Import new Cytoplasm library based off of code from Telodendria.

Telodendria doesn't use this library yet, but it will soon.

src/Base64.c

@@ -0,0 +1,244 @@
+/*
+ * Copyright (C) 2022-2023 Jordan Bancino <@jordan:bancino.net>
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include <Base64.h>
+
+#include <Memory.h>
+
+static const char Base64EncodeMap[] =
+"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+static const int Base64DecodeMap[] = {
+    62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58,
+    59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 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, -1, -1, -1, -1, -1, -1, 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
+};
+
+size_t
+Base64EncodedSize(size_t inputSize)
+{
+    size_t size = inputSize;
+
+    if (inputSize % 3)
+    {
+        size += 3 - (inputSize % 3);
+    }
+
+    size /= 3;
+    size *= 4;
+
+    return size;
+}
+
+size_t
+Base64DecodedSize(const char *base64, size_t len)
+{
+    size_t ret;
+    size_t i;
+
+    if (!base64)
+    {
+        return 0;
+    }
+
+    ret = len / 4 * 3;
+
+    for (i = len; i > 0; i--)
+    {
+        if (base64[i] == '=')
+        {
+            ret--;
+        }
+        else
+        {
+            break;
+        }
+    }
+
+    return ret;
+}
+
+char *
+Base64Encode(const char *input, size_t len)
+{
+    char *out;
+    size_t outLen;
+    size_t i, j, v;
+
+    if (!input || !len)
+    {
+        return NULL;
+    }
+
+    outLen = Base64EncodedSize(len);
+    out = Malloc(outLen + 1);
+    if (!out)
+    {
+        return NULL;
+    }
+    out[outLen] = '\0';
+
+    for (i = 0, j = 0; i < len; i += 3, j += 4)
+    {
+        v = input[i];
+        v = i + 1 < len ? v << 8 | input[i + 1] : v << 8;
+        v = i + 2 < len ? v << 8 | input[i + 2] : v << 8;
+
+        out[j] = Base64EncodeMap[(v >> 18) & 0x3F];
+        out[j + 1] = Base64EncodeMap[(v >> 12) & 0x3F];
+
+        if (i + 1 < len)
+        {
+            out[j + 2] = Base64EncodeMap[(v >> 6) & 0x3F];
+        }
+        else
+        {
+            out[j + 2] = '=';
+        }
+        if (i + 2 < len)
+        {
+            out[j + 3] = Base64EncodeMap[v & 0x3F];
+        }
+        else
+        {
+            out[j + 3] = '=';
+        }
+    }
+
+    return out;
+}
+
+static int
+Base64IsValidChar(char c)
+{
+    return (c >= '0' && c <= '9') ||
+    (c >= 'A' && c <= 'Z') ||
+    (c >= 'a' && c <= 'z') ||
+    (c == '+') ||
+    (c == '/') ||
+    (c == '=');
+}
+
+char *
+Base64Decode(const char *input, size_t len)
+{
+    size_t i, j;
+    int v;
+    size_t outLen;
+    char *out;
+
+    if (!input)
+    {
+        return NULL;
+    }
+
+    outLen = Base64DecodedSize(input, len);
+    if (len % 4)
+    {
+        /* Invalid length; must have incorrect padding */
+        return NULL;
+    }
+
+    /* Scan for invalid characters. */
+    for (i = 0; i < len; i++)
+    {
+        if (!Base64IsValidChar(input[i]))
+        {
+            return NULL;
+        }
+    }
+
+    out = Malloc(outLen + 1);
+    if (!out)
+    {
+        return NULL;
+    }
+
+    out[outLen] = '\0';
+
+    for (i = 0, j = 0; i < len; i += 4, j += 3)
+    {
+        v = Base64DecodeMap[input[i] - 43];
+        v = (v << 6) | Base64DecodeMap[input[i + 1] - 43];
+        v = input[i + 2] == '=' ? v << 6 : (v << 6) | Base64DecodeMap[input[i + 2] - 43];
+        v = input[i + 3] == '=' ? v << 6 : (v << 6) | Base64DecodeMap[input[i + 3] - 43];
+
+        out[j] = (v >> 16) & 0xFF;
+        if (input[i + 2] != '=')
+            out[j + 1] = (v >> 8) & 0xFF;
+        if (input[i + 3] != '=')
+            out[j + 2] = v & 0xFF;
+    }
+
+    return out;
+}
+
+extern void
+Base64Unpad(char *base64, size_t length)
+{
+    if (!base64)
+    {
+        return;
+    }
+
+    while (base64[length - 1] == '=')
+    {
+        length--;
+    }
+
+    base64[length] = '\0';
+}
+
+extern int
+Base64Pad(char **base64Ptr, size_t length)
+{
+    char *tmp;
+    size_t newSize;
+    size_t i;
+
+    if (length % 4 == 0)
+    {
+        return length;             /* Success: no padding needed */
+    }
+
+    newSize = length + (4 - (length % 4));
+
+    tmp = Realloc(*base64Ptr, newSize + 100);;
+    if (!tmp)
+    {
+        return 0;                  /* Memory error */
+    }
+    *base64Ptr = tmp;
+
+    for (i = length; i < newSize; i++)
+    {
+        (*base64Ptr)[i] = '=';
+    }
+
+    (*base64Ptr)[newSize] = '\0';
+
+    return newSize;
+}