/src/gnutls/lib/str.c

Source
/*
 * Copyright (C) 2002-2012 Free Software Foundation, Inc.
 * Copyright (C) 2016-2017 Red Hat, Inc.
 *
 * Author: Nikos Mavrogiannopoulos
 *
 * This file is part of GnuTLS.
 *
 * The GnuTLS is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>
 *
 */

#include "gnutls_int.h"
#include "errors.h"
#include "num.h"
#include "str.h"
#include <stdarg.h>
#include <c-ctype.h>
#include <intprops.h>
#include <nettle/base64.h>
#include "extras/hex.h"

/* These functions are like strcat, strcpy. They only
 * do bound checking (they shouldn't cause buffer overruns),
 * and they always produce null terminated strings.
 *
 * They should be used only with null terminated strings.
 */
void _gnutls_str_cat(char *dest, size_t dest_tot_size, const char *src)
{
  size_t str_size = strlen(src);
  size_t dest_size = strlen(dest);

  if (dest_tot_size - dest_size > str_size) {
    strcat(dest, src);
  } else {
    if (dest_tot_size - dest_size > 0) {
      strncat(dest, src, (dest_tot_size - dest_size) - 1);
      dest[dest_tot_size - 1] = 0;
    }
  }
}

void _gnutls_str_cpy(char *dest, size_t dest_tot_size, const char *src)
{
  size_t str_size = strlen(src);

  if (dest_tot_size > str_size) {
    strcpy(dest, src);
  } else {
    if (dest_tot_size > 0) {
      memcpy(dest, src, (dest_tot_size)-1);
      dest[dest_tot_size - 1] = 0;
    }
  }
}

void _gnutls_buffer_init(gnutls_buffer_st *str)
{
  str->data = str->allocd = NULL;
  str->max_length = 0;
  str->length = 0;
}

void _gnutls_buffer_clear(gnutls_buffer_st *str)
{
  if (str == NULL || str->allocd == NULL)
    return;
  gnutls_free(str->allocd);

  str->data = NULL;
  str->max_length = 0;
  str->length = 0;
}

#define MIN_CHUNK 1024

/**
 * gnutls_buffer_append_data:
 * @dest: the buffer to append to
 * @data: the data
 * @data_size: the size of @data
 *
 * Appends the provided @data to the destination buffer.
 *
 * Returns: %GNUTLS_E_SUCCESS on success, otherwise a negative error code.
 *
 * Since: 3.4.0
 **/
int gnutls_buffer_append_data(gnutls_buffer_t dest, const void *data,
            size_t data_size)
{
  size_t tot_len;
  int ret;

  if (unlikely(dest->data != NULL && dest->allocd == NULL))
    return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

  if (data_size == 0)
    return 0;

  if (!INT_ADD_OK(data_size, dest->length, &tot_len))
    return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);

  ret = _gnutls_buffer_resize(dest, tot_len);
  if (ret < 0) {
    return ret;
  }
  assert(dest->data != NULL);

  memcpy(&dest->data[dest->length], data, data_size);
  dest->length = tot_len;

  return 0;
}

/* Use a simpler logic for reallocation; i.e., always call
 * gnutls_realloc_fast() and do not reclaim the no-longer-used
 * area which has been removed from the beginning of buffer
 * with _gnutls_buffer_pop_datum().  This helps hit more
 * issues when running under valgrind.
 */
static int buffer_resize_no_reclaim(gnutls_buffer_st *dest, size_t new_size)
{
  size_t unused;
  size_t alloc_len;

  if (unlikely(dest->data != NULL && dest->allocd == NULL))
    return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

  unused = MEMSUB(dest->data, dest->allocd);

  if (!INT_ADD_OK(new_size, unused, &alloc_len))
    return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);

  dest->allocd = gnutls_realloc_fast(dest->allocd, alloc_len);
  if (dest->allocd == NULL) {
    gnutls_assert();
    return GNUTLS_E_MEMORY_ERROR;
  }
  dest->max_length = new_size + unused;
  dest->data = dest->allocd + unused;

  return 0;
}

static void align_allocd_with_data(gnutls_buffer_st *dest)
{
  assert(dest->allocd != NULL);
  assert(dest->data != NULL);
  if (dest->length)
    memmove(dest->allocd, dest->data, dest->length);
  dest->data = dest->allocd;
}

