Zeroize internal buffers and variables in MD hashes

Zeroising of local buffers and variables which are used for calculations in
mbedtls_internal_md*_process() and mbedtls_internal_ripemd160_process()
functions to erase sensitive data from memory.
Checked all function for possible missing zeroisation in MD.

Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>
This commit is contained in:
gabor-mezei-arm 2020-08-19 14:03:06 +02:00
parent 4553dd46d6
commit d1c98fcf5e
No known key found for this signature in database
GPG Key ID: 106F5A41ECC305BD
5 changed files with 32 additions and 1 deletions

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@ -1,5 +1,6 @@
Security
* Zeroising of local buffers and variables which are used for calculations
in mbedtls_pkcs5_pbkdf2_hmac() and mbedtls_internal_sha*_process()
in mbedtls_pkcs5_pbkdf2_hmac(), mbedtls_internal_sha*_process(),
mbedtls_internal_md*_process() and mbedtls_internal_ripemd160_process()
functions to erase sensitive data from memory. Reported by
Johan Malmgren and Johan Uppman Bruce from Sectra.

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@ -149,6 +149,9 @@ int mbedtls_internal_md2_process( mbedtls_md2_context *ctx )
t = ctx->cksum[i];
}
/* Zeroise variables to clear sensitive data from memory. */
mbedtls_platform_zeroize( &t, sizeof( t ) );
return( 0 );
}

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@ -231,6 +231,13 @@ int mbedtls_internal_md4_process( mbedtls_md4_context *ctx,
ctx->state[2] += C;
ctx->state[3] += D;
/* Zeroise variables to clear sensitive data from memory. */
mbedtls_platform_zeroize( &X, sizeof( X ) );
mbedtls_platform_zeroize( &A, sizeof( A ) );
mbedtls_platform_zeroize( &B, sizeof( B ) );
mbedtls_platform_zeroize( &C, sizeof( C ) );
mbedtls_platform_zeroize( &D, sizeof( D ) );
return( 0 );
}

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@ -237,6 +237,13 @@ int mbedtls_internal_md5_process( mbedtls_md5_context *ctx,
ctx->state[2] += C;
ctx->state[3] += D;
/* Zeroise variables to clear sensitive data from memory. */
mbedtls_platform_zeroize( &X, sizeof( X ) );
mbedtls_platform_zeroize( &A, sizeof( A ) );
mbedtls_platform_zeroize( &B, sizeof( B ) );
mbedtls_platform_zeroize( &C, sizeof( C ) );
mbedtls_platform_zeroize( &D, sizeof( D ) );
return( 0 );
}

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@ -300,6 +300,19 @@ int mbedtls_internal_ripemd160_process( mbedtls_ripemd160_context *ctx,
ctx->state[4] = ctx->state[0] + B + Cp;
ctx->state[0] = C;
/* Zeroise variables to clear sensitive data from memory. */
mbedtls_platform_zeroize( &A, sizeof( A ) );
mbedtls_platform_zeroize( &B, sizeof( B ) );
mbedtls_platform_zeroize( &C, sizeof( C ) );
mbedtls_platform_zeroize( &D, sizeof( D ) );
mbedtls_platform_zeroize( &E, sizeof( E ) );
mbedtls_platform_zeroize( &Ap, sizeof( Ap ) );
mbedtls_platform_zeroize( &Bp, sizeof( Bp ) );
mbedtls_platform_zeroize( &Cp, sizeof( Cp ) );
mbedtls_platform_zeroize( &Dp, sizeof( Dp ) );
mbedtls_platform_zeroize( &Ep, sizeof( Ep ) );
mbedtls_platform_zeroize( &X, sizeof( X ) );
return( 0 );
}