jboeuf | befd265 | 2014-12-12 15:39:47 -0800 | [diff] [blame] | 1 | /* |
| 2 | * |
murgatroid99 | 3466c4b | 2016-01-12 10:26:04 -0800 | [diff] [blame] | 3 | * Copyright 2015-2016, Google Inc. |
jboeuf | befd265 | 2014-12-12 15:39:47 -0800 | [diff] [blame] | 4 | * All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions are |
| 8 | * met: |
| 9 | * |
| 10 | * * Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * * Redistributions in binary form must reproduce the above |
| 13 | * copyright notice, this list of conditions and the following disclaimer |
| 14 | * in the documentation and/or other materials provided with the |
| 15 | * distribution. |
| 16 | * * Neither the name of Google Inc. nor the names of its |
| 17 | * contributors may be used to endorse or promote products derived from |
| 18 | * this software without specific prior written permission. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 21 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 22 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 23 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 24 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 25 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 26 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 27 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 28 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 29 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 30 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 31 | * |
| 32 | */ |
| 33 | |
Craig Tiller | 732a875 | 2016-02-22 15:59:19 -0800 | [diff] [blame] | 34 | #include "src/core/security/b64.h" |
jboeuf | befd265 | 2014-12-12 15:39:47 -0800 | [diff] [blame] | 35 | |
Ian Coolidge | 069384d | 2016-01-11 13:41:02 -0800 | [diff] [blame] | 36 | #include <stdint.h> |
jboeuf | befd265 | 2014-12-12 15:39:47 -0800 | [diff] [blame] | 37 | #include <string.h> |
| 38 | |
| 39 | #include <grpc/support/alloc.h> |
| 40 | #include <grpc/support/log.h> |
| 41 | #include <grpc/support/useful.h> |
| 42 | |
| 43 | /* --- Constants. --- */ |
| 44 | |
Ian Coolidge | 069384d | 2016-01-11 13:41:02 -0800 | [diff] [blame] | 45 | static const int8_t base64_bytes[] = { |
jboeuf | befd265 | 2014-12-12 15:39:47 -0800 | [diff] [blame] | 46 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 47 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 48 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 49 | -1, -1, -1, -1, -1, -1, -1, 0x3E, -1, -1, -1, 0x3F, |
| 50 | 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, -1, -1, |
| 51 | -1, 0x7F, -1, -1, -1, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, |
| 52 | 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, |
| 53 | 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, -1, -1, -1, -1, -1, |
| 54 | -1, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, |
| 55 | 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, |
| 56 | 0x31, 0x32, 0x33, -1, -1, -1, -1, -1}; |
| 57 | |
| 58 | static const char base64_url_unsafe_chars[] = |
| 59 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
| 60 | static const char base64_url_safe_chars[] = |
| 61 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"; |
| 62 | |
| 63 | #define GRPC_BASE64_PAD_CHAR '=' |
| 64 | #define GRPC_BASE64_PAD_BYTE 0x7F |
| 65 | #define GRPC_BASE64_MULTILINE_LINE_LEN 76 |
| 66 | #define GRPC_BASE64_MULTILINE_NUM_BLOCKS (GRPC_BASE64_MULTILINE_LINE_LEN / 4) |
| 67 | |
| 68 | /* --- base64 functions. --- */ |
| 69 | |
| 70 | char *grpc_base64_encode(const void *vdata, size_t data_size, int url_safe, |
| 71 | int multiline) { |
| 72 | const unsigned char *data = vdata; |
| 73 | const char *base64_chars = |
| 74 | url_safe ? base64_url_safe_chars : base64_url_unsafe_chars; |
