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+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2013 Tatsuhiro Tsujikawa
+ *
+ * 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 substantial 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.
+ */
+#ifndef BASE64_H
+#define BASE64_H
+
+#include "nghttp2_config.h"
+
+#include <string>
+
+#include "template.h"
+#include "allocator.h"
+
+namespace nghttp2 {
+
+namespace base64 {
+
+namespace {
+constexpr char B64_CHARS[] = {
+ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
+ 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
+ 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
+ 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
+ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/',
+};
+} // namespace
+
+template <typename InputIt> std::string encode(InputIt first, InputIt last) {
+ std::string res;
+ size_t len = last - first;
+ if (len == 0) {
+ return res;
+ }
+ size_t r = len % 3;
+ res.resize((len + 2) / 3 * 4);
+ auto j = last - r;
+ auto p = std::begin(res);
+ while (first != j) {
+ uint32_t n = static_cast<uint8_t>(*first++) << 16;
+ n += static_cast<uint8_t>(*first++) << 8;
+ n += static_cast<uint8_t>(*first++);
+ *p++ = B64_CHARS[n >> 18];
+ *p++ = B64_CHARS[(n >> 12) & 0x3fu];
+ *p++ = B64_CHARS[(n >> 6) & 0x3fu];
+ *p++ = B64_CHARS[n & 0x3fu];
+ }
+
+ if (r == 2) {
+ uint32_t n = static_cast<uint8_t>(*first++) << 16;
+ n += static_cast<uint8_t>(*first++) << 8;
+ *p++ = B64_CHARS[n >> 18];
+ *p++ = B64_CHARS[(n >> 12) & 0x3fu];
+ *p++ = B64_CHARS[(n >> 6) & 0x3fu];
+ *p++ = '=';
+ } else if (r == 1) {
+ uint32_t n = static_cast<uint8_t>(*first++) << 16;
+ *p++ = B64_CHARS[n >> 18];
+ *p++ = B64_CHARS[(n >> 12) & 0x3fu];
+ *p++ = '=';
+ *p++ = '=';
+ }
+ return res;
+}
+
+constexpr size_t encode_length(size_t n) { return (n + 2) / 3 * 4; }
+
+template <typename InputIt, typename OutputIt>
+OutputIt encode(InputIt first, InputIt last, OutputIt d_first) {
+ size_t len = last - first;
+ if (len == 0) {
+ return d_first;
+ }
+ auto r = len % 3;
+ auto j = last - r;
+ auto p = d_first;
+ while (first != j) {
+ uint32_t n = static_cast<uint8_t>(*first++) << 16;
+ n += static_cast<uint8_t>(*first++) << 8;
+ n += static_cast<uint8_t>(*first++);
+ *p++ = B64_CHARS[n >> 18];
+ *p++ = B64_CHARS[(n >> 12) & 0x3fu];
+ *p++ = B64_CHARS[(n >> 6) & 0x3fu];
+ *p++ = B64_CHARS[n & 0x3fu];
+ }
+
+ switch (r) {
+ case 2: {
+ uint32_t n = static_cast<uint8_t>(*first++) << 16;
+ n += static_cast<uint8_t>(*first++) << 8;
+ *p++ = B64_CHARS[n >> 18];
+ *p++ = B64_CHARS[(n >> 12) & 0x3fu];
+ *p++ = B64_CHARS[(n >> 6) & 0x3fu];
+ *p++ = '=';
+ break;
+ }
+ case 1: {
+ uint32_t n = static_cast<uint8_t>(*first++) << 16;
+ *p++ = B64_CHARS[n >> 18];
+ *p++ = B64_CHARS[(n >> 12) & 0x3fu];
+ *p++ = '=';
+ *p++ = '=';
+ break;
+ }
+ }
+ return p;
+}
+
+template <typename InputIt>
+InputIt next_decode_input(InputIt first, InputIt last, const int *tbl) {
+ for (; first != last; ++first) {
+ if (tbl[static_cast<size_t>(*first)] != -1 || *first == '=') {
+ break;
+ }
+ }
+ return first;
+}
+
+template <typename InputIt, typename OutputIt>
+OutputIt decode(InputIt first, InputIt last, OutputIt d_first) {
+ static constexpr int INDEX_TABLE[] = {
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, 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, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1};
+ assert(std::distance(first, last) % 4 == 0);
+ auto p = d_first;
+ for (; first != last;) {
+ uint32_t n = 0;
+ for (int i = 1; i <= 4; ++i, ++first) {
+ auto idx = INDEX_TABLE[static_cast<size_t>(*first)];
+ if (idx == -1) {
+ if (i <= 2) {
+ return d_first;
+ }
+ if (i == 3) {
+ if (*first == '=' && *(first + 1) == '=' && first + 2 == last) {
+ *p++ = n >> 16;
+ return p;
+ }
+ return d_first;
+ }
+ if (*first == '=' && first + 1 == last) {
+ *p++ = n >> 16;
+ *p++ = n >> 8 & 0xffu;
+ return p;
+ }
+ return d_first;
+ }
+
+ n += idx << (24 - i * 6);
+ }
+
+ *p++ = n >> 16;
+ *p++ = n >> 8 & 0xffu;
+ *p++ = n & 0xffu;
+ }
+
+ return p;
+}
+
+template <typename InputIt> std::string decode(InputIt first, InputIt last) {
+ auto len = std::distance(first, last);
+ if (len % 4 != 0) {
+ return "";
+ }
+ std::string res;
+ res.resize(len / 4 * 3);
+
+ res.erase(decode(first, last, std::begin(res)), std::end(res));
+
+ return res;
+}
+
+template <typename InputIt>
+StringRef decode(BlockAllocator &balloc, InputIt first, InputIt last) {
+ auto len = std::distance(first, last);
+ if (len % 4 != 0) {
+ return StringRef::from_lit("");
+ }
+ auto iov = make_byte_ref(balloc, len / 4 * 3 + 1);
+ auto p = iov.base;
+
+ p = decode(first, last, p);
+ *p = '\0';
+
+ return StringRef{iov.base, p};
+}
+
+} // namespace base64
+
+} // namespace nghttp2
+
+#endif // BASE64_H
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-10 20:46:06 +0000