X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Frand%2Fmd_rand.c;h=48cc2e84a84bde86740600f1cc3504b591dcd92b;hp=d4d2f36ad4f2acf998d93b6bcc7c44b26c8fcc67;hb=d40a1b865fddc3d67f8c06ff1f1466fad331c8f7;hpb=47b0f48dd9f849f0149f5a5809292e322e129080

diff --git a/crypto/rand/md_rand.c b/crypto/rand/md_rand.c
index d4d2f36ad4..48cc2e84a8 100644
--- a/crypto/rand/md_rand.c
+++ b/crypto/rand/md_rand.c
@@ -56,7 +56,7 @@
  * [including the GNU Public Licence.]
  */
 /* ====================================================================
- * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
+ * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -144,20 +144,21 @@ static int initialized=0;
 static unsigned int crypto_lock_rand = 0; /* may be set only when a thread
                                            * holds CRYPTO_LOCK_RAND
                                            * (to prevent double locking) */
-static unsigned long locking_thread = 0; /* valid iff crypto_lock_rand is set */
+/* access to lockin_thread is synchronized by CRYPTO_LOCK_RAND2 */
+static CRYPTO_THREADID locking_threadid; /* valid iff crypto_lock_rand is set */
 
 
 #ifdef PREDICT
 int rand_predictable=0;
 #endif
 
-const char *RAND_version="RAND" OPENSSL_VERSION_PTEXT;
+const char RAND_version[]="RAND" OPENSSL_VERSION_PTEXT;
 
 static void ssleay_rand_cleanup(void);
-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);
-static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num);
+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_status(void);
 
 RAND_METHOD rand_ssleay_meth={
@@ -176,22 +177,24 @@ RAND_METHOD *RAND_SSLeay(void)
 
 static void ssleay_rand_cleanup(void)
 	{
-	memset(state,0,sizeof(state));
+	OPENSSL_cleanse(state,sizeof(state));
 	state_num=0;
 	state_index=0;
-	memset(md,0,MD_DIGEST_LENGTH);
+	OPENSSL_cleanse(md,MD_DIGEST_LENGTH);
 	md_count[0]=0;
 	md_count[1]=0;
 	entropy=0;
 	initialized=0;
 	}
 
-static void ssleay_rand_add(const void *buf, int num, double add)
+static void ssleay_rand_add(const void *buf, size_t num, double add)
 	{
-	int i,j,k,st_idx;
+	int i,st_idx;
+	size_t j;
+	ssize_t k;
 	long md_c[2];
 	unsigned char local_md[MD_DIGEST_LENGTH];
-	MD_CTX m;
+	EVP_MD_CTX m;
 	int do_not_lock;
 
 	/*
@@ -210,7 +213,16 @@ static void ssleay_rand_add(const void *buf, int num, double add)
 	 */
 
 	/* check if we already have the lock */
-	do_not_lock = crypto_lock_rand && (locking_thread == CRYPTO_thread_id());
+	if (crypto_lock_rand)
+		{
+		CRYPTO_THREADID cur;
+		CRYPTO_THREADID_current(&cur);
+		CRYPTO_r_lock(CRYPTO_LOCK_RAND2);
+		do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur);
+		CRYPTO_r_unlock(CRYPTO_LOCK_RAND2);
+		}
+	else
+		do_not_lock = 0;
 
 	if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND);
 	st_idx=state_index;
@@ -246,6 +258,7 @@ static void ssleay_rand_add(const void *buf, int 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);
@@ -264,7 +277,7 @@ static void ssleay_rand_add(const void *buf, int num, double add)
 			
 		MD_Update(&m,buf,j);
 		MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));
-		MD_Final(local_md,&m);
+		MD_Final(&m,local_md);
 		md_c[1]++;
 
 		buf=(const char *)buf + j;
@@ -284,14 +297,14 @@ static void ssleay_rand_add(const void *buf, int num, double add)
 				st_idx=0;
 			}
 		}
-	memset((char *)&m,0,sizeof(m));
+	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
 	 * 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 < sizeof(md); k++)
 		{
 		md[k] ^= local_md[k];
 		}
@@ -304,19 +317,22 @@ static void ssleay_rand_add(const void *buf, int num, double add)
 #endif
 	}
 
-static void ssleay_rand_seed(const void *buf, int num)
+static void ssleay_rand_seed(const void *buf, size_t num)
 	{
-	ssleay_rand_add(buf, num, num);
+	ssleay_rand_add(buf, num, (double)num);
 	}
 
