/src/hostap/src/tls/tlsv1_server_read.c

Source (jump to first uncovered line)
/*
 * TLSv1 server - read handshake message
 * Copyright (c) 2006-2014, Jouni Malinen <j@w1.fi>
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 */

#include "includes.h"

#include "common.h"
#include "crypto/md5.h"
#include "crypto/sha1.h"
#include "crypto/sha256.h"
#include "crypto/tls.h"
#include "x509v3.h"
#include "tlsv1_common.h"
#include "tlsv1_record.h"
#include "tlsv1_server.h"
#include "tlsv1_server_i.h"


static int tls_process_client_key_exchange(struct tlsv1_server *conn, u8 ct,
             const u8 *in_data, size_t *in_len);
static int tls_process_change_cipher_spec(struct tlsv1_server *conn,
            u8 ct, const u8 *in_data,
            size_t *in_len);


static int testing_cipher_suite_filter(struct tlsv1_server *conn, u16 suite)
{
#ifdef CONFIG_TESTING_OPTIONS
  if ((conn->test_flags &
       (TLS_BREAK_SRV_KEY_X_HASH | TLS_BREAK_SRV_KEY_X_SIGNATURE |
        TLS_DHE_PRIME_511B | TLS_DHE_PRIME_767B | TLS_DHE_PRIME_15 |
        TLS_DHE_PRIME_58B | TLS_DHE_NON_PRIME)) &&
      suite != TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 &&
      suite != TLS_DHE_RSA_WITH_AES_256_CBC_SHA &&
      suite != TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 &&
      suite != TLS_DHE_RSA_WITH_AES_128_CBC_SHA &&
      suite != TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA)
    return 1;
#endif /* CONFIG_TESTING_OPTIONS */

  return 0;
}


static void tls_process_status_request_item(struct tlsv1_server *conn,
              const u8 *req, size_t req_len)
{
  const u8 *pos, *end;
  u8 status_type;

  pos = req;
  end = req + req_len;

  /*
   * RFC 6961, 2.2:
   * struct {
   *   CertificateStatusType status_type;
   *   uint16 request_length;
   *   select (status_type) {
   *     case ocsp: OCSPStatusRequest;
   *     case ocsp_multi: OCSPStatusRequest;
   *   } request;
   * } CertificateStatusRequestItemV2;
   *
   * enum { ocsp(1), ocsp_multi(2), (255) } CertificateStatusType;
   */

  if (end - pos < 1)
    return; /* Truncated data */

  status_type = *pos++;
  wpa_printf(MSG_DEBUG, "TLSv1: CertificateStatusType %u", status_type);
  if (status_type != 1 && status_type != 2)
    return; /* Unsupported status type */
  /*
   * For now, only OCSP stapling is supported, so ignore the specific
   * request, if any.
   */
  wpa_hexdump(MSG_DEBUG, "TLSv1: OCSPStatusRequest", pos, end - pos);

  if (status_type == 2)
    conn->status_request_multi = 1;
}


static void tls_process_status_request_v2(struct tlsv1_server *conn,
            const u8 *ext, size_t ext_len)
{
  const u8 *pos, *end;

  conn->status_request_v2 = 1;

  pos = ext;
  end = ext + ext_len;

  /*
   * RFC 6961, 2.2:
   * struct {
   *   CertificateStatusRequestItemV2
   *                    certificate_status_req_list<1..2^16-1>;
   * } CertificateStatusRequestListV2;
   */

  while (end - pos >= 2) {
    u16 len;

    len = WPA_GET_BE16(pos);
    pos += 2;
    if (len > end - pos)
      break; /* Truncated data */
    tls_process_status_request_item(conn, pos, len);
    pos += len;
  }
}


static int tls_process_client_hello(struct tlsv1_server *conn, u8 ct,
            const u8 *in_data, size_t *in_len)
{
  const u8 *pos, *end, *c;
  size_t left, len, i, j;
  u16 cipher_suite;
  u16 num_suites;
  int compr_null_found;
  u16 ext_type, ext_len;

  if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
    tlsv1_server_log(conn, "Expected Handshake; received content type 0x%x",
         ct);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_UNEXPECTED_MESSAGE);
    return -1;
  }

  pos = in_data;
  left = *in_len;

  if (left < 4) {
    tlsv1_server_log(conn,
         "Truncated handshake message (expected ClientHello)");
    goto decode_error;
  }

  /* HandshakeType msg_type */
  if (*pos != TLS_HANDSHAKE_TYPE_CLIENT_HELLO) {
    tlsv1_server_log(conn, "Received unexpected handshake message %d (expected ClientHello)",
         *pos);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_UNEXPECTED_MESSAGE);
    return -1;
  }
  tlsv1_server_log(conn, "Received ClientHello");
  pos++;
  /* uint24 length */
  len = WPA_GET_BE24(pos);
  pos += 3;
  left -= 4;

  if (len > left) {
    tlsv1_server_log(conn,
         "Truncated ClientHello (len=%d left=%d)",
         (int) len, (int) left);
    goto decode_error;
  }

  /* body - ClientHello */

  wpa_hexdump(MSG_MSGDUMP, "TLSv1: ClientHello", pos, len);
  end = pos + len;

