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Diffstat (limited to 'third_party/abseil_cpp/absl/strings/escaping.cc')
| -rw-r--r-- | third_party/abseil_cpp/absl/strings/escaping.cc | 949 |
1 files changed, 0 insertions, 949 deletions
diff --git a/third_party/abseil_cpp/absl/strings/escaping.cc b/third_party/abseil_cpp/absl/strings/escaping.cc deleted file mode 100644 index 18b20b83fd36..000000000000 --- a/third_party/abseil_cpp/absl/strings/escaping.cc +++ /dev/null @@ -1,949 +0,0 @@ -// Copyright 2017 The Abseil Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// https://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -#include "absl/strings/escaping.h" - -#include <algorithm> -#include <cassert> -#include <cstdint> -#include <cstring> -#include <iterator> -#include <limits> -#include <string> - -#include "absl/base/internal/endian.h" -#include "absl/base/internal/raw_logging.h" -#include "absl/base/internal/unaligned_access.h" -#include "absl/strings/internal/char_map.h" -#include "absl/strings/internal/escaping.h" -#include "absl/strings/internal/resize_uninitialized.h" -#include "absl/strings/internal/utf8.h" -#include "absl/strings/str_cat.h" -#include "absl/strings/str_join.h" -#include "absl/strings/string_view.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace { - -// These are used for the leave_nulls_escaped argument to CUnescapeInternal(). -constexpr bool kUnescapeNulls = false; - -inline bool is_octal_digit(char c) { return ('0' <= c) && (c <= '7'); } - -inline int hex_digit_to_int(char c) { - static_assert('0' == 0x30 && 'A' == 0x41 && 'a' == 0x61, - "Character set must be ASCII."); - assert(absl::ascii_isxdigit(c)); - int x = static_cast<unsigned char>(c); - if (x > '9') { - x += 9; - } - return x & 0xf; -} - -inline bool IsSurrogate(char32_t c, absl::string_view src, std::string* error) { - if (c >= 0xD800 && c <= 0xDFFF) { - if (error) { - *error = absl::StrCat("invalid surrogate character (0xD800-DFFF): \\", - src); - } - return true; - } - return false; -} - -// ---------------------------------------------------------------------- -// CUnescapeInternal() -// Implements both CUnescape() and CUnescapeForNullTerminatedString(). -// -// Unescapes C escape sequences and is the reverse of CEscape(). -// -// If 'source' is valid, stores the unescaped string and its size in -// 'dest' and 'dest_len' respectively, and returns true. Otherwise -// returns false and optionally stores the error description in -// 'error'. Set 'error' to nullptr to disable error reporting. -// -// 'dest' should point to a buffer that is at least as big as 'source'. -// 'source' and 'dest' may be the same. -// -// NOTE: any changes to this function must also be reflected in the older -// UnescapeCEscapeSequences(). -// ---------------------------------------------------------------------- -bool CUnescapeInternal(absl::string_view source, bool leave_nulls_escaped, - char* dest, ptrdiff_t* dest_len, std::string* error) { - char* d = dest; - const char* p = source.data(); - const char* end = p + source.size(); - const char* last_byte = end - 1; - - // Small optimization for case where source = dest and there's no escaping - while (p == d && p < end && *p != '\\') p++, d++; - - while (p < end) { - if (*p != '\\') { - *d++ = *p++; - } else { - if (++p > last_byte) { // skip past the '\\' - if (error) *error = "String cannot end with \\"; - return false; - } - switch (*p) { - case 'a': *d++ = '\a'; break; - case 'b': *d++ = '\b'; break; - case 'f': *d++ = '\f'; break; - case 'n': *d++ = '\n'; break; - case 'r': *d++ = '\r'; break; - case 't': *d++ = '\t'; break; - case 'v': *d++ = '\v'; break; - case '\\': *d++ = '\\'; break; - case '?': *d++ = '\?'; break; // \? Who knew? - case '\'': *d++ = '\''; break; - case '"': *d++ = '\"'; break; - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': { - // octal digit: 1 to 3 digits - const char* octal_start = p; - unsigned int ch = *p - '0'; - if (p < last_byte && is_octal_digit(p[1])) ch = ch * 8 + *++p - '0'; - if (p < last_byte && is_octal_digit(p[1])) - ch = ch * 8 + *++p - '0'; // now points at last digit - if (ch > 0xff) { - if (error) { - *error = "Value of \\" + - std::string(octal_start, p + 1 - octal_start) + - " exceeds 0xff"; - } - return false; - } - if ((ch == 0) && leave_nulls_escaped) { - // Copy the escape sequence for the null character - const ptrdiff_t octal_size = p + 1 - octal_start; - *d++ = '\\'; - memmove(d, octal_start, octal_size); - d += octal_size; - break; - } - *d++ = ch; - break; - } - case 'x': - case 'X': { - if (p >= last_byte) { - if (error) *error = "String cannot end with \\x"; - return false; - } else if (!absl::ascii_isxdigit(p[1])) { - if (error) *error = "\\x cannot be followed by a non-hex digit"; - return false; - } - unsigned int ch = 0; - const char* hex_start = p; - while (p < last_byte && absl::ascii_isxdigit(p[1])) - // Arbitrarily many hex digits - ch = (ch << 4) + hex_digit_to_int(*++p); - if (ch > 0xFF) { - if (error) { - *error = "Value of \\" + - std::string(hex_start, p + 1 - hex_start) + - " exceeds 0xff"; - } - return false; - } - if ((ch == 0) && leave_nulls_escaped) { - // Copy the escape sequence for the null character - const ptrdiff_t hex_size = p + 1 - hex_start; - *d++ = '\\'; - memmove(d, hex_start, hex_size); - d += hex_size; - break; - } - *d++ = ch; - break; - } - case 'u': { - // \uhhhh => convert 4 hex digits to UTF-8 - char32_t rune = 0; - const char* hex_start = p; - if (p + 4 >= end) { - if (error) { - *error = "\\u must be followed by 4 hex digits: \\" + - std::string(hex_start, p + 1 - hex_start); - } - return false; - } - for (int i = 0; i < 4; ++i) { - // Look one char ahead. - if (absl::ascii_isxdigit(p[1])) { - rune = (rune << 4) + hex_digit_to_int(*++p); // Advance p. - } else { - if (error) { - *error = "\\u must be followed by 4 hex digits: \\" + - std::string(hex_start, p + 1 - hex_start); - } - return false; - } - } - if ((rune == 0) && leave_nulls_escaped) { - // Copy the escape sequence for the null character - *d++ = '\\'; - memmove(d, hex_start, 5); // u0000 - d += 5; - break; - } - if (IsSurrogate(rune, absl::string_view(hex_start, 5), error)) { - return false; - } - d += strings_internal::EncodeUTF8Char(d, rune); - break; - } - case 'U': { - // \Uhhhhhhhh => convert 8 hex digits to UTF-8 - char32_t rune = 0; - const char* hex_start = p; - if (p + 8 >= end) { - if (error) { - *error = "\\U must be followed by 8 hex digits: \\" + - std::string(hex_start, p + 1 - hex_start); - } - return false; - } - for (int i = 0; i < 8; ++i) { - // Look one char ahead. - if (absl::ascii_isxdigit(p[1])) { - // Don't change rune until we're sure this - // is within the Unicode limit, but do advance p. - uint32_t newrune = (rune << 4) + hex_digit_to_int(*++p); - if (newrune > 0x10FFFF) { - if (error) { - *error = "Value of \\" + - std::string(hex_start, p + 1 - hex_start) + - " exceeds Unicode limit (0x10FFFF)"; - } - return false; - } else { - rune = newrune; - } - } else { - if (error) { - *error = "\\U must be followed by 8 hex digits: \\" + - std::string(hex_start, p + 1 - hex_start); - } - return false; - } - } - if ((rune == 0) && leave_nulls_escaped) { - // Copy the escape sequence for the null character - *d++ = '\\'; - memmove(d, hex_start, 9); // U00000000 - d += 9; - break; - } - if (IsSurrogate(rune, absl::string_view(hex_start, 9), error)) { - return false; - } - d += strings_internal::EncodeUTF8Char(d, rune); - break; - } - default: { - if (error) *error = std::string("Unknown escape sequence: \\") + *p; - return false; - } - } - p++; // read past letter we escaped - } - } - *dest_len = d - dest; - return true; -} - -// ---------------------------------------------------------------------- -// CUnescapeInternal() -// -// Same as above but uses a std::string for output. 