eden-emu/mbedtls
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Protect setting of hello_random flag

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The handshake flag tells when the handshake hello.random
is set and can be used later to decide if we have the correct
keys.
This commit is contained in:
Jarno Lamsa 2019-12-17 15:57:41 +02:00
parent b57d7fd568
commit 98801af26b
2 changed files with 34 additions and 7 deletions
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23
library/ssl_cli.c
View file

@ -687,7 +687,7 @@ static int ssl_generate_random( mbedtls_ssl_context *ssl )
#if defined(MBEDTLS_HAVE_TIME) #if defined(MBEDTLS_HAVE_TIME)
mbedtls_time_t t; mbedtls_time_t t;
#endif #endif
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_UNSET;
/* /*
* When responding to a verify request, MUST reuse random (RFC 6347 4.2.1) * When responding to a verify request, MUST reuse random (RFC 6347 4.2.1)
*/ */
@ -713,13 +713,19 @@ static int ssl_generate_random( mbedtls_ssl_context *ssl )
p += 4; p += 4;
#endif /* MBEDTLS_HAVE_TIME */ #endif /* MBEDTLS_HAVE_TIME */
if( ( ret = mbedtls_ssl_conf_get_frng( ssl->conf ) ret = mbedtls_ssl_conf_get_frng( ssl->conf )
( mbedtls_ssl_conf_get_prng( ssl->conf ), p, 28 ) ) != 0 ) ( mbedtls_ssl_conf_get_prng( ssl->conf ), p, 28 );
if( ret == 0 )
{ {
return( ret ); mbedtls_platform_enforce_volatile_reads();
if( ret == 0 )
{
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_SET;
return( 0 );
}
} }
return( 0 ); return( ret );
} }
/** /**
@ -1719,8 +1725,15 @@ static int ssl_parse_server_hello( mbedtls_ssl_context *ssl )
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu", MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu",
(unsigned long)mbedtls_platform_get_uint32_be( &buf[2] ) ) ); (unsigned long)mbedtls_platform_get_uint32_be( &buf[2] ) ) );
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_UNSET;
mbedtls_platform_memcpy( ssl->handshake->randbytes + 32, buf + 2, 32 ); mbedtls_platform_memcpy( ssl->handshake->randbytes + 32, buf + 2, 32 );
if( mbedtls_platform_memcmp( ssl->handshake->randbytes + 32, buf + 2, 32 ) == 0 )
{
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_SET;
}
n = buf[34]; n = buf[34];
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 2, 32 ); MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 2, 32 );

18
library/ssl_srv.c
View file

@ -1223,8 +1223,14 @@ static int ssl_parse_client_hello_v2( mbedtls_ssl_context *ssl )
mbedtls_platform_memcpy( ssl->session_negotiate->id, p, ssl->session_negotiate->id_len ); mbedtls_platform_memcpy( ssl->session_negotiate->id, p, ssl->session_negotiate->id_len );
p += sess_len; p += sess_len;
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_UNSET;
memset( ssl->handshake->randbytes, 0, 64 ); memset( ssl->handshake->randbytes, 0, 64 );
mbedtls_platform_memcpy( ssl->handshake->randbytes + 32 - chal_len, p, chal_len ); mbedtls_platform_memcpy( ssl->handshake->randbytes + 32 - chal_len, p, chal_len );
if( mbedtls_platform_memcmp( ssl->handshake->randbytes + 32 - chal_len, p, chal_len ) == 0 )
{
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_SET;
}
/* /*
* Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV * Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV
@ -1717,10 +1723,14 @@ read_record_header:
/* /*
* Save client random (inc. Unix time) * Save client random (inc. Unix time)
*/ */
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_UNSET;
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes", buf + 2, 32 ); MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes", buf + 2, 32 );
mbedtls_platform_memcpy( ssl->handshake->randbytes, buf + 2, 32 ); mbedtls_platform_memcpy( ssl->handshake->randbytes, buf + 2, 32 );
if( mbedtls_platform_memcmp( ssl->handshake->randbytes, buf + 2, 32 ) == 0 )
{
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_SET;
}
/* /*
* Check the session ID length and save session ID * Check the session ID length and save session ID
*/ */
@ -2814,8 +2824,12 @@ static int ssl_write_server_hello( mbedtls_ssl_context *ssl )
} }
p += 28; p += 28;
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_UNSET;
mbedtls_platform_memcpy( ssl->handshake->randbytes + 32, buf + 6, 32 ); mbedtls_platform_memcpy( ssl->handshake->randbytes + 32, buf + 6, 32 );
if( mbedtls_platform_memcmp( ssl->handshake->randbytes + 32, buf + 6, 32 ) == 0 )
{
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_SET;
}
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 6, 32 ); MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 6, 32 );