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Diffstat (limited to 'src/core/lib/slice/percent_encoding.c')
| -rw-r--r-- | src/core/lib/slice/percent_encoding.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/src/core/lib/slice/percent_encoding.c b/src/core/lib/slice/percent_encoding.c new file mode 100644 index 0000000000..b9e35f1c71 --- /dev/null +++ b/src/core/lib/slice/percent_encoding.c @@ -0,0 +1,180 @@ +/* + * + * 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/slice/percent_encoding.h" + +#include <grpc/support/log.h> + +const uint8_t grpc_url_percent_encoding_unreserved_bytes[256 / 8] = { + 0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0xff, 0x03, 0xfe, 0xff, 0xff, + 0x87, 0xfe, 0xff, 0xff, 0x47, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; +const uint8_t grpc_compatible_percent_encoding_unreserved_bytes[256 / 8] = { + 0x00, 0x00, 0x00, 0x00, 0xdf, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0x7f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; + +static bool is_unreserved_character(uint8_t c, + const uint8_t *unreserved_bytes) { + return ((unreserved_bytes[c / 8] >> (c % 8)) & 1) != 0; +} + +grpc_slice grpc_percent_encode_slice(grpc_slice slice, + const uint8_t *unreserved_bytes) { + 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 = GRPC_SLICE_START_PTR(slice); + const uint8_t *slice_end = GRPC_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, unreserved_bytes); + output_length += unres ? 1 : 3; + any_reserved_bytes |= !unres; + } + // no unreserved bytes: return the string unmodified + if (!any_reserved_bytes) { + return grpc_slice_ref(slice); + } + // second pass: actually encode + grpc_slice out = grpc_slice_malloc(output_length); + uint8_t *q = GRPC_SLICE_START_PTR(out); + for (p = slice_start; p < slice_end; p++) { + if (is_unreserved_character(*p, unreserved_bytes)) { + *q++ = *p; + } else { + *q++ = '%'; + *q++ = hex[*p >> 4]; + *q++ = hex[*p & 15]; + } + } + GPR_ASSERT(q == GRPC_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 grpc_strict_percent_decode_slice(grpc_slice slice_in, + const uint8_t *unreserved_bytes, + grpc_slice *slice_out) { + const uint8_t *p = GRPC_SLICE_START_PTR(slice_in); + const uint8_t *in_end = GRPC_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++; + out_length++; + any_percent_encoded_stuff = true; + } else if (is_unreserved_character(*p, unreserved_bytes)) { + p++; + out_length++; + } else { + return false; + } + } + if (!any_percent_encoded_stuff) { + *slice_out = grpc_slice_ref(slice_in); + return true; + } + p = GRPC_SLICE_START_PTR(slice_in); + *slice_out = grpc_slice_malloc(out_length); + uint8_t *q = GRPC_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 == GRPC_SLICE_END_PTR(*slice_out)); + return true; +} + +grpc_slice grpc_permissive_percent_decode_slice(grpc_slice slice_in) { + const uint8_t *p = GRPC_SLICE_START_PTR(slice_in); + const uint8_t *in_end = GRPC_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 + 1, in_end) || !valid_hex(p + 2, in_end)) { + p++; + out_length++; + } else { + p += 3; + out_length++; + any_percent_encoded_stuff = true; + } + } else { + p++; + out_length++; + } + } + if (!any_percent_encoded_stuff) { + return grpc_slice_ref(slice_in); + } + p = GRPC_SLICE_START_PTR(slice_in); + grpc_slice out = grpc_slice_malloc(out_length); + uint8_t *q = GRPC_SLICE_START_PTR(out); + while (p != in_end) { + if (*p == '%') { + if (!valid_hex(p + 1, in_end) || !valid_hex(p + 2, in_end)) { + *q++ = *p++; + } else { + *q++ = (uint8_t)(dehex(p[1]) << 4) | (dehex(p[2])); + p += 3; + } + } else { + *q++ = *p++; + } + } + GPR_ASSERT(q == GRPC_SLICE_END_PTR(out)); + return out; +} |