Third time lucky

[openssh.git] / helper.c

diff --git a/helper.c b/helper.c
index 3b0402ecf9cf1cff1fb0aea673ef6e3b6f002287..bf4e145b27a0630d475764c72275723800b4015b 100644 (file)
--- a/helper.c
+++ b/helper.c
@@ -41,30 +41,81 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/un.h>
 #include <fcntl.h>
 
-#include "rc4.h"
 #include "xmalloc.h"
-
+#include "ssh.h"
+#include "config.h"
 #include "helper.h"
 
+#ifndef offsetof
+#define offsetof(type, member) ((size_t) &((type *)0)->member)
+#endif
+
+#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 setproctitle(const char *fmt, ...)
+void rc4_key(rc4_t *r, unsigned char *key, int len)
 {
-       /* FIXME */
+       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;
 }
 
-unsigned char arc4random(void)
+void rc4_getbytes(rc4_t *r, unsigned char *buffer, int len)
 {
-       unsigned char r;
+       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;
 
        if (rc4 == NULL)
                arc4random_stir();
        
-       rc4_getbytes(rc4, &r, 1);
+       rc4_getbytes(rc4, (unsigned char *)&r, sizeof(r));
        
        return(r);
 }
@@ -82,27 +133,82 @@ void arc4random_stir(void)
 
 void get_random_bytes(unsigned char *buf, int len)
 {
-       int urandom;
+       static int random_pool;
        int c;
+#ifdef HAVE_EGD
+       char egd_message[2] = { 0x02, 0x00 };
+       struct sockaddr_un addr;
+       int addr_len;
+
+       memset(&addr, '\0', sizeof(addr));
+       addr.sun_family = AF_UNIX;
        
-       urandom = open("/dev/urandom", O_RDONLY);
-       if (urandom == -1)
-       {
-               fprintf(stderr, "Couldn't open /dev/urandom: %s", strerror(errno));
-               exit(1);
-       }
+       /* FIXME: compile time check? */
+       if (sizeof(RANDOM_POOL) > sizeof(addr.sun_path))
+               fatal("Random pool path is too long");
+       
+       strcpy(addr.sun_path, RANDOM_POOL);
+       
+       addr_len = offsetof(struct sockaddr_un, sun_path) + sizeof(RANDOM_POOL);
+       
+       random_pool = socket(AF_UNIX, SOCK_STREAM, 0);
        
-       c = read(urandom, buf, len);
+       if (random_pool == -1)
+               fatal("Couldn't create AF_UNIX socket: %s", strerror(errno));
+       
+       if (connect(random_pool, (struct sockaddr*)&addr, addr_len) == -1)
+               fatal("Couldn't connect to EGD socket \"%s\": %s", addr.sun_path, strerror(errno));
+
+       if (len > 255)
+               fatal("Too many bytes to read from EGD");
+       
+       /* Send blocking read request to EGD */
+       egd_message[1] = len;
+
+       c = atomicio(write, random_pool, egd_message, sizeof(egd_message));
        if (c == -1)
-       {
-               fprintf(stderr, "Couldn't read from /dev/urandom: %s", strerror(errno));
-               exit(1);
-       }
+               fatal("Couldn't write to EGD socket \"%s\": %s", RANDOM_POOL, strerror(errno));
 
-       if (c != len)
-       {
-               fprintf(stderr, "Short read from /dev/urandom");
-               exit(1);
-       }
+#else /* HAVE_EGD */
+
+       random_pool = open(RANDOM_POOL, O_RDONLY);
+       if (random_pool == -1)
+               fatal("Couldn't open random pool \"%s\": %s", RANDOM_POOL, strerror(errno));
+
+#endif /* HAVE_EGD */
+
+       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);
 }
+#endif /* !HAVE_ARC4RANDOM */
 
+#ifndef HAVE_SETPROCTITLE
+void setproctitle(const char *fmt, ...)
+{
+       /* FIXME */
+}
+#endif /* !HAVE_SETPROCTITLE */
+
+#ifndef HAVE_SETENV
+int setenv(const char *name, const char *value, int overwrite)
+{
+       char *env_string;
+       int result;
+       
+       /* Don't overwrite existing env. var if overwrite is 0 */
+       if (!overwrite && (getenv(name) != NULL))
+               return(0);
+       
+       env_string = xmalloc(strlen(name) + strlen(value) + 2);
+       sprintf(env_string, "%s=%s", name, value);
+       
+       result = putenv(env_string);
+       
+       xfree(env_string);
+       
+       return(result); 
+}
+#endif /* !HAVE_SETENV */