantiate really zeroes */
-    if (!TEST_mem_eq(zero, sizeof(drbg->ctr), &drbg->ctr, sizeof(drbg->ctr)))
+    if (!TEST_mem_eq(zero, sizeof(drbg->data), &drbg->data, sizeof(drbg->data)))
         goto err;
 
     ret = 1;
@@ -475,19 +484,457 @@ err:
     return rv;
 }
 
-#define RAND_ADD_SIZE 500
+/*
+ * Hook context data, attached as EXDATA to the RAND_DRBG
+ */
+typedef struct hook_ctx_st {
+    RAND_DRBG *drbg;
+    /*
+     * Currently, all DRBGs use the same get_entropy() callback.
+     * The tests however, don't assume this and store
+     * the original callback for every DRBG separately.
+     */
+    RAND_DRBG_get_entropy_fn get_entropy;
+    /* forces a failure of the get_entropy() call if nonzero */
+    int fail;
+    /* counts successful reseeds */
+    int reseed_count;
+} HOOK_CTX;
 
-static int test_rand_add(void)
+static HOOK_CTX master_ctx, public_ctx, private_ctx;
+
+static HOOK_CTX *get_hook_ctx(RAND_DRBG *drbg)
+{
+    return (HOOK_CTX *)RAND_DRBG_get_ex_data(drbg, app_data_index);
+}
+
+/* Intercepts and counts calls to the get_entropy() callback */
+static size_t get_entropy_hook(RAND_DRBG *drbg, unsigned char **pout,
+                              int entropy, size_t min_len, size_t max_len,
+                              int prediction_resistance)
+{
+    size_t ret;
+    HOOK_CTX *ctx = get_hook_ctx(drbg);
+
+    if (ctx->fail != 0)
+        return 0;
+
+    ret = ctx->get_entropy(drbg, pout, entropy, min_len, max_len,
+                           prediction_resistance);
+
+    if (ret != 0)
+        ctx->reseed_count++;
+    return ret;
+}
+
+/* Installs a hook for the get_entropy() callback of the given drbg */
+static void hook_drbg(RAND_DRBG *drbg, HOOK_CTX *ctx)
+{
+    memset(ctx, 0, sizeof(*ctx));
+    ctx->drbg = drbg;
+    ctx->get_entropy = drbg->get_entropy;
+    drbg->get_entropy = get_entropy_hook;
+    RAND_DRBG_set_ex_data(drbg, app_data_index, ctx);
+}
+
+/* Installs the hook for the get_entropy() callback of the given drbg */
+static void unhook_drbg(RAND_DRBG *drbg)
 {
-    char *p;
+    HOOK_CTX *ctx = get_hook_ctx(drbg);
+
+    drbg->get_entropy = ctx->get_entropy;
+    CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data);
+}
+
+/* Resets the given hook context */
+static void reset_hook_ctx(HOOK_CTX *ctx)
+{
+    ctx->fail = 0;
+    ctx->reseed_count = 0;
+}
+
+/* Resets all drbg hook contexts */
+static void reset_drbg_hook_ctx()
+{
+    reset_hook_ctx(&master_ctx);
+    reset_hook_ctx(&public_ctx);
+    reset_hook_ctx(&private_ctx);
+}
+
+/*
+ * Generates random output using RAND_bytes() and RAND_priv_bytes()
+ * and checks whether the three shared DRBGs were reseeded as
+ * expected.
+ *
+ * |expect_success|: expected outcome (as reported by RAND_status())
+ * |master|, |public|, |private|: pointers to the three shared DRBGs
+ * |expect_xxx_reseed| =
+ *       1:  it is expected that the specified DRBG is reseeded
+ *       0:  it is expected that the specified DRBG is not reseeded
+ *      -1:  don't check whether the specified DRBG was reseeded or not
+ */
+static int test_drbg_reseed(int expect_success,
+                            RAND_DRBG *master,
+                            RAND_DRBG *public,
+                            RAND_DRBG *private,
+                            int expect_master_reseed,
+                            int expect_public_reseed,
+                            int expect_private_reseed
+                           )
+{
+    unsigned char buf[32];
+    time_t before_reseed, after_reseed;
+    int expected_state = (expect_success ? DRBG_READY : DRBG_ERROR);
+
+    /*
+     * step 1: check preconditions
+     */
+
+    /* Test whether seed propagation is enabled */
+    if (!TEST_int_ne(master->reseed_counter, 0)
+        || !TEST_int_ne(public->reseed_counter, 0)
+        || !TEST_int_ne(private->reseed_counter, 0))
+        return 0;
+
+    /* Check whether the master DRBG's reseed counter is the largest one */
+    if (!TEST_int_le(public->reseed_counter, master->reseed_counter)
+        || !TEST_int_le(private->reseed_counter, master->reseed_counter))
+        return 0;
+
+    /*
+     * step 2: generate random output
+     */
 
