Reorganize redbean EncodeBase32 code

net/http/base32.c

@@ -0,0 +1,72 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2021 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/macros.internal.h"
+#include "libc/mem/mem.h"
+#include "libc/str/str.h"
+
+asm(".ident\t\"\\n\\n\
+Apache License, Version 2.0\\n\
+Copyright 2010 Google Inc.\"");
+asm(".include \"libc/disclaimer.inc\"");
+
+int tobits(int b) {
+  int bits = 0; while (b && (b >>= 1)) bits++;
+  return bits;
+}
+
+// the next function is based on
+// https://github.com/google/google-authenticator-libpam/blob/master/src/base32.c
+// Copyright 2010 Google Inc.; Author: Markus Gutschke
+// licensed under Apache License, Version 2.0
+char* EncodeBase32(const char *s, size_t sl,
+                   const char *a, size_t al,
+                   size_t *ol) {
+  unassert(2 <= al && al <= 256);
+  size_t count = 0;
+  char *r;
+  int bl = tobits(al);
+  int mask = (1 << bl) - 1;
+  *ol = (sl * 8 + bl - 1) / bl; // calculate exact output length
+  if (!(r = malloc(*ol + 1))) {
+    *ol = 0;
+    return r;
+  }
+  if (sl > 0) {
+    int buffer = s[0];
+    size_t next = 1;
+    int bitsLeft = 8;
+    while (count < *ol && (bitsLeft > 0 || next < sl)) {
+      if (bitsLeft < bl) {
+        if (next < sl) {
+          buffer <<= 8;
+          buffer |= s[next++] & 0xFF;
+          bitsLeft += 8;
+        } else {
+          int pad = bl - bitsLeft;
+          buffer <<= pad;
+          bitsLeft += pad;
+        }
+      }
+      bitsLeft -= bl;
+      r[count++] = a[mask & (buffer >> bitsLeft)];
+    }
+  }
+  if (count < *ol) r[count] = '\000';
+  return r;
+}

net/http/escape.h

@@ -34,6 +34,7 @@ char *EncodeLatin1(const char *, size_t, size_t *, int);
 char *EncodeHttpHeaderValue(const char *, size_t, size_t *);
 char *VisualizeControlCodes(const char *, size_t, size_t *);
 char *IndentLines(const char *, size_t, size_t *, size_t);
+char *EncodeBase32(const char *, size_t, const char, size_t, size_t *);
 char *EncodeBase64(const char *, size_t, size_t *);
 char *DecodeBase64(const char *, size_t, size_t *);
 

tool/net/lfuncs.c

@@ -605,61 +605,17 @@ int LuaEncodeLatin1(lua_State *L) {
   }
 }
 
-int tobits(int b) {
-  int bits = 0; while (b && (b >>= 1)) bits++;
-  return bits;
-}
-
-// the next function is based on
-// https://github.com/google/google-authenticator-libpam/blob/master/src/base32.c
-// Copyright 2010 Google Inc.; Author: Markus Gutschke
-// licensed under Apache License, Version 2.0
-// p already has ol bytes allocated
-// which is enough to store encoded result
-char* base32pcpy(char *p, const char *s, size_t sl,
-                 const char *a, size_t al,
-                 size_t ol) {
-  size_t count = 0;
-  int bl = tobits(al);
-  int mask = (1 << bl) - 1;
-  if (sl > 0) {
-    int buffer = s[0];
-    size_t next = 1;
-    int bitsLeft = 8;
-    while (count < ol && (bitsLeft > 0 || next < sl)) {
-      if (bitsLeft < bl) {
-        if (next < sl) {
-          buffer <<= 8;
-          buffer |= s[next++] & 0xFF;
-          bitsLeft += 8;
-        } else {
-          int pad = bl - bitsLeft;
-          buffer <<= pad;
-          bitsLeft += pad;
-        }
-      }
-      bitsLeft -= bl;
-      p[count++] = a[mask & (buffer >> bitsLeft)];
-    }
-  }
-  if (count < ol) p[count] = '\000';
-  return p;
-}
-
 int LuaEncodeBase32(lua_State *L) {
   char *p;
-  size_t sl, al, ol; // source, alphabet, and output lengths
-  const char *s, *a;
-  luaL_Buffer buf;
-  s = luaL_checklstring(L, 1, &sl);
-  a = luaL_optlstring(L, 2, "0123456789abcdefghjkmnpqrstvwxyz", &al);
+  size_t sl, al; // source/output and alphabet lengths
+  const char *s = luaL_checklstring(L, 1, &sl);
+  const char *a = luaL_optlstring(L, 2, "0123456789abcdefghjkmnpqrstvwxyz", &al);
   if (al & (al - 1) || al > 256 || al < 2)
     return luaL_error(L, "alphabet length is not a power of 2 in range 2..256");
-  ol = tobits(al);
-  ol = (sl * 8 + ol - 1) / ol; // calculate exact output length
-  p = luaL_buffinitsize(L, &buf, ol);
-  base32pcpy(p, s, sl, a, al, ol);
-  luaL_pushresultsize(&buf, ol);
+  if (!(p = EncodeBase32(s, sl, a, al, &sl)))
+    return luaL_error(L, "out of memory");
+  lua_pushlstring(L, p, sl);
+  free(p);
   return 1;
 }