yuzu/mbedtls
1
0
Fork 0
mirror of https://github.com/yuzu-emu/mbedtls.git synced 2025-03-04 18:59:44 +00:00
Code Issues Packages Projects Releases Wiki Activity

Zeroize internal buffers and variables in PKCS and SHA

Browse source 
Zeroising of local buffers and variables which are used for calculations in
mbedtls_pkcs5_pbkdf2_hmac() and mbedtls_internal_sha*_process() functions
to erase sensitive data from memory.
Checked all function for possible missing zeroisation in PKCS and SHA.

Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>
This commit is contained in:
gabor-mezei-arm 2020-07-30 16:41:25 +02:00
parent d4c464ff22
commit 461c5a89df
No known key found for this signature in database
GPG key ID: 106F5A41ECC305BD
5 changed files with 42 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
ChangeLog.d/zeroizations_of_sensitive_data_in_PKCS5_and_SHA.txt Normal file
View file

@ -0,0 +1,5 @@
Security
* Zeroising of local buffers and variables which are used for calculations
in mbedtls_pkcs5_pbkdf2_hmac() and mbedtls_internal_sha*_process()
functions to erase sensitive data from memory. Reported by
Johan Malmgren and Johan Uppman Bruce from Sectra.

9
library/pkcs5.c
View file

@ -79,6 +79,11 @@
#define mbedtls_printf printf #define mbedtls_printf printf
#endif #endif
/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize( void *v, size_t n ) {
volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
}
#if defined(MBEDTLS_ASN1_PARSE_C) #if defined(MBEDTLS_ASN1_PARSE_C)
static int pkcs5_parse_pbkdf2_params( const mbedtls_asn1_buf *params, static int pkcs5_parse_pbkdf2_params( const mbedtls_asn1_buf *params,
mbedtls_asn1_buf *salt, int *iterations, mbedtls_asn1_buf *salt, int *iterations,
@ -312,6 +317,10 @@ int mbedtls_pkcs5_pbkdf2_hmac( mbedtls_md_context_t *ctx, const unsigned char *p
break; break;
} }
/* Zeroise buffers to clear sensitive data from memory. */
mbedtls_zeroize( work, MBEDTLS_MD_MAX_SIZE );
mbedtls_zeroize( md1, MBEDTLS_MD_MAX_SIZE );
return( 0 ); return( 0 );
} }

9
library/sha1.c
View file

@ -300,6 +300,15 @@ int mbedtls_internal_sha1_process( mbedtls_sha1_context *ctx,
ctx->state[3] += D; ctx->state[3] += D;
ctx->state[4] += E; ctx->state[4] += E;
/* Zeroise buffers and variables to clear sensitive data from memory. */
mbedtls_zeroize( &A, sizeof( A ) );
mbedtls_zeroize( &B, sizeof( B ) );
mbedtls_zeroize( &C, sizeof( C ) );
mbedtls_zeroize( &D, sizeof( D ) );
mbedtls_zeroize( &E, sizeof( E ) );
mbedtls_zeroize( &W, sizeof( W ) );
mbedtls_zeroize( &temp, sizeof( temp ) );
return( 0 ); return( 0 );
} }

6
library/sha256.c
View file

@ -269,6 +269,12 @@ int mbedtls_internal_sha256_process( mbedtls_sha256_context *ctx,
for( i = 0; i < 8; i++ ) for( i = 0; i < 8; i++ )
ctx->state[i] += A[i]; ctx->state[i] += A[i];
/* Zeroise buffers and variables to clear sensitive data from memory. */
mbedtls_zeroize( &A, sizeof( A ) );
mbedtls_zeroize( &W, sizeof( W ) );
mbedtls_zeroize( &temp1, sizeof( temp1 ) );
mbedtls_zeroize( &temp2, sizeof( temp2 ) );
return( 0 ); return( 0 );
} }

13
library/sha512.c
View file

@ -300,6 +300,19 @@ int mbedtls_internal_sha512_process( mbedtls_sha512_context *ctx,
ctx->state[6] += G; ctx->state[6] += G;
ctx->state[7] += H; ctx->state[7] += H;
/* Zeroise buffers and variables to clear sensitive data from memory. */
mbedtls_zeroize( &A, sizeof( A ) );
mbedtls_zeroize( &B, sizeof( B ) );
mbedtls_zeroize( &C, sizeof( C ) );
mbedtls_zeroize( &D, sizeof( D ) );
mbedtls_zeroize( &E, sizeof( E ) );
mbedtls_zeroize( &F, sizeof( F ) );
mbedtls_zeroize( &G, sizeof( G ) );
mbedtls_zeroize( &H, sizeof( H ) );
mbedtls_zeroize( &W, sizeof( W ) );
mbedtls_zeroize( &temp1, sizeof( temp1 ) );
mbedtls_zeroize( &temp2, sizeof( temp2 ) );
return( 0 ); return( 0 );
} }