-    if (!TEST_ptr(p = malloc(RAND_ADD_SIZE)))
+    /* Generate random output from the public and private DRBG */
+    before_reseed = expect_master_reseed == 1 ? time(NULL) : 0;
+    if (!TEST_int_eq(RAND_bytes(buf, sizeof(buf)), expect_success)
+        || !TEST_int_eq(RAND_priv_bytes(buf, sizeof(buf)), expect_success))
         return 0;
-    RAND_add(p, RAND_ADD_SIZE, RAND_ADD_SIZE);
-    free(p);
+    after_reseed = time(NULL);
+
+
+    /*
+     * step 3: check postconditions
+     */
+
+    /* Test whether reseeding succeeded as expected */
+    if (!TEST_int_eq(master->state, expected_state)
+        || !TEST_int_eq(public->state, expected_state)
+        || !TEST_int_eq(private->state, expected_state))
+        return 0;
+
+    if (expect_master_reseed >= 0) {
+        /* Test whether master DRBG was reseeded as expected */
+        if (!TEST_int_eq(master_ctx.reseed_count, expect_master_reseed))
+            return 0;
+    }
+
+    if (expect_public_reseed >= 0) {
+        /* Test whether public DRBG was reseeded as expected */
+        if (!TEST_int_eq(public_ctx.reseed_count, expect_public_reseed))
+            return 0;
+    }
+
+    if (expect_private_reseed >= 0) {
+        /* Test whether public DRBG was reseeded as expected */
+        if (!TEST_int_eq(private_ctx.reseed_count, expect_private_reseed))
+            return 0;
+    }
+
+    if (expect_success == 1) {
+        /* Test whether all three reseed counters are synchronized */
+        if (!TEST_int_eq(public->reseed_counter, master->reseed_counter)
+            || !TEST_int_eq(private->reseed_counter, master->reseed_counter))
+            return 0;
+
+        /* Test whether reseed time of master DRBG is set correctly */
+        if (!TEST_time_t_le(before_reseed, master->reseed_time)
+            || !TEST_time_t_le(master->reseed_time, after_reseed))
+            return 0;
+
+        /* Test whether reseed times of child DRBGs are synchronized with master */
+        if (!TEST_time_t_ge(public->reseed_time, master->reseed_time)
+            || !TEST_time_t_ge(private->reseed_time, master->reseed_time))
+            return 0;
+    } else {
+        ERR_clear_error();
+    }
+
     return 1;
 }
 
