extlibs/mbedtls/CVE-2017-14032.patch

   1 From e8bd647d8271174d3737dcf68086126b73a73df6 Mon Sep 17 00:00:00 2001
   2 From: Oleksii Beketov <ol.beketov@samsung.com>
   3 Date: Mon, 18 Dec 2017 15:23:28 +0200
   4 Subject: [PATCH] CVE-2017-14032
   5
   6 Signed-off-by: Oleksii Beketov <ol.beketov@samsung.com>
   7 ---
   8  include/mbedtls/error.h    |  2 +-
   9  include/mbedtls/ssl.h      |  2 +-
  10  include/mbedtls/x509.h     |  1 +
  11  include/mbedtls/x509_crt.h |  8 +++++++-
  12  library/error.c            |  2 ++
  13  library/x509_crt.c         | 30 ++++++++++++++++++++++--------
  14  6 files changed, 34 insertions(+), 11 deletions(-)
  15
  16 diff --git a/include/mbedtls/error.h b/include/mbedtls/error.h
  17 index 5e549f6..31591e2 100644
  18 --- a/include/mbedtls/error.h
  19 +++ b/include/mbedtls/error.h
  20 @@ -71,7 +71,7 @@
  21   * Name      ID  Nr of Errors
  22   * PEM       1   9
  23   * PKCS#12   1   4 (Started from top)
  24 - * X509      2   19
  25 + * X509      2   20
  26   * PKCS5     2   4 (Started from top)
  27   * DHM       3   9
  28   * PK        3   14 (Started from top)
  29 diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
  30 index 495e02c..4f171e0 100644
  31 --- a/include/mbedtls/ssl.h
  32 +++ b/include/mbedtls/ssl.h
  33 @@ -1042,7 +1042,7 @@ void mbedtls_ssl_conf_authmode( mbedtls_ssl_config *conf, int authmode );
  34   *
  35   *                 If set, the verify callback is called for each
  36   *                 certificate in the chain. For implementation
  37 - *                 information, please see \c x509parse_verify()
  38 + *                 information, please see \c mbedtls_x509_crt_verify()
  39   *
  40   * \param conf     SSL configuration
  41   * \param f_vrfy   verification function
  42 diff --git a/include/mbedtls/x509.h b/include/mbedtls/x509.h
  43 index f219bf1..128eade 100644
  44 --- a/include/mbedtls/x509.h
  45 +++ b/include/mbedtls/x509.h
  46 @@ -76,6 +76,7 @@
  47  #define MBEDTLS_ERR_X509_ALLOC_FAILED                     -0x2880  /**< Allocation of memory failed. */
  48  #define MBEDTLS_ERR_X509_FILE_IO_ERROR                    -0x2900  /**< Read/write of file failed. */
  49  #define MBEDTLS_ERR_X509_BUFFER_TOO_SMALL                 -0x2980  /**< Destination buffer is too small. */
  50 +#define MBEDTLS_ERR_X509_FATAL_ERROR                      -0x3000  /**< A fatal error occured, eg the chain is too long or the vrfy callback failed. */
  51  /* \} name */
  52
  53  /**
  54 diff --git a/include/mbedtls/x509_crt.h b/include/mbedtls/x509_crt.h
  55 index 383e484..fd20336 100644
  56 --- a/include/mbedtls/x509_crt.h
  57 +++ b/include/mbedtls/x509_crt.h
  58 @@ -267,7 +267,13 @@ int mbedtls_x509_crt_verify_info( char *buf, size_t size, const char *prefix,
  59   *
  60   *                 All flags left after returning from the callback
  61   *                 are also returned to the application. The function should
  62 - *                 return 0 for anything but a fatal error.
  63 + *                 return 0 for anything (including invalid certificates)
  64 + *                 other than fatal error, as a non-zero return code
  65 + *                 immediately aborts the verification process. For fatal
  66 + *                 errors, a specific error code should be used (different
  67 + *                 from MBEDTLS_ERR_X509_CERT_VERIFY_FAILED which should not
  68 + *                 be returned at this point), or MBEDTLS_ERR_X509_FATAL_ERROR
  69 + *                 can be used if no better code is available.
