--- /dev/null
+/*
+ *
+ * Copyright 2016 gRPC 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
+ *
+ * http://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 <grpc/support/port_platform.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include "src/core/ext/transport/chttp2/transport/bin_decoder.h"
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/slice/slice_internal.h"
+#include "src/core/lib/slice/slice_string_helpers.h"
+
+static uint8_t decode_table[] = {
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 62, 0x40, 0x40, 0x40, 63,
+ 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 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, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 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, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40};
+
+static const uint8_t tail_xtra[4] = {0, 0, 1, 2};
+
+static bool input_is_valid(const uint8_t* input_ptr, size_t length) {
+ size_t i;
+
+ for (i = 0; i < length; ++i) {
+ if (GPR_UNLIKELY((decode_table[input_ptr[i]] & 0xC0) != 0)) {
+ gpr_log(GPR_ERROR,
+ "Base64 decoding failed, invalid character '%c' in base64 "
+ "input.\n",
+ static_cast<char>(*input_ptr));
+ return false;
+ }
+ }
+ return true;
+}
+
+#define COMPOSE_OUTPUT_BYTE_0(input_ptr) \
+ (uint8_t)((decode_table[input_ptr[0]] << 2) | \
+ (decode_table[input_ptr[1]] >> 4))
+
+#define COMPOSE_OUTPUT_BYTE_1(input_ptr) \
+ (uint8_t)((decode_table[input_ptr[1]] << 4) | \
+ (decode_table[input_ptr[2]] >> 2))
+
+#define COMPOSE_OUTPUT_BYTE_2(input_ptr) \
+ (uint8_t)((decode_table[input_ptr[2]] << 6) | decode_table[input_ptr[3]])
+
+// By RFC 4648, if the length of the encoded string without padding is 4n+r,
+// the length of decoded string is: 1) 3n if r = 0, 2) 3n + 1 if r = 2, 3, or
+// 3) invalid if r = 1.
+size_t grpc_chttp2_base64_infer_length_after_decode(const grpc_slice& slice) {
+ size_t len = GRPC_SLICE_LENGTH(slice);
+ const uint8_t* bytes = GRPC_SLICE_START_PTR(slice);
+ while (len > 0 && bytes[len - 1] == '=') {
+ len--;
+ }
+ if (GPR_UNLIKELY(GRPC_SLICE_LENGTH(slice) - len > 2)) {
+ gpr_log(GPR_ERROR,
+ "Base64 decoding failed. Input has more than 2 paddings.");
+ return 0;
+ }
+ size_t tuples = len / 4;
+ size_t tail_case = len % 4;
+ if (GPR_UNLIKELY(tail_case == 1)) {
+ gpr_log(GPR_ERROR,
+ "Base64 decoding failed. Input has a length of %zu (without"
+ " padding), which is invalid.\n",
+ len);
+ return 0;
+ }
+ return tuples * 3 + tail_xtra[tail_case];
+}
+
+bool grpc_base64_decode_partial(struct grpc_base64_decode_context* ctx) {
+ size_t input_tail;
+
+ if (ctx->input_cur > ctx->input_end || ctx->output_cur > ctx->output_end) {
+ return false;
+ }
+
+ // Process a block of 4 input characters and 3 output bytes
+ while (ctx->input_end >= ctx->input_cur + 4 &&
+ ctx->output_end >= ctx->output_cur + 3) {
+ if (!input_is_valid(ctx->input_cur, 4)) return false;
+ ctx->output_cur[0] = COMPOSE_OUTPUT_BYTE_0(ctx->input_cur);
+ ctx->output_cur[1] = COMPOSE_OUTPUT_BYTE_1(ctx->input_cur);
+ ctx->output_cur[2] = COMPOSE_OUTPUT_BYTE_2(ctx->input_cur);
+ ctx->output_cur += 3;
+ ctx->input_cur += 4;
+ }
+
+ // Process the tail of input data
+ input_tail = static_cast<size_t>(ctx->input_end - ctx->input_cur);
+ if (input_tail == 4) {
+ // Process the input data with pad chars
+ if (ctx->input_cur[3] == '=') {
+ if (ctx->input_cur[2] == '=' && ctx->output_end >= ctx->output_cur + 1) {
+ if (!input_is_valid(ctx->input_cur, 2)) return false;
+ *(ctx->output_cur++) = COMPOSE_OUTPUT_BYTE_0(ctx->input_cur);
+ ctx->input_cur += 4;
+ } else if (ctx->output_end >= ctx->output_cur + 2) {
+ if (!input_is_valid(ctx->input_cur, 3)) return false;
