| /* |
| * RFC 1521 base64 encoding/decoding |
| * |
| * Copyright The Mbed TLS Contributors |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * 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 "common.h" |
| |
| #if defined(MBEDTLS_BASE64_C) |
| |
| # include "mbedtls/base64.h" |
| |
| # include <stdint.h> |
| |
| # if defined(MBEDTLS_SELF_TEST) |
| # include <string.h> |
| # if defined(MBEDTLS_PLATFORM_C) |
| # include "mbedtls/platform.h" |
| # else |
| # include <stdio.h> |
| # define mbedtls_printf printf |
| # endif /* MBEDTLS_PLATFORM_C */ |
| # endif /* MBEDTLS_SELF_TEST */ |
| |
| static const unsigned char base64_enc_map[64] = { |
| 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', |
| 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', |
| 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', |
| 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', |
| '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' |
| }; |
| |
| static const unsigned char base64_dec_map[128] = { |
| 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, |
| 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, |
| 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 62, 127, |
| 127, 127, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 127, 127, |
| 127, 64, 127, 127, 127, 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, 127, 127, 127, 127, 127, 127, 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, 127, 127, 127, 127, 127 |
| }; |
| |
| # define BASE64_SIZE_T_MAX ((size_t)-1) /* SIZE_T_MAX is not standard */ |
| |
| /* |
| * Constant flow conditional assignment to unsigned char |
| */ |
| static void mbedtls_base64_cond_assign_uchar(unsigned char *dest, |
| const unsigned char *const src, |
| unsigned char condition) |
| { |
| /* MSVC has a warning about unary minus on unsigned integer types, |
| * but this is well-defined and precisely what we want to do here. */ |
| # if defined(_MSC_VER) |
| # pragma warning(push) |
| # pragma warning(disable : 4146) |
| # endif |
| |
| /* Generate bitmask from condition, mask will either be 0xFF or 0 */ |
| unsigned char mask = (condition | -condition); |
| mask >>= 7; |
| mask = -mask; |
| |
| # if defined(_MSC_VER) |
| # pragma warning(pop) |
| # endif |
| |
| *dest = ((*src) & mask) | ((*dest) & ~mask); |
| } |
| |
| /* |
| * Constant flow conditional assignment to uint_32 |
| */ |
| static void mbedtls_base64_cond_assign_uint32(uint32_t *dest, |
| const uint32_t src, |
| uint32_t condition) |
| { |
| /* MSVC has a warning about unary minus on unsigned integer types, |
| * but this is well-defined and precisely what we want to do here. */ |
| # if defined(_MSC_VER) |
| # pragma warning(push) |
| # pragma warning(disable : 4146) |
| # endif |
| |
| /* Generate bitmask from condition, mask will either be 0xFFFFFFFF or 0 */ |
| uint32_t mask = (condition | -condition); |
| mask >>= 31; |
| mask = -mask; |
| |
| # if defined(_MSC_VER) |
| # pragma warning(pop) |
| # endif |
| |
| *dest = (src & mask) | ((*dest) & ~mask); |
| } |
| |
| /* |
| * Constant flow check for equality |
| */ |
| static unsigned char mbedtls_base64_eq(size_t in_a, size_t in_b) |
| { |
| size_t difference = in_a ^ in_b; |
| |
| /* MSVC has a warning about unary minus on unsigned integer types, |