  70   *
  71   * \note           In case verification failed, the results can be displayed
  72   *                 using \c mbedtls_x509_crt_verify_info()
  73 diff --git a/library/error.c b/library/error.c
  74 index dd2db0c..db42381 100644
  75 --- a/library/error.c
  76 +++ b/library/error.c
  77 @@ -480,6 +480,8 @@ void mbedtls_strerror( int ret, char *buf, size_t buflen )
  78              mbedtls_snprintf( buf, buflen, "X509 - Read/write of file failed" );
  79          if( use_ret == -(MBEDTLS_ERR_X509_BUFFER_TOO_SMALL) )
  80              mbedtls_snprintf( buf, buflen, "X509 - Destination buffer is too small" );
  81 +        if( use_ret == -(MBEDTLS_ERR_X509_FATAL_ERROR) )
  82 +            mbedtls_snprintf( buf, buflen, "X509 - A fatal error occured, eg the chain is too long or the vrfy callback failed" );
  83  #endif /* MBEDTLS_X509_USE_C || MBEDTLS_X509_CREATE_C */
  84          // END generated code
  85
  86 diff --git a/library/x509_crt.c b/library/x509_crt.c
  87 index 234f145..1f31a6b 100644
  88 --- a/library/x509_crt.c
  89 +++ b/library/x509_crt.c
  90 @@ -2055,8 +2055,8 @@ static int x509_crt_verify_child(
  91      /* path_cnt is 0 for the first intermediate CA */
  92      if( 1 + path_cnt > MBEDTLS_X509_MAX_INTERMEDIATE_CA )
  93      {
  94 -        *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
  95 -        return( MBEDTLS_ERR_X509_CERT_VERIFY_FAILED );
  96 +        /* return immediately as the goal is to avoid unbounded recursion */
  97 +        return( MBEDTLS_ERR_X509_FATAL_ERROR );
  98      }
  99
 100      if( mbedtls_x509_time_is_past( &child->valid_to ) )
 101 @@ -2200,11 +2200,14 @@ int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt,
 102      mbedtls_x509_sequence *cur = NULL;
 103      mbedtls_pk_type_t pk_type;
 104
 105 -    if( profile == NULL )
 106 -        return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
 107 -
 108      *flags = 0;
 109
 110 +    if( profile == NULL )
 111 +    {
 112 +        ret = MBEDTLS_ERR_X509_BAD_INPUT_DATA;
 113 +        goto exit;
 114 +    }
 115 +
 116      if( cn != NULL )
 117      {
 118          name = &crt->subject;
 119 @@ -2278,7 +2281,7 @@ int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt,
 120          ret = x509_crt_verify_top( crt, parent, ca_crl, profile,
 121                                     pathlen, selfsigned, flags, f_vrfy, p_vrfy );
 122          if( ret != 0 )
 123 -            return( ret );
 124 +            goto exit;
 125      }
 126      else
 127      {
 128 @@ -2293,17 +2296,28 @@ int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt,
 129              ret = x509_crt_verify_child( crt, parent, trust_ca, ca_crl, profile,
 130                                           pathlen, selfsigned, flags, f_vrfy, p_vrfy );
 131              if( ret != 0 )
 132 -                return( ret );
 133 +                goto exit;
 134          }
 135          else
 136          {
 137              ret = x509_crt_verify_top( crt, trust_ca, ca_crl, profile,
 138                                         pathlen, selfsigned, flags, f_vrfy, p_vrfy );
 139              if( ret != 0 )
 140 -                return( ret );
 141 +                goto exit;
 142          }
 143      }
 144
 145 +exit:
 146 +    /* prevent misuse of the vrfy callback */
 147 +    if( ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED )
 148 +        ret = MBEDTLS_ERR_X509_FATAL_ERROR;
 149 +
 150 +    if( ret != 0 )
 151 +    {
 152 +        *flags = (uint32_t) -1;
 153 +        return( ret );
 154 +    }
 155 +
 156      if( *flags != 0 )
 157          return( MBEDTLS_ERR_X509_CERT_VERIFY_FAILED );
 158
 159 --
 160 1.9.1
 161