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See http://spamassassin.org/tag/ for more details. 0.2 HEADER_FROM_DIFFERENT_DOMAINS From and EnvelopeFrom 2nd level mail domains are different 0.0 URIBL_BLOCKED ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [URIs: rfc2549.org] 0.0 SPF_NONE SPF: sender does not publish an SPF Record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.1 AWL AWL: Adjusted score from AWL reputation of From: address X-Headers-End: 1jPLoD-004cUR-S9 Subject: [Openvpn-devel] [PATCH v2 1/3] Use crypto library functions for const time memcmp when possible X-BeenThere: openvpn-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: openvpn-devel-bounces@lists.sourceforge.net X-getmail-retrieved-from-mailbox: Inbox Signed-off-by: Arne Schwabe --- src/openvpn/crypto.h | 16 +--------------- src/openvpn/crypto_mbedtls.c | 20 ++++++++++++++++++++ src/openvpn/crypto_openssl.c | 5 +++++ 3 files changed, 26 insertions(+), 15 deletions(-) diff --git a/src/openvpn/crypto.h b/src/openvpn/crypto.h index 18a86ceb..dadf0a90 100644 --- a/src/openvpn/crypto.h +++ b/src/openvpn/crypto.h @@ -528,21 +528,7 @@ void crypto_read_openvpn_key(const struct key_type *key_type, * As memcmp(), but constant-time. * Returns 0 when data is equal, non-zero otherwise. */ -static inline int -memcmp_constant_time(const void *a, const void *b, size_t size) -{ - const uint8_t *a1 = a; - const uint8_t *b1 = b; - int ret = 0; - size_t i; - - for (i = 0; i < size; i++) - { - ret |= *a1++ ^ *b1++; - } - - return ret; -} +int memcmp_constant_time(const void *a, const void *b, size_t size); static inline bool key_ctx_bi_defined(const struct key_ctx_bi *key) diff --git a/src/openvpn/crypto_mbedtls.c b/src/openvpn/crypto_mbedtls.c index 3e77fa9e..1f6a23f8 100644 --- a/src/openvpn/crypto_mbedtls.c +++ b/src/openvpn/crypto_mbedtls.c @@ -972,4 +972,24 @@ hmac_ctx_final(mbedtls_md_context_t *ctx, uint8_t *dst) ASSERT(0 == mbedtls_md_hmac_finish(ctx, dst)); } +int +memcmp_constant_time(const void *a, const void *b, size_t size) +{ + /* mbed TLS has a no const time memcmp function. + * Adapt the function mbedtls_safer_memcmp that mbedtls + * internally uses as it considers that to be safe. */ + volatile const unsigned char *A = (volatile const unsigned char *)a; + volatile const unsigned char *B = (volatile const unsigned char *)b; + volatile unsigned char diff = 0; + + for (size_t i = 0; i < size; i++) + { + /* this conversion was introduced by mbedTLS to suppress a IAR + * compiler warning. We keep it as it is. */ + unsigned char x = A[i], y = B[i]; + diff |= x ^ y; + } + + return diff; +} #endif /* ENABLE_CRYPTO_MBEDTLS */ diff --git a/src/openvpn/crypto_openssl.c b/src/openvpn/crypto_openssl.c index a81dcfd8..9e7ea0ff 100644 --- a/src/openvpn/crypto_openssl.c +++ b/src/openvpn/crypto_openssl.c @@ -1066,4 +1066,9 @@ hmac_ctx_final(HMAC_CTX *ctx, uint8_t *dst) HMAC_Final(ctx, dst, &in_hmac_len); } +int +memcmp_constant_time(const void *a, const void *b, size_t size) +{ + return CRYPTO_memcmp(a, b, size); +} #endif /* ENABLE_CRYPTO_OPENSSL */