  /* ProtocolVersion client_version */
  if (end - pos < 2) {
    tlsv1_server_log(conn, "Truncated ClientHello/client_version");
    goto decode_error;
  }
  conn->client_version = WPA_GET_BE16(pos);
  tlsv1_server_log(conn, "Client version %d.%d",
       conn->client_version >> 8,
       conn->client_version & 0xff);
  if (conn->client_version < TLS_VERSION_1) {
    tlsv1_server_log(conn, "Unexpected protocol version in ClientHello %u.%u",
         conn->client_version >> 8,
         conn->client_version & 0xff);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_PROTOCOL_VERSION);
    return -1;
  }
  pos += 2;

  if (TLS_VERSION == TLS_VERSION_1)
    conn->rl.tls_version = TLS_VERSION_1;
#ifdef CONFIG_TLSV12
  else if (conn->client_version >= TLS_VERSION_1_2)
    conn->rl.tls_version = TLS_VERSION_1_2;
#endif /* CONFIG_TLSV12 */
  else if (conn->client_version > TLS_VERSION_1_1)
    conn->rl.tls_version = TLS_VERSION_1_1;
  else
    conn->rl.tls_version = conn->client_version;
  tlsv1_server_log(conn, "Using TLS v%s",
       tls_version_str(conn->rl.tls_version));

  /* Random random */
  if (end - pos < TLS_RANDOM_LEN) {
    tlsv1_server_log(conn, "Truncated ClientHello/client_random");
    goto decode_error;
  }

  os_memcpy(conn->client_random, pos, TLS_RANDOM_LEN);
  pos += TLS_RANDOM_LEN;
  wpa_hexdump(MSG_MSGDUMP, "TLSv1: client_random",
        conn->client_random, TLS_RANDOM_LEN);

  /* SessionID session_id */
  if (end - pos < 1) {
    tlsv1_server_log(conn, "Truncated ClientHello/session_id len");
    goto decode_error;
  }
  if (end - pos < 1 + *pos || *pos > TLS_SESSION_ID_MAX_LEN) {
    tlsv1_server_log(conn, "Truncated ClientHello/session_id");
    goto decode_error;
  }
  wpa_hexdump(MSG_MSGDUMP, "TLSv1: client session_id", pos + 1, *pos);
  pos += 1 + *pos;
  /* TODO: add support for session resumption */

  /* CipherSuite cipher_suites<2..2^16-1> */
  if (end - pos < 2) {
    tlsv1_server_log(conn,
         "Truncated ClientHello/cipher_suites len");
    goto decode_error;
  }
  num_suites = WPA_GET_BE16(pos);
  pos += 2;
  if (end - pos < num_suites) {
    tlsv1_server_log(conn, "Truncated ClientHello/cipher_suites");
    goto decode_error;
  }
  wpa_hexdump(MSG_MSGDUMP, "TLSv1: client cipher suites",
        pos, num_suites);
  if (num_suites & 1) {
    tlsv1_server_log(conn, "Odd len ClientHello/cipher_suites");
    goto decode_error;
  }
  num_suites /= 2;

  cipher_suite = 0;
  for (i = 0; !cipher_suite && i < conn->num_cipher_suites; i++) {
    if (testing_cipher_suite_filter(conn, conn->cipher_suites[i]))
      continue;
    c = pos;
    for (j = 0; j < num_suites; j++) {
      u16 tmp = WPA_GET_BE16(c);
      c += 2;
      if (!cipher_suite && tmp == conn->cipher_suites[i]) {
        cipher_suite = tmp;
        break;
      }
    }
  }
  pos += num_suites * 2;
  if (!cipher_suite) {
    tlsv1_server_log(conn, "No supported cipher suite available");
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_ILLEGAL_PARAMETER);
    return -1;
  }

  if (tlsv1_record_set_cipher_suite(&conn->rl, cipher_suite) < 0) {
    wpa_printf(MSG_DEBUG, "TLSv1: Failed to set CipherSuite for "
         "record layer");
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_INTERNAL_ERROR);
    return -1;
  }

  conn->cipher_suite = cipher_suite;

  /* CompressionMethod compression_methods<1..2^8-1> */
  if (end - pos < 1) {
    tlsv1_server_log(conn,
         "Truncated ClientHello/compression_methods len");
    goto decode_error;
  }
  num_suites = *pos++;
  if (end - pos < num_suites) {
    tlsv1_server_log(conn,
         "Truncated ClientHello/compression_methods");
    goto decode_error;
  }
  wpa_hexdump(MSG_MSGDUMP, "TLSv1: client compression_methods",
        pos, num_suites);
  compr_null_found = 0;
  for (i = 0; i < num_suites; i++) {
    if (*pos++ == TLS_COMPRESSION_NULL)
      compr_null_found = 1;
  }
  if (!compr_null_found) {
    tlsv1_server_log(conn, "Client does not accept NULL compression");
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_ILLEGAL_PARAMETER);
    return -1;
  }

  if (end - pos == 1) {
    tlsv1_server_log(conn, "Unexpected extra octet in the end of ClientHello: 0x%02x",
         *pos);
    goto decode_error;
  }

  if (end - pos >= 2) {
    /* Extension client_hello_extension_list<0..2^16-1> */
    ext_len = WPA_GET_BE16(pos);
    pos += 2;

    tlsv1_server_log(conn, "%u bytes of ClientHello extensions",
         ext_len);
    if (end - pos != ext_len) {
      tlsv1_server_log(conn, "Invalid ClientHello extension list length %u (expected %u)",
           ext_len, (unsigned int) (end - pos));
      goto decode_error;
    }