+/*
+ * Test whether the default rand_method (RAND_OpenSSL()) is
+ * setup correctly, in particular whether reseeding  works
+ * as designed.
+ */
+static int test_rand_reseed(void)
+{
+    RAND_DRBG *master, *public, *private;
+    unsigned char rand_add_buf[256];
+    int rv=0;
+
+    /* Check whether RAND_OpenSSL() is the default method */
+    if (!TEST_ptr_eq(RAND_get_rand_method(), RAND_OpenSSL()))
+        return 0;
+
+    /* All three DRBGs should be non-null */
+    if (!TEST_ptr(master = RAND_DRBG_get0_master())
+        || !TEST_ptr(public = RAND_DRBG_get0_public())
+        || !TEST_ptr(private = RAND_DRBG_get0_private()))
+        return 0;
+
+    /* There should be three distinct DRBGs, two of them chained to master */
+    if (!TEST_ptr_ne(public, private)
+        || !TEST_ptr_ne(public, master)
+        || !TEST_ptr_ne(private, master)
+        || !TEST_ptr_eq(public->parent, master)
+        || !TEST_ptr_eq(private->parent, master))
+        return 0;
+
+    /* uninstantiate the three global DRBGs */
+    RAND_DRBG_uninstantiate(private);
+    RAND_DRBG_uninstantiate(public);
+    RAND_DRBG_uninstantiate(master);
+
+
+    /* Install hooks for the following tests */
+    hook_drbg(master,  &master_ctx);
+    hook_drbg(public,  &public_ctx);
+    hook_drbg(private, &private_ctx);
+
+
+    /*
+     * Test initial seeding of shared DRBGs
+     */
+    if (!TEST_true(test_drbg_reseed(1, master, public, private, 1, 1, 1)))
+        goto error;
+    reset_drbg_hook_ctx();
+
+
+    /*
+     * Test initial state of shared DRBGs
+     */
+    if (!TEST_true(test_drbg_reseed(1, master, public, private, 0, 0, 0)))
+        goto error;
+    reset_drbg_hook_ctx();
+
+    /*
+     * Test whether the public and private DRBG are both reseeded when their
+     * reseed counters differ from the master's reseed counter.
+     */
+    master->reseed_counter++;
+    if (!TEST_true(test_drbg_reseed(1, master, public, private, 0, 1, 1)))
+        goto error;
+    reset_drbg_hook_ctx();
+
+    /*
+     * Test whether the public DRBG is reseeded when its reseed counter differs
+     * from the master's reseed counter.
+     */
+    master->reseed_counter++;
+    private->reseed_counter++;
+    if (!TEST_true(test_drbg_reseed(1, master, public, private, 0, 1, 0)))
+        goto error;
+    reset_drbg_hook_ctx();
+
+    /*
+     * Test whether the private DRBG is reseeded when its reseed counter differs
+     * from the master's reseed counter.
+     */
+    master->reseed_counter++;
+    public->reseed_counter++;
+    if (!TEST_true(test_drbg_reseed(1, master, public, private, 0, 0, 1)))
+        goto error;
+    reset_drbg_hook_ctx();
+
+
+    /* fill 'randomness' buffer with some arbitrary data */
+    memset(rand_add_buf, 'r', sizeof(rand_add_buf));
+
+    /*
+     * Test whether all three DRBGs are reseeded by RAND_add()
+     */
+    RAND_add(rand_add_buf, sizeof(rand_add_buf), sizeof(rand_add_buf));
+    if (!TEST_true(test_drbg_reseed(1, master, public, private, 1, 1, 1)))
+        goto error;
+    reset_drbg_hook_ctx();
+
+
+    /*
+     * Test whether none of the DRBGs is reseed if the master fails to reseed
+     */
+    master_ctx.fail = 1;
+    master->reseed_counter++;
+    RAND_add(rand_add_buf, sizeof(rand_add_buf), sizeof(rand_add_buf));
+    if (!TEST_true(test_drbg_reseed(0, master, public, private, 0, 0, 0)))
+        goto error;
+    reset_drbg_hook_ctx();
+
+    rv = 1;
+
+error:
+    /* Remove hooks  */
+    unhook_drbg(master);
+    unhook_drbg(public);
+    unhook_drbg(private);
+
+    return rv;
+}
+
+#if defined(OPENSSL_THREADS)
+static int multi_thread_rand_bytes_succeeded = 1;
+static int multi_thread_rand_priv_bytes_succeeded = 1;
+
+static void run_multi_thread_test(void)
+{
+    unsigned char buf[256];
+    time_t start = time(NULL);
+    RAND_DRBG *public, *private;
+
+    public = RAND_DRBG_get0_public();
+    private = RAND_DRBG_get0_private();
