Return if ssleay_rand_add called with zero num.
[openssl.git] / crypto / rand / md_rand.c
index cac3e8b..67ac5ac 100644 (file)
  *
  */
 
+#define OPENSSL_FIPSAPI
+
 #ifdef MD_RAND_DEBUG
 # ifndef NDEBUG
 #   define NDEBUG
 
 #include "e_os.h"
 
+#if !(defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYSNAME_DSPBIOS))
+# include <sys/time.h>
+#endif
+#if defined(OPENSSL_SYS_VXWORKS)
+# include <time.h>
+#endif
+
+#include <openssl/crypto.h>
 #include <openssl/rand.h>
 #include "rand_lcl.h"
 
-#include <openssl/crypto.h>
 #include <openssl/err.h>
 
+#ifdef OPENSSL_FIPS
+#include <openssl/fips.h>
+#endif
+
 #ifdef BN_DEBUG
 # define PREDICT
 #endif
@@ -154,16 +167,19 @@ int rand_predictable=0;
 
 const char RAND_version[]="RAND" OPENSSL_VERSION_PTEXT;
 
+static void rand_hw_seed(EVP_MD_CTX *ctx);
+
 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 int ssleay_rand_seed(const void *buf, int num);
+static int 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={
+static 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,
@@ -187,14 +203,17 @@ static void ssleay_rand_cleanup(void)
        initialized=0;
        }
 
-static void ssleay_rand_add(const void *buf, size_t num, double add)
+static int ssleay_rand_add(const void *buf, int num, double add)
        {
-       int i,st_idx;
-       ssize_t j,k;
+       int i,j,k,st_idx;
        long md_c[2];
        unsigned char local_md[MD_DIGEST_LENGTH];
        EVP_MD_CTX m;
        int do_not_lock;
+       int rv = 0;
+
+       if (!num)
+               return;
 
        /*
         * (Based on the rand(3) manpage)
@@ -211,6 +230,7 @@ static void ssleay_rand_add(const void *buf, size_t num, double add)
          * hash function.
         */
 
+       EVP_MD_CTX_init(&m);
        /* check if we already have the lock */
        if (crypto_lock_rand)
                {
@@ -257,26 +277,41 @@ static void ssleay_rand_add(const void *buf, size_t num, double add)
 
        if (!do_not_lock) CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
 
-       EVP_MD_CTX_init(&m);
        for (i=0; i<num; i+=MD_DIGEST_LENGTH)
                {
                j=(num-i);
                j=(j > MD_DIGEST_LENGTH)?MD_DIGEST_LENGTH:j;
 
-               MD_Init(&m);
-               MD_Update(&m,local_md,MD_DIGEST_LENGTH);
+               if (!MD_Init(&m))
+                       goto err;
+               if (!MD_Update(&m,local_md,MD_DIGEST_LENGTH))
+                       goto err;
                k=(st_idx+j)-STATE_SIZE;
                if (k > 0)
                        {
-                       MD_Update(&m,&(state[st_idx]),j-k);
-                       MD_Update(&m,&(state[0]),k);
+                       if (!MD_Update(&m,&(state[st_idx]),j-k))
+                               goto err;
+                       if (!MD_Update(&m,&(state[0]),k))
+                               goto err;
                        }
                else
-                       MD_Update(&m,&(state[st_idx]),j);
-                       
-               MD_Update(&m,buf,j);
-               MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));
-               MD_Final(&m,local_md);
+                       if (!MD_Update(&m,&(state[st_idx]),j))
+                               goto err;
+
+               /* DO NOT REMOVE THE FOLLOWING CALL TO MD_Update()! */
+               if (!MD_Update(&m,buf,j))
+                       goto err;
+               /* 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. */
+
+               if (!MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c)))
+                       goto err;
+               if (!MD_Final(&m,local_md))
+                       goto err;
                md_c[1]++;
 
