| /* |
| * |
| * Copyright 2015 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 "src/core/lib/slice/b64.h" |
| |
| #include <stdint.h> |
| #include <string.h> |
| |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/log.h> |
| |
| #include "src/core/lib/gpr/useful.h" |
| #include "src/core/lib/slice/slice_internal.h" |
| |
| /* --- Constants. --- */ |
| |
| static const int8_t base64_bytes[] = { |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, 0x3E, -1, -1, -1, 0x3F, |
| 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, -1, -1, |
| -1, 0x7F, -1, -1, -1, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, |
| 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, |
| 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, -1, -1, -1, -1, -1, |
| -1, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, |
| 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, |
| 0x31, 0x32, 0x33, -1, -1, -1, -1, -1}; |
| |
| static const char base64_url_unsafe_chars[] = |
| "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
| static const char base64_url_safe_chars[] = |
| "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"; |
| |
| #define GRPC_BASE64_PAD_CHAR '=' |
| #define GRPC_BASE64_PAD_BYTE 0x7F |
| #define GRPC_BASE64_MULTILINE_LINE_LEN 76 |
| #define GRPC_BASE64_MULTILINE_NUM_BLOCKS (GRPC_BASE64_MULTILINE_LINE_LEN / 4) |
| |
| /* --- base64 functions. --- */ |
| |
| char* grpc_base64_encode(const void* vdata, size_t data_size, int url_safe, |
| int multiline) { |
| size_t result_projected_size = |
| grpc_base64_estimate_encoded_size(data_size, url_safe, multiline); |
| char* result = static_cast<char*>(gpr_malloc(result_projected_size)); |
| grpc_base64_encode_core(result, vdata, data_size, url_safe, multiline); |
| return result; |
| } |
| |
| size_t grpc_base64_estimate_encoded_size(size_t data_size, int url_safe, |
| int multiline) { |
| size_t result_projected_size = |
| 4 * ((data_size + 3) / 3) + |
| 2 * (multiline ? (data_size / (3 * GRPC_BASE64_MULTILINE_NUM_BLOCKS)) |
| : 0) + |
| 1; |
| return result_projected_size; |
| } |
| |
| void grpc_base64_encode_core(char* result, const void* vdata, size_t data_size, |
| int url_safe, int multiline) { |
| const unsigned char* data = static_cast<const unsigned char*>(vdata); |
| const char* base64_chars = |
| url_safe ? base64_url_safe_chars : base64_url_unsafe_chars; |
| const size_t result_projected_size = |
| grpc_base64_estimate_encoded_size(data_size, url_safe, multiline); |
| |
| char* current = result; |
| size_t num_blocks = 0; |
| size_t i = 0; |
| |
| /* Encode each block. */ |
| while (data_size >= 3) { |
| *current++ = base64_chars[(data[i] >> 2) & 0x3F]; |
| *current++ = |
| base64_chars[((data[i] & 0x03) << 4) | ((data[i + 1] >> 4) & 0x0F)]; |
| *current++ = |
| base64_chars[((data[i + 1] & 0x0F) << 2) | ((data[i + 2] >> 6) & 0x03)]; |
| *current++ = base64_chars[data[i + 2] & 0x3F]; |
| |
| data_size -= 3; |
| i += 3; |
| if (multiline && (++num_blocks == GRPC_BASE64_MULTILINE_NUM_BLOCKS)) { |
| *current++ = '\r'; |
| *current++ = '\n'; |
| num_blocks = 0; |
| } |
| } |
| |
| /* Take care of the tail. */ |
| if (data_size == 2) { |
| *current++ = base64_chars[(data[i] >> 2) & 0x3F]; |
| *current++ = |
| base64_chars[((data[i] & 0x03) << 4) | ((data[i + 1] >> 4) & 0x0F)]; |
| *current++ = base64_chars[(data[i + 1] & 0x0F) << 2]; |
| *current++ = GRPC_BASE64_PAD_CHAR; |
| } else if (data_size == 1) { |
| *current++ = base64_chars[(data[i] >> 2) & 0x3F]; |
| *current++ = base64_chars[(data[i] & 0x03) << 4]; |
| *current++ = GRPC_BASE64_PAD_CHAR; |
| *current++ = GRPC_BASE64_PAD_CHAR; |
| } |
| |
| GPR_ASSERT(current >= result); |
| GPR_ASSERT((uintptr_t)(current - result) < result_projected_size); |