static int buffer_resize_reclaim(gnutls_buffer_st *dest, size_t new_size)
{
  if (unlikely(dest->data != NULL && dest->allocd == NULL))
    return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

  if (dest->max_length >= new_size) {
    size_t unused = MEMSUB(dest->data, dest->allocd);
    if (dest->max_length - unused <= new_size) {
      align_allocd_with_data(dest);
    }

    return 0;
  } else {
    size_t unused = MEMSUB(dest->data, dest->allocd);
    size_t alloc_len;

    if (!INT_ADD_OK(MAX(new_size, MIN_CHUNK),
        MAX(dest->max_length, MIN_CHUNK), &alloc_len))
      return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);

    dest->allocd = gnutls_realloc_fast(dest->allocd, alloc_len);
    if (dest->allocd == NULL) {
      gnutls_assert();
      return GNUTLS_E_MEMORY_ERROR;
    }
    dest->max_length = alloc_len;
    dest->data = dest->allocd + unused;

    align_allocd_with_data(dest);

    return 0;
  }
}

int (*_gnutls_buffer_resize)(gnutls_buffer_st *,
           size_t) = buffer_resize_reclaim;

void _gnutls_buffer_set_reclaiming(bool reclaiming)
{
  _gnutls_buffer_resize = reclaiming ? buffer_resize_reclaim :
               buffer_resize_no_reclaim;
}

/* Appends the provided string. The null termination byte is appended
 * but not included in length.
 */
int _gnutls_buffer_append_str(gnutls_buffer_st *dest, const char *src)
{
  int ret;
  ret = _gnutls_buffer_append_data(dest, src, strlen(src) + 1);
  if (ret >= 0)
    dest->length--;

  return ret;
}

/* returns data from a string in a constant buffer.
 * The data will NOT be valid if buffer is released or
 * data are appended in the buffer.
 */
void _gnutls_buffer_pop_datum(gnutls_buffer_st *str, gnutls_datum_t *data,
            size_t req_size)
{
  if (str->length == 0) {
    data->data = NULL;
    data->size = 0;
    return;
  }

  if (req_size > str->length)
    req_size = str->length;

  data->data = str->data;
  data->size = req_size;

  str->data += req_size;
  str->length -= req_size;

  /* if string becomes empty start from beginning */
  if (str->length == 0) {
    str->data = str->allocd;
  }

  return;
}

/* converts the buffer to a datum if possible. After this call
 * (failed or not) the buffer should be considered deinitialized.
 */
int _gnutls_buffer_to_datum(gnutls_buffer_st *str, gnutls_datum_t *data,
          unsigned is_str)
{
  int ret;

  if (str->length == 0) {
    data->data = NULL;
    data->size = 0;
    ret = 0;
    goto fail;
  }

  if (is_str) {
    ret = _gnutls_buffer_append_data(str, "\x00", 1);
    if (ret < 0) {
      gnutls_assert();
      goto fail;
    }
  }

  if (str->allocd != str->data) {
    data->data = gnutls_malloc(str->length);
    if (data->data == NULL) {
      gnutls_assert();
      ret = GNUTLS_E_MEMORY_ERROR;
      goto fail;
    }
    memcpy(data->data, str->data, str->length);
    data->size = str->length;
    _gnutls_buffer_clear(str);
  } else {
    data->data = str->data;
    data->size = str->length;
    _gnutls_buffer_init(str);
  }

  if (is_str) {
    data->size--;
  }

  return 0;
fail:
  _gnutls_buffer_clear(str);
  return ret;
}

/* returns data from a string in a constant buffer. Will
 * fail with GNUTLS_E_PARSING_ERROR, if the string has not enough data.
 */
int _gnutls_buffer_pop_data(gnutls_buffer_st *str, void *data, size_t req_size)
{
  gnutls_datum_t tdata;