                buf=(const char *)buf + j;
@@ -296,7 +331,6 @@ static void ssleay_rand_add(const void *buf, size_t num, double add)
                                st_idx=0;
                        }
                }
-       EVP_MD_CTX_cleanup(&m);
 
        if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND);
        /* Don't just copy back local_md into md -- this could mean that
@@ -314,18 +348,21 @@ static void ssleay_rand_add(const void *buf, size_t num, double add)
 #if !defined(OPENSSL_THREADS) && !defined(OPENSSL_SYS_WIN32)
        assert(md_c[1] == md_count[1]);
 #endif
+       rv = 1;
+       err:
+       EVP_MD_CTX_cleanup(&m);
+       return rv;
        }
 
-static void ssleay_rand_seed(const void *buf, size_t num)
+static int ssleay_rand_seed(const void *buf, int num)
        {
-       ssleay_rand_add(buf, num, (double)num);
+       return 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;
-       ssize_t j,k;
+       int i,j,k,st_num,st_idx;
        int num_ceil;
        int ok;
        long md_c[2];
@@ -334,7 +371,28 @@ static int ssleay_rand_bytes(unsigned char *buf, size_t num)
 #ifndef GETPID_IS_MEANINGLESS
        pid_t curr_pid = getpid();
 #endif
+       time_t curr_time = time(NULL);
        int do_stir_pool = 0;
+/* time value for various platforms */
+#ifdef OPENSSL_SYS_WIN32
+       FILETIME tv;
+# ifdef _WIN32_WCE
+       SYSTEMTIME t;
+       GetSystemTime(&t);
+       SystemTimeToFileTime(&t, &tv);
+# else
+       GetSystemTimeAsFileTime(&tv);
+# endif
+#elif defined(OPENSSL_SYS_VXWORKS)
+       struct timespec tv;
+       clock_gettime(CLOCK_REALTIME, &ts);
+#elif defined(OPENSSL_SYSNAME_DSPBIOS)
+       unsigned long long tv, OPENSSL_rdtsc();
+       tv = OPENSSL_rdtsc();
+#else
+       struct timeval tv;
+       gettimeofday(&tv, NULL);
+#endif
 
 #ifdef PREDICT
        if (rand_predictable)
@@ -458,28 +516,58 @@ static int ssleay_rand_bytes(unsigned char *buf, size_t num)
                /* num_ceil -= MD_DIGEST_LENGTH/2 */
                j=(num >= MD_DIGEST_LENGTH/2)?MD_DIGEST_LENGTH/2:num;
                num-=j;
-               MD_Init(&m);
+               if (!MD_Init(&m))
+                       goto err;
 #ifndef GETPID_IS_MEANINGLESS
                if (curr_pid) /* just in the first iteration to save time */
                        {
-                       MD_Update(&m,(unsigned char*)&curr_pid,sizeof curr_pid);
+                       if (!MD_Update(&m,(unsigned char*)&curr_pid,
+                                      sizeof curr_pid))
+                               goto err;
                        curr_pid = 0;
                        }
 #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 */
+               if (curr_time) /* just in the first iteration to save time */
+                       {
+                       if (!MD_Update(&m,(unsigned char*)&curr_time,
+                                      sizeof curr_time))
+                               goto err;
+                       if (!MD_Update(&m,(unsigned char*)&tv,
+                                      sizeof tv))
+                               goto err;
+                       curr_time = 0;
+                       rand_hw_seed(&m);
+                       }
+               if (!MD_Update(&m,local_md,MD_DIGEST_LENGTH))
+                       goto err;
+               if (!MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c)))
+                       goto err;
+
+#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.
+                */
+               if (!MD_Update(&m,buf,j))
+                       goto err;
 #endif
+
                k=(st_idx+MD_DIGEST_LENGTH/2)-st_num;
                if (k > 0)
                        {
-                       MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2-k);
-                       MD_Update(&m,&(state[0]),k);
+                       if (!MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2-k))
+                               goto err;
+                       if (!MD_Update(&m,&(state[0]),k))
+                               goto err;
                        }
                else
-                       MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2);
-               MD_Final(&m,local_md);
+                       if (!MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2))
+                               goto err;
+               if (!MD_Final(&m,local_md))
+                       goto err;
 
                for (i=0; i<MD_DIGEST_LENGTH/2; i++)
                        {
@@ -491,42 +579,47 @@ static int ssleay_rand_bytes(unsigned char *buf, size_t num)
                        }
                }
 