| * but this is well-defined and precisely what we want to do here. */ |
| # if defined(_MSC_VER) |
| # pragma warning(push) |
| # pragma warning(disable : 4146) |
| # endif |
| |
| difference |= -difference; |
| |
| # if defined(_MSC_VER) |
| # pragma warning(pop) |
| # endif |
| |
| /* cope with the varying size of size_t per platform */ |
| difference >>= (sizeof(difference) * 8 - 1); |
| |
| return (unsigned char)(1 ^ difference); |
| } |
| |
| /* |
| * Constant flow lookup into table. |
| */ |
| static unsigned char |
| mbedtls_base64_table_lookup(const unsigned char *const table, |
| const size_t table_size, |
| const size_t table_index) |
| { |
| size_t i; |
| unsigned char result = 0; |
| |
| for (i = 0; i < table_size; ++i) { |
| mbedtls_base64_cond_assign_uchar(&result, &table[i], |
| mbedtls_base64_eq(i, table_index)); |
| } |
| |
| return result; |
| } |
| |
| /* |
| * Encode a buffer into base64 format |
| */ |
| int mbedtls_base64_encode(unsigned char *dst, |
| size_t dlen, |
| size_t *olen, |
| const unsigned char *src, |
| size_t slen) |
| { |
| size_t i, n; |
| int C1, C2, C3; |
| unsigned char *p; |
| |
| if (slen == 0) { |
| *olen = 0; |
| return 0; |
| } |
| |
| n = slen / 3 + (slen % 3 != 0); |
| |
| if (n > (BASE64_SIZE_T_MAX - 1) / 4) { |
| *olen = BASE64_SIZE_T_MAX; |
| return MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL; |
| } |
| |
| n *= 4; |
| |
| if ((dlen < n + 1) || (NULL == dst)) { |
| *olen = n + 1; |
| return MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL; |
| } |
| |
| n = (slen / 3) * 3; |
| |
| for (i = 0, p = dst; i < n; i += 3) { |
| C1 = *src++; |
| C2 = *src++; |
| C3 = *src++; |
| |
| *p++ = mbedtls_base64_table_lookup( |
| base64_enc_map, sizeof(base64_enc_map), ((C1 >> 2) & 0x3F)); |
| |
| *p++ = |
| mbedtls_base64_table_lookup(base64_enc_map, sizeof(base64_enc_map), |
| ((((C1 & 3) << 4) + (C2 >> 4)) & 0x3F)); |
| |
| *p++ = mbedtls_base64_table_lookup( |
| base64_enc_map, sizeof(base64_enc_map), |
| ((((C2 & 15) << 2) + (C3 >> 6)) & 0x3F)); |
| |
| *p++ = mbedtls_base64_table_lookup(base64_enc_map, |
| sizeof(base64_enc_map), (C3 & 0x3F)); |
| } |
| |
| if (i < slen) { |
| C1 = *src++; |
| C2 = ((i + 1) < slen) ? *src++ : 0; |
| |
| *p++ = mbedtls_base64_table_lookup( |
| base64_enc_map, sizeof(base64_enc_map), ((C1 >> 2) & 0x3F)); |
| |
| *p++ = |
| mbedtls_base64_table_lookup(base64_enc_map, sizeof(base64_enc_map), |
| ((((C1 & 3) << 4) + (C2 >> 4)) & 0x3F)); |
| |
| if ((i + 1) < slen) |
| *p++ = mbedtls_base64_table_lookup(base64_enc_map, |
| sizeof(base64_enc_map), |
| (((C2 & 15) << 2) & 0x3F)); |
| else |
| *p++ = '='; |
| |
| *p++ = '='; |
| } |
| |
| *olen = p - dst; |
| *p = 0; |
| |
| return 0; |
| } |
| |
| /* |
| * Decode a base64-formatted buffer |
| */ |
| int mbedtls_base64_decode(unsigned char *dst, |
| size_t dlen, |
| size_t *olen, |
| const unsigned char *src, |
| size_t slen) |
| { |
| size_t i, n; |
| uint32_t j, x; |
| unsigned char *p; |
| unsigned char dec_map_lookup; |
| |
| /* First pass: check for validity and get output length */ |
| for (i = n = j = 0; i < slen; i++) { |
| /* Skip spaces before checking for EOL */ |
| x = 0; |
| while (i < slen && src[i] == ' ') { |
| ++i; |
| ++x; |
| } |
| |
| /* Spaces at end of buffer are OK */ |
| if (i == slen) |
| break; |
