AFAICS lst1 stands for "lshift test" not "list".

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

diff --git a/crypto/rand/md_rand.c b/crypto/rand/md_rand.c
index 26bb1244d06f3af1405debd5b85813b8ca5a0892..7b8cde94012241467524596eadde681ca444aff4 100644 (file)
--- a/crypto/rand/md_rand.c
+++ b/crypto/rand/md_rand.c
@@ -56,6 +56,8 @@
  * [including the GNU Public Licence.]
  */
 
+#define ENTROPY_NEEDED 32  /* require 128 bits of randomness */
+
 #ifndef MD_RAND_DEBUG
 # ifndef NDEBUG
 #   define NDEBUG
@@ -70,6 +72,7 @@
 #include "openssl/e_os.h"
 
 #include <openssl/crypto.h>
+#include <openssl/err.h>
 
 #if !defined(USE_MD5_RAND) && !defined(USE_SHA1_RAND) && !defined(USE_MDC2_RAND) && !defined(USE_MD2_RAND)
 #if !defined(NO_SHA) && !defined(NO_SHA1)
@@ -135,17 +138,22 @@ static int state_num=0,state_index=0;
 static unsigned char state[STATE_SIZE+MD_DIGEST_LENGTH];
 static unsigned char md[MD_DIGEST_LENGTH];
 static long md_count[2]={0,0};
+static int entropy=0;
 
 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_bytes(unsigned char *buf, int num);
+static void ssleay_rand_add(const void *buf, int num, int add_entropy);
+static int ssleay_rand_bytes(unsigned char *buf, int num);
+static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num);
 
 RAND_METHOD rand_ssleay_meth={
        ssleay_rand_seed,
        ssleay_rand_bytes,
        ssleay_rand_cleanup,
+       ssleay_rand_add,
+       ssleay_rand_pseudo_bytes,
        }; 
 
 RAND_METHOD *RAND_SSLeay(void)
@@ -161,9 +169,10 @@ static void ssleay_rand_cleanup(void)
        memset(md,0,MD_DIGEST_LENGTH);
        md_count[0]=0;
        md_count[1]=0;
+       entropy=0;
        }
 
-static void ssleay_rand_seed(const void *buf, int num)
+static void ssleay_rand_add(const void *buf, int num, int add)
        {
        int i,j,k,st_idx;
        long md_c[2];
@@ -276,19 +285,25 @@ static void ssleay_rand_seed(const void *buf, int num)
 #ifndef THREADS        
        assert(md_c[1] == md_count[1]);
 #endif
+       entropy += add;
+       }
+
+static void ssleay_rand_seed(const void *buf, int num)
+       {
+       ssleay_rand_add(buf, num, num);
        }
 
-static void ssleay_rand_bytes(unsigned char *buf, int num)
+static int ssleay_rand_bytes(unsigned char *buf, int num)
        {
        int i,j,k,st_num,st_idx;
+       int ok;
        long md_c[2];
        unsigned char local_md[MD_DIGEST_LENGTH];
        MD_CTX m;
        static int init=1;
        unsigned long l;
-#ifndef MSDOS
-       static pid_t prev_pid = 0;
-       pid_t curr_pid;
+#ifndef GETPID_IS_MEANINGLESS
+       pid_t curr_pid = getpid();
 #endif
 #ifdef DEVRANDOM
        FILE *fh;
@@ -300,7 +315,7 @@ static void ssleay_rand_bytes(unsigned char *buf, int num)
 
        for (i=0; i<num; i++)
                buf[i]=val++;
-       return;
+       return(1);
        }
 #endif
 
@@ -327,16 +342,15 @@ static void ssleay_rand_bytes(unsigned char *buf, int num)
                CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
                /* put in some default random data, we need more than
                 * just this */
-               RAND_seed(&m,sizeof(m));
-#ifndef MSDOS
-               prev_pid = getpid();
-               l=prev_pid;
-               RAND_seed(&l,sizeof(l));
+               RAND_add(&m,sizeof(m),0);
+#ifndef GETPID_IS_MEANINGLESS
+               l=curr_pid;
+               RAND_add(&l,sizeof(l),0);
                l=getuid();
-               RAND_seed(&l,sizeof(l));
+               RAND_add(&l,sizeof(l),0);
 #endif
                l=time(NULL);
-               RAND_seed(&l,sizeof(l));
+               RAND_add(&l,sizeof(l),0);
 
 #ifdef DEVRANDOM
                /* 
@@ -348,15 +362,13 @@ static void ssleay_rand_bytes(unsigned char *buf, int num)
                 */
                if ((fh = fopen(DEVRANDOM, "r")) != NULL)
                        {
-                       unsigned char tmpbuf[32];
+                       unsigned char tmpbuf[ENTROPY_NEEDED];
+                       int n;
 
-                       fread((unsigned char *)tmpbuf,1,32,fh);
-                       /* we don't care how many bytes we read,
-                        * we will just copy the 'stack' if there is
-                        * nothing else :-) */
+                       n=fread((unsigned char *)tmpbuf,1,ENTROPY_NEEDED,fh);
                        fclose(fh);
-                       RAND_seed(tmpbuf,32);
-                       memset(tmpbuf,0,32);
+                       RAND_add(tmpbuf,sizeof tmpbuf,n);
+                       memset(tmpbuf,0,n);
                        }
 #endif
 #ifdef PURIFY
@@ -367,19 +379,7 @@ static void ssleay_rand_bytes(unsigned char *buf, int num)
                init=0;
                }
 
-#ifndef MSDOS
-       /* make sure we have unique states when a program forks
-        * (new with OpenSSL 0.9.5; for earlier versions, applications
-        * must take care of this) */
-       curr_pid = getpid();
-       if (prev_pid != curr_pid)
-               {
-               prev_pid = curr_pid;
-               CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
-               RAND_seed(&curr_pid, sizeof curr_pid);
-               CRYPTO_w_lock(CRYPTO_LOCK_RAND);
-               }
-#endif
+       ok = (entropy >= ENTROPY_NEEDED);
 
        st_idx=state_index;
        st_num=state_num;
@@ -402,6 +402,13 @@ static void ssleay_rand_bytes(unsigned char *buf, int num)
                j=(num >= MD_DIGEST_LENGTH/2)?MD_DIGEST_LENGTH/2:num;
                num-=j;
                MD_Init(&m);
+#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);
+                       curr_pid = 0;
+                       }
+#endif
                MD_Update(&m,&(local_md[MD_DIGEST_LENGTH/2]),MD_DIGEST_LENGTH/2);
                MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c));
 #ifndef PURIFY
@@ -435,6 +442,30 @@ static void ssleay_rand_bytes(unsigned char *buf, int num)
        CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
 
        memset(&m,0,sizeof(m));
+       if (ok)
+               return(1);
+       else
+               {
+               RANDerr(RAND_F_SSLEAY_RAND_BYTES,RAND_R_PRNG_NOT_SEEDED);
+               return(0);
+               }
+       }
+
+/* pseudo-random bytes that are guaranteed to be unique but not
+   unpredictable */
+static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num) 
+       {
+       int ret, 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)
+                       (void)ERR_get_error();
+               }
+       return (ret);
        }
 
 #ifdef WINDOWS