  _gnutls_buffer_pop_datum(str, &tdata, req_size);
  if (tdata.data == NULL || tdata.size != req_size) {
    return GNUTLS_E_PARSING_ERROR;
  }

  memcpy(data, tdata.data, tdata.size);

  return 0;
}

int _gnutls_buffer_append_printf(gnutls_buffer_st *dest, const char *fmt, ...)
{
  va_list args;
  int len;
  char *str = NULL;

  va_start(args, fmt);
  len = vasprintf(&str, fmt, args);
  va_end(args);

  if (len < 0 || !str)
    return -1;

  len = _gnutls_buffer_append_str(dest, str);

  free(str);

  return len;
}

static int _gnutls_buffer_insert_data(gnutls_buffer_st *dest, int pos,
              const void *str, size_t str_size)
{
  size_t orig_length = dest->length;
  int ret;

  ret = _gnutls_buffer_resize(
    dest, dest->length + str_size); /* resize to make space */
  if (ret < 0)
    return ret;

  assert(dest->data != NULL);

  memmove(&dest->data[pos + str_size], &dest->data[pos],
    orig_length - pos);

  memcpy(&dest->data[pos], str, str_size);
  dest->length += str_size;

  return 0;
}

static void _gnutls_buffer_delete_data(gnutls_buffer_st *dest, int pos,
               size_t str_size)
{
  memmove(&dest->data[pos], &dest->data[pos + str_size],
    dest->length - pos - str_size);

  dest->length -= str_size;

  return;
}

int _gnutls_buffer_append_escape(gnutls_buffer_st *dest, const void *data,
         size_t data_size, const char *invalid_chars)
{
  int rv = -1;
  char t[5];
  unsigned int pos = dest->length;

  rv = _gnutls_buffer_append_data(dest, data, data_size);
  if (rv < 0)
    return gnutls_assert_val(rv);

  while (pos < dest->length) {
    if (dest->data[pos] == '\\' ||
        strchr(invalid_chars, dest->data[pos]) ||
        !c_isgraph(dest->data[pos])) {
      snprintf(t, sizeof(t), "%%%.2X",
         (unsigned int)dest->data[pos]);

      _gnutls_buffer_delete_data(dest, pos, 1);

      if (_gnutls_buffer_insert_data(dest, pos, t, 3) < 0) {
        rv = -1;
        goto cleanup;
      }
      pos += 3;
    } else
      pos++;
  }

  rv = 0;

cleanup:
  return rv;
}

int _gnutls_buffer_unescape(gnutls_buffer_st *dest)
{
  int rv = -1;
  unsigned int pos = 0;

  while (pos < dest->length) {
    if (dest->data[pos] == '%') {
      if (pos + 1 < dest->length &&
          dest->data[pos + 1] == '%') {
        // %% -> %
        _gnutls_buffer_delete_data(dest, pos, 1);
      } else if (pos + 2 < dest->length &&
           c_isxdigit(dest->data[pos + 1]) &&
           c_isxdigit(dest->data[pos + 2])) {
        unsigned char x;

        hex_decode((char *)dest->data + pos + 1, 2, &x,
             1);

        _gnutls_buffer_delete_data(dest, pos, 3);
        _gnutls_buffer_insert_data(dest, pos, &x, 1);
      }
    }
    pos++;
  }

  rv = 0;

  return rv;
}

/* Converts the given string (old) to hex. A buffer must be provided
 * to hold the new hex string. The new string will be null terminated.
 * If the buffer does not have enough space to hold the string, a
 * truncated hex string is returned (always null terminated).
 */
char *_gnutls_bin2hex(const void *_old, size_t oldlen, char *buffer,
          size_t buffer_size, const char *separator)
{
  size_t i, j;
  const uint8_t *old = _old;
  int step = 2;
  const char empty[] = "";

  if (unlikely(oldlen == 0)) {
    if (buffer_size == 0) {
      gnutls_assert();
      return NULL;
    }
    buffer[0] = '\0';
    return buffer;
  }

  if (separator != NULL) {
    step += strlen(separator);
  } else
    separator = empty;

  if (buffer_size < 3) {
    gnutls_assert();
    return NULL;
  }

  i = j = 0;
  sprintf(&buffer[j], "%.2x", old[i]);
  j += 2;
  i++;

  for (; i < oldlen && j + step < buffer_size; j += step) {
    sprintf(&buffer[j], "%s%.2x", separator, old[i]);
    i++;
  }
  buffer[j] = '\0';

  return buffer;
}

/**
 * gnutls_hex2bin:
 * @hex_data: string with data in hex format
 * @hex_size: size of hex data
 * @bin_data: output array with binary data
 * @bin_size: when calling should hold maximum size of @bin_data,
 *      on return will hold actual length of @bin_data.
 *
 * Convert a buffer with hex data to binary data. This function
 * unlike gnutls_hex_decode() can parse hex data with separators
 * between numbers. That is, it ignores any non-hex characters.
 *
 * Returns: %GNUTLS_E_SUCCESS on success, otherwise a negative error code.
 *
 * Since: 2.4.0
 **/
int gnutls_hex2bin(const char *hex_data, size_t hex_size, void *bin_data,
       size_t *bin_size)
{
  return _gnutls_hex2bin(hex_data, hex_size, (void *)bin_data, bin_size);
}