| |
| if ((slen - i) >= 2 && src[i] == '\r' && src[i + 1] == '\n') |
| continue; |
| |
| if (src[i] == '\n') |
| continue; |
| |
| /* Space inside a line is an error */ |
| if (x != 0) |
| return MBEDTLS_ERR_BASE64_INVALID_CHARACTER; |
| |
| if (src[i] == '=' && ++j > 2) |
| return MBEDTLS_ERR_BASE64_INVALID_CHARACTER; |
| |
| dec_map_lookup = mbedtls_base64_table_lookup( |
| base64_dec_map, sizeof(base64_dec_map), src[i]); |
| |
| if (src[i] > 127 || dec_map_lookup == 127) |
| return MBEDTLS_ERR_BASE64_INVALID_CHARACTER; |
| |
| if (dec_map_lookup < 64 && j != 0) |
| return MBEDTLS_ERR_BASE64_INVALID_CHARACTER; |
| |
| n++; |
| } |
| |
| if (n == 0) { |
| *olen = 0; |
| return 0; |
| } |
| |
| /* The following expression is to calculate the following formula without |
| * risk of integer overflow in n: |
| * n = ( ( n * 6 ) + 7 ) >> 3; |
| */ |
| n = (6 * (n >> 3)) + ((6 * (n & 0x7) + 7) >> 3); |
| n -= j; |
| |
| if (dst == NULL || dlen < n) { |
| *olen = n; |
| return MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL; |
| } |
| |
| for (j = 3, n = x = 0, p = dst; i > 0; i--, src++) { |
| if (*src == '\r' || *src == '\n' || *src == ' ') |
| continue; |
| |
| dec_map_lookup = mbedtls_base64_table_lookup( |
| base64_dec_map, sizeof(base64_dec_map), *src); |
| |
| mbedtls_base64_cond_assign_uint32( |
| &j, j - 1, mbedtls_base64_eq(dec_map_lookup, 64)); |
| x = (x << 6) | (dec_map_lookup & 0x3F); |
| |
| if (++n == 4) { |
| n = 0; |
| if (j > 0) |
| *p++ = (unsigned char)(x >> 16); |
| if (j > 1) |
| *p++ = (unsigned char)(x >> 8); |
| if (j > 2) |
| *p++ = (unsigned char)(x); |
| } |
| } |
| |
| *olen = p - dst; |
| |
| return 0; |
| } |
| |
| # if defined(MBEDTLS_SELF_TEST) |
| |
| static const unsigned char base64_test_dec[64] = { |
| 0x24, 0x48, 0x6E, 0x56, 0x87, 0x62, 0x5A, 0xBD, 0xBF, 0x17, 0xD9, |
| 0xA2, 0xC4, 0x17, 0x1A, 0x01, 0x94, 0xED, 0x8F, 0x1E, 0x11, 0xB3, |
| 0xD7, 0x09, 0x0C, 0xB6, 0xE9, 0x10, 0x6F, 0x22, 0xEE, 0x13, 0xCA, |
| 0xB3, 0x07, 0x05, 0x76, 0xC9, 0xFA, 0x31, 0x6C, 0x08, 0x34, 0xFF, |
| 0x8D, 0xC2, 0x6C, 0x38, 0x00, 0x43, 0xE9, 0x54, 0x97, 0xAF, 0x50, |
| 0x4B, 0xD1, 0x41, 0xBA, 0x95, 0x31, 0x5A, 0x0B, 0x97 |
| }; |
| |
| static const unsigned char base64_test_enc[] = |
| "JEhuVodiWr2/F9mixBcaAZTtjx4Rs9cJDLbpEG8i7hPK" |
| "swcFdsn6MWwINP+Nwmw4AEPpVJevUEvRQbqVMVoLlw=="; |
| |
| /* |
| * Checkup routine |
| */ |
| int mbedtls_base64_self_test(int verbose) |
| { |
| size_t len; |
| const unsigned char *src; |
| unsigned char buffer[128]; |
| |
| if (verbose != 0) |
| mbedtls_printf(" Base64 encoding test: "); |
| |
| src = base64_test_dec; |
| |
| if (mbedtls_base64_encode(buffer, sizeof(buffer), &len, src, 64) != 0 || |
| memcmp(base64_test_enc, buffer, 88) != 0) { |
| if (verbose != 0) |
| mbedtls_printf("failed\n"); |
| |
| return 1; |
| } |
| |
| if (verbose != 0) |
| mbedtls_printf("passed\n Base64 decoding test: "); |
| |
| src = base64_test_enc; |
| |
| if (mbedtls_base64_decode(buffer, sizeof(buffer), &len, src, 88) != 0 || |
| memcmp(base64_test_dec, buffer, 64) != 0) { |
| if (verbose != 0) |
| mbedtls_printf("failed\n"); |
| |
| return 1; |
| } |
| |
| if (verbose != 0) |
| mbedtls_printf("passed\n\n"); |
| |
| return 0; |
| } |
| |
| # endif /* MBEDTLS_SELF_TEST */ |
| |
| #endif /* MBEDTLS_BASE64_C */ |