    /*
     * struct {
     *   ExtensionType extension_type (0..65535)
     *   opaque extension_data<0..2^16-1>
     * } Extension;
     */

    while (pos < end) {
      if (end - pos < 2) {
        tlsv1_server_log(conn, "Invalid extension_type field");
        goto decode_error;
      }

      ext_type = WPA_GET_BE16(pos);
      pos += 2;

      if (end - pos < 2) {
        tlsv1_server_log(conn, "Invalid extension_data length field");
        goto decode_error;
      }

      ext_len = WPA_GET_BE16(pos);
      pos += 2;

      if (end - pos < ext_len) {
        tlsv1_server_log(conn, "Invalid extension_data field");
        goto decode_error;
      }

      tlsv1_server_log(conn, "ClientHello Extension type %u",
           ext_type);
      wpa_hexdump(MSG_MSGDUMP, "TLSv1: ClientHello "
            "Extension data", pos, ext_len);

      if (ext_type == TLS_EXT_SESSION_TICKET) {
        os_free(conn->session_ticket);
        conn->session_ticket = os_malloc(ext_len);
        if (conn->session_ticket) {
          os_memcpy(conn->session_ticket, pos,
              ext_len);
          conn->session_ticket_len = ext_len;
        }
      } else if (ext_type == TLS_EXT_STATUS_REQUEST) {
        conn->status_request = 1;
      } else if (ext_type == TLS_EXT_STATUS_REQUEST_V2) {
        tls_process_status_request_v2(conn, pos,
                    ext_len);
      }

      pos += ext_len;
    }
  }

  *in_len = end - in_data;

  tlsv1_server_log(conn, "ClientHello OK - proceed to ServerHello");
  conn->state = SERVER_HELLO;

  return 0;

decode_error:
  tlsv1_server_log(conn, "Failed to decode ClientHello");
  tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
         TLS_ALERT_DECODE_ERROR);
  return -1;
}


static int tls_process_certificate(struct tlsv1_server *conn, u8 ct,
           const u8 *in_data, size_t *in_len)
{
  const u8 *pos, *end;
  size_t left, len, list_len, cert_len, idx;
  u8 type;
  struct x509_certificate *chain = NULL, *last = NULL, *cert;
  int reason;

  if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
    tlsv1_server_log(conn, "Expected Handshake; received content type 0x%x",
         ct);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_UNEXPECTED_MESSAGE);
    return -1;
  }

  pos = in_data;
  left = *in_len;

  if (left < 4) {
    tlsv1_server_log(conn, "Too short Certificate message (len=%lu)",
         (unsigned long) left);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  type = *pos++;
  len = WPA_GET_BE24(pos);
  pos += 3;
  left -= 4;

  if (len > left) {
    tlsv1_server_log(conn, "Unexpected Certificate message length (len=%lu != left=%lu)",
         (unsigned long) len, (unsigned long) left);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  if (type == TLS_HANDSHAKE_TYPE_CLIENT_KEY_EXCHANGE) {
    if (conn->verify_peer) {
      tlsv1_server_log(conn, "Client did not include Certificate");
      tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
             TLS_ALERT_UNEXPECTED_MESSAGE);
      return -1;
    }

    return tls_process_client_key_exchange(conn, ct, in_data,
                   in_len);
  }
  if (type != TLS_HANDSHAKE_TYPE_CERTIFICATE) {
    tlsv1_server_log(conn, "Received unexpected handshake message %d (expected Certificate/ClientKeyExchange)",
         type);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_UNEXPECTED_MESSAGE);
    return -1;
  }

  tlsv1_server_log(conn, "Received Certificate (certificate_list len %lu)",
       (unsigned long) len);

  /*
   * opaque ASN.1Cert<2^24-1>;
   *
   * struct {
   *     ASN.1Cert certificate_list<1..2^24-1>;
   * } Certificate;
   */

  end = pos + len;

  if (end - pos < 3) {
    tlsv1_server_log(conn, "Too short Certificate (left=%lu)",
         (unsigned long) left);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  list_len = WPA_GET_BE24(pos);
  pos += 3;

  if ((size_t) (end - pos) != list_len) {
    tlsv1_server_log(conn, "Unexpected certificate_list length (len=%lu left=%lu)",
         (unsigned long) list_len,
         (unsigned long) (end - pos));
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  idx = 0;
  while (pos < end) {
    if (end - pos < 3) {
      tlsv1_server_log(conn, "Failed to parse certificate_list");
      tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
             TLS_ALERT_DECODE_ERROR);
      x509_certificate_chain_free(chain);
      return -1;
    }