| 75 | size_t result_projected_size = |
| 76 | 4 * ((data_size + 3) / 3) + |
| 77 | 2 * (multiline ? (data_size / (3 * GRPC_BASE64_MULTILINE_NUM_BLOCKS)) |
| 78 | : 0) + |
| 79 | 1; |
| 80 | char *result = gpr_malloc(result_projected_size); |
| 81 | char *current = result; |
| 82 | size_t num_blocks = 0; |
| 83 | size_t i = 0; |
| 84 | |
| 85 | /* Encode each block. */ |
| 86 | while (data_size >= 3) { |
| 87 | *current++ = base64_chars[(data[i] >> 2) & 0x3F]; |
| 88 | *current++ = |
| 89 | base64_chars[((data[i] & 0x03) << 4) | ((data[i + 1] >> 4) & 0x0F)]; |
| 90 | *current++ = |
| 91 | base64_chars[((data[i + 1] & 0x0F) << 2) | ((data[i + 2] >> 6) & 0x03)]; |
| 92 | *current++ = base64_chars[data[i + 2] & 0x3F]; |
| 93 | |
| 94 | data_size -= 3; |
| 95 | i += 3; |
| 96 | if (multiline && (++num_blocks == GRPC_BASE64_MULTILINE_NUM_BLOCKS)) { |
| 97 | *current++ = '\r'; |
| 98 | *current++ = '\n'; |
| 99 | num_blocks = 0; |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | /* Take care of the tail. */ |
| 104 | if (data_size == 2) { |
| 105 | *current++ = base64_chars[(data[i] >> 2) & 0x3F]; |
| 106 | *current++ = |
| 107 | base64_chars[((data[i] & 0x03) << 4) | ((data[i + 1] >> 4) & 0x0F)]; |
| 108 | *current++ = base64_chars[(data[i + 1] & 0x0F) << 2]; |
| 109 | *current++ = GRPC_BASE64_PAD_CHAR; |
| 110 | } else if (data_size == 1) { |
| 111 | *current++ = base64_chars[(data[i] >> 2) & 0x3F]; |
| 112 | *current++ = base64_chars[(data[i] & 0x03) << 4]; |
| 113 | *current++ = GRPC_BASE64_PAD_CHAR; |
| 114 | *current++ = GRPC_BASE64_PAD_CHAR; |
| 115 | } |
| 116 | |
Nicolas "Pixel" Noble | 213ed91 | 2015-01-30 02:11:35 +0100 | [diff] [blame] | 117 | GPR_ASSERT(current >= result); |
Craig Tiller | 7536af0 | 2015-12-22 13:49:30 -0800 | [diff] [blame] | 118 | GPR_ASSERT((uintptr_t)(current - result) < result_projected_size); |
jboeuf | befd265 | 2014-12-12 15:39:47 -0800 | [diff] [blame] | 119 | result[current - result] = '\0'; |
| 120 | return result; |
| 121 | } |
| 122 | |
| 123 | gpr_slice grpc_base64_decode(const char *b64, int url_safe) { |
Julien Boeuf | 3e55b9f | 2015-06-25 17:54:19 +0200 | [diff] [blame] | 124 | return grpc_base64_decode_with_len(b64, strlen(b64), url_safe); |
| 125 | } |
| 126 | |
| 127 | static void decode_one_char(const unsigned char *codes, unsigned char *result, |
| 128 | size_t *result_offset) { |
Craig Tiller | 7536af0 | 2015-12-22 13:49:30 -0800 | [diff] [blame] | 129 | uint32_t packed = ((uint32_t)codes[0] << 2) | ((uint32_t)codes[1] >> 4); |
Julien Boeuf | 3e55b9f | 2015-06-25 17:54:19 +0200 | [diff] [blame] | 130 | result[(*result_offset)++] = (unsigned char)packed; |
| 131 | } |
| 132 | |
| 133 | static void decode_two_chars(const unsigned char *codes, unsigned char *result, |
| 134 | size_t *result_offset) { |
Craig Tiller | 7536af0 | 2015-12-22 13:49:30 -0800 | [diff] [blame] | 135 | uint32_t packed = ((uint32_t)codes[0] << 10) | ((uint32_t)codes[1] << 4) | |
| 136 | ((uint32_t)codes[2] >> 2); |
Julien Boeuf | 3e55b9f | 2015-06-25 17:54:19 +0200 | [diff] [blame] | 137 | result[(*result_offset)++] = (unsigned char)(packed >> 8); |
| 138 | result[(*result_offset)++] = (unsigned char)(packed); |
| 139 | } |
| 140 | |
| 141 | static int decode_group(const unsigned char *codes, size_t num_codes, |
| 142 | unsigned char *result, size_t *result_offset) { |
| 143 | GPR_ASSERT(num_codes <= 4); |
| 144 | |
| 145 | /* Short end groups that may not have padding. */ |
| 146 | if (num_codes == 1) { |
| 147 | gpr_log(GPR_ERROR, "Invalid group. Must be at least 2 bytes."); |
| 148 | return 0; |
| 149 | } |
| 150 | if (num_codes == 2) { |
| 151 | decode_one_char(codes, result, result_offset); |
| 152 | return 1; |
| 153 | } |
| 154 | if (num_codes == 3) { |
| 155 | decode_two_chars(codes, result, result_offset); |
