refactor(deps): Use only base64 routines under the BSD license

The code from stackoverflow was (by default) under CC-BY-SA license. This has raised some unclear points concerning copyleft.
in-hub · Aug 2, 2024 · 8d7fabc · 8d7fabc
1 parent bd2e96f
commit 8d7fabc
Showing 1 changed file with 61 additions and 55 deletions.
diff --git a/deps/base64.c b/deps/base64.c
@@ -1,10 +1,9 @@
 /*
- * Base64 encoding: Copyright (c) 2005-2011, Jouni Malinen <j@w1.fi>
- * This software may be distributed under the terms of the BSD license.
+ * Base64 encoding/decoding (RFC1341)
+ * Copyright (c) 2005-2011, Jouni Malinen <j@w1.fi>
  *
- * Base64 decoding: Copyright (c) 2016, polfosol
- * Posted at https://stackoverflow.com/a/37109258 under the CC-BY-SA Creative
- * Commons license.
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
  */
 
 #include "base64.h"
@@ -55,61 +54,68 @@ UA_base64(const unsigned char *src, size_t len, size_t *out_len) {
 	return out;
 }
 
-static const uint32_t from_b64[256] = {
-    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
-    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
-    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  62, 63, 62, 62, 63,
-    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 0,  0,  0,  0,  0,  0,
-    0,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13, 14,
-    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 0,  0,  0,  0,  63,
-    0,  26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
-    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51};
+static unsigned char dtable[256] = {
+	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 62  , 0x80, 62  , 0x80, 63  ,
+	52  , 53  , 54  , 55  , 56  , 57  , 58  , 59  , 60  , 61  , 0x80, 0x80, 0x80, 0, 0x80, 0x80,
+	0x80, 0   , 1   , 2   , 3   , 4   , 5   , 6   , 7   , 8   , 9   , 10  , 11  , 12  , 13  , 14  ,
+	15  , 16  , 17  , 18  , 19  , 20  , 21  , 22  , 23  , 24  , 25  , 0x80, 0x80, 0x80, 0x80, 63  ,
+	0x80, 26  , 27  , 28  , 29  , 30  , 31  , 32  , 33  , 34  , 35  , 36  , 37  , 38  , 39  , 40  ,
+	41  , 42  , 43  , 44  , 45  , 46  , 47  , 48  , 49  , 50  , 51  , 0x80, 0x80, 0x80, 0x80, 0x80,
+	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80
+};
 
 unsigned char *
 UA_unbase64(const unsigned char *src, size_t len, size_t *out_len) {
-    // we need a minimum length
-    if(len <= 2) {
-        *out_len = 0;
-        return (unsigned char*)UA_EMPTY_ARRAY_SENTINEL;
-    }
-
-    const unsigned char *p = src;
-    size_t pad1 = len % 4 || p[len - 1] == '=';
-    size_t pad2 = pad1 && (len % 4 > 2 || p[len - 2] != '=');
-    const size_t last = (len - pad1) / 4 << 2;
+	if(len == 0)
+		return NULL;
 
-    unsigned char *str = (unsigned char*)UA_malloc(last / 4 * 3 + pad1 + pad2);
-    if(!str)
-        return NULL;
+    unsigned char *out, *pos;
+	size_t olen = len / 4 * 3;
+	pos = out = (unsigned char*)UA_malloc(olen);
+	if(!out)
+		return NULL;
 
-    unsigned char *pos = str;
-    for(size_t i = 0; i < last; i += 4) {
-        uint32_t n = from_b64[p[i]] << 18 | from_b64[p[i + 1]] << 12 |
-                     from_b64[p[i + 2]] << 6 | from_b64[p[i + 3]];
-        *pos++ = (unsigned char)(n >> 16);
-        *pos++ = (unsigned char)(n >> 8 & 0xFF);
-        *pos++ = (unsigned char)(n & 0xFF);
-    }
+	int pad = 0;
+	size_t count = 0;
+    unsigned char block[4];
+	for(size_t i = 0; i < len; i++) {
+		unsigned char tmp = dtable[src[i]];
+		if(tmp == 0x80)
+			continue;
 
-    if(pad1) {
-        if (last + 1 >= len) {
-            UA_free(str);
-            *out_len = 0;
-            return (unsigned char*)UA_EMPTY_ARRAY_SENTINEL;
-        }
-        uint32_t n = from_b64[p[last]] << 18 | from_b64[p[last + 1]] << 12;
-        *pos++ = (unsigned char)(n >> 16);
-        if(pad2) {
-            if (last + 2 >= len) {
-                UA_free(str);
-                *out_len = 0;
-                return (unsigned char*)UA_EMPTY_ARRAY_SENTINEL;
-            }
-            n |= from_b64[p[last + 2]] << 6;
-            *pos++ = (unsigned char)(n >> 8 & 0xFF);
-        }
-    }
+		if(src[i] == '=')
+			pad++;
+		block[count] = tmp;
+		count++;
+		if(count == 4) {
+			*pos++ = (block[0] << 2) | (block[1] >> 4);
+			*pos++ = (block[1] << 4) | (block[2] >> 2);
+			*pos++ = (block[2] << 6) | block[3];
+			count = 0;
+			if(pad) {
+				if(pad == 1)
+					pos--;
+				else if(pad == 2)
+					pos -= 2;
+				else {
+					/* Invalid padding */
+					UA_free(out);
+					return NULL;
+				}
+				break;
+			}
+		}
+	}
 
-    *out_len = (uintptr_t)(pos - str);
-    return str;
+	*out_len = (size_t)(pos - out);
+	return out;
 }