int _gnutls_hex2bin(const char *hex_data, size_t hex_size, uint8_t *bin_data,
        size_t *bin_size)
{
  unsigned int i, j;
  uint8_t hex2_data[3];
  unsigned long val;

  hex2_data[2] = 0;

  for (i = j = 0; i < hex_size;) {
    if (!isxdigit(
          hex_data[i])) { /* skip non-hex such as the ':' in 00:FF */
      i++;
      continue;
    }
    if (j >= *bin_size) {
      gnutls_assert();
      return GNUTLS_E_SHORT_MEMORY_BUFFER;
    }

    if (i + 1 >= hex_size)
      return gnutls_assert_val(GNUTLS_E_PARSING_ERROR);

    hex2_data[0] = hex_data[i];
    hex2_data[1] = hex_data[i + 1];
    i += 2;

    val = strtoul((char *)hex2_data, NULL, 16);
    if (val == ULONG_MAX) {
      gnutls_assert();
      return GNUTLS_E_PARSING_ERROR;
    }
    bin_data[j] = val;
    j++;
  }
  *bin_size = j;

  return 0;
}

/**
 * gnutls_hex_decode2:
 * @hex_data: contain the encoded data
 * @result: the result in an allocated string
 *
 * This function will decode the given encoded data, using the hex
 * encoding used by PSK password files.
 *
 * Returns: %GNUTLS_E_PARSING_ERROR on invalid hex data, or 0 on success.
 **/
int gnutls_hex_decode2(const gnutls_datum_t *hex_data, gnutls_datum_t *result)
{
  int ret;
  int size = hex_data_size(hex_data->size);

  result->data = gnutls_malloc(size);
  if (result->data == NULL) {
    gnutls_assert();
    return GNUTLS_E_MEMORY_ERROR;
  }

  result->size = size;
  ret = hex_decode((char *)hex_data->data, hex_data->size, result->data,
       result->size);
  if (ret == 0) {
    gnutls_assert();
    gnutls_free(result->data);
    return GNUTLS_E_PARSING_ERROR;
  }

  return 0;
}

/**
 * gnutls_hex_decode:
 * @hex_data: contain the encoded data
 * @result: the place where decoded data will be copied
 * @result_size: holds the size of the result
 *
 * This function will decode the given encoded data, using the hex
 * encoding used by PSK password files.
 *
 * Initially @result_size must hold the maximum size available in
 * @result, and on return it will contain the number of bytes written.
 *
 * Returns: %GNUTLS_E_SHORT_MEMORY_BUFFER if the buffer given is not
 *   long enough, %GNUTLS_E_PARSING_ERROR on invalid hex data, or 0 on success.
 **/
int gnutls_hex_decode(const gnutls_datum_t *hex_data, void *result,
          size_t *result_size)
{
  int ret;
  size_t size = hex_data_size(hex_data->size);

  if (*result_size < size) {
    gnutls_assert();
    return GNUTLS_E_SHORT_MEMORY_BUFFER;
  }

  ret = hex_decode((char *)hex_data->data, hex_data->size, result, size);
  if (ret == 0) {
    return gnutls_assert_val(GNUTLS_E_PARSING_ERROR);
  }
  *result_size = size;

  return 0;
}

/**
 * gnutls_hex_encode:
 * @data: contain the raw data
 * @result: the place where hex data will be copied
 * @result_size: holds the size of the result
 *
 * This function will convert the given data to printable data, using
 * the hex encoding, as used in the PSK password files.
 *
 * Note that the size of the result includes the null terminator.
 *
 * Returns: %GNUTLS_E_SHORT_MEMORY_BUFFER if the buffer given is not
 * long enough, or 0 on success.
 **/
int gnutls_hex_encode(const gnutls_datum_t *data, char *result,
          size_t *result_size)
{
  int ret;
  size_t size = hex_str_size(data->size);

  if (*result_size < size) {
    gnutls_assert();
    return GNUTLS_E_SHORT_MEMORY_BUFFER;
  }

  ret = hex_encode(data->data, data->size, result, *result_size);
  if (ret == 0) {
    return gnutls_assert_val(GNUTLS_E_PARSING_ERROR);
  }