'source' and 'dest' -// may be the same. -// ---------------------------------------------------------------------- -bool CUnescapeInternal(absl::string_view source, bool leave_nulls_escaped, - std::string* dest, std::string* error) { - strings_internal::STLStringResizeUninitialized(dest, source.size()); - - ptrdiff_t dest_size; - if (!CUnescapeInternal(source, - leave_nulls_escaped, - &(*dest)[0], - &dest_size, - error)) { - return false; - } - dest->erase(dest_size); - return true; -} - -// ---------------------------------------------------------------------- -// CEscape() -// CHexEscape() -// Utf8SafeCEscape() -// Utf8SafeCHexEscape() -// Escapes 'src' using C-style escape sequences. This is useful for -// preparing query flags. The 'Hex' version uses hexadecimal rather than -// octal sequences. The 'Utf8Safe' version does not touch UTF-8 bytes. -// -// Escaped chars: \n, \r, \t, ", ', \, and !absl::ascii_isprint(). -// ---------------------------------------------------------------------- -std::string CEscapeInternal(absl::string_view src, bool use_hex, - bool utf8_safe) { - std::string dest; - bool last_hex_escape = false; // true if last output char was \xNN. - - for (unsigned char c : src) { - bool is_hex_escape = false; - switch (c) { - case '\n': dest.append("\\" "n"); break; - case '\r': dest.append("\\" "r"); break; - case '\t': dest.append("\\" "t"); break; - case '\"': dest.append("\\" "\""); break; - case '\'': dest.append("\\" "'"); break; - case '\\': dest.append("\\" "\\"); break; - default: - // Note that if we emit \xNN and the src character after that is a hex - // digit then that digit must be escaped too to prevent it being - // interpreted as part of the character code by C. - if ((!utf8_safe || c < 0x80) && - (!absl::ascii_isprint(c) || - (last_hex_escape && absl::ascii_isxdigit(c)))) { - if (use_hex) { - dest.append("\\" "x"); - dest.push_back(numbers_internal::kHexChar[c / 16]); - dest.push_back(numbers_internal::kHexChar[c % 16]); - is_hex_escape = true; - } else { - dest.append("\\"); - dest.push_back(numbers_internal::kHexChar[c / 64]); - dest.push_back(numbers_internal::kHexChar[(c % 64) / 8]); - dest.push_back(numbers_internal::kHexChar[c % 8]); - } - } else { - dest.push_back(c); - break; - } - } - last_hex_escape = is_hex_escape; - } - - return dest; -} - -/* clang-format off */ -constexpr char c_escaped_len[256] = { - 4, 4, 4, 4, 4, 4, 4, 4, 4, 2, 2, 4, 4, 2, 4, 4, // \t, \n, \r - 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, - 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, // ", ' - 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // '0'..'9' - 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 'A'..'O' - 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, // 'P'..'Z', '\' - 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 'a'..'o' - 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, // 'p'..'z', DEL - 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, - 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, - 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, - 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, - 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, - 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, - 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, - 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, -}; -/* clang-format on */ - -// Calculates the length of the C-style escaped version of 'src'. -// Assumes that non-printable characters are escaped using octal sequences, and -// that UTF-8 bytes are not handled specially. -inline size_t CEscapedLength(absl::string_view src) { - size_t escaped_len = 0; - for (unsigned char c : src) escaped_len += c_escaped_len[c]; - return escaped_len; -} - -void CEscapeAndAppendInternal(absl::string_view src, std::string* dest) { - size_t escaped_len = CEscapedLength(src); - if (escaped_len == src.size()) { - dest->append(src.data(), src.size()); - return; - } - - size_t cur_dest_len = dest->size(); - strings_internal::STLStringResizeUninitialized(dest, - cur_dest_len + escaped_len); - char* append_ptr = &(*dest)[cur_dest_len]; - - for (unsigned