+ *(ctx->output_cur++) = COMPOSE_OUTPUT_BYTE_0(ctx->input_cur);
+ *(ctx->output_cur++) = COMPOSE_OUTPUT_BYTE_1(ctx->input_cur);
+ ;
+ ctx->input_cur += 4;
+ }
+ }
+
+ } else if (ctx->contains_tail && input_tail > 1) {
+ // Process the input data without pad chars, but constains_tail is set
+ if (ctx->output_end >= ctx->output_cur + tail_xtra[input_tail]) {
+ if (!input_is_valid(ctx->input_cur, input_tail)) return false;
+ switch (input_tail) {
+ case 3:
+ ctx->output_cur[1] = COMPOSE_OUTPUT_BYTE_1(ctx->input_cur);
+ /* fallthrough */
+ case 2:
+ ctx->output_cur[0] = COMPOSE_OUTPUT_BYTE_0(ctx->input_cur);
+ }
+ ctx->output_cur += tail_xtra[input_tail];
+ ctx->input_cur += input_tail;
+ }
+ }
+
+ return true;
+}
+
+grpc_slice grpc_chttp2_base64_decode(const grpc_slice& input) {
+ size_t input_length = GRPC_SLICE_LENGTH(input);
+ size_t output_length = input_length / 4 * 3;
+ struct grpc_base64_decode_context ctx;
+ grpc_slice output;
+
+ if (GPR_UNLIKELY(input_length % 4 != 0)) {
+ gpr_log(GPR_ERROR,
+ "Base64 decoding failed, input of "
+ "grpc_chttp2_base64_decode has a length of %d, which is not a "
+ "multiple of 4.\n",
+ static_cast<int>(input_length));
+ return grpc_empty_slice();
+ }
+
+ if (input_length > 0) {
+ const uint8_t* input_end = GRPC_SLICE_END_PTR(input);
+ if (*(--input_end) == '=') {
+ output_length--;
+ if (*(--input_end) == '=') {
+ output_length--;
+ }
+ }
+ }
+ output = GRPC_SLICE_MALLOC(output_length);
+
+ ctx.input_cur = GRPC_SLICE_START_PTR(input);
+ ctx.input_end = GRPC_SLICE_END_PTR(input);
+ ctx.output_cur = GRPC_SLICE_START_PTR(output);
+ ctx.output_end = GRPC_SLICE_END_PTR(output);
+ ctx.contains_tail = false;
+
+ if (GPR_UNLIKELY(!grpc_base64_decode_partial(&ctx))) {
+ char* s = grpc_slice_to_c_string(input);
+ gpr_log(GPR_ERROR, "Base64 decoding failed, input string:\n%s\n", s);
+ gpr_free(s);
+ grpc_slice_unref_internal(output);
+ return grpc_empty_slice();
+ }
+ GPR_ASSERT(ctx.output_cur == GRPC_SLICE_END_PTR(output));
+ GPR_ASSERT(ctx.input_cur == GRPC_SLICE_END_PTR(input));
+ return output;
+}
+
+grpc_slice grpc_chttp2_base64_decode_with_length(const grpc_slice& input,
+ size_t output_length) {
+ size_t input_length = GRPC_SLICE_LENGTH(input);
+ grpc_slice output = GRPC_SLICE_MALLOC(output_length);
+ struct grpc_base64_decode_context ctx;
+
+ // The length of a base64 string cannot be 4 * n + 1
+ if (GPR_UNLIKELY(input_length % 4 == 1)) {
+ gpr_log(GPR_ERROR,
+ "Base64 decoding failed, input of "
+ "grpc_chttp2_base64_decode_with_length has a length of %d, which "
+ "has a tail of 1 byte.\n",
+ static_cast<int>(input_length));
+ grpc_slice_unref_internal(output);
+ return grpc_empty_slice();
+ }
+
+ if (GPR_UNLIKELY(output_length >
+ input_length / 4 * 3 + tail_xtra[input_length % 4])) {
+ gpr_log(
+ GPR_ERROR,
+ "Base64 decoding failed, output_length %d is longer "
+ "than the max possible output length %d.\n",
+ static_cast<int>(output_length),
+ static_cast<int>(input_length / 4 * 3 + tail_xtra[input_length % 4]));
+ grpc_slice_unref_internal(output);
+ return grpc_empty_slice();
+ }
+
+ ctx.input_cur = GRPC_SLICE_START_PTR(input);
+ ctx.input_end = GRPC_SLICE_END_PTR(input);
+ ctx.output_cur = GRPC_SLICE_START_PTR(output);
+ ctx.output_end = GRPC_SLICE_END_PTR(output);
+ ctx.contains_tail = true;
+
+ if (GPR_UNLIKELY(!grpc_base64_decode_partial(&ctx))) {
+ char* s = grpc_slice_to_c_string(input);
+ gpr_log(GPR_ERROR, "Base64 decoding failed, input string:\n%s\n", s);
+ gpr_free(s);
+ grpc_slice_unref_internal(output);
+ return grpc_empty_slice();
+ }
+ GPR_ASSERT(ctx.output_cur == GRPC_SLICE_END_PTR(output));
+ GPR_ASSERT(ctx.input_cur <= GRPC_SLICE_END_PTR(input));
+ return output;
+}
git://repos.xcallymotion.com / motion2.git / blobdiff