/** * Copyright (c) 2023 Trezor Company s.r.o. * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT HMAC_SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ #include <stdlib.h> #include <string.h> #include "buffer.h" void buffer_reader_init(BUFFER_READER *reader, const uint8_t *data, size_t size) { reader->data = data; reader->size = size; reader->pos = 0; } void buffer_writer_init(BUFFER_WRITER *writer, uint8_t *data, size_t size) { writer->data = data; writer->size = size; writer->pos = 0; } size_t buffer_remaining(BUFFER_READER *buf) { if ((buf->data == NULL) || (buf->pos > buf->size)) { return 0; } return buf->size - buf->pos; } bool buffer_ptr(BUFFER_READER *buf, const uint8_t **ptr) { if ((buf->data == NULL) || (buf->pos > buf->size)) { return false; } *ptr = &buf->data[buf->pos]; return true; } bool buffer_peek(const BUFFER_READER *buf, uint8_t *byte) { if ((buf->data == NULL) || (buf->pos >= buf->size)) { return false; } *byte = buf->data[buf->pos]; return true; } bool buffer_get(BUFFER_READER *buf, uint8_t *byte) { if (!buffer_peek(buf, byte)) { return false; } buf->pos += 1; return true; } bool buffer_seek(BUFFER_READER *buf, size_t pos) { if ((buf->data == NULL) || (pos > buf->size)) { return false; } buf->pos = pos; return true; } bool buffer_read_buffer(BUFFER_READER *src, BUFFER_READER *dest, size_t size) { if ((src->data == NULL) || (src->pos + size > src->size)) { return false; } buffer_reader_init(dest, &src->data[src->pos], size); src->pos += size; return true; } void buffer_lstrip(BUFFER_READER *buf, uint8_t byte) { if (buf->data == NULL) { return; } while ((buf->pos < buf->size) && (buf->data[buf->pos] == byte)) { buf->pos += 1; } return; } bool buffer_put(BUFFER_WRITER *writer, uint8_t byte) { if ((writer->data == NULL) || (writer->pos >= writer->size)) { return false; } writer->data[writer->pos] = byte; writer->pos += 1; return true; } bool buffer_write_array(BUFFER_WRITER *writer, const uint8_t *src, size_t size) { if ((writer->data == NULL) || (writer->pos + size > writer->size)) { return false; } memcpy(&writer->data[writer->pos], src, size); writer->pos += size; return true; } bool buffer_write_buffer(BUFFER_WRITER *dest, BUFFER_READER *src) { if ((src->data == NULL) || (src->pos > src->size)) { return false; } if (!buffer_write_array(dest, &src->data[src->pos], src->size - src->pos)) { return false; } src->pos = src->size; return true; } size_t buffer_written_size(BUFFER_WRITER *writer) { return writer->pos; }