char c : src) { - int char_len = c_escaped_len[c]; - if (char_len == 1) { - *append_ptr++ = c; - } else if (char_len == 2) { - switch (c) { - case '\n': - *append_ptr++ = '\\'; - *append_ptr++ = 'n'; - break; - case '\r': - *append_ptr++ = '\\'; - *append_ptr++ = 'r'; - break; - case '\t': - *append_ptr++ = '\\'; - *append_ptr++ = 't'; - break; - case '\"': - *append_ptr++ = '\\'; - *append_ptr++ = '\"'; - break; - case '\'': - *append_ptr++ = '\\'; - *append_ptr++ = '\''; - break; - case '\\': - *append_ptr++ = '\\'; - *append_ptr++ = '\\'; - break; - } - } else { - *append_ptr++ = '\\'; - *append_ptr++ = '0' + c / 64; - *append_ptr++ = '0' + (c % 64) / 8; - *append_ptr++ = '0' + c % 8; - } - } -} - -bool Base64UnescapeInternal(const char* src_param, size_t szsrc, char* dest, - size_t szdest, const signed char* unbase64, - size_t* len) { - static const char kPad64Equals = '='; - static const char kPad64Dot = '.'; - - size_t destidx = 0; - int decode = 0; - int state = 0; - unsigned int ch = 0; - unsigned int temp = 0; - - // If "char" is signed by default, using *src as an array index results in - // accessing negative array elements. Treat the input as a pointer to - // unsigned char to avoid this. - const unsigned char* src = reinterpret_cast<const unsigned char*>(src_param); - - // The GET_INPUT macro gets the next input character, skipping - // over any whitespace, and stopping when we reach the end of the - // string or when we read any non-data character. The arguments are - // an arbitrary identifier (used as a label for goto) and the number - // of data bytes that must remain in the input to avoid aborting the - // loop. -#define GET_INPUT(label, remain) \ - label: \ - --szsrc; \ - ch = *src++; \ - decode = unbase64[ch]; \ - if (decode < 0) { \ - if (absl::ascii_isspace(ch) && szsrc >= remain) goto label; \ - state = 4 - remain; \ - break; \ - } - - // if dest is null, we're just checking to see if it's legal input - // rather than producing output. (I suspect this could just be done - // with a regexp...). We duplicate the loop so this test can be - // outside it instead of in every iteration. - - if (dest) { - // This loop consumes 4 input bytes and produces 3 output bytes - // per iteration. We can't know at the start that there is enough - // data left in the string for a full iteration, so the loop may - // break out in the middle; if so 'state' will be set to the - // number of input bytes read. - - while (szsrc >= 4) { - // We'll start by optimistically assuming that the next four - // bytes of the string (src[0..3]) are four good data bytes - // (that is, no nulls, whitespace, padding chars, or illegal - // chars). We need to test src[0..2] for nulls individually - // before constructing temp to preserve the property that we - // never read past a null in the string (no matter how long - // szsrc claims the string is). - - if (!src[0] || !src[1] || !src[2] || - ((temp = ((unsigned(unbase64[src[0]]) << 18) | - (unsigned(unbase64[src[1]]) << 12) | - (unsigned(unbase64[src[2]]) << 6) | - (unsigned(unbase64[src[3]])))) & - 0x80000000)) { - // Iff any of those four characters was bad (null, illegal, - // whitespace, padding), then temp's high bit will be set - // (because unbase64[] is -1 for all bad characters). - // - // We'll back up and resort to the slower decoder, which knows - // how to handle those cases. - - GET_INPUT(first, 4); - temp = decode; - GET_INPUT(second, 3); - temp = (temp << 6) | decode; - GET_INPUT(third, 2); - temp = (temp << 6) | decode; - GET_INPUT(fourth, 1); - temp = (temp << 6) | decode; - } else { - // We really did have four good data bytes, so advance four - // characters in the string. - - szsrc -= 4; - src += 4; - } - - // temp has 24 bits of input, so write that out as three bytes. - - if (destidx + 3 > szdest) return false; - dest[destidx + 2] = temp; - temp >>= 8; - dest[destidx + 1] = temp; - temp >>= 8; - dest[destidx] = temp; - destidx += 3; - } - } else { - while (szsrc >= 4) { - if (!src[0] || !src[1] || !src[2] || - ((temp = ((unsigned(unbase64[src[0]]) << 18) | - (unsigned(unbase64[src[1]]) << 12) | - (unsigned(unbase64[src[2]]) << 6) | - (unsigned(unbase64[src[3]])))) & - 0x80000000)) { - GET_INPUT(first_no_dest, 4); - GET_INPUT(second_no_dest, 3); - GET_INPUT(third_no_dest, 2); - GET_INPUT(fourth_no_dest, 1); - } else { - szsrc -= 4; - src += 4; - } - destidx += 3; - } - } - -#undef GET_INPUT - - // if the loop terminated because we read a bad character, return - // now. - if (decode < 0 && ch != kPad64Equals && ch != kPad64Dot && - !absl::ascii_isspace(ch)) - return false; - - if (ch == kPad64Equals || ch == kPad64Dot) { - // if we stopped by hitting an '=' or '.', un-read that character -- we'll - // look at it again when we count to check for the proper number of - // equals signs at the end. - ++szsrc; - --src; - } else { - // This loop consumes 1 input byte per iteration. It's used to - // clean up the 0-3 input bytes remaining when the first, faster - // loop finishes. 'temp' contains the data from 'state' input - // characters read by the first loop. - while (szsrc > 0) { - --szsrc; - ch = *src++; - decode = unbase64[ch]; - if (decode < 0) { - if (absl::ascii_isspace(ch)) { - continue; - } else if (ch == kPad64Equals || ch == kPad64Dot) { - // back up one character; we'll read it again when we check - // for the correct number of pad characters at the end. - ++szsrc; - --src; - break; - } else { - return false; - } - } - - // Each input character gives us six bits of output. - temp = (temp << 6) | decode; - ++state; - if (state == 4) { - // If we've accumulated 24 bits of output, write that out as - // three bytes. - if (dest) { - if (destidx + 3 > szdest) return false; - dest[destidx + 2] = temp; - temp >>= 8; - dest[destidx + 1] = temp; - temp >>= 8; - dest[destidx] = temp; - } - destidx += 3; - state = 0; - temp = 0; - } - } - } - - // Process the leftover data contained in 'temp' at the end of the input. - int expected_equals = 0; - switch (state) { - case 0: - // Nothing left over; output is a multiple of 3 bytes. - break; - - case 1: - // Bad input; we have 6 bits left over. - return false; - - case 2: - // Produce one more output byte from the 12 input bits we have left. - if (dest) { - if (destidx + 1 > szdest) return false; - temp >>= 4; - dest[destidx] = temp; - } - ++destidx; - expected_equals = 2; - break; - - case 3: - // Produce two more output bytes from the 18 input bits we have left. - if (dest) { - if (destidx + 2 > szdest) return false; - temp >>= 2; - dest[destidx + 1] = temp; - temp >>= 8; - dest[destidx] = temp; - } - destidx += 2; - expected_equals = 1; - break; - - default: - // state should have no other values at this point. - ABSL_RAW_LOG(FATAL, "This can't happen; base64 decoder state = %d", - state); - } - - // The remainder of the string should be all whitespace, mixed with - // exactly 0 equals signs, or exactly 'expected_equals' equals - // signs. (Always accepting 0 equals signs is an Abseil extension - // not covered in the RFC, as is accepting dot as the pad character.) - - int equals = 0; - while (szsrc > 0) { - if (*src == kPad64Equals || *src == kPad64Dot) - ++equals; - else if (!absl::ascii_isspace(*src)) - return false; - --szsrc; - ++src; - } - - const bool ok = (equals == 0 || equals == expected_equals); - if (ok) *len = destidx; - return ok; -} - -// The arrays below were generated by the following code -// #include <sys/time.h> -// #include <stdlib.h> -// #include <string.h> -// main() -// { -// static const char Base64[] = -// "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; -// char* pos; -// int idx, i, j; -// printf(" "); -// for (i = 0; i < 255; i += 8) { -// for (j = i; j < i + 8; j++) { -// pos = strchr(Base64, j); -// if ((pos == nullptr) || (j == 0)) -// idx = -1; -// else -// idx = pos - Base64; -// if (idx == -1) -// printf(" %2d, ", idx); -// else -// printf(" %2d/*%c*/,", idx, j); -// } -// printf("\n "); -// } -// } -// -// where the