1 files changed, 33 insertions, 39 deletions

diff --git a/lib/base32.c b/lib/base32.c
index 50f9d42..270c505 100644
--- a/lib/base32.c
+++ b/lib/base32.c
@@ -1,5 +1,5 @@
 /* base32.c -- Encode binary data using printable characters.
-   Copyright (C) 1999-2001, 2004-2006, 2009-2023 Free Software Foundation, Inc.
+   Copyright (C) 1999-2001, 2004-2006, 2009-2024 Free Software Foundation, Inc.
 
    This file is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as
@@ -40,6 +40,7 @@
 #include <config.h>
 
 /* Get prototype. */
+#define BASE32_INLINE _GL_EXTERN_INLINE
 #include "base32.h"
 
 /* Get imalloc. */
@@ -47,9 +48,6 @@
 
 #include <intprops.h>
 
-/* Get UCHAR_MAX. */
-#include <limits.h>
-
 #include <string.h>
 
 /* Convert 'char' to 'unsigned char' without casting.  */
@@ -205,7 +203,7 @@ base32_encode_alloc (const char *in, idx_t inlen, char **out)
    : (_) == '7' ? 31                            \
    : -1)
 
-static const signed char b32[0x100] = {
+signed char const base32_to_int[256] = {
   B32 (0), B32 (1), B32 (2), B32 (3),
   B32 (4), B32 (5), B32 (6), B32 (7),
   B32 (8), B32 (9), B32 (10), B32 (11),
@@ -272,28 +270,6 @@ static const signed char b32[0x100] = {
   B32 (252), B32 (253), B32 (254), B32 (255)
 };
 
-#if UCHAR_MAX == 255
-# define uchar_in_range(c) true
-#else
-# define uchar_in_range(c) ((c) <= 255)
-#endif
-
-/* Return true if CH is a character from the Base32 alphabet, and
-   false otherwise.  Note that '=' is padding and not considered to be
-   part of the alphabet.  */
-bool
-isbase32 (char ch)
-{
-  return uchar_in_range (to_uchar (ch)) && 0 <= b32[to_uchar (ch)];
-}
-
-/* Initialize decode-context buffer, CTX.  */
-void
-base32_decode_ctx_init (struct base32_decode_context *ctx)
-{
-  ctx->i = 0;
-}
-
 /* If CTX->i is 0 or 8, there are eight or more bytes in [*IN..IN_END), and
    none of those eight is a newline, then return *IN.  Otherwise, copy up to
    4 - CTX->i non-newline bytes from that range into CTX->buf, starting at
@@ -368,8 +344,8 @@ decode_8 (char const *restrict in, idx_t inlen,
 
   if (*outleft)
     {
-      *out++ = ((b32[to_uchar (in[0])] << 3)
-                | (b32[to_uchar (in[1])] >> 2));
+      *out++ = ((base32_to_int[to_uchar (in[0])] << 3)
+                | (base32_to_int[to_uchar (in[1])] >> 2));
       --*outleft;
     }
 
@@ -378,6 +354,10 @@ decode_8 (char const *restrict in, idx_t inlen,
       if (in[3] != '=' || in[4] != '=' || in[5] != '='
           || in[6] != '=' || in[7] != '=')
         return_false;
+
+      /* Reject non-canonical encodings.  */
+      if (base32_to_int[to_uchar (in[1])] & 0x03)
+        return_false;
     }
   else
     {
@@ -386,9 +366,9 @@ decode_8 (char const *restrict in, idx_t inlen,
 
       if (*outleft)
         {
-          *out++ = ((b32[to_uchar (in[1])] << 6)
-                    | (b32[to_uchar (in[2])] << 1)
-                    | (b32[to_uchar (in[3])] >> 4));
+          *out++ = ((base32_to_int[to_uchar (in[1])] << 6)
+                    | (base32_to_int[to_uchar (in[2])] << 1)
+                    | (base32_to_int[to_uchar (in[3])] >> 4));
           --*outleft;
         }
 
@@ -396,6 +376,10 @@ decode_8 (char const *restrict in, idx_t inlen,
         {
           if (in[5] != '=' || in[6] != '=' || in[7] != '=')
             return_false;
+
+          /* Reject non-canonical encodings.  */
+          if (base32_to_int[to_uchar (in[3])] & 0x0f)
+            return_false;
         }
       else
         {
@@ -404,8 +388,8 @@ decode_8 (char const *restrict in, idx_t inlen,
 
           if (*outleft)
             {
-              *out++ = ((b32[to_uchar (in[3])] << 4)
-                        | (b32[to_uchar (in[4])] >> 1));
+              *out++ = ((base32_to_int[to_uchar (in[3])] << 4)
+                        | (base32_to_int[to_uchar (in[4])] >> 1));
               --*outleft;
             }
 
@@ -413,6 +397,10 @@ decode_8 (char const *restrict in, idx_t inlen,
             {
               if (in[6] != '=' || in[7] != '=')
                 return_false;
+
+              /* Reject non-canonical encodings.  */
+              if (base32_to_int[to_uchar (in[4])] & 0x01)
+                return_false;
             }
           else
             {
@@ -421,9 +409,9 @@ decode_8 (char const *restrict in, idx_t inlen,
 
               if (*outleft)
                 {
-                  *out++ = ((b32[to_uchar (in[4])] << 7)
-                            | (b32[to_uchar (in[5])] << 2)
-                            | (b32[to_uchar (in[6])] >> 3));
+                  *out++ = ((base32_to_int[to_uchar (in[4])] << 7)
+                            | (base32_to_int[to_uchar (in[5])] << 2)
+                            | (base32_to_int[to_uchar (in[6])] >> 3));
                   --*outleft;
                 }
 
@@ -434,11 +422,17 @@ decode_8 (char const *restrict in, idx_t inlen,
 
                   if (*outleft)
                     {
-                      *out++ = ((b32[to_uchar (in[6])] << 5)
-                                | (b32[to_uchar (in[7])]));
+                      *out++ = ((base32_to_int[to_uchar (in[6])] << 5)
+                                | (base32_to_int[to_uchar (in[7])]));
                       --*outleft;
                     }
                 }
+              else
+                {
+                  /* Reject non-canonical encodings.  */
+                  if (base32_to_int[to_uchar (in[6])] & 0x07)
+                    return_false;
+                }
             }
         }
     }