-       MD_Init(&m);
-       MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));
-       MD_Update(&m,local_md,MD_DIGEST_LENGTH);
+       if (!MD_Init(&m)
+               || !MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c))
+               || !MD_Update(&m,local_md,MD_DIGEST_LENGTH))
+               goto err;
        CRYPTO_w_lock(CRYPTO_LOCK_RAND);
-       MD_Update(&m,md,MD_DIGEST_LENGTH);
-       MD_Final(&m,md);
+       if (!MD_Update(&m,md,MD_DIGEST_LENGTH) || !MD_Final(&m,md))
+               {
+               CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
+               goto err;
+               }
        CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
 
        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, "
                        "http://www.openssl.org/support/faq.html");
                return(0);
                }
+       err:
+       EVP_MD_CTX_cleanup(&m);
+       RANDerr(RAND_F_SSLEAY_RAND_BYTES,ERR_R_EVP_LIB);
+       return 0;
+
+       }
+
+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)
@@ -576,3 +669,79 @@ static int ssleay_rand_status(void)
        
        return ret;
        }
+
+/* rand_hw_seed: get seed data from any available hardware RNG.
+ * only currently supports rdrand.
+ */
+
+/* Adapted from eng_rdrand.c */
+
+#if (defined(__i386)   || defined(__i386__)   || defined(_M_IX86) || \
+     defined(__x86_64) || defined(__x86_64__) || \
+     defined(_M_AMD64) || defined (_M_X64)) && defined(OPENSSL_CPUID_OBJ)
+
+#define RDRAND_CALLS   4
+
+size_t OPENSSL_ia32_rdrand(void);
+extern unsigned int OPENSSL_ia32cap_P[];
+
+static void rand_hw_seed(EVP_MD_CTX *ctx)
+       {
+       int i;
+       if (!(OPENSSL_ia32cap_P[1] & (1<<(62-32))))
+               return;
+       for (i = 0; i < RDRAND_CALLS; i++)
+               {
+               size_t rnd;
+               rnd = OPENSSL_ia32_rdrand();
+               if (rnd == 0)
+                       return;
+               MD_Update(ctx, (unsigned char *)&rnd, sizeof(size_t));
+               }
+       }
+
+/* XOR an existing buffer with random data */
+
+void rand_hw_xor(unsigned char *buf, size_t num)
+       {
+       size_t rnd;
+       if (!(OPENSSL_ia32cap_P[1] & (1<<(62-32))))
+               return;
+       while (num >= sizeof(size_t))
+               {
+               rnd = OPENSSL_ia32_rdrand();
+               if (rnd == 0)
+                       return;
+               *((size_t *)buf) ^= rnd;
+               buf += sizeof(size_t);
+               num -= sizeof(size_t);
+               }
+       if (num)
+               {
+               rnd = OPENSSL_ia32_rdrand();
+               if (rnd == 0)
+                       return;
+               while(num)
+                       {
+                       *buf ^= rnd & 0xff;
+                       rnd >>= 8;
+                       buf++;
+                       num--;
+                       }
+               }
+       }
+
+
+#else
+
+static void rand_hw_seed(EVP_MD_CTX *ctx)
+       {
+       return;
+       }
+
+void rand_hw_xor(unsigned char *buf, size_t num)
+       {
+       return;
+       }
+
+#endif