value of "Base64[]" was replaced by one of the base-64 conversion -// tables from the functions below. -/* clang-format off */ -constexpr signed char kUnBase64[] = { - -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/*0*/, 53/*1*/, 54/*2*/, 55/*3*/, 56/*4*/, 57/*5*/, 58/*6*/, 59/*7*/, - 60/*8*/, 61/*9*/, -1, -1, -1, -1, -1, -1, - -1, 0/*A*/, 1/*B*/, 2/*C*/, 3/*D*/, 4/*E*/, 5/*F*/, 6/*G*/, - 07/*H*/, 8/*I*/, 9/*J*/, 10/*K*/, 11/*L*/, 12/*M*/, 13/*N*/, 14/*O*/, - 15/*P*/, 16/*Q*/, 17/*R*/, 18/*S*/, 19/*T*/, 20/*U*/, 21/*V*/, 22/*W*/, - 23/*X*/, 24/*Y*/, 25/*Z*/, -1, -1, -1, -1, -1, - -1, 26/*a*/, 27/*b*/, 28/*c*/, 29/*d*/, 30/*e*/, 31/*f*/, 32/*g*/, - 33/*h*/, 34/*i*/, 35/*j*/, 36/*k*/, 37/*l*/, 38/*m*/, 39/*n*/, 40/*o*/, - 41/*p*/, 42/*q*/, 43/*r*/, 44/*s*/, 45/*t*/, 46/*u*/, 47/*v*/, 48/*w*/, - 49/*x*/, 50/*y*/, 51/*z*/, -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 -}; - -constexpr signed char kUnWebSafeBase64[] = { - -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, 62/*-*/, -1, -1, - 52/*0*/, 53/*1*/, 54/*2*/, 55/*3*/, 56/*4*/, 57/*5*/, 58/*6*/, 59/*7*/, - 60/*8*/, 61/*9*/, -1, -1, -1, -1, -1, -1, - -1, 0/*A*/, 1/*B*/, 2/*C*/, 3/*D*/, 4/*E*/, 5/*F*/, 6/*G*/, - 07/*H*/, 8/*I*/, 9/*J*/, 10/*K*/, 11/*L*/, 12/*M*/, 13/*N*/, 14/*O*/, - 15/*P*/, 16/*Q*/, 17/*R*/, 18/*S*/, 19/*T*/, 20/*U*/, 21/*V*/, 22/*W*/, - 23/*X*/, 24/*Y*/, 25/*Z*/, -1, -1, -1, -1, 63/*_*/, - -1, 26/*a*/, 27/*b*/, 28/*c*/, 29/*d*/, 30/*e*/, 31/*f*/, 32/*g*/, - 33/*h*/, 34/*i*/, 35/*j*/, 36/*k*/, 37/*l*/, 38/*m*/, 39/*n*/, 40/*o*/, - 41/*p*/, 42/*q*/, 43/*r*/, 44/*s*/, 45/*t*/, 46/*u*/, 47/*v*/, 48/*w*/, - 49/*x*/, 50/*y*/, 51/*z*/, -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 -}; -/* clang-format on */ - -constexpr char kWebSafeBase64Chars[] = - "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"; - -template <typename String> -bool Base64UnescapeInternal(const char* src, size_t slen, String* dest, - const signed char* unbase64) { - // Determine the size of the output string. Base64 encodes every 3 bytes into - // 4 characters. any leftover chars are added directly for good measure. - // This is documented in the base64 RFC: http://tools.ietf.org/html/rfc3548 - const size_t dest_len = 3 * (slen / 4) + (slen % 4); - - strings_internal::STLStringResizeUninitialized(dest, dest_len); - - // We are getting the destination buffer by getting the beginning of the - // string and converting it into a char *. - size_t len; - const bool ok = - Base64UnescapeInternal(src, slen, &(*dest)[0], dest_len, unbase64, &len); - if (!ok) { - dest->clear(); - return false; - } - - // could be shorter if there was padding - assert(len <= dest_len); - dest->erase(len); - - return true; -} - -/* clang-format off */ -constexpr char kHexValueLenient[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, 0, 0, 0, 0, 0, - 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0, // '0'..'9' - 0, 10, 11, 12, 13, 14, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 'A'..'F' - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 10, 11, 12, 13, 14, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 'a'..'f' - 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, 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, 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, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -}; - -/* clang-format on */ - -// This is a templated function so that T can be either a char* -// or a string. This works because we use the [] operator to access -// individual characters at a time. -template <typename T> -void HexStringToBytesInternal(const char* from, T to, ptrdiff_t num) { - for (int i = 0; i < num; i++) { - to[i] = (kHexValueLenient[from[i * 2] & 0xFF] << 4) + - (kHexValueLenient[from[i * 2 + 1] & 0xFF]); - } -} - -// This is a templated function so that T can be either a char* or a -// std::string. -template <typename T> -void BytesToHexStringInternal(const unsigned char* src, T dest, ptrdiff_t num) { - auto dest_ptr = &dest[0]; - for (auto src_ptr = src; src_ptr != (src + num); ++src_ptr, dest_ptr += 2) { - const char* hex_p = &numbers_internal::kHexTable[*src_ptr * 2]; - std::copy(hex_p, hex_p + 2, dest_ptr); - } -} - -} // namespace - -// ---------------------------------------------------------------------- -// CUnescape() -// -// See CUnescapeInternal() for implementation details. -// ---------------------------------------------------------------------- -bool CUnescape(absl::string_view source, std::string* dest, - std::string* error) { - return CUnescapeInternal(source, kUnescapeNulls, dest, error); -} - -std::string CEscape(absl::string_view src) { - std::string dest; - CEscapeAndAppendInternal(src, &dest); - return dest; -} - -std::string CHexEscape(absl::string_view src) { - return CEscapeInternal(src, true, false); -} - -std::string Utf8SafeCEscape(absl::string_view src) { - return CEscapeInternal(src, false, true); -} - -std::string Utf8SafeCHexEscape(absl::string_view src) { - return CEscapeInternal(src, true, true); -} - -// ---------------------------------------------------------------------- -// Base64Unescape() - base64 decoder -// Base64Escape() - base64 encoder -// WebSafeBase64Unescape() - Google's variation of base64 decoder -// WebSafeBase64Escape() - Google's variation of base64 encoder -// -// Check out -// http://tools.ietf.org/html/rfc2045 for formal description, but what we -// care about is that... -// Take the encoded stuff in groups of 4 characters and turn each -// character into a code 0 to 63 thus: -// A-Z map to 0 to 25 -// a-z map to 26 to 51 -// 0-9 map to 52 to 61 -// +(- for WebSafe) maps to 62 -// /(_ for WebSafe) maps to 63 -// There will be four numbers, all less than 64 which can be represented -// by a 6 digit binary number (aaaaaa, bbbbbb, cccccc, dddddd respectively). -// Arrange the 6 digit binary numbers into three bytes as such: -// aaaaaabb bbbbcccc ccdddddd -// Equals signs (one or two) are used at the end of the encoded block to -// indicate that the text was not an integer multiple of three bytes long. -// ---------------------------------------------------------------------- - -bool Base64Unescape(absl::string_view src, std::string* dest) { - return Base64UnescapeInternal(src.data(), src.size(), dest, kUnBase64); -} - -bool WebSafeBase64Unescape(absl::string_view src, std::string* dest) { - return Base64UnescapeInternal(src.data(), src.size(), dest, kUnWebSafeBase64); -} - -void Base64Escape(absl::string_view src, std::string* dest) { - strings_internal::Base64EscapeInternal( - reinterpret_cast<const unsigned char*>(src.data()), src.size(), dest, - true, strings_internal::kBase64Chars); -} - -void WebSafeBase64Escape(absl::string_view src, std::string* dest) { - strings_internal::Base64EscapeInternal( - reinterpret_cast<const unsigned char*>(src.data()), src.size(), dest, - false, kWebSafeBase64Chars); -} - -std::string Base64Escape(absl::string_view src) { - std::string dest; - strings_internal::Base64EscapeInternal( - reinterpret_cast<const unsigned char*>(src.data()), src.size(), &dest, - true, strings_internal::kBase64Chars); - return dest; -} - -std::string WebSafeBase64Escape(absl::string_view src) { - std::string dest; - strings_internal::Base64EscapeInternal( - reinterpret_cast<const unsigned char*>(src.data()), src.size(), &dest, - false, kWebSafeBase64Chars); - return dest; -} - -std::string HexStringToBytes(absl::string_view from) { - std::string result; - const auto num = from.size() / 2; - strings_internal::STLStringResizeUninitialized(&result, num); - absl::HexStringToBytesInternal<std::string&>(from.data(), result, num); - return result; -} - -std::string BytesToHexString(absl::string_view from) { - std::string result; - strings_internal::STLStringResizeUninitialized(&result, 2 * from.size()); - absl::BytesToHexStringInternal<std::string&>( - reinterpret_cast<const unsigned char*>(from.data()), result, from.size()); - return result; -} - -ABSL_NAMESPACE_END -} // namespace absl |