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/*
*
* Copyright 2016, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "src/core/lib/support/percent_encoding.h"
#include <grpc/support/log.h>
static bool is_unreserved_character(uint8_t c) {
return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') ||
(c >= '0' && c <= '9') || c == '-' || c == '_' || c == '.' || c == '~';
}
gpr_slice gpr_percent_encode_slice(gpr_slice slice) {
static const uint8_t hex[] = "0123456789ABCDEF";
// first pass: count the number of bytes needed to output this string
size_t output_length = 0;
const uint8_t *slice_start = GPR_SLICE_START_PTR(slice);
const uint8_t *slice_end = GPR_SLICE_END_PTR(slice);
const uint8_t *p;
bool any_reserved_bytes = false;
for (p = slice_start; p < slice_end; p++) {
bool unres = is_unreserved_character(*p);
output_length += unres ? 1 : 3;
any_reserved_bytes |= !unres;
}
// no unreserved bytes: return the string unmodified
if (!any_reserved_bytes) {
return gpr_slice_ref(slice);
}
// second pass: actually encode
gpr_slice out = gpr_slice_malloc(output_length);
uint8_t *q = GPR_SLICE_START_PTR(out);
for (p = slice_start; p < slice_end; p++) {
if (is_unreserved_character(*p)) {
*q++ = *p;
} else {
*q++ = '%';
*q++ = hex[*p >> 4];
*q++ = hex[*p & 15];
}
}
GPR_ASSERT(q == GPR_SLICE_END_PTR(out));
return out;
}
static bool valid_hex(const uint8_t *p, const uint8_t *end) {
if (p == end) return false;
return (*p >= '0' && *p <= '9') || (*p >= 'a' && *p <= 'f') ||
(*p >= 'A' && *p <= 'F');
}
static uint8_t dehex(uint8_t c) {
if (c >= '0' && c <= '9') return (uint8_t)(c - '0');
if (c >= 'A' && c <= 'F') return (uint8_t)(c - 'A' + 10);
if (c >= 'a' && c <= 'f') return (uint8_t)(c - 'a' + 10);
GPR_UNREACHABLE_CODE(return 255);
}
bool gpr_percent_decode_slice(gpr_slice slice_in, gpr_slice *slice_out) {
const uint8_t *p = GPR_SLICE_START_PTR(slice_in);
const uint8_t *in_end = GPR_SLICE_END_PTR(slice_in);
size_t out_length = 0;
bool any_percent_encoded_stuff = false;
while (p != in_end) {
if (*p == '%') {
if (!valid_hex(++p, in_end)) return false;
if (!valid_hex(++p, in_end)) return false;
p++;
any_percent_encoded_stuff = true;
out_length++;
} else {
p++;
out_length++;
}
}
if (!any_percent_encoded_stuff) {
*slice_out = gpr_slice_ref(slice_in);
return true;
}
p = GPR_SLICE_START_PTR(slice_in);
*slice_out = gpr_slice_malloc(out_length);
uint8_t *q = GPR_SLICE_START_PTR(*slice_out);
while (p != in_end) {
if (*p == '%') {
*q++ = (uint8_t)(dehex(p[1]) << 4) | (dehex(p[2]));
p += 3;
} else {
*q++ = *p++;
}
}
GPR_ASSERT(q == GPR_SLICE_END_PTR(*slice_out));
return true;
}
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