1 files changed, 53 insertions, 11 deletions

diff --git a/helper.c b/helper.c
index 91a78b577..bf4e145b2 100644
--- a/helper.c
+++ b/helper.c
@@ -45,7 +45,6 @@
 #include <sys/un.h>
 #include <fcntl.h>
 
-#include "rc4.h"
 #include "xmalloc.h"
 #include "ssh.h"
 #include "config.h"
@@ -57,10 +56,58 @@
 
 #ifndef HAVE_ARC4RANDOM
 
+typedef struct
+{
+        unsigned int s[256];
+        int i;
+        int j;
+} rc4_t;
+
 void get_random_bytes(unsigned char *buf, int len);
+void rc4_key(rc4_t *r, unsigned char *key, int len);
+void rc4_getbytes(rc4_t *r, unsigned char *buffer, int len);
 
 static rc4_t *rc4 = NULL;
 
+void rc4_key(rc4_t *r, unsigned char *key, int len)
+{
+        int t;
+        
+        for(r->i = 0; r->i < 256; r->i++)
+                r->s[r->i] = r->i;
+
+        r->j = 0;
+        for(r->i = 0; r->i < 256; r->i++)
+        {
+                r->j = (r->j + r->s[r->i] + key[r->i % len]) % 256;
+                t = r->s[r->i];
+                r->s[r->i] = r->s[r->j];
+                r->s[r->j] = t;
+        }
+        r->i = r->j = 0;
+}
+
+void rc4_getbytes(rc4_t *r, unsigned char *buffer, int len)
+{
+        int t;
+        int c;
+
+        c = 0;  
+        while(c < len)
+        {
+                r->i = (r->i + 1) % 256;
+                r->j = (r->j + r->s[r->i]) % 256;
+                t = r->s[r->i];
+                r->s[r->i] = r->s[r->j];
+                r->s[r->j] = t;
+
+                t = (r->s[r->i] + r->s[r->j]) % 256;
+                
+                buffer[c] = r->s[t];
+                c++;
+        }
+}
+
 unsigned int arc4random(void)
 {
         unsigned int r;
@@ -117,7 +164,8 @@ void get_random_bytes(unsigned char *buf, int len)
         
         /* Send blocking read request to EGD */
         egd_message[1] = len;
-        c = write(random_pool, egd_message, sizeof(egd_message));
+
+        c = atomicio(write, random_pool, egd_message, sizeof(egd_message));
         if (c == -1)
                 fatal("Couldn't write to EGD socket \"%s\": %s", RANDOM_POOL, strerror(errno));
 
@@ -129,15 +177,9 @@ void get_random_bytes(unsigned char *buf, int len)
 
 #endif /* HAVE_EGD */
 
-        do {
-                c = read(random_pool, buf, len);
-
-                if ((c == -1) && (errno != EINTR))
-                        fatal("Couldn't read from random pool \"%s\": %s", RANDOM_POOL, strerror(errno));
-        } while (c == -1);
-
-        if (c != len)
-                fatal("Short read from random pool \"%s\"", RANDOM_POOL);
+        c = atomicio(read, random_pool, buf, len);
+        if (c <= 0)
+                fatal("Couldn't read from random pool \"%s\": %s", RANDOM_POOL, strerror(errno));
         
         close(random_pool);
 }