X-Git-Url: https://diplodocus.org/git/nmh/blobdiff_plain/aaf014c77a4fb19bdc33370f5b6af5b8497decf8..cf57870921b26703aad420c6741c524b33736ff1:/sbr/base64.c

diff --git a/sbr/base64.c b/sbr/base64.c
index 79d7aa94..a1e54c92 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,
@@ -243,7 +243,8 @@ decodeBase64 (const char *encoded, unsigned char **decoded, size_t *len,
     charstring_t decoded_c = charstring_create (strlen (encoded));
     MD5_CTX mdContext;
 
-    if (digest) { MD5Init (&mdContext); }
+    if (digest)
+        MD5Init (&mdContext);
 
     bitno = 18;
     bits = 0L;
@@ -259,7 +260,7 @@ decodeBase64 (const char *encoded, unsigned char **decoded, size_t *len,
                 }
                 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;
 
@@ -274,19 +275,22 @@ test_end:
                     if (! skip_crs  ||  b != '\r') {
                         charstring_push_back (decoded_c, b);
                     }
-                    if (digest) { MD5Update (&mdContext, (unsigned char *) &b, 1); }
+                    if (digest)
+                        MD5Update (&mdContext, (unsigned char *) &b, 1);
                     if (skip < 2) {
                         b = (bits >> 8) & 0xff;
                         if (! skip_crs  ||  b != '\r') {
                             charstring_push_back (decoded_c, b);
                         }
-                        if (digest) { MD5Update (&mdContext, (unsigned char *) &b, 1); }
+                        if (digest)
+                            MD5Update (&mdContext, (unsigned char *) &b, 1);
                         if (skip < 1) {
                             b = bits & 0xff;
                             if (! skip_crs  ||  b != '\r') {
                                 charstring_push_back (decoded_c, b);
                             }
-                            if (digest) { MD5Update (&mdContext, (unsigned char *) &b, 1); }
+                            if (digest)
+                                MD5Update (&mdContext, (unsigned char *) &b, 1);
                         }
                     }
 
@@ -307,7 +311,12 @@ 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;