Fix invalid pointer arithmetic.

[nmh] / sbr / ruserpass.c

diff --git a/sbr/ruserpass.c b/sbr/ruserpass.c
index f5ef74a418187eba33e72b681cb332f2113ececd..5c47aa114a733872bf013af3b38d9b5087918db9 100644 (file)
--- a/sbr/ruserpass.c
+++ b/sbr/ruserpass.c
@@ -1,4 +1,5 @@
-/*
+/* ruserpass.c -- parse .netrc-format file.
+ *
  * Portions of this code are
  * Copyright (c) 1985 Regents of the University of California.
  * All rights reserved.
@@ -23,10 +24,10 @@
 #include <h/mh.h>
 #include <h/utils.h>
 #include <pwd.h>
-#include <errno.h>
 
 static FILE *cfile;
 
+#define TOK_EOF 0
 #define        DEFAULT 1
 #define        LOGIN   2
 #define        PASSWD  3
@@ -35,7 +36,7 @@ static FILE *cfile;
 #define        ID      10
 #define        MACH    11
 
-static char tokval[100];
+#define MAX_TOKVAL_SIZE 1024 /* Including terminating NUL. */
 
 struct toktab {
     char *tokstr;
@@ -43,6 +44,7 @@ struct toktab {
 };
 
 static struct toktab toktabs[] = {
+    { "",         TOK_EOF },
     { "default",  DEFAULT },
     { "login",    LOGIN },
     { "password", PASSWD },
@@ -56,11 +58,11 @@ static struct toktab toktabs[] = {
 /*
  * prototypes
  */
-static int token(void);
+static int token(char *);
 
 
 void
-ruserpass(char *host, char **aname, char **apass)
+ruserpass(const char *host, char **aname, char **apass, int flags)
 {
     int t, usedefault = 0;
     struct stat stb;
@@ -72,15 +74,18 @@ ruserpass(char *host, char **aname, char **apass)
        if (errno != ENOENT)
            perror (credentials_file);
     } else {
-       while ((t = token())) {
+        char tokval[MAX_TOKVAL_SIZE];
+        tokval[0] = '\0';
+
+       while ((t = token(tokval))) {
            switch(t) {
            case DEFAULT:
                usedefault = 1;
-               /* FALL THROUGH */
+               /* FALLTHRU */
 
            case MACH:
                if (!usedefault) {
-                   if (token() != ID)
+                   if (token(tokval) != ID)
                        continue;
                    /*
                     * Allow match either for user's host name.
@@ -90,29 +95,26 @@ ruserpass(char *host, char **aname, char **apass)
                    continue;
                }
            match:
-               while ((t = token()) && t != MACH && t != DEFAULT) {
+               while ((t = token(tokval)) && t != MACH && t != DEFAULT) {
                    switch(t) {
                    case LOGIN:
-                       if (token() && *aname == 0) {
-                           *aname = mh_xmalloc((size_t) strlen(tokval) + 1);
-                           strcpy(*aname, tokval);
-                       }
+                       if (token(tokval) && *aname == 0)
+                            *aname = mh_xstrdup(tokval);
                        break;
 
                    case PASSWD:
-                       if (fstat(fileno(cfile), &stb) >= 0 &&
+                       if (!credentials_no_perm_check &&
+                           fstat(fileno(cfile), &stb) >= 0 &&
                            (stb.st_mode & 077) != 0) {
                            /* We make this a fatal error to force the
                               user to correct it. */
-                           advise(NULL, "Error - file %s must not be world or "
-                                  "group readable.", credentials_file);
+                            inform("group or other permissions, %#o, "
+                                "forbidden: %s", stb.st_mode, credentials_file);
                            adios(NULL, "Remove password or correct file "
                                  "permissions.");
                        }
-                       if (token() && *apass == 0) {
-                           *apass = mh_xmalloc((size_t) strlen(tokval) + 1);
-                           strcpy(*apass, tokval);
-                       }
+                       if (token(tokval) && *apass == 0)
+                            *apass = mh_xstrdup(tokval);
                        break;
 
                    case ACCOUNT:
@@ -134,7 +136,7 @@ ruserpass(char *host, char **aname, char **apass)
        }
     }
 
