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/*
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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 "error/s2n_errno.h"
#include "stuffer/s2n_stuffer.h"
#include "utils/s2n_annotations.h"
#include "utils/s2n_safety.h"
/* Writes length bytes of input to stuffer, in network order, starting from the smallest byte of input. */
int s2n_stuffer_write_network_order(struct s2n_stuffer *stuffer, const uint64_t input, const uint8_t length)
{
POSIX_ENSURE(length <= sizeof(input), S2N_ERR_SAFETY);
POSIX_GUARD(s2n_stuffer_skip_write(stuffer, length));
uint8_t *data = (stuffer->blob.data) ? (stuffer->blob.data + stuffer->write_cursor - length) : NULL;
for (int i = 0; i < length; i++) {
S2N_INVARIANT(i <= length);
uint8_t shift = (length - i - 1) * CHAR_BIT;
data[i] = (input >> (shift)) & UINT8_MAX;
}
POSIX_POSTCONDITION(s2n_stuffer_validate(stuffer));
return S2N_SUCCESS;
}
int s2n_stuffer_reserve(struct s2n_stuffer *stuffer, struct s2n_stuffer_reservation *reservation, const uint8_t length)
{
POSIX_PRECONDITION(s2n_stuffer_validate(stuffer));
POSIX_ENSURE_REF(reservation);
*reservation = (struct s2n_stuffer_reservation){ .stuffer = stuffer,
.write_cursor = stuffer->write_cursor,
.length = length };
POSIX_GUARD(s2n_stuffer_skip_write(stuffer, reservation->length));
POSIX_CHECKED_MEMSET(stuffer->blob.data + reservation->write_cursor, S2N_WIPE_PATTERN, reservation->length);
POSIX_POSTCONDITION(s2n_stuffer_reservation_validate(reservation));
return S2N_SUCCESS;
}
int s2n_stuffer_read_uint8(struct s2n_stuffer *stuffer, uint8_t *u)
{
POSIX_GUARD(s2n_stuffer_read_bytes(stuffer, u, sizeof(uint8_t)));
return S2N_SUCCESS;
}
int s2n_stuffer_write_uint8(struct s2n_stuffer *stuffer, const uint8_t u)
{
POSIX_GUARD(s2n_stuffer_write_bytes(stuffer, &u, sizeof(u)));
return S2N_SUCCESS;
}
int s2n_stuffer_reserve_uint8(struct s2n_stuffer *stuffer, struct s2n_stuffer_reservation *reservation)
{
return s2n_stuffer_reserve(stuffer, reservation, sizeof(uint8_t));
}
int s2n_stuffer_read_uint16(struct s2n_stuffer *stuffer, uint16_t *u)
{
POSIX_ENSURE_REF(u);
uint8_t data[sizeof(uint16_t)];
POSIX_GUARD(s2n_stuffer_read_bytes(stuffer, data, sizeof(data)));
*u = data[0] << 8;
*u |= data[1];
return S2N_SUCCESS;
}
int s2n_stuffer_write_uint16(struct s2n_stuffer *stuffer, const uint16_t u)
{
return s2n_stuffer_write_network_order(stuffer, u, sizeof(u));
}
int s2n_stuffer_reserve_uint16(struct s2n_stuffer *stuffer, struct s2n_stuffer_reservation *reservation)
{
return s2n_stuffer_reserve(stuffer, reservation, sizeof(uint16_t));
}
int s2n_stuffer_read_uint24(struct s2n_stuffer *stuffer, uint32_t *u)
{
POSIX_ENSURE_REF(u);
uint8_t data[SIZEOF_UINT24];
POSIX_GUARD(s2n_stuffer_read_bytes(stuffer, data, sizeof(data)));
*u = data[0] << 16;
*u |= data[1] << 8;
*u |= data[2];
return S2N_SUCCESS;
}
int s2n_stuffer_write_uint24(struct s2n_stuffer *stuffer, const uint32_t u)
{