-static int ssleay_rand_bytes(unsigned char *buf, int num)
+static int ssleay_rand_bytes(unsigned char *buf, size_t num)
 	{
 	static volatile int stirred_pool = 0;
-	int i,j,k,st_num,st_idx;
+	int i,st_num,st_idx;
+	size_t j;
+	ssize_t k;
+	int num_ceil;
 	int ok;
 	long md_c[2];
 	unsigned char local_md[MD_DIGEST_LENGTH];
-	MD_CTX m;
+	EVP_MD_CTX m;
 #ifndef GETPID_IS_MEANINGLESS
 	pid_t curr_pid = getpid();
 #endif
@@ -333,19 +349,25 @@ static int ssleay_rand_bytes(unsigned char *buf, int num)
 		}
 #endif
 
+	if (num <= 0)
+		return 1;
+
+	EVP_MD_CTX_init(&m);
+	/* round upwards to multiple of MD_DIGEST_LENGTH/2 */
+	num_ceil = (1 + (num-1)/(MD_DIGEST_LENGTH/2)) * (MD_DIGEST_LENGTH/2);
+
 	/*
 	 * (Based on the rand(3) manpage:)
 	 *
 	 * For each group of 10 bytes (or less), we do the following:
 	 *
-	 * Input into the hash function the top 10 bytes from the
-	 * local 'md' (which is initialized from the global 'md'
-	 * before any bytes are generated), the bytes that are
-	 * to be overwritten by the random bytes, and bytes from the
-	 * 'state' (incrementing looping index).  From this digest output
-	 * (which is kept in 'md'), the top (up to) 10 bytes are
-	 * returned to the caller and the bottom (up to) 10 bytes are xored
-	 * into the 'state'.
+	 * Input into the hash function the local 'md' (which is initialized from
+	 * the global 'md' before any bytes are generated), the bytes that are to
+	 * be overwritten by the random bytes, and bytes from the 'state'
+	 * (incrementing looping index). From this digest output (which is kept
+	 * in 'md'), the top (up to) 10 bytes are returned to the caller and the
+	 * bottom 10 bytes are xored into the 'state'.
+	 * 
 	 * Finally, after we have finished 'num' random bytes for the
 	 * caller, 'count' (which is incremented) and the local and global 'md'
 	 * are fed into the hash function and the results are kept in the
@@ -355,8 +377,10 @@ static int ssleay_rand_bytes(unsigned char *buf, int num)
 	CRYPTO_w_lock(CRYPTO_LOCK_RAND);
 
 	/* prevent ssleay_rand_bytes() from trying to obtain the lock again */
+	CRYPTO_w_lock(CRYPTO_LOCK_RAND2);
+	CRYPTO_THREADID_current(&locking_threadid);
+	CRYPTO_w_unlock(CRYPTO_LOCK_RAND2);
 	crypto_lock_rand = 1;
-	locking_thread = CRYPTO_thread_id();
 
 	if (!initialized)
 		{
@@ -389,11 +413,11 @@ static int ssleay_rand_bytes(unsigned char *buf, int num)
 
 	if (do_stir_pool)
 		{
-		/* Our output function chains only half of 'md', so we better
-		 * make sure that the required entropy gets 'evenly distributed'
-		 * through 'state', our randomness pool.  The input function
-		 * (ssleay_rand_add) chains all of 'md', which makes it more
-		 * suitable for this purpose.
+		/* In the output function only half of 'md' remains secret,
+		 * so we better make sure that the required entropy gets
+		 * 'evenly distributed' through 'state', our randomness pool.
+		 * The input function (ssleay_rand_add) chains all of 'md',
+		 * which makes it more suitable for this purpose.
 		 */
 
 		int n = STATE_SIZE; /* so that the complete pool gets accessed */
@@ -418,22 +442,22 @@ static int ssleay_rand_bytes(unsigned char *buf, int num)
 	md_c[1] = md_count[1];
 	memcpy(local_md, md, sizeof md);
 
-	state_index+=num;
+	state_index+=num_ceil;
 	if (state_index > state_num)
 		state_index %= state_num;
 
-	/* state[st_idx], ..., state[(st_idx + num - 1) % st_num]
+	/* state[st_idx], ..., state[(st_idx + num_ceil - 1) % st_num]
 	 * are now ours (but other threads may use them too) */
 
 	md_count[0] += 1;
 