  *result_size = size;

  return 0;
}

/**
 * gnutls_hex_encode2:
 * @data: contain the raw data
 * @result: the result in an allocated string
 *
 * This function will convert the given data to printable data, using
 * the hex encoding, as used in the PSK password files.
 *
 * Note that the size of the result does NOT include the null terminator.
 *
 * Returns: %GNUTLS_E_SUCCESS on success, otherwise a negative error code.
 **/
int gnutls_hex_encode2(const gnutls_datum_t *data, gnutls_datum_t *result)
{
  int ret;
  int size = hex_str_size(data->size);

  result->data = gnutls_malloc(size);
  if (result->data == NULL) {
    gnutls_assert();
    return GNUTLS_E_MEMORY_ERROR;
  }

  ret = hex_encode((char *)data->data, data->size, (char *)result->data,
       size);
  if (ret == 0) {
    gnutls_free(result->data);
    return gnutls_assert_val(GNUTLS_E_PARSING_ERROR);
  }

  result->size = size - 1;

  return 0;
}

static int hostname_compare_raw(const char *certname, size_t certnamesize,
        const char *hostname)
{
  if (certnamesize == strlen(hostname) &&
      memcmp(hostname, certname, certnamesize) == 0)
    return 1;
  return 0;
}

static int hostname_compare_ascii(const char *certname, size_t certnamesize,
          const char *hostname)
{
  for (; *certname && *hostname &&
         c_toupper(*certname) == c_toupper(*hostname);
       certname++, hostname++, certnamesize--)
    ;

  /* the strings are the same */
  if (certnamesize == 0 && *hostname == '\0')
    return 1;

  return 0;
}

/* compare hostname against certificate, taking account of wildcards
 * return 1 on success or 0 on error
 *
 * note: certnamesize is required as X509 certs can contain embedded NULs in
 * the strings such as CN or subjectAltName.
 *
 * Wildcards are taken into account only if they are the leftmost
 * component, and if the string is ascii only (partial advice from rfc6125)
 *
 */
int _gnutls_hostname_compare(const char *certname, size_t certnamesize,
           const char *hostname, unsigned vflags)
{
  char *p;
  unsigned i;

  for (i = 0; i < certnamesize; i++) {
    if (c_isprint(certname[i]) == 0)
      return hostname_compare_raw(certname, certnamesize,
                hostname);
  }

  if (*certname == '*' &&
      !(vflags & GNUTLS_VERIFY_DO_NOT_ALLOW_WILDCARDS)) {
    /* a wildcard certificate */

    /* ensure that we have at least two domain components after
     * the wildcard. */
    p = strrchr(certname, '.');
    if (p == NULL || strchr(certname, '.') == p || p[1] == 0) {
      return 0;
    }

    certname++;
    certnamesize--;

    while (1) {
      if (hostname_compare_ascii(certname, certnamesize,
               hostname))
        return 1;

      /* wildcards are only allowed to match a single domain
         component or component fragment */
      if (*hostname == '\0' || *hostname == '.')
        break;
      hostname++;
    }

    return 0;
  } else {
    return hostname_compare_ascii(certname, certnamesize, hostname);
  }
}

int _gnutls_buffer_append_prefix(gnutls_buffer_st *buf, int pfx_size,
         size_t data_size)
{
  uint8_t ss[4];

  if (pfx_size == 32) {
    _gnutls_write_uint32(data_size, ss);
    pfx_size = 4;
  } else if (pfx_size == 24) {
    _gnutls_write_uint24(data_size, ss);
    pfx_size = 3;
  } else if (pfx_size == 16) {
    _gnutls_write_uint16(data_size, ss);
    pfx_size = 2;
  } else if (pfx_size == 8) {
    ss[0] = data_size;
    pfx_size = 1;
  } else
    return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

  return _gnutls_buffer_append_data(buf, ss, pfx_size);
}

int _gnutls_buffer_pop_prefix8(gnutls_buffer_st *buf, uint8_t *data, int check)
{
  if (buf->length < 1) {
    gnutls_assert();
    return GNUTLS_E_PARSING_ERROR;
  }

