X-Git-Url: https://diplodocus.org/git/nmh/blobdiff_plain/b00f2105a2c0e4ed04452a0bbfc3b34f6b7b0bed..03ac84e952499359b8fae0f9fcdc78b5967ebd00:/sbr/base64.c

diff --git a/sbr/base64.c b/sbr/base64.c
index f1fec4ed..e8ddee7a 100644
--- a/sbr/base64.c
+++ b/sbr/base64.c
@@ -11,7 +11,7 @@
 #include <h/md5.h>
 #include <inttypes.h>
 
-static char nib2b64[0x40+1] =
+static const char nib2b64[0x40+1] =
 	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 
 int
@@ -209,7 +209,7 @@ writeBase64raw (const unsigned char *in, size_t length, unsigned char *out)
 }
 
 
-static unsigned char b642nib[0x80] = {
+static const unsigned char b642nib[0x80] = {
     0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
     0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
     0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
@@ -233,8 +233,8 @@ static unsigned char b642nib[0x80] = {
  * See description of arguments with declaration in h/prototypes.h.
  */
 int
-decodeBase64 (const char *encoded, const char **decoded, size_t *len, int skip_crs,
-              unsigned char *digest) {
+decodeBase64 (const char *encoded, unsigned char **decoded, size_t *len,
+	      int skip_crs, unsigned char *digest) {
     const char *cp = encoded;
     int self_delimiting = 0;
     int bitno, skip;
@@ -259,7 +259,7 @@ decodeBase64 (const char *encoded, const char **decoded, size_t *len, int skip_c
                 }
                 if (skip  ||  (((unsigned char) *cp) & 0x80)  ||
                     (value = b642nib[((unsigned char) *cp) & 0x7f]) > 0x3f) {
-                    advise (NULL, "invalid BASE64 encoding in %s", encoded);
+                    advise (NULL, "invalid BASE64 encoding in %s", cp);
                     charstring_free (decoded_c);
                     *decoded = NULL;
 
@@ -307,14 +307,19 @@ test_end:
     }
 
     if (! self_delimiting  &&  bitno != 18) {
-        advise (NULL, "premature ending (bitno %d) in %s", bitno, encoded);
+        int i;
+
+        /* Show some context for the error. */
+        for (i = 0; i < 20  &&  cp > encoded; ++i, --cp) {}
+        advise (NULL, "premature ending (bitno %d) near %s", bitno,
+                cp ? cp : encoded);
         charstring_free (decoded_c);
         *decoded = NULL;
 
         return NOTOK;
     }
 
-    *decoded = charstring_buffer_copy (decoded_c);
+    *decoded = (unsigned char *) charstring_buffer_copy (decoded_c);
     *len = charstring_bytes (decoded_c);
     charstring_free (decoded_c);