return s2n_stuffer_write_network_order(stuffer, u, SIZEOF_UINT24);
}
int s2n_stuffer_reserve_uint24(struct s2n_stuffer *stuffer, struct s2n_stuffer_reservation *reservation)
{
return s2n_stuffer_reserve(stuffer, reservation, SIZEOF_UINT24);
}
int s2n_stuffer_read_uint32(struct s2n_stuffer *stuffer, uint32_t *u)
{
POSIX_ENSURE_REF(u);
uint8_t data[sizeof(uint32_t)];
POSIX_GUARD(s2n_stuffer_read_bytes(stuffer, data, sizeof(data)));
*u = ((uint32_t) data[0]) << 24;
*u |= data[1] << 16;
*u |= data[2] << 8;
*u |= data[3];
return S2N_SUCCESS;
}
int s2n_stuffer_write_uint32(struct s2n_stuffer *stuffer, const uint32_t u)
{
return s2n_stuffer_write_network_order(stuffer, u, sizeof(u));
}
int s2n_stuffer_read_uint64(struct s2n_stuffer *stuffer, uint64_t *u)
{
POSIX_ENSURE_REF(u);
uint8_t data[sizeof(uint64_t)];
POSIX_GUARD(s2n_stuffer_read_bytes(stuffer, data, sizeof(data)));
*u = ((uint64_t) data[0]) << 56;
*u |= ((uint64_t) data[1]) << 48;
*u |= ((uint64_t) data[2]) << 40;
*u |= ((uint64_t) data[3]) << 32;
*u |= ((uint64_t) data[4]) << 24;
*u |= ((uint64_t) data[5]) << 16;
*u |= ((uint64_t) data[6]) << 8;
*u |= data[7];
return S2N_SUCCESS;
}
int s2n_stuffer_write_uint64(struct s2n_stuffer *stuffer, const uint64_t u)
{
return s2n_stuffer_write_network_order(stuffer, u, sizeof(u));
}
static int length_matches_value_check(uint32_t value, uint8_t length)
{
/* Value is represented as a uint32_t, so shouldn't be assumed larger */
POSIX_ENSURE(length <= sizeof(uint32_t), S2N_ERR_SIZE_MISMATCH);
if (length < sizeof(uint32_t)) {
/* Value should be less than the maximum for its length */
POSIX_ENSURE(value < (0x01 << (length * 8)), S2N_ERR_SIZE_MISMATCH);
}
return S2N_SUCCESS;
}
static int s2n_stuffer_write_reservation_impl(struct s2n_stuffer_reservation *reservation, const uint32_t u)
{
reservation->stuffer->write_cursor = reservation->write_cursor;
POSIX_PRECONDITION(s2n_stuffer_validate(reservation->stuffer));
POSIX_GUARD(length_matches_value_check(u, reservation->length));
POSIX_GUARD(s2n_stuffer_write_network_order(reservation->stuffer, u, reservation->length));
POSIX_POSTCONDITION(s2n_stuffer_validate(reservation->stuffer));
return S2N_SUCCESS;
}
int s2n_stuffer_write_reservation(struct s2n_stuffer_reservation *reservation, const uint32_t u)
{
POSIX_PRECONDITION(s2n_stuffer_reservation_validate(reservation));
uint32_t old_write_cursor = reservation->stuffer->write_cursor;
int result = s2n_stuffer_write_reservation_impl(reservation, u);
reservation->stuffer->write_cursor = old_write_cursor;
return result;
}
int s2n_stuffer_write_vector_size(struct s2n_stuffer_reservation *reservation)
{
POSIX_PRECONDITION(s2n_stuffer_reservation_validate(reservation));
uint32_t size = 0;
POSIX_GUARD(s2n_sub_overflow(reservation->stuffer->write_cursor, reservation->write_cursor, &size));
POSIX_GUARD(s2n_sub_overflow(size, reservation->length, &size));
return s2n_stuffer_write_reservation(reservation, size);
}
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