| 156 | return 1; |
| 157 | } |
| 158 | |
| 159 | /* Regular 4 byte groups with padding or not. */ |
| 160 | GPR_ASSERT(num_codes == 4); |
| 161 | if (codes[0] == GRPC_BASE64_PAD_BYTE || codes[1] == GRPC_BASE64_PAD_BYTE) { |
| 162 | gpr_log(GPR_ERROR, "Invalid padding detected."); |
| 163 | return 0; |
| 164 | } |
| 165 | if (codes[2] == GRPC_BASE64_PAD_BYTE) { |
| 166 | if (codes[3] == GRPC_BASE64_PAD_BYTE) { |
| 167 | decode_one_char(codes, result, result_offset); |
Julien Boeuf | 73d8b57 | 2015-06-30 11:43:18 +0200 | [diff] [blame] | 168 | } else { |
Julien Boeuf | 3e55b9f | 2015-06-25 17:54:19 +0200 | [diff] [blame] | 169 | gpr_log(GPR_ERROR, "Invalid padding detected."); |
| 170 | return 0; |
| 171 | } |
| 172 | } else if (codes[3] == GRPC_BASE64_PAD_BYTE) { |
| 173 | decode_two_chars(codes, result, result_offset); |
| 174 | } else { |
| 175 | /* No padding. */ |
Craig Tiller | 7536af0 | 2015-12-22 13:49:30 -0800 | [diff] [blame] | 176 | uint32_t packed = ((uint32_t)codes[0] << 18) | ((uint32_t)codes[1] << 12) | |
| 177 | ((uint32_t)codes[2] << 6) | codes[3]; |
Julien Boeuf | 3e55b9f | 2015-06-25 17:54:19 +0200 | [diff] [blame] | 178 | result[(*result_offset)++] = (unsigned char)(packed >> 16); |
| 179 | result[(*result_offset)++] = (unsigned char)(packed >> 8); |
| 180 | result[(*result_offset)++] = (unsigned char)(packed); |
| 181 | } |
| 182 | return 1; |
| 183 | } |
| 184 | |
| 185 | gpr_slice grpc_base64_decode_with_len(const char *b64, size_t b64_len, |
| 186 | int url_safe) { |
jboeuf | befd265 | 2014-12-12 15:39:47 -0800 | [diff] [blame] | 187 | gpr_slice result = gpr_slice_malloc(b64_len); |
| 188 | unsigned char *current = GPR_SLICE_START_PTR(result); |
| 189 | size_t result_size = 0; |
| 190 | unsigned char codes[4]; |
| 191 | size_t num_codes = 0; |
| 192 | |
| 193 | while (b64_len--) { |
murgatroid99 | e582d09 | 2015-06-19 12:28:27 -0700 | [diff] [blame] | 194 | unsigned char c = (unsigned char)(*b64++); |
jboeuf | befd265 | 2014-12-12 15:39:47 -0800 | [diff] [blame] | 195 | signed char code; |
| 196 | if (c >= GPR_ARRAY_SIZE(base64_bytes)) continue; |
| 197 | if (url_safe) { |
| 198 | if (c == '+' || c == '/') { |
| 199 | gpr_log(GPR_ERROR, "Invalid character for url safe base64 %c", c); |
| 200 | goto fail; |
| 201 | } |
| 202 | if (c == '-') { |
| 203 | c = '+'; |
| 204 | } else if (c == '_') { |
| 205 | c = '/'; |
| 206 | } |
| 207 | } |
| 208 | code = base64_bytes[c]; |
| 209 | if (code == -1) { |
| 210 | if (c != '\r' && c != '\n') { |
| 211 | gpr_log(GPR_ERROR, "Invalid character %c", c); |
| 212 | goto fail; |
| 213 | } |
| 214 | } else { |
murgatroid99 | e582d09 | 2015-06-19 12:28:27 -0700 | [diff] [blame] | 215 | codes[num_codes++] = (unsigned char)code; |
jboeuf | befd265 | 2014-12-12 15:39:47 -0800 | [diff] [blame] | 216 | if (num_codes == 4) { |
Julien Boeuf | 3e55b9f | 2015-06-25 17:54:19 +0200 | [diff] [blame] | 217 | if (!decode_group(codes, num_codes, current, &result_size)) goto fail; |
jboeuf | befd265 | 2014-12-12 15:39:47 -0800 | [diff] [blame] | 218 | num_codes = 0; |
| 219 | } |
| 220 | } |
| 221 | } |
| 222 | |
Julien Boeuf | 3e55b9f | 2015-06-25 17:54:19 +0200 | [diff] [blame] | 223 | if (num_codes != 0 && |
| 224 | !decode_group(codes, num_codes, current, &result_size)) { |
| 225 | goto fail; |
jboeuf | befd265 | 2014-12-12 15:39:47 -0800 | [diff] [blame] | 226 | } |
murgatroid99 | 4fca87a | 2015-06-19 16:15:13 -0700 | [diff] [blame] | 227 | GPR_SLICE_SET_LENGTH(result, result_size); |
jboeuf | befd265 | 2014-12-12 15:39:47 -0800 | [diff] [blame] | 228 | return result; |
| 229 | |
| 230 | fail: |
| 231 | gpr_slice_unref(result); |
| 232 | return gpr_empty_slice(); |
Craig Tiller | 190d360 | 2015-02-18 09:23:38 -0800 | [diff] [blame] | 233 | } |