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Diffstat (limited to 'src/core/ext/transport/chttp2/transport/bin_decoder.c')
-rw-r--r--src/core/ext/transport/chttp2/transport/bin_decoder.c232
1 files changed, 232 insertions, 0 deletions
diff --git a/src/core/ext/transport/chttp2/transport/bin_decoder.c b/src/core/ext/transport/chttp2/transport/bin_decoder.c
new file mode 100644
index 0000000000..2d90b01cd8
--- /dev/null
+++ b/src/core/ext/transport/chttp2/transport/bin_decoder.c
@@ -0,0 +1,232 @@
+/*
+ *
+ * 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/ext/transport/chttp2/transport/bin_decoder.h"
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include "src/core/lib/support/string.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(uint8_t *input_ptr, size_t length) {
+ size_t i;
+
+ for (i = 0; i < length; ++i) {
+ if ((decode_table[input_ptr[i]] & 0xC0) != 0) {
+ gpr_log(GPR_ERROR,
+ "Base64 decoding failed, invalid character '%c' in base64 "
+ "input.\n",
+ (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]])
+
+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 = (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);
+ 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;
+}
+
+gpr_slice grpc_chttp2_base64_decode(gpr_slice input) {
+ size_t input_length = GPR_SLICE_LENGTH(input);
+ size_t output_length = input_length / 4 * 3;
+ struct grpc_base64_decode_context ctx;
+ gpr_slice output;
+
+ if (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",
+ (int)input_length);
+ return gpr_empty_slice();
+ }
+
+ if (input_length > 0) {
+ uint8_t *input_end = GPR_SLICE_END_PTR(input);
+ if (*(--input_end) == '=') {
+ output_length--;
+ if (*(--input_end) == '=') {
+ output_length--;
+ }
+ }
+ }
+ output = gpr_slice_malloc(output_length);
+
+ ctx.input_cur = GPR_SLICE_START_PTR(input);
+ ctx.input_end = GPR_SLICE_END_PTR(input);
+ ctx.output_cur = GPR_SLICE_START_PTR(output);
+ ctx.output_end = GPR_SLICE_END_PTR(output);
+ ctx.contains_tail = false;
+
+ if (!grpc_base64_decode_partial(&ctx)) {
+ char *s = gpr_dump_slice(input, GPR_DUMP_ASCII);
+ gpr_log(GPR_ERROR, "Base64 decoding failed, input string:\n%s\n", s);
+ gpr_free(s);
+ gpr_slice_unref(output);
+ return gpr_empty_slice();
+ }
+ GPR_ASSERT(ctx.output_cur == GPR_SLICE_END_PTR(output));
+ GPR_ASSERT(ctx.input_cur == GPR_SLICE_END_PTR(input));
+ return output;
+}
+
+gpr_slice grpc_chttp2_base64_decode_with_length(gpr_slice input,
+ size_t output_length) {
+ size_t input_length = GPR_SLICE_LENGTH(input);
+ gpr_slice output = gpr_slice_malloc(output_length);
+ struct grpc_base64_decode_context ctx;
+
+ // The length of a base64 string cannot be 4 * n + 1
+ if (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",
+ (int)input_length);
+ gpr_slice_unref(output);
+ return gpr_empty_slice();
+ }
+
+ if (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",
+ (int)output_length,
+ (int)(input_length / 4 * 3 + tail_xtra[input_length % 4]));
+ gpr_slice_unref(output);
+ return gpr_empty_slice();
+ }
+
+ ctx.input_cur = GPR_SLICE_START_PTR(input);
+ ctx.input_end = GPR_SLICE_END_PTR(input);
+ ctx.output_cur = GPR_SLICE_START_PTR(output);
+ ctx.output_end = GPR_SLICE_END_PTR(output);
+ ctx.contains_tail = true;
+
+ if (!grpc_base64_decode_partial(&ctx)) {
+ char *s = gpr_dump_slice(input, GPR_DUMP_ASCII);
+ gpr_log(GPR_ERROR, "Base64 decoding failed, input string:\n%s\n", s);
+ gpr_free(s);
+ gpr_slice_unref(output);
+ return gpr_empty_slice();
+ }
+ GPR_ASSERT(ctx.output_cur == GPR_SLICE_END_PTR(output));
+ GPR_ASSERT(ctx.input_cur <= GPR_SLICE_END_PTR(input));
+ return output;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-03 16:04:34 +0000