From 15fdb7f9ff8985f236f78dbfef3e6201cba295b7 Mon Sep 17 00:00:00 2001 From: Andres AG Date: Mon, 26 Sep 2016 09:52:41 +0100 Subject: [PATCH] Fix 1 byte overread in mbedtls_asn1_get_int() --- ChangeLog | 5 ++++- library/asn1parse.c | 2 +- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/ChangeLog b/ChangeLog index 61603c7d5..2609aeefd 100644 --- a/ChangeLog +++ b/ChangeLog @@ -10,7 +10,10 @@ Bugfix when GCM is used. #441 * Fix for key exchanges based on ECDH-RSA or ECDH-ECDSA which weren't enabled unless others were also present. Found by David Fernandez. #428 - * Fixed configuration of debug output in cert_app sample program. + * Fixed cert_app sample program for debug output and for use when no root + certificates are provided. + * Fix conditional statement that would cause a 1 byte overread in + mbedtls_asn1_get_int(). Found and fixed by Guido Vranken. * Fixed the sample applications gen_key.c, cert_req.c and cert_write.c for builds where the configuration POLARSSL_PEM_WRITE_C is not defined. Found by inestlerode. #559. diff --git a/library/asn1parse.c b/library/asn1parse.c index e4f46eb0a..8c167df5f 100644 --- a/library/asn1parse.c +++ b/library/asn1parse.c @@ -154,7 +154,7 @@ int asn1_get_int( unsigned char **p, if( ( ret = asn1_get_tag( p, end, &len, ASN1_INTEGER ) ) != 0 ) return( ret ); - if( len > sizeof( int ) || ( **p & 0x80 ) != 0 ) + if( len == 0 || len > sizeof( int ) || ( **p & 0x80 ) != 0 ) return( POLARSSL_ERR_ASN1_INVALID_LENGTH ); *val = 0;