+    RAND_DRBG_set_reseed_time_interval(public, 1);
+    RAND_DRBG_set_reseed_time_interval(private, 1);
+
+    do {
+        if (RAND_bytes(buf, sizeof(buf)) <= 0)
+            multi_thread_rand_bytes_succeeded = 0;
+        if (RAND_priv_bytes(buf, sizeof(buf)) <= 0)
+            multi_thread_rand_priv_bytes_succeeded = 0;
+    }
+    while(time(NULL) - start < 5);
+}
+
+# if defined(OPENSSL_SYS_WINDOWS)
+
+typedef HANDLE thread_t;
+
+static DWORD WINAPI thread_run(LPVOID arg)
+{
+    run_multi_thread_test();
+    return 0;
+}
+
+static int run_thread(thread_t *t)
+{
+    *t = CreateThread(NULL, 0, thread_run, NULL, 0, NULL);
+    return *t != NULL;
+}
+
+static int wait_for_thread(thread_t thread)
+{
+    return WaitForSingleObject(thread, INFINITE) == 0;
+}
+
+# else
+
+typedef pthread_t thread_t;
+
+static void *thread_run(void *arg)
+{
+    run_multi_thread_test();
+    return NULL;
+}
+
+static int run_thread(thread_t *t)
+{
+    return pthread_create(t, NULL, thread_run, NULL) == 0;
+}
+
+static int wait_for_thread(thread_t thread)
+{
+    return pthread_join(thread, NULL) == 0;
+}
+
+# endif
+
+/*
+ * The main thread will also run the test, so we'll have THREADS+1 parallel
+ * tests running
+ */
+# define THREADS 3
+
+static int test_multi_thread(void)
+{
+    thread_t t[THREADS];
+    int i;
+
+    for (i = 0; i < THREADS; i++)
+        run_thread(&t[i]);
+    run_multi_thread_test();
+    for (i = 0; i < THREADS; i++)
+        wait_for_thread(t[i]);
+
+    if (!TEST_true(multi_thread_rand_bytes_succeeded))
+        return 0;
+    if (!TEST_true(multi_thread_rand_priv_bytes_succeeded))
+        return 0;
+
+    return 1;
+}
+#endif
+
+/*
+ * This function only returns the entropy already added with RAND_add(),
+ * and does not get entropy from the OS.
+ *
+ * Returns 0 on failure and the size of the buffer on success.
+ */
+static size_t get_pool_entropy(RAND_DRBG *drbg,
+                               unsigned char **pout,
+                               int entropy, size_t min_len, size_t max_len,
+                               int prediction_resistance)
+{
+    if (drbg->pool == NULL)
+        return 0;
+
+    if (drbg->pool->entropy < (size_t)entropy || drbg->pool->len < min_len
+        || drbg->pool->len > max_len)
+        return 0;
+
+    *pout = drbg->pool->buffer;
+    return drbg->pool->len;
+}
+
+/*
+ * Clean up the entropy that get_pool_entropy() returned.
+ */
+static void cleanup_pool_entropy(RAND_DRBG *drbg, unsigned char *out, size_t outlen)
+{
+    OPENSSL_secure_clear_free(drbg->pool->buffer, drbg->pool->max_len);
+    OPENSSL_free(drbg->pool);
+    drbg->pool = NULL;
+}
+
+/*
+ * Test that instantiating works when OS entropy is not available and that
+ * RAND_add() is enough to reseed it.
+ */
+static int test_rand_add(void)
+{
+    RAND_DRBG *master = RAND_DRBG_get0_master();
+    RAND_DRBG_get_entropy_fn old_get_entropy = master->get_entropy;
+    RAND_DRBG_cleanup_entropy_fn old_cleanup_entropy = master->cleanup_entropy;
+    int rv = 0;
+    unsigned char rand_add_buf[256];
+
+    master->get_entropy = get_pool_entropy;
+    master->cleanup_entropy = cleanup_pool_entropy;
+    master->reseed_counter++;
+    RAND_DRBG_uninstantiate(master);
+    memset(rand_add_buf, 0xCD, sizeof(rand_add_buf));
+    RAND_add(rand_add_buf, sizeof(rand_add_buf), sizeof(rand_add_buf));
+    if (!TEST_true(RAND_DRBG_instantiate(master, NULL, 0)))
+        goto error;
+
+    rv = 1;
+
+error:
+    master->get_entropy = old_get_entropy;
+    master->cleanup_entropy = old_cleanup_entropy;
+    return rv;
+}
 
 int setup_tests(void)
 {
@@ -495,6 +942,10 @@ int setup_tests(void)
 
     ADD_ALL_TESTS(test_kats, OSSL_NELEM(drbg_test));
     ADD_ALL_TESTS(test_error_checks, OSSL_NELEM(drbg_test));
+    ADD_TEST(test_rand_reseed);
     ADD_TEST(test_rand_add);
+#if defined(OPENSSL_THREADS)
+    ADD_TEST(test_multi_thread);
+#endif
     return 1;
 }