/* * * Copyright 2015-2016, 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/security/base64.h" #include #include #include #include #include /* --- 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) { const unsigned char *data = vdata; const char *base64_chars = url_safe ? base64_url_safe_chars : base64_url_unsafe_chars; size_t result_projected_size = 4 * ((data_size + 3) / 3) + 2 * (multiline ? (data_size / (3 * GRPC_BASE64_MULTILINE_NUM_BLOCKS)) : 0) + 1; char *result = gpr_malloc(result_projected_size); 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'; return result; } gpr_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 = ((uint32_t)codes[0] << 2) | ((uint32_t)codes[1] >> 4); result[(*result_offset)++] = (unsigned char)packed; } static void decode_two_chars(const unsigned char *codes, unsigned char *result, size_t *result_offset) { uint32_t packed = ((uint32_t)codes[0] << 10) | ((uint32_t)codes[1] << 4) | ((uint32_t)codes[2] >> 2); result[(*result_offset)++] = (unsigned char)(packed >> 8); result[(*result_offset)++] = (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 = ((uint32_t)codes[0] << 18) | ((uint32_t)codes[1] << 12) | ((uint32_t)codes[2] << 6) | codes[3]; result[(*result_offset)++] = (unsigned char)(packed >> 16); result[(*result_offset)++] = (unsigned char)(packed >> 8); result[(*result_offset)++] = (unsigned char)(packed); } return 1; } gpr_slice grpc_base64_decode_with_len(const char *b64, size_t b64_len, int url_safe) { gpr_slice result = gpr_slice_malloc(b64_len); unsigned char *current = GPR_SLICE_START_PTR(result); size_t result_size = 0; unsigned char codes[4]; size_t num_codes = 0; while (b64_len--) { unsigned char c = (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++] = (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; } GPR_SLICE_SET_LENGTH(result, result_size); return result; fail: gpr_slice_unref(result); return gpr_empty_slice(); }