fread() of /dev/random reads an entire huge stdio buffer, instead of the 32

bytes that we actually need, thus wasting a lot of system entropy. found by
alecm@coyote.uk.sun.com, passed on by Pete.Zaytsev@EBay.Sun.COM

2 files changed, 18 insertions, 10 deletions

diff --git a/src/lib/libcrypto/rand/md_rand.c b/src/lib/libcrypto/rand/md_rand.c
index 6bd1960e1d..c9a071bd22 100644
--- a/src/lib/libcrypto/rand/md_rand.c
+++ b/src/lib/libcrypto/rand/md_rand.c
@@ -58,6 +58,7 @@
 
 #include <stdio.h>
 #include <sys/types.h>
+#include <fcntl.h>
 #include <time.h>
 #include <string.h>
 
@@ -226,7 +227,7 @@ static void ssleay_rand_bytes(unsigned char *buf, int num)
         static int init=1;
         unsigned long l;
 #ifdef DEVRANDOM
-        FILE *fh;
+        int fd;
 #endif
 
 #ifdef PREDICT
@@ -259,20 +260,23 @@ static void ssleay_rand_bytes(unsigned char *buf, int num)
 /* #ifdef DEVRANDOM */
                 /* 
                  * Use a random entropy pool device.
-                 * Linux 1.3.x and FreeBSD-Current has 
+                 * Linux 1.3.x, OpenBSD, and FreeBSD have
                  * this. Use /dev/urandom if you can
                  * as /dev/random will block if it runs out
                  * of random entries.
                  */
-                if ((fh = fopen(DEVRANDOM, "r")) != NULL)
+                if ((fd = open(DEVRANDOM, O_RDONLY)) != NULL)
                         {
                         unsigned char tmpbuf[32];
 
-                        fread((unsigned char *)tmpbuf,1,32,fh);
+                        read(fd, tmpbuf, sizeof(tmpbuf));
                         /* we don't care how many bytes we read,
                          * we will just copy the 'stack' if there is
                          * nothing else :-) */
-                        fclose(fh);
+                        /* the above comment is EVIL.  Security software
+                         * RELIES ON THESE PRIMITIVES HAVING MORE SECURE
+                         * BEHAVIOUR! Secure entropy is required in
+                         * many cases! */
                         RAND_seed(tmpbuf,32);
                         memset(tmpbuf,0,32);
                         }
diff --git a/src/lib/libssl/src/crypto/rand/md_rand.c b/src/lib/libssl/src/crypto/rand/md_rand.c
index 6bd1960e1d..c9a071bd22 100644
--- a/src/lib/libssl/src/crypto/rand/md_rand.c
+++ b/src/lib/libssl/src/crypto/rand/md_rand.c
@@ -58,6 +58,7 @@
 
 #include <stdio.h>
 #include <sys/types.h>
+#include <fcntl.h>
 #include <time.h>
 #include <string.h>
 
@@ -226,7 +227,7 @@ static void ssleay_rand_bytes(unsigned char *buf, int num)
         static int init=1;
         unsigned long l;
 #ifdef DEVRANDOM
-        FILE *fh;
+        int fd;
 #endif
 
 #ifdef PREDICT
@@ -259,20 +260,23 @@ static void ssleay_rand_bytes(unsigned char *buf, int num)
 /* #ifdef DEVRANDOM */
                 /* 
                  * Use a random entropy pool device.
-                 * Linux 1.3.x and FreeBSD-Current has 
+                 * Linux 1.3.x, OpenBSD, and FreeBSD have
                  * this. Use /dev/urandom if you can
                  * as /dev/random will block if it runs out
                  * of random entries.
                  */
-                if ((fh = fopen(DEVRANDOM, "r")) != NULL)
+                if ((fd = open(DEVRANDOM, O_RDONLY)) != NULL)
                         {
                         unsigned char tmpbuf[32];
 
-                        fread((unsigned char *)tmpbuf,1,32,fh);
+                        read(fd, tmpbuf, sizeof(tmpbuf));
                         /* we don't care how many bytes we read,
                          * we will just copy the 'stack' if there is
                          * nothing else :-) */
-                        fclose(fh);
+                        /* the above comment is EVIL.  Security software
+                         * RELIES ON THESE PRIMITIVES HAVING MORE SECURE
+                         * BEHAVIOUR! Secure entropy is required in
+                         * many cases! */
                         RAND_seed(tmpbuf,32);
                         memset(tmpbuf,0,32);
                         }