    cert_len = WPA_GET_BE24(pos);
    pos += 3;

    if ((size_t) (end - pos) < cert_len) {
      tlsv1_server_log(conn, "Unexpected certificate length (len=%lu left=%lu)",
           (unsigned long) cert_len,
           (unsigned long) (end - pos));
      tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
             TLS_ALERT_DECODE_ERROR);
      x509_certificate_chain_free(chain);
      return -1;
    }

    tlsv1_server_log(conn, "Certificate %lu (len %lu)",
         (unsigned long) idx, (unsigned long) cert_len);

    if (idx == 0) {
      crypto_public_key_free(conn->client_rsa_key);
      if (tls_parse_cert(pos, cert_len,
             &conn->client_rsa_key)) {
        tlsv1_server_log(conn, "Failed to parse the certificate");
        tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
               TLS_ALERT_BAD_CERTIFICATE);
        x509_certificate_chain_free(chain);
        return -1;
      }
    }

    cert = x509_certificate_parse(pos, cert_len);
    if (cert == NULL) {
      tlsv1_server_log(conn, "Failed to parse the certificate");
      tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
             TLS_ALERT_BAD_CERTIFICATE);
      x509_certificate_chain_free(chain);
      return -1;
    }

    if (last == NULL)
      chain = cert;
    else
      last->next = cert;
    last = cert;

    idx++;
    pos += cert_len;
  }

  if (x509_certificate_chain_validate(conn->cred->trusted_certs, chain,
              &reason, 0) < 0) {
    int tls_reason;
    tlsv1_server_log(conn, "Server certificate chain validation failed (reason=%d)",
         reason);
    switch (reason) {
    case X509_VALIDATE_BAD_CERTIFICATE:
      tls_reason = TLS_ALERT_BAD_CERTIFICATE;
      break;
    case X509_VALIDATE_UNSUPPORTED_CERTIFICATE:
      tls_reason = TLS_ALERT_UNSUPPORTED_CERTIFICATE;
      break;
    case X509_VALIDATE_CERTIFICATE_REVOKED:
      tls_reason = TLS_ALERT_CERTIFICATE_REVOKED;
      break;
    case X509_VALIDATE_CERTIFICATE_EXPIRED:
      tls_reason = TLS_ALERT_CERTIFICATE_EXPIRED;
      break;
    case X509_VALIDATE_CERTIFICATE_UNKNOWN:
      tls_reason = TLS_ALERT_CERTIFICATE_UNKNOWN;
      break;
    case X509_VALIDATE_UNKNOWN_CA:
      tls_reason = TLS_ALERT_UNKNOWN_CA;
      break;
    default:
      tls_reason = TLS_ALERT_BAD_CERTIFICATE;
      break;
    }
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL, tls_reason);
    x509_certificate_chain_free(chain);
    return -1;
  }

  if (chain && (chain->extensions_present & X509_EXT_EXT_KEY_USAGE) &&
      !(chain->ext_key_usage &
        (X509_EXT_KEY_USAGE_ANY | X509_EXT_KEY_USAGE_CLIENT_AUTH))) {
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_BAD_CERTIFICATE);
    x509_certificate_chain_free(chain);
    return -1;
  }

  x509_certificate_chain_free(chain);

  *in_len = end - in_data;

  conn->state = CLIENT_KEY_EXCHANGE;

  return 0;
}


static int tls_process_client_key_exchange_rsa(
  struct tlsv1_server *conn, const u8 *pos, const u8 *end)
{
  u8 *out;
  size_t outlen, outbuflen;
  u16 encr_len;
  int res;
  int use_random = 0;

  if (end - pos < 2) {
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  encr_len = WPA_GET_BE16(pos);
  pos += 2;
  if (pos + encr_len > end) {
    tlsv1_server_log(conn, "Invalid ClientKeyExchange format: encr_len=%u left=%u",
         encr_len, (unsigned int) (end - pos));
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  outbuflen = outlen = end - pos;
  out = os_malloc(outlen >= TLS_PRE_MASTER_SECRET_LEN ?
      outlen : TLS_PRE_MASTER_SECRET_LEN);
  if (out == NULL) {
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_INTERNAL_ERROR);
    return -1;
  }

  /*
   * struct {
   *   ProtocolVersion client_version;
   *   opaque random[46];
   * } PreMasterSecret;
   *
   * struct {
   *   public-key-encrypted PreMasterSecret pre_master_secret;
   * } EncryptedPreMasterSecret;
   */

