make scan_content() work correctly with content containing NULs

switched from fgets to getline for unambiguous reads in the face of
NUL bytes.  added a checkfornuls flag, and use it to cause the correct
encoding when content-types of application or text contain NULs.

diff --git a/uip/mhbuildsbr.c b/uip/mhbuildsbr.c
index a973fd9caef8a911c93276f0e73b3027bc941cfd..fb6db3bc211debc49e0482b8f977d8a2c8753bdd 100644 (file)
--- a/uip/mhbuildsbr.c
+++ b/uip/mhbuildsbr.c
@@ -1279,13 +1279,17 @@ raw:
 static int
 scan_content (CT ct, size_t maxunencoded)
 {
-    int len;
+    int prefix_len;
     int check8bit = 0, contains8bit = 0;  /* check if contains 8bit data */
+    int checknul = 0, containsnul = 0;  /* check if contains NULs */
     int checklinelen = 0, linelen = 0;  /* check for long lines */ 
     int checkllinelen = 0; /* check for extra-long lines */
     int checkboundary = 0, boundaryclash = 0; /* check if clashes with multipart boundary   */
     int checklinespace = 0, linespace = 0;  /* check if any line ends with space          */
-    char *cp = NULL, buffer[BUFSIZ];
+    char *cp = NULL;
+    char *bufp = NULL;
+    size_t buflen;
+    ssize_t gotlen;
     struct text *t = NULL;
     FILE *in = NULL;
     CE ce = &ct->c_cefile;
@@ -1326,8 +1330,10 @@ scan_content (CT ct, size_t maxunencoded)
 
     if (ct->c_type == CT_TEXT) {
        t = (struct text *) ct->c_ctparams;
-       if (t->tx_charset == CHARSET_UNSPECIFIED)
+       if (t->tx_charset == CHARSET_UNSPECIFIED) {
            check8bit = 1;
+           checknul = 1;
+       }
     }
 
     switch (ct->c_reqencoding) {
@@ -1355,6 +1361,7 @@ scan_content (CT ct, size_t maxunencoded)
 
        case CT_APPLICATION:
            check8bit = 1;
+           checknul = 1;
            checklinelen = 1;
            checklinespace = 1;
            checkboundary = 1;
@@ -1394,29 +1401,31 @@ scan_content (CT ct, size_t maxunencoded)
      * Scan the unencoded content
      */
     if (check8bit || checklinelen || checklinespace || checkboundary ||
-       checkllinelen) {
+       checkllinelen || checknul) {
        if ((in = fopen (ce->ce_file, "r")) == NULL)
            adios (ce->ce_file, "unable to open for reading");
-       len = strlen (prefix);
+       prefix_len = strlen (prefix);
 
-       while (fgets (buffer, sizeof(buffer) - 1, in)) {
+       while ((gotlen = getline(&bufp, &buflen, in)) != -1) {
            /*
-            * Check for 8bit data.
+            * Check for 8bit and NUL data.
             */
-           if (check8bit) {
-               for (cp = buffer; *cp; cp++) {
-                   if (!isascii ((unsigned char) *cp)) {
-                       contains8bit = 1;
-                       check8bit = 0;  /* no need to keep checking */
-                       break;
-                   }
+           for (cp = bufp; (check8bit || checknul) &&
+                                       cp < bufp + gotlen; cp++) {
+               if (!isascii ((unsigned char) *cp)) {
+                   contains8bit = 1;
+                   check8bit = 0;      /* no need to keep checking */
+               }
+               if (!*cp) {
+                   containsnul = 1;
+                   checknul = 0;       /* no need to keep checking */
                }
            }
 
            /*
             * Check line length.
             */
-           if (checklinelen && (strlen (buffer) > maxunencoded + 1)) {
+           if (checklinelen && ((size_t)gotlen > maxunencoded + 1)) {
                linelen = 1;
                checklinelen = 0;       /* no need to keep checking */
            }
@@ -1428,7 +1437,7 @@ scan_content (CT ct, size_t maxunencoded)
             */
 
            if (checkllinelen && !linelen &&
-                                       (strlen(buffer) > MAXLONGLINE + 1)) {
+                                       (gotlen > MAXLONGLINE + 1)) {
                adios(NULL, "Line in content exceeds maximum line limit (%d)",
                      MAXLONGLINE);
            }
@@ -1436,7 +1445,8 @@ scan_content (CT ct, size_t maxunencoded)
            /*
             * Check if line ends with a space.
             */
-           if (checklinespace && (cp = buffer + strlen (buffer) - 2) > buffer && isspace ((unsigned char) *cp)) {
+           if (checklinespace && (cp = bufp + gotlen - 2) > bufp &&
+                       isspace ((unsigned char) *cp)) {
                linespace = 1;
                checklinespace = 0;     /* no need to keep checking */
            }
@@ -1445,18 +1455,20 @@ scan_content (CT ct, size_t maxunencoded)
             * Check if content contains a line that clashes
             * with our standard boundary for multipart messages.
             */
-           if (checkboundary && buffer[0] == '-' && buffer[1] == '-') {
-               for (cp = buffer + strlen (buffer) - 1; cp >= buffer; cp--)
+           if (checkboundary && bufp[0] == '-' && bufp[1] == '-') {
+               for (cp = bufp + gotlen - 1; cp >= bufp; cp--)
                    if (!isspace ((unsigned char) *cp))
                        break;
                *++cp = '\0';
-               if (!strncmp(buffer + 2, prefix, len) && isdigit((unsigned char) buffer[2 + len])) {
+               if (!strncmp(bufp + 2, prefix, prefix_len) &&
+                           isdigit((unsigned char) bufp[2 + prefix_len])) {
                    boundaryclash = 1;
                    checkboundary = 0;  /* no need to keep checking */
                }
            }
        }
        fclose (in);
+       free(bufp);
     }
 
     /*
@@ -1484,9 +1496,9 @@ scan_content (CT ct, size_t maxunencoded)
     else
        switch (ct->c_type) {
        case CT_TEXT:
-           if (contains8bit && !linelen && !linespace && !checksw)
+           if (contains8bit && !containsnul && !linelen && !linespace && !checksw)
                ct->c_encoding = CE_8BIT;
-           else if (contains8bit || linelen || linespace || checksw)
+           else if (contains8bit || containsnul || linelen || linespace || checksw)
                ct->c_encoding = CE_QUOTED;
            else
                ct->c_encoding = CE_7BIT;
@@ -1494,7 +1506,7 @@ scan_content (CT ct, size_t maxunencoded)
 
        case CT_APPLICATION:
            /* For application type, use base64, except when postscript */
-           if (contains8bit || linelen || linespace || checksw)
+           if (containsnul || contains8bit || linelen || linespace || checksw)
                ct->c_encoding = (ct->c_subtype == APPLICATION_POSTSCRIPT)
                    ? CE_QUOTED : CE_BASE64;
            else