diff --git a/library/pk_wrap.c b/library/pk_wrap.c index 1b626c75a..9fc7e22b9 100644 --- a/library/pk_wrap.c +++ b/library/pk_wrap.c @@ -523,14 +523,6 @@ static int extract_ecdsa_sig( unsigned char **p, const unsigned char *end, int ret; size_t tmp_size; - if( ( end - *p ) < 1 ) - { - return( MBEDTLS_ERR_ASN1_OUT_OF_DATA ); - } - - if( sig == NULL ) - return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); - if( ( ret = mbedtls_asn1_get_tag( p, end, &tmp_size, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) return( ret ); @@ -562,7 +554,7 @@ static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg, psa_algorithm_t psa_sig_md, psa_md; psa_ecc_curve_t curve = mbedtls_psa_translate_ecc_group( ( (mbedtls_ecdsa_context *) ctx )->grp.id ); - size_t signature_part_size = ( ( (mbedtls_ecdsa_context *) ctx ) ->grp.nbits + 7 ) / 8; + const size_t signature_part_size = ( ( (mbedtls_ecdsa_context *) ctx )->grp.nbits + 7 ) / 8; if( curve == 0 ) return( MBEDTLS_ERR_PK_BAD_INPUT_DATA ); @@ -599,19 +591,26 @@ static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg, goto cleanup; } - /* Reuse the buffer of an already imported key */ + /* We don't need the exported key anymore and can + * reuse its buffer for signature extraction. */ if( 2 * signature_part_size > sizeof( buf ) ) { ret = MBEDTLS_ERR_PK_BAD_INPUT_DATA; goto cleanup; } - if( ( ret = extract_ecdsa_sig( &p, p + sig_len, buf, + if( ( ret = extract_ecdsa_sig( &p, sig + sig_len, buf, signature_part_size ) ) != 0 ) { goto cleanup; } + if( p != sig + sig_len ) + { + ret = MBEDTLS_ERR_PK_SIG_LEN_MISMATCH; + goto cleanup; + } + if( psa_asymmetric_verify( key_slot, psa_sig_md, hash, hash_len, buf, 2 * signature_part_size )