  /*
   * Note: To avoid Bleichenbacher attack, we do not report decryption or
   * parsing errors from EncryptedPreMasterSecret processing to the
   * client. Instead, a random pre-master secret is used to force the
   * handshake to fail.
   */

  if (crypto_private_key_decrypt_pkcs1_v15(conn->cred->key,
             pos, encr_len,
             out, &outlen) < 0) {
    wpa_printf(MSG_DEBUG, "TLSv1: Failed to decrypt "
         "PreMasterSecret (encr_len=%u outlen=%lu)",
         encr_len, (unsigned long) outlen);
    use_random = 1;
  }

  if (!use_random && outlen != TLS_PRE_MASTER_SECRET_LEN) {
    tlsv1_server_log(conn, "Unexpected PreMasterSecret length %lu",
         (unsigned long) outlen);
    use_random = 1;
  }

  if (!use_random && WPA_GET_BE16(out) != conn->client_version) {
    tlsv1_server_log(conn, "Client version in ClientKeyExchange does not match with version in ClientHello");
    use_random = 1;
  }

  if (use_random) {
    wpa_printf(MSG_DEBUG, "TLSv1: Using random premaster secret "
         "to avoid revealing information about private key");
    outlen = TLS_PRE_MASTER_SECRET_LEN;
    if (os_get_random(out, outlen)) {
      wpa_printf(MSG_DEBUG, "TLSv1: Failed to get random "
           "data");
      tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
             TLS_ALERT_INTERNAL_ERROR);
      os_free(out);
      return -1;
    }
  }

  res = tlsv1_server_derive_keys(conn, out, outlen);

  /* Clear the pre-master secret since it is not needed anymore */
  os_memset(out, 0, outbuflen);
  os_free(out);

  if (res) {
    wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive keys");
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_INTERNAL_ERROR);
    return -1;
  }

  return 0;
}


static int tls_process_client_key_exchange_dh(
  struct tlsv1_server *conn, const u8 *pos, const u8 *end)
{
  const u8 *dh_yc;
  u16 dh_yc_len;
  u8 *shared;
  size_t shared_len;
  int res;
  const u8 *dh_p;
  size_t dh_p_len;

  /*
   * struct {
   *   select (PublicValueEncoding) {
   *     case implicit: struct { };
   *     case explicit: opaque dh_Yc<1..2^16-1>;
   *   } dh_public;
   * } ClientDiffieHellmanPublic;
   */

  tlsv1_server_log(conn, "ClientDiffieHellmanPublic received");
  wpa_hexdump(MSG_MSGDUMP, "TLSv1: ClientDiffieHellmanPublic",
        pos, end - pos);

  if (end == pos) {
    wpa_printf(MSG_DEBUG, "TLSv1: Implicit public value encoding "
         "not supported");
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_INTERNAL_ERROR);
    return -1;
  }

  if (end - pos < 3) {
    tlsv1_server_log(conn, "Invalid client public value length");
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  dh_yc_len = WPA_GET_BE16(pos);
  dh_yc = pos + 2;

  if (dh_yc_len > end - dh_yc) {
    tlsv1_server_log(conn, "Client public value overflow (length %d)",
         dh_yc_len);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  wpa_hexdump(MSG_DEBUG, "TLSv1: DH Yc (client's public value)",
        dh_yc, dh_yc_len);

  if (conn->cred == NULL || conn->cred->dh_p == NULL ||
      conn->dh_secret == NULL) {
    wpa_printf(MSG_DEBUG, "TLSv1: No DH parameters available");
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_INTERNAL_ERROR);
    return -1;
  }

  tlsv1_server_get_dh_p(conn, &dh_p, &dh_p_len);

  shared_len = dh_p_len;
  shared = os_malloc(shared_len);
  if (shared == NULL) {
    wpa_printf(MSG_DEBUG, "TLSv1: Could not allocate memory for "
         "DH");
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_INTERNAL_ERROR);
    return -1;
  }

  /* shared = Yc^secret mod p */
  if (crypto_mod_exp(dh_yc, dh_yc_len, conn->dh_secret,
         conn->dh_secret_len, dh_p, dh_p_len,
         shared, &shared_len)) {
    os_free(shared);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_INTERNAL_ERROR);
    return -1;
  }
  wpa_hexdump_key(MSG_DEBUG, "TLSv1: Shared secret from DH key exchange",
      shared, shared_len);

  os_memset(conn->dh_secret, 0, conn->dh_secret_len);
  os_free(conn->dh_secret);
  conn->dh_secret = NULL;

  res = tlsv1_server_derive_keys(conn, shared, shared_len);

  /* Clear the pre-master secret since it is not needed anymore */
  os_memset(shared, 0, shared_len);
  os_free(shared);

  if (res) {
    wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive keys");
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_INTERNAL_ERROR);
    return -1;
  }

  return 0;
}


static int tls_process_client_key_exchange(struct tlsv1_server *conn, u8 ct,
             const u8 *in_data, size_t *in_len)
{
  const u8 *pos, *end;
  size_t left, len;
  u8 type;
  tls_key_exchange keyx;
  const struct tls_cipher_suite *suite;

  if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
    tlsv1_server_log(conn, "Expected Handshake; received content type 0x%x",
         ct);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_UNEXPECTED_MESSAGE);
    return -1;
  }

  pos = in_data;
  left = *in_len;

  if (left < 4) {
    tlsv1_server_log(conn, "Too short ClientKeyExchange (Left=%lu)",
         (unsigned long) left);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  type = *pos++;
  len = WPA_GET_BE24(pos);
  pos += 3;
  left -= 4;

  if (len > left) {
    tlsv1_server_log(conn, "Mismatch in ClientKeyExchange length (len=%lu != left=%lu)",
         (unsigned long) len, (unsigned long) left);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  end = pos + len;

