Commit bd045777 authored by Dr. Matthias St. Pierre's avatar Dr. Matthias St. Pierre
Browse files

md_rand.c: don't stop polling until properly initialized 



Previously, the RNG sets `initialized=1` after the first call to
RAND_poll(), although its criterion for being initialized actually
is whether condition `entropy >= ENTROPY_NEEDED` is true.

This commit now assigns `initialized=(entropy >= ENTROPY_NEEDED)`,
which has the effect that on the next call, RAND_poll() will be
called again, if it previously failed to obtain enough entropy.

Reviewed-by: default avatarPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7438)
parent f2828a14

crypto/rand/md_rand.c

+4 −6
Original line number Diff line number Diff line
@@ -275,7 +275,6 @@ static int rand_bytes(unsigned char *buf, int num, int pseudo) 
    static volatile int stirred_pool = 0;

    int i, j, k;

    size_t num_ceil, st_idx, st_num;

    int ok;

    long md_c[2];

    unsigned char local_md[MD_DIGEST_LENGTH];

    EVP_MD_CTX *m;
@@ -362,14 +361,13 @@ static int rand_bytes(unsigned char *buf, int num, int pseudo) 


    if (!initialized) {

        RAND_poll();

        initialized = 1;

        initialized = (entropy >= ENTROPY_NEEDED);

    }



    if (!stirred_pool)

        do_stir_pool = 1;



    ok = (entropy >= ENTROPY_NEEDED);

    if (!ok) {

    if (!initialized) {

        /*

         * If the PRNG state is not yet unpredictable, then seeing the PRNG

         * output may help attackers to determine the new state; thus we have
@@ -408,7 +406,7 @@ static int rand_bytes(unsigned char *buf, int num, int pseudo) 
            rand_add(DUMMY_SEED, MD_DIGEST_LENGTH, 0.0);

            n -= MD_DIGEST_LENGTH;

        }

        if (ok)

        if (initialized)

            stirred_pool = 1;

    }
@@ -500,7 +498,7 @@ static int rand_bytes(unsigned char *buf, int num, int pseudo) 
    CRYPTO_THREAD_unlock(rand_lock);



    EVP_MD_CTX_free(m);

    if (ok)

    if (initialized)

        return (1);

    else if (pseudo)

        return 0;