Commit c22aa33e authored by Rob Percival's avatar Rob Percival Committed by Rich Salz
Browse files

By default, allow SCT timestamps to be up to 5 minutes in the future 

As requested in
https://github.com/openssl/openssl/pull/1554#issuecomment-246371575

.

Reviewed-by: default avatarViktor Dukhovni <viktor@openssl.org>
Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1554)
parent f0f535e9

crypto/ct/ct_policy.c

+7 −1
Original line number Diff line number Diff line
@@ -17,6 +17,12 @@ 


#include "ct_locl.h"



// Number of seconds in the future that an SCT timestamp can be, by default,

// without being considered invalid. This is added to time() when setting a

// default value for CT_POLICY_EVAL_CTX.epoch_time_in_ms.

// It can be overridden by calling CT_POLICY_EVAL_CTX_set_time().

static const time_t SCT_CLOCK_DRIFT_TOLERANCE = 300;



CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new(void)

{

    CT_POLICY_EVAL_CTX *ctx = OPENSSL_zalloc(sizeof(CT_POLICY_EVAL_CTX));
@@ -27,7 +33,7 @@ CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new(void) 
    }



    // time(NULL) shouldn't ever fail, so don't bother checking for -1.

    ctx->epoch_time_in_ms = time(NULL) * 1000;

    ctx->epoch_time_in_ms = (time(NULL) + SCT_CLOCK_DRIFT_TOLERANCE) * 1000;

    return ctx;

}

doc/man3/CT_POLICY_EVAL_CTX_new.pod

+2 −2
Original line number Diff line number Diff line
@@ -68,8 +68,8 @@ CT_POLICY_EVAL_CTX. 


The SCT timestamp will be compared to this time to check whether the SCT was

issued in the future. RFC6962 states that "TLS clients MUST reject SCTs whose

timestamp is in the future". By default, this will be set to the

current time (obtained by calling time()) if possible.

timestamp is in the future". By default, this will be set to 5 minutes in the

future (e.g. (time() + 300) * 1000), to allow for clock drift.



The time should be in milliseconds since the Unix epoch.