  if (type != TLS_HANDSHAKE_TYPE_CLIENT_KEY_EXCHANGE) {
    tlsv1_server_log(conn, "Received unexpected handshake message %d (expected ClientKeyExchange)",
         type);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_UNEXPECTED_MESSAGE);
    return -1;
  }

  tlsv1_server_log(conn, "Received ClientKeyExchange");

  wpa_hexdump(MSG_DEBUG, "TLSv1: ClientKeyExchange", pos, len);

  suite = tls_get_cipher_suite(conn->rl.cipher_suite);
  if (suite == NULL)
    keyx = TLS_KEY_X_NULL;
  else
    keyx = suite->key_exchange;

  if ((keyx == TLS_KEY_X_DH_anon || keyx == TLS_KEY_X_DHE_RSA) &&
      tls_process_client_key_exchange_dh(conn, pos, end) < 0)
    return -1;

  if (keyx != TLS_KEY_X_DH_anon && keyx != TLS_KEY_X_DHE_RSA &&
      tls_process_client_key_exchange_rsa(conn, pos, end) < 0)
    return -1;

  *in_len = end - in_data;

  conn->state = CERTIFICATE_VERIFY;

  return 0;
}


static int tls_process_certificate_verify(struct tlsv1_server *conn, u8 ct,
            const u8 *in_data, size_t *in_len)
{
  const u8 *pos, *end;
  size_t left, len;
  u8 type;
  size_t hlen;
  u8 hash[MD5_MAC_LEN + SHA1_MAC_LEN], *hpos;
  u8 alert;

  if (ct == TLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC) {
    if (conn->verify_peer) {
      tlsv1_server_log(conn, "Client did not include CertificateVerify");
      tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
             TLS_ALERT_UNEXPECTED_MESSAGE);
      return -1;
    }

    return tls_process_change_cipher_spec(conn, ct, in_data,
                  in_len);
  }

  if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
    tlsv1_server_log(conn, "Expected Handshake; received content type 0x%x",
         ct);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_UNEXPECTED_MESSAGE);
    return -1;
  }

  pos = in_data;
  left = *in_len;

  if (left < 4) {
    tlsv1_server_log(conn, "Too short CertificateVerify message (len=%lu)",
         (unsigned long) left);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  type = *pos++;
  len = WPA_GET_BE24(pos);
  pos += 3;
  left -= 4;

  if (len > left) {
    tlsv1_server_log(conn, "Unexpected CertificateVerify message length (len=%lu != left=%lu)",
         (unsigned long) len, (unsigned long) left);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  end = pos + len;

  if (type != TLS_HANDSHAKE_TYPE_CERTIFICATE_VERIFY) {
    tlsv1_server_log(conn, "Received unexpected handshake message %d (expected CertificateVerify)",
         type);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_UNEXPECTED_MESSAGE);
    return -1;
  }

  tlsv1_server_log(conn, "Received CertificateVerify");

  /*
   * struct {
   *   Signature signature;
   * } CertificateVerify;
   */

  hpos = hash;

#ifdef CONFIG_TLSV12
  if (conn->rl.tls_version == TLS_VERSION_1_2) {
    /*
     * RFC 5246, 4.7:
     * TLS v1.2 adds explicit indication of the used signature and
     * hash algorithms.
     *
     * struct {
     *   HashAlgorithm hash;
     *   SignatureAlgorithm signature;
     * } SignatureAndHashAlgorithm;
     */
    if (end - pos < 2) {
      tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
             TLS_ALERT_DECODE_ERROR);
      return -1;
    }
    if (pos[0] != TLS_HASH_ALG_SHA256 ||
        pos[1] != TLS_SIGN_ALG_RSA) {
      wpa_printf(MSG_DEBUG, "TLSv1.2: Unsupported hash(%u)/"
           "signature(%u) algorithm",
           pos[0], pos[1]);
      tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
             TLS_ALERT_INTERNAL_ERROR);
      return -1;
    }
    pos += 2;

    hlen = SHA256_MAC_LEN;
    if (conn->verify.sha256_cert == NULL ||
        crypto_hash_finish(conn->verify.sha256_cert, hpos, &hlen) <
        0) {
      conn->verify.sha256_cert = NULL;
      tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
             TLS_ALERT_INTERNAL_ERROR);
      return -1;
    }
    conn->verify.sha256_cert = NULL;
  } else {
#endif /* CONFIG_TLSV12 */

  hlen = MD5_MAC_LEN;
  if (conn->verify.md5_cert == NULL ||
      crypto_hash_finish(conn->verify.md5_cert, hpos, &hlen) < 0) {
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_INTERNAL_ERROR);
    conn->verify.md5_cert = NULL;
    crypto_hash_finish(conn->verify.sha1_cert, NULL, NULL);
    conn->verify.sha1_cert = NULL;
    return -1;
  }
  hpos += MD5_MAC_LEN;

  conn->verify.md5_cert = NULL;
  hlen = SHA1_MAC_LEN;
  if (conn->verify.sha1_cert == NULL ||
      crypto_hash_finish(conn->verify.sha1_cert, hpos, &hlen) < 0) {
    conn->verify.sha1_cert = NULL;
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_INTERNAL_ERROR);
    return -1;
  }
  conn->verify.sha1_cert = NULL;

  hlen += MD5_MAC_LEN;