 	/* before unlocking, we must clear 'crypto_lock_rand' */
 	crypto_lock_rand = 0;
-	locking_thread = 0;
 	CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
 
 	while (num > 0)
 		{
+		/* num_ceil -= MD_DIGEST_LENGTH/2 */
 		j=(num >= MD_DIGEST_LENGTH/2)?MD_DIGEST_LENGTH/2:num;
 		num-=j;
 		MD_Init(&m);
@@ -444,39 +468,40 @@ static int ssleay_rand_bytes(unsigned char *buf, int num)
 			curr_pid = 0;
 			}
 #endif
-		MD_Update(&m,&(local_md[MD_DIGEST_LENGTH/2]),MD_DIGEST_LENGTH/2);
+		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 */
 #endif
-		k=(st_idx+j)-st_num;
+		k=(st_idx+MD_DIGEST_LENGTH/2)-st_num;
 		if (k > 0)
 			{
-			MD_Update(&m,&(state[st_idx]),j-k);
+			MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2-k);
 			MD_Update(&m,&(state[0]),k);
 			}
 		else
-			MD_Update(&m,&(state[st_idx]),j);
-		MD_Final(local_md,&m);
+			MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2);
+		MD_Final(&m,local_md);
 
-		for (i=0; i<j; i++)
+		for (i=0; i<MD_DIGEST_LENGTH/2; i++)
 			{
 			state[st_idx++]^=local_md[i]; /* may compete with other threads */
-			*(buf++)=local_md[i+MD_DIGEST_LENGTH/2];
 			if (st_idx >= st_num)
 				st_idx=0;
+			if (i < j)
+				*(buf++)=local_md[i+MD_DIGEST_LENGTH/2];
 			}
 		}
 
 	MD_Init(&m);
-	MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));
+	MD_Update(&m,&(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);
-	MD_Final(md,&m);
+	MD_Final(&m,md);
 	CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
 
-	memset(&m,0,sizeof(m));
+	EVP_MD_CTX_cleanup(&m);
 	if (ok)
 		return(1);
 	else
@@ -490,7 +515,7 @@ static int ssleay_rand_bytes(unsigned char *buf, int num)
 
 /* pseudo-random bytes that are guaranteed to be unique but not
    unpredictable */
-static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num) 
+static int ssleay_rand_pseudo_bytes(unsigned char *buf, size_t num) 
 	{
 	int ret;
 	unsigned long err;
@@ -501,27 +526,38 @@ static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num)
 		err = ERR_peek_error();
 		if (ERR_GET_LIB(err) == ERR_LIB_RAND &&
 		    ERR_GET_REASON(err) == RAND_R_PRNG_NOT_SEEDED)
-			(void)ERR_get_error();
+			ERR_clear_error();
 		}
 	return (ret);
 	}
 
 static int ssleay_rand_status(void)
 	{
+	CRYPTO_THREADID cur;
 	int ret;
 	int do_not_lock;
 
+	CRYPTO_THREADID_current(&cur);
 	/* check if we already have the lock
 	 * (could happen if a RAND_poll() implementation calls RAND_status()) */
-	do_not_lock = crypto_lock_rand && (locking_thread == CRYPTO_thread_id());
+	if (crypto_lock_rand)
+		{
+		CRYPTO_r_lock(CRYPTO_LOCK_RAND2);
+		do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur);
+		CRYPTO_r_unlock(CRYPTO_LOCK_RAND2);
+		}
+	else
+		do_not_lock = 0;
 	
 	if (!do_not_lock)
 		{
 		CRYPTO_w_lock(CRYPTO_LOCK_RAND);
 		
 		/* prevent ssleay_rand_bytes() from trying to obtain the lock again */
+		CRYPTO_w_lock(CRYPTO_LOCK_RAND2);
+		CRYPTO_THREADID_cpy(&locking_threadid, &cur);
+		CRYPTO_w_unlock(CRYPTO_LOCK_RAND2);
 		crypto_lock_rand = 1;
-		locking_thread = CRYPTO_thread_id();
 		}
 	
 	if (!initialized)
@@ -536,7 +572,6 @@ static int ssleay_rand_status(void)
 		{
 		/* before unlocking, we must clear 'crypto_lock_rand' */
 		crypto_lock_rand = 0;
-		locking_thread = 0;
 		
 		CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
 		}