  *data = buf->data[0];

  if (check && *data > buf->length - 1) {
    gnutls_assert();
    return GNUTLS_E_PARSING_ERROR;
  }

  buf->data++;
  buf->length--;

  return 0;
}

int _gnutls_buffer_pop_prefix16(gnutls_buffer_st *buf, size_t *data_size,
        int check)
{
  size_t size;

  if (buf->length < 2) {
    gnutls_assert();
    return GNUTLS_E_PARSING_ERROR;
  }

  size = _gnutls_read_uint16(buf->data);
  if (check && size > buf->length - 2) {
    gnutls_assert();
    return GNUTLS_E_PARSING_ERROR;
  }

  buf->data += 2;
  buf->length -= 2;

  *data_size = size;

  return 0;
}

int _gnutls_buffer_pop_prefix24(gnutls_buffer_st *buf, size_t *data_size,
        int check)
{
  size_t size;

  if (buf->length < 3) {
    gnutls_assert();
    return GNUTLS_E_PARSING_ERROR;
  }

  size = _gnutls_read_uint24(buf->data);
  if (check && size > buf->length - 3) {
    gnutls_assert();
    return GNUTLS_E_PARSING_ERROR;
  }

  buf->data += 3;
  buf->length -= 3;

  *data_size = size;

  return 0;
}

/* Reads an uint32 number from the buffer. If check is non zero it will also check whether
 * the number read, is less than the data in the buffer
 */
int _gnutls_buffer_pop_prefix32(gnutls_buffer_st *buf, size_t *data_size,
        int check)
{
  size_t size;

  if (buf->length < 4) {
    gnutls_assert();
    return GNUTLS_E_PARSING_ERROR;
  }

  size = _gnutls_read_uint32(buf->data);
  if (check && size > buf->length - 4) {
    gnutls_assert();
    return GNUTLS_E_PARSING_ERROR;
  }

  buf->data += 4;
  buf->length -= 4;

  *data_size = size;

  return 0;
}

int _gnutls_buffer_pop_datum_prefix32(gnutls_buffer_st *buf,
              gnutls_datum_t *data)
{
  size_t size;
  int ret;

  ret = _gnutls_buffer_pop_prefix32(buf, &size, 1);
  if (ret < 0) {
    gnutls_assert();
    return ret;
  }

  if (size > 0) {
    size_t osize = size;
    _gnutls_buffer_pop_datum(buf, data, size);
    if (osize != data->size) {
      gnutls_assert();
      return GNUTLS_E_PARSING_ERROR;
    }
  } else {
    data->size = 0;
    data->data = NULL;
  }

  return 0;
}

int _gnutls_buffer_pop_datum_prefix24(gnutls_buffer_st *buf,
              gnutls_datum_t *data)
{
  size_t size;
  int ret;

  ret = _gnutls_buffer_pop_prefix24(buf, &size, 1);
  if (ret < 0) {
    gnutls_assert();
    return ret;
  }

  if (size > 0) {
    size_t osize = size;
    _gnutls_buffer_pop_datum(buf, data, size);
    if (osize != data->size) {
      gnutls_assert();
      return GNUTLS_E_PARSING_ERROR;
    }
  } else {
    data->size = 0;
    data->data = NULL;
  }

  return 0;
}

int _gnutls_buffer_pop_datum_prefix16(gnutls_buffer_st *buf,
              gnutls_datum_t *data)
{
  size_t size;

  if (buf->length < 2) {
    gnutls_assert();
    return GNUTLS_E_PARSING_ERROR;
  }

  size = _gnutls_read_uint16(buf->data);

  buf->data += 2;
  buf->length -= 2;

  if (size > 0) {
    size_t osize = size;
    _gnutls_buffer_pop_datum(buf, data, size);
    if (osize != data->size) {
      gnutls_assert();
      return GNUTLS_E_PARSING_ERROR;
    }
  } else {
    data->size = 0;
    data->data = NULL;
  }

  return 0;
}

int _gnutls_buffer_pop_datum_prefix8(gnutls_buffer_st *buf,
             gnutls_datum_t *data)
{
  size_t size;

  if (buf->length < 1) {
    gnutls_assert();
    return GNUTLS_E_PARSING_ERROR;
  }

  size = buf->data[0];

  buf->data++;
  buf->length--;

  if (size > 0) {
    size_t osize = size;
    _gnutls_buffer_pop_datum(buf, data, size);
    if (osize != data->size) {
      gnutls_assert();
      return GNUTLS_E_PARSING_ERROR;
    }
  } else {
    data->size = 0;
    data->data = NULL;
  }