#ifdef CONFIG_TLSV12
  }
#endif /* CONFIG_TLSV12 */

  wpa_hexdump(MSG_MSGDUMP, "TLSv1: CertificateVerify hash", hash, hlen);

  if (tls_verify_signature(conn->rl.tls_version, conn->client_rsa_key,
         hash, hlen, pos, end - pos, &alert) < 0) {
    tlsv1_server_log(conn, "Invalid Signature in CertificateVerify");
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL, alert);
    return -1;
  }

  *in_len = end - in_data;

  conn->state = CHANGE_CIPHER_SPEC;

  return 0;
}


static int tls_process_change_cipher_spec(struct tlsv1_server *conn,
            u8 ct, const u8 *in_data,
            size_t *in_len)
{
  const u8 *pos;
  size_t left;

  if (ct != TLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC) {
    tlsv1_server_log(conn, "Expected ChangeCipherSpec; received content type 0x%x",
         ct);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_UNEXPECTED_MESSAGE);
    return -1;
  }

  pos = in_data;
  left = *in_len;

  if (left < 1) {
    tlsv1_server_log(conn, "Too short ChangeCipherSpec");
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  if (*pos != TLS_CHANGE_CIPHER_SPEC) {
    tlsv1_server_log(conn, "Expected ChangeCipherSpec; received data 0x%x",
         *pos);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_UNEXPECTED_MESSAGE);
    return -1;
  }

  tlsv1_server_log(conn, "Received ChangeCipherSpec");
  if (tlsv1_record_change_read_cipher(&conn->rl) < 0) {
    wpa_printf(MSG_DEBUG, "TLSv1: Failed to change read cipher "
         "for record layer");
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_INTERNAL_ERROR);
    return -1;
  }

  *in_len = pos + 1 - in_data;

  conn->state = CLIENT_FINISHED;

  return 0;
}


static int tls_process_client_finished(struct tlsv1_server *conn, u8 ct,
               const u8 *in_data, size_t *in_len)
{
  const u8 *pos, *end;
  size_t left, len, hlen;
  u8 verify_data[TLS_VERIFY_DATA_LEN];
  u8 hash[MD5_MAC_LEN + SHA1_MAC_LEN];

#ifdef CONFIG_TESTING_OPTIONS
  if ((conn->test_flags &
       (TLS_BREAK_SRV_KEY_X_HASH | TLS_BREAK_SRV_KEY_X_SIGNATURE)) &&
      !conn->test_failure_reported) {
    tlsv1_server_log(conn, "TEST-FAILURE: Client Finished received after invalid ServerKeyExchange");
    conn->test_failure_reported = 1;
  }

  if ((conn->test_flags & TLS_DHE_PRIME_15) &&
      !conn->test_failure_reported) {
    tlsv1_server_log(conn, "TEST-FAILURE: Client Finished received after bogus DHE \"prime\" 15");
    conn->test_failure_reported = 1;
  }

  if ((conn->test_flags & TLS_DHE_PRIME_58B) &&
      !conn->test_failure_reported) {
    tlsv1_server_log(conn, "TEST-FAILURE: Client Finished received after short 58-bit DHE prime in long container");
    conn->test_failure_reported = 1;
  }

  if ((conn->test_flags & TLS_DHE_PRIME_511B) &&
      !conn->test_failure_reported) {
    tlsv1_server_log(conn, "TEST-WARNING: Client Finished received after short 511-bit DHE prime (insecure)");
    conn->test_failure_reported = 1;
  }

  if ((conn->test_flags & TLS_DHE_PRIME_767B) &&
      !conn->test_failure_reported) {
    tlsv1_server_log(conn, "TEST-NOTE: Client Finished received after 767-bit DHE prime (relatively insecure)");
    conn->test_failure_reported = 1;
  }

  if ((conn->test_flags & TLS_DHE_NON_PRIME) &&
      !conn->test_failure_reported) {
    tlsv1_server_log(conn, "TEST-NOTE: Client Finished received after non-prime claimed as DHE prime");
    conn->test_failure_reported = 1;
  }
#endif /* CONFIG_TESTING_OPTIONS */

  if (ct != TLS_CONTENT_TYPE_HANDSHAKE) {
    tlsv1_server_log(conn, "Expected Finished; received content type 0x%x",
         ct);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_UNEXPECTED_MESSAGE);
    return -1;
  }

  pos = in_data;
  left = *in_len;

  if (left < 4) {
    tlsv1_server_log(conn, "Too short record (left=%lu) forFinished",
         (unsigned long) left);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }

  if (pos[0] != TLS_HANDSHAKE_TYPE_FINISHED) {
    wpa_printf(MSG_DEBUG, "TLSv1: Expected Finished; received "
         "type 0x%x", pos[0]);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_UNEXPECTED_MESSAGE);
    return -1;
  }

  len = WPA_GET_BE24(pos + 1);

  pos += 4;
  left -= 4;

  if (len > left) {
    tlsv1_server_log(conn, "Too short buffer for Finished (len=%lu > left=%lu)",
         (unsigned long) len, (unsigned long) left);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }
  end = pos + len;
  if (len != TLS_VERIFY_DATA_LEN) {
    tlsv1_server_log(conn, "Unexpected verify_data length in Finished: %lu (expected %d)",
         (unsigned long) len, TLS_VERIFY_DATA_LEN);
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECODE_ERROR);
    return -1;
  }
  wpa_hexdump(MSG_MSGDUMP, "TLSv1: verify_data in Finished",
        pos, TLS_VERIFY_DATA_LEN);