| result[current - result] = '\0'; |
| } |
| |
| grpc_slice grpc_base64_decode(const char* b64, int url_safe) { |
| return grpc_base64_decode_with_len(b64, strlen(b64), url_safe); |
| } |
| |
| static void decode_one_char(const unsigned char* codes, unsigned char* result, |
| size_t* result_offset) { |
| uint32_t packed = (static_cast<uint32_t>(codes[0]) << 2) | |
| (static_cast<uint32_t>(codes[1]) >> 4); |
| result[(*result_offset)++] = static_cast<unsigned char>(packed); |
| } |
| |
| static void decode_two_chars(const unsigned char* codes, unsigned char* result, |
| size_t* result_offset) { |
| uint32_t packed = (static_cast<uint32_t>(codes[0]) << 10) | |
| (static_cast<uint32_t>(codes[1]) << 4) | |
| (static_cast<uint32_t>(codes[2]) >> 2); |
| result[(*result_offset)++] = static_cast<unsigned char>(packed >> 8); |
| result[(*result_offset)++] = static_cast<unsigned char>(packed); |
| } |
| |
| static int decode_group(const unsigned char* codes, size_t num_codes, |
| unsigned char* result, size_t* result_offset) { |
| GPR_ASSERT(num_codes <= 4); |
| |
| /* Short end groups that may not have padding. */ |
| if (num_codes == 1) { |
| gpr_log(GPR_ERROR, "Invalid group. Must be at least 2 bytes."); |
| return 0; |
| } |
| if (num_codes == 2) { |
| decode_one_char(codes, result, result_offset); |
| return 1; |
| } |
| if (num_codes == 3) { |
| decode_two_chars(codes, result, result_offset); |
| return 1; |
| } |
| |
| /* Regular 4 byte groups with padding or not. */ |
| GPR_ASSERT(num_codes == 4); |
| if (codes[0] == GRPC_BASE64_PAD_BYTE || codes[1] == GRPC_BASE64_PAD_BYTE) { |
| gpr_log(GPR_ERROR, "Invalid padding detected."); |
| return 0; |
| } |
| if (codes[2] == GRPC_BASE64_PAD_BYTE) { |
| if (codes[3] == GRPC_BASE64_PAD_BYTE) { |
| decode_one_char(codes, result, result_offset); |
| } else { |
| gpr_log(GPR_ERROR, "Invalid padding detected."); |
| return 0; |
| } |
| } else if (codes[3] == GRPC_BASE64_PAD_BYTE) { |
| decode_two_chars(codes, result, result_offset); |
| } else { |
| /* No padding. */ |
| uint32_t packed = (static_cast<uint32_t>(codes[0]) << 18) | |
| (static_cast<uint32_t>(codes[1]) << 12) | |
| (static_cast<uint32_t>(codes[2]) << 6) | codes[3]; |
| result[(*result_offset)++] = static_cast<unsigned char>(packed >> 16); |
| result[(*result_offset)++] = static_cast<unsigned char>(packed >> 8); |
| result[(*result_offset)++] = static_cast<unsigned char>(packed); |
| } |
| return 1; |
| } |
| |
| grpc_slice grpc_base64_decode_with_len(const char* b64, size_t b64_len, |
| int url_safe) { |
| grpc_slice result = GRPC_SLICE_MALLOC(b64_len); |
| unsigned char* current = GRPC_SLICE_START_PTR(result); |
| size_t result_size = 0; |
| unsigned char codes[4]; |
| size_t num_codes = 0; |
| |
| while (b64_len--) { |
| unsigned char c = static_cast<unsigned char>(*b64++); |
| signed char code; |
| if (c >= GPR_ARRAY_SIZE(base64_bytes)) continue; |
| if (url_safe) { |
| if (c == '+' || c == '/') { |
| gpr_log(GPR_ERROR, "Invalid character for url safe base64 %c", c); |
| goto fail; |
| } |
| if (c == '-') { |
| c = '+'; |
| } else if (c == '_') { |
| c = '/'; |
| } |
| } |
| code = base64_bytes[c]; |
| if (code == -1) { |
| if (c != '\r' && c != '\n') { |
| gpr_log(GPR_ERROR, "Invalid character %c", c); |
| goto fail; |
| } |
| } else { |
| codes[num_codes++] = static_cast<unsigned char>(code); |
| if (num_codes == 4) { |
| if (!decode_group(codes, num_codes, current, &result_size)) goto fail; |
| num_codes = 0; |
| } |
| } |
| } |
| |
| if (num_codes != 0 && |
| !decode_group(codes, num_codes, current, &result_size)) { |
| goto fail; |
| } |
| GRPC_SLICE_SET_LENGTH(result, result_size); |
| return result; |
| |
| fail: |
| grpc_slice_unref_internal(result); |
| return grpc_empty_slice(); |
| } |