Improve reading from external data source for session id creation.

Improve generating the string representation of the md5 session id.

diff --git a/ext/session/session.c b/ext/session/session.c
index d737f841f2b84f3dea2414561eb31022d0d42c21..9be12ff7e53ca3fe23974c387ecca6fa17e1255b 100644 (file)
--- a/ext/session/session.c
+++ b/ext/session/session.c
@@ -458,6 +458,8 @@ static void php_session_decode(const char *val, int vallen PSLS_DC)
        }
 }
 
+static char hexconvtab[] = "0123456789abcdef";
+
 static char *_php_create_id(int *newlen PSLS_DC)
 {
        PHP_MD5_CTX context;
@@ -465,6 +467,8 @@ static char *_php_create_id(int *newlen PSLS_DC)
        char buf[256];
        struct timeval tv;
        int i;
+       int j = 0;
+       unsigned char c;
 
        gettimeofday(&tv, NULL);
        PHP_MD5Init(&context);
@@ -477,27 +481,31 @@ static char *_php_create_id(int *newlen PSLS_DC)
 
                fd = VCWD_OPEN((PS(entropy_file), O_RDONLY));
                if (fd >= 0) {
-                       char *p;
+                       char buf[2048];
                        int n;
+                       int to_read = PS(entropy_length);
                        
-                       p = emalloc(PS(entropy_length));
-                       n = read(fd, p, PS(entropy_length));
-                       if (n > 0) {
-                               PHP_MD5Update(&context, p, n);
+                       while (to_read > 0) {
+                               n = read(fd, buf, MIN(to_read, sizeof(buf)));
+                               if (n <= 0) break;
+                               PHP_MD5Update(&context, buf, n);
+                               to_read -= n;
                        }
-                       efree(p);
                        close(fd);
                }
        }
 
        PHP_MD5Final(digest, &context);
-
-       for (i = 0; i < 16; i++)
-               sprintf(buf + (i << 1), "%02x", digest[i]);
-       buf[i << 1] = '\0';
+       
+       for (i = 0; i < 16; i++) {
+               c = digest[i];
+               buf[j++] = hexconvtab[c >> 4];
+               buf[j++] = hexconvtab[c & 15];
+       }
+       buf[j] = '\0';
        
        if (newlen) 
-               *newlen = i << 1;
+               *newlen = j;
        return estrdup(buf);
 }