diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/auth/mbedtls/mbedtls_x509_parser.c | 39 |
1 files changed, 37 insertions, 2 deletions
diff --git a/drivers/auth/mbedtls/mbedtls_x509_parser.c b/drivers/auth/mbedtls/mbedtls_x509_parser.c index 1a6a9a75..73da9d1e 100644 --- a/drivers/auth/mbedtls/mbedtls_x509_parser.c +++ b/drivers/auth/mbedtls/mbedtls_x509_parser.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: @@ -36,6 +36,7 @@ * extensions field, such as an image hash or a public key. */ +#include <arch_helpers.h> #include <assert.h> #include <img_parser_mod.h> #include <mbedtls_common.h> @@ -64,6 +65,26 @@ static mbedtls_asn1_buf sig_alg; static mbedtls_asn1_buf signature; /* + * Clear all static temporary variables. + */ +static void clear_temp_vars(void) +{ +#define ZERO_AND_CLEAN(x) \ + do { \ + memset(&x, 0, sizeof(x)); \ + clean_dcache_range((uintptr_t)&x, sizeof(x)); \ + } while (0); + + ZERO_AND_CLEAN(tbs) + ZERO_AND_CLEAN(v3_ext); + ZERO_AND_CLEAN(pk); + ZERO_AND_CLEAN(sig_alg); + ZERO_AND_CLEAN(signature); + +#undef ZERO_AND_CLEAN +} + +/* * Get X509v3 extension * * Global variable 'v3_ext' must point to the extensions region @@ -134,7 +155,12 @@ static int get_ext(const char *oid, void **ext, unsigned int *ext_len) /* * Check the integrity of the certificate ASN.1 structure. + * * Extract the relevant data that will be used later during authentication. + * + * This function doesn't clear the static variables located on the top of this + * file in case of an error. It is only called from check_integrity(), which + * performs the cleanup if necessary. */ static int cert_parse(void *img, unsigned int img_len) { @@ -398,9 +424,18 @@ static void init(void) mbedtls_init(); } +/* + * Wrapper for cert_parse() that clears the static variables used by it in case + * of an error. + */ static int check_integrity(void *img, unsigned int img_len) { - return cert_parse(img, img_len); + int rc = cert_parse(img, img_len); + + if (rc != IMG_PARSER_OK) + clear_temp_vars(); + + return rc; } /* |