Backport from HEAD:

[oweals/openssl.git] / crypto / rand / md_rand.c

diff --git a/crypto/rand/md_rand.c b/crypto/rand/md_rand.c
index 48cc2e84a84bde86740600f1cc3504b591dcd92b..fcdd3f2a845feeedd724a59706ea3d2c9243ad37 100644 (file)
--- a/crypto/rand/md_rand.c
+++ b/crypto/rand/md_rand.c
@@ -109,6 +109,8 @@
  *
  */
 
+#define OPENSSL_FIPSEVP
+
 #ifdef MD_RAND_DEBUG
 # ifndef NDEBUG
 #   define NDEBUG
@@ -155,15 +157,16 @@ int rand_predictable=0;
 const char RAND_version[]="RAND" OPENSSL_VERSION_PTEXT;
 
 static void ssleay_rand_cleanup(void);
-static void ssleay_rand_seed(const void *buf, size_t num);
-static void ssleay_rand_add(const void *buf, size_t num, double add_entropy);
-static int ssleay_rand_bytes(unsigned char *buf, size_t num);
-static int ssleay_rand_pseudo_bytes(unsigned char *buf, size_t num);
+static void ssleay_rand_seed(const void *buf, int num);
+static void ssleay_rand_add(const void *buf, int num, double add_entropy);
+static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo);
+static int ssleay_rand_nopseudo_bytes(unsigned char *buf, int num);
+static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num);
 static int ssleay_rand_status(void);
 
 RAND_METHOD rand_ssleay_meth={
        ssleay_rand_seed,
-       ssleay_rand_bytes,
+       ssleay_rand_nopseudo_bytes,
        ssleay_rand_cleanup,
        ssleay_rand_add,
        ssleay_rand_pseudo_bytes,
@@ -187,11 +190,9 @@ static void ssleay_rand_cleanup(void)
        initialized=0;
        }
 
-static void ssleay_rand_add(const void *buf, size_t num, double add)
+static void ssleay_rand_add(const void *buf, int num, double add)
        {
-       int i,st_idx;
-       size_t j;
-       ssize_t k;
+       int i,j,k,st_idx;
        long md_c[2];
        unsigned char local_md[MD_DIGEST_LENGTH];
        EVP_MD_CTX m;
@@ -274,8 +275,16 @@ static void ssleay_rand_add(const void *buf, size_t num, double add)
                        }
                else
                        MD_Update(&m,&(state[st_idx]),j);
-                       
+
+               /* DO NOT REMOVE THE FOLLOWING CALL TO MD_Update()! */
                MD_Update(&m,buf,j);
+               /* We know that line may cause programs such as
+                  purify and valgrind to complain about use of
+                  uninitialized data.  The problem is not, it's
+                  with the caller.  Removing that line will make
+                  sure you get really bad randomness and thereby
+                  other problems such as very insecure keys. */
+
                MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));
                MD_Final(&m,local_md);
                md_c[1]++;
@@ -304,7 +313,7 @@ static void ssleay_rand_add(const void *buf, size_t num, double add)
         * other thread's seeding remains without effect (except for
         * the incremented counter).  By XORing it we keep at least as
         * much entropy as fits into md. */
-       for (k = 0; k < sizeof(md); k++)
+       for (k = 0; k < (int)sizeof(md); k++)
                {
                md[k] ^= local_md[k];
                }
@@ -317,17 +326,15 @@ static void ssleay_rand_add(const void *buf, size_t num, double add)
 #endif
        }
 
-static void ssleay_rand_seed(const void *buf, size_t num)
+static void ssleay_rand_seed(const void *buf, int num)
        {
        ssleay_rand_add(buf, num, (double)num);
        }
 
-static int ssleay_rand_bytes(unsigned char *buf, size_t num)
+static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo)
        {
        static volatile int stirred_pool = 0;
-       int i,st_num,st_idx;
-       size_t j;
-       ssize_t k;
+       int i,j,k,st_num,st_idx;
        int num_ceil;
        int ok;
        long md_c[2];
@@ -470,9 +477,18 @@ static int ssleay_rand_bytes(unsigned char *buf, size_t num)
 #endif
                MD_Update(&m,local_md,MD_DIGEST_LENGTH);
                MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));
-#ifndef PURIFY
-               MD_Update(&m,buf,j); /* purify complains */
+
+#ifndef PURIFY /* purify complains */
+               /* The following line uses the supplied buffer as a small
+                * source of entropy: since this buffer is often uninitialised
+                * it may cause programs such as purify or valgrind to
+                * complain. So for those builds it is not used: the removal
+                * of such a small source of entropy has negligible impact on
+                * security.
+                */
+               MD_Update(&m,buf,j);
 #endif
+
                k=(st_idx+MD_DIGEST_LENGTH/2)-st_num;
                if (k > 0)
                        {
@@ -494,7 +510,7 @@ static int ssleay_rand_bytes(unsigned char *buf, size_t num)
                }
 
        MD_Init(&m);
-       MD_Update(&m,&(md_c[0]),sizeof(md_c));
+       MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));
        MD_Update(&m,local_md,MD_DIGEST_LENGTH);
        CRYPTO_w_lock(CRYPTO_LOCK_RAND);
        MD_Update(&m,md,MD_DIGEST_LENGTH);
@@ -504,7 +520,9 @@ static int ssleay_rand_bytes(unsigned char *buf, size_t num)
        EVP_MD_CTX_cleanup(&m);
        if (ok)
                return(1);
-       else
+       else if (pseudo)
+               return 0;
+       else 
                {
                RANDerr(RAND_F_SSLEAY_RAND_BYTES,RAND_R_PRNG_NOT_SEEDED);
                ERR_add_error_data(1, "You need to read the OpenSSL FAQ, "
@@ -513,22 +531,16 @@ static int ssleay_rand_bytes(unsigned char *buf, size_t num)
                }
        }
 
+static int ssleay_rand_nopseudo_bytes(unsigned char *buf, int num)
+       {
+       return ssleay_rand_bytes(buf, num, 0);
+       }
+
 /* pseudo-random bytes that are guaranteed to be unique but not
    unpredictable */
-static int ssleay_rand_pseudo_bytes(unsigned char *buf, size_t num) 
+static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num) 
        {
-       int ret;
-       unsigned long err;
-
-       ret = RAND_bytes(buf, num);
-       if (ret == 0)
-               {
-               err = ERR_peek_error();
-               if (ERR_GET_LIB(err) == ERR_LIB_RAND &&
-                   ERR_GET_REASON(err) == RAND_R_PRNG_NOT_SEEDED)
-                       ERR_clear_error();
-               }
-       return (ret);
+       return ssleay_rand_bytes(buf, num, 1);
        }
 
 static int ssleay_rand_status(void)