  return 0;
}

int _gnutls_buffer_append_data_prefix(gnutls_buffer_st *buf, int pfx_size,
              const void *data, size_t data_size)
{
  int ret;

  ret = _gnutls_buffer_append_prefix(buf, pfx_size, data_size);
  if (ret < 0)
    return gnutls_assert_val(ret);

  if (data_size > 0) {
    ret = _gnutls_buffer_append_data(buf, data, data_size);
    if (ret < 0)
      return gnutls_assert_val(ret);
  }

  return 0;
}

int _gnutls_buffer_append_mpi(gnutls_buffer_st *buf, int pfx_size, bigint_t mpi,
            int lz)
{
  gnutls_datum_t dd;
  int ret;

  if (lz)
    ret = _gnutls_mpi_dprint_lz(mpi, &dd);
  else
    ret = _gnutls_mpi_dprint(mpi, &dd);

  if (ret < 0)
    return gnutls_assert_val(ret);

  ret = _gnutls_buffer_append_data_prefix(buf, pfx_size, dd.data,
            dd.size);

  _gnutls_free_datum(&dd);

  return ret;
}

/* Appends an MPI of fixed-size in bytes left-padded with zeros if necessary */
int _gnutls_buffer_append_fixed_mpi(gnutls_buffer_st *buf, bigint_t mpi,
            unsigned size)
{
  gnutls_datum_t dd;
  unsigned pad, i;
  int ret;

  ret = _gnutls_mpi_dprint(mpi, &dd);
  if (ret < 0)
    return gnutls_assert_val(ret);

  if (size < dd.size) {
    ret = gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
    goto cleanup;
  }

  pad = size - dd.size;
  for (i = 0; i < pad; i++) {
    ret = _gnutls_buffer_append_data(buf, "\x00", 1);
    if (ret < 0) {
      gnutls_assert();
      goto cleanup;
    }
  }

  /* append the rest */
  ret = _gnutls_buffer_append_data(buf, dd.data, dd.size);

cleanup:
  _gnutls_free_datum(&dd);
  return ret;
}

void _gnutls_buffer_hexprint(gnutls_buffer_st *str, const void *_data,
           size_t len)
{
  size_t j;
  const unsigned char *data = _data;

  if (len == 0)
    _gnutls_buffer_append_str(str, "00");
  else {
    for (j = 0; j < len; j++)
      _gnutls_buffer_append_printf(str, "%.2x",
                 (unsigned)data[j]);
  }
}

int _gnutls_buffer_base64print(gnutls_buffer_st *str, const void *_data,
             size_t len)
{
  const unsigned char *data = _data;
  unsigned b64len = BASE64_ENCODE_RAW_LENGTH(len);
  int ret;

  ret = _gnutls_buffer_resize(str, str->length + b64len + 1);
  if (ret < 0) {
    return gnutls_assert_val(ret);
  }

  base64_encode_raw((void *)&str->data[str->length], len, data);
  str->length += b64len;
  str->data[str->length] = 0;

  return 0;
}

void _gnutls_buffer_hexdump(gnutls_buffer_st *str, const void *_data,
          size_t len, const char *spc)
{
  size_t j;
  const unsigned char *data = _data;

  if (spc)
    _gnutls_buffer_append_str(str, spc);
  for (j = 0; j < len; j++) {
    if (((j + 1) % 16) == 0) {
      _gnutls_buffer_append_printf(str, "%.2x\n",
                 (unsigned)data[j]);
      if (spc && j != (len - 1))
        _gnutls_buffer_append_str(str, spc);
    } else if (j == (len - 1))
      _gnutls_buffer_append_printf(str, "%.2x",
                 (unsigned)data[j]);
    else
      _gnutls_buffer_append_printf(
        str, "%.2x:", (unsigned)data[j]);
  }
  if ((j % 16) != 0)
    _gnutls_buffer_append_str(str, "\n");
}

void _gnutls_buffer_asciiprint(gnutls_buffer_st *str, const char *data,
             size_t len)
{
  size_t j;

  for (j = 0; j < len; j++)
    if (c_isprint(data[j]))
      _gnutls_buffer_append_printf(str, "%c",
                 (unsigned char)data[j]);
    else
      _gnutls_buffer_append_printf(str, ".");
}

Coverage Report

Created: 2026-02-14 07:17