-    if (!*aname) {
+    if (!*aname && ! (flags & RUSERPASS_NO_PROMPT_USER)) {
        char tmp[80];
        char *myname;
 
@@ -146,68 +148,77 @@ ruserpass(char *host, char **aname, char **apass)
        }
        printf("Name (%s:%s): ", host, myname);
 
-       fgets(tmp, sizeof(tmp) - 1, stdin);
-       tmp[strlen(tmp) - 1] = '\0';
-       if (*tmp != '\0') {
+       if (fgets(tmp, sizeof tmp, stdin) == NULL) {
+           advise ("tmp", "fgets");
+       }
+        trim_suffix_c(tmp, '\n');
+       if (*tmp != '\0' || myname == NULL) {
            myname = tmp;
        }
 
-       *aname = mh_xmalloc((size_t) strlen(myname) + 1);
-       strcpy (*aname, myname);
+        *aname = mh_xstrdup(myname);
     }
 
-    if (!*apass) {
+    if (!*apass && ! (flags & RUSERPASS_NO_PROMPT_PASSWORD)) {
        char prompt[256];
        char *mypass;
 
        snprintf(prompt, sizeof(prompt), "Password (%s:%s): ", host, *aname);
        mypass = nmh_getpass(prompt);
-       
+
        if (*mypass == '\0') {
            mypass = *aname;
        }
 
-       *apass = mh_xmalloc((size_t) strlen(mypass) + 1);
-       strcpy (*apass, mypass);
+        *aname = mh_xstrdup(mypass);
     }
 
 }
 
 static int
-token(void)
+token(char *tokval)
 {
-    char *cp;
     int c;
+    const char normalStop[] = "\t\n ,"; /* Each breaks a word. */
+    const char *stop;
+    char *cp;
     struct toktab *t;
 
-    if (feof(cfile))
-       return (0);
-    while ((c = getc(cfile)) != EOF &&
-          (c == '\n' || c == '\t' || c == ' ' || c == ','))
-       continue;
+    if (feof(cfile) || ferror(cfile))
+       return TOK_EOF;
+
+    stop = normalStop;
+    while ((c = getc(cfile)) != EOF && c && strchr(stop, c))
+        ;
     if (c == EOF)
-       return (0);
+       return TOK_EOF;
+
     cp = tokval;
-    if (c == '"') {
-       while ((c = getc(cfile)) != EOF && c != '"') {
-           if (c == '\\')
-               c = getc(cfile);
-           *cp++ = c;
-       }
-    } else {
-       *cp++ = c;
-       while ((c = getc(cfile)) != EOF
-              && c != '\n' && c != '\t' && c != ' ' && c != ',') {
-           if (c == '\\')
-               c = getc(cfile);
-           *cp++ = c;
-       }
+    if (c == '"')
+        /* FIXME: Where is the quoted-string syntax of netrc documented?
+         * This code treats «"foo""bar"» as two tokens without further
+         * separators. */
+        stop = "\"";
+    else
+        /* Might be backslash.  Get it again later.  It's handled then. */
+        if (ungetc(c, cfile) == EOF)
+            return TOK_EOF;
+
+    while ((c = getc(cfile)) != EOF && c && !strchr(stop, c)) {
+        if (c == '\\' && (c = getc(cfile)) == EOF)
+            return TOK_EOF; /* Discard whole token. */
+
+        *cp++ = c;
+        if (cp - tokval > MAX_TOKVAL_SIZE-1) {
+            adios(NULL, "credential tokens restricted to length %d",
+                  MAX_TOKVAL_SIZE - 1);
+        }
     }
-    *cp = 0;
-    if (tokval[0] == 0)
-       return (0);
+    *cp = '\0';
+
     for (t = toktabs; t->tokstr; t++)
        if (!strcmp(t->tokstr, tokval))
-           return (t->tval);
-    return (ID);
+           return t->tval;
+
+    return ID;
 }