#ifdef CONFIG_TLSV12
  if (conn->rl.tls_version >= TLS_VERSION_1_2) {
    hlen = SHA256_MAC_LEN;
    if (conn->verify.sha256_client == NULL ||
        crypto_hash_finish(conn->verify.sha256_client, hash, &hlen)
        < 0) {
      tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
             TLS_ALERT_INTERNAL_ERROR);
      conn->verify.sha256_client = NULL;
      return -1;
    }
    conn->verify.sha256_client = NULL;
  } else {
#endif /* CONFIG_TLSV12 */

  hlen = MD5_MAC_LEN;
  if (conn->verify.md5_client == NULL ||
      crypto_hash_finish(conn->verify.md5_client, hash, &hlen) < 0) {
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_INTERNAL_ERROR);
    conn->verify.md5_client = NULL;
    crypto_hash_finish(conn->verify.sha1_client, NULL, NULL);
    conn->verify.sha1_client = NULL;
    return -1;
  }
  conn->verify.md5_client = NULL;
  hlen = SHA1_MAC_LEN;
  if (conn->verify.sha1_client == NULL ||
      crypto_hash_finish(conn->verify.sha1_client, hash + MD5_MAC_LEN,
             &hlen) < 0) {
    conn->verify.sha1_client = NULL;
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_INTERNAL_ERROR);
    return -1;
  }
  conn->verify.sha1_client = NULL;
  hlen = MD5_MAC_LEN + SHA1_MAC_LEN;

#ifdef CONFIG_TLSV12
  }
#endif /* CONFIG_TLSV12 */

  if (tls_prf(conn->rl.tls_version,
        conn->master_secret, TLS_MASTER_SECRET_LEN,
        "client finished", hash, hlen,
        verify_data, TLS_VERIFY_DATA_LEN)) {
    wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive verify_data");
    tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
           TLS_ALERT_DECRYPT_ERROR);
    return -1;
  }
  wpa_hexdump_key(MSG_DEBUG, "TLSv1: verify_data (client)",
      verify_data, TLS_VERIFY_DATA_LEN);

  if (os_memcmp_const(pos, verify_data, TLS_VERIFY_DATA_LEN) != 0) {
    tlsv1_server_log(conn, "Mismatch in verify_data");
    conn->state = FAILED;
    return -1;
  }

  tlsv1_server_log(conn, "Received Finished");

  *in_len = end - in_data;

  if (conn->use_session_ticket) {
    /* Abbreviated handshake using session ticket; RFC 4507 */
    tlsv1_server_log(conn, "Abbreviated handshake completed successfully");
    conn->state = ESTABLISHED;
  } else {
    /* Full handshake */
    conn->state = SERVER_CHANGE_CIPHER_SPEC;
  }

  return 0;
}


int tlsv1_server_process_handshake(struct tlsv1_server *conn, u8 ct,
           const u8 *buf, size_t *len)
{
  if (ct == TLS_CONTENT_TYPE_ALERT) {
    if (*len < 2) {
      tlsv1_server_log(conn, "Alert underflow");
      tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
             TLS_ALERT_DECODE_ERROR);
      return -1;
    }
    tlsv1_server_log(conn, "Received alert %d:%d", buf[0], buf[1]);
    *len = 2;
    conn->state = FAILED;
    return -1;
  }

  switch (conn->state) {
  case CLIENT_HELLO:
    if (tls_process_client_hello(conn, ct, buf, len))
      return -1;
    break;
  case CLIENT_CERTIFICATE:
    if (tls_process_certificate(conn, ct, buf, len))
      return -1;
    break;
  case CLIENT_KEY_EXCHANGE:
    if (tls_process_client_key_exchange(conn, ct, buf, len))
      return -1;
    break;
  case CERTIFICATE_VERIFY:
    if (tls_process_certificate_verify(conn, ct, buf, len))
      return -1;
    break;
  case CHANGE_CIPHER_SPEC:
    if (tls_process_change_cipher_spec(conn, ct, buf, len))
      return -1;
    break;
  case CLIENT_FINISHED:
    if (tls_process_client_finished(conn, ct, buf, len))
      return -1;
    break;
  default:
    tlsv1_server_log(conn, "Unexpected state %d while processing received message",
         conn->state);
    return -1;
  }

  if (ct == TLS_CONTENT_TYPE_HANDSHAKE)
    tls_verify_hash_add(&conn->verify, buf, *len);

  return 0;
}

Coverage Report

Created: 2025-04-24 06:18