From: Beat Bolli <dev+git@drbeat.li>
Date: Wed, 11 Mar 2026 22:00:25 GMT
Subject: Re: [PATCH 3/4] imap-send: remove two string length checks
Message-ID: <d9338d30-3e73-4cb7-9f8f-cc1ce21c9de4@drbeat.li>
In-Reply-To: <xmqq4immp56h.fsf@gitster.g>

Hi Junio

On 11.03.2026 19:55, Junio C Hamano wrote:
> Beat Bolli <dev+git@drbeat.li> writes:
> 
>> At this point, these two checks verify that the ASN1_STRINGs are
>> internally consistent. This may have been ok when the fields were
>> accessed directly, but now that the API is used, is unnecessary.
>>
>> Remove the two checks.
> 
> Oswald already gave a similar comment, but
> 
>   * I am not sure what you meant by "ok" in "may have been ok".  Do
>     you mean "with raw access to the fields, it may have been made
>     send to ensure validity of ASN1_STRING"?
> 
>   * I am also not sure what you meant by "now that the API is used".
>     Who in the code uses which API function so that we do not have to
>     do our sanity checking?
> 
>     The call to host_matches() that these extra checks protect are
>     still passing raw "const char *" in this step, and the change to
>     pass ASN1_STRING does not happen until [4/4], so you did not mean
>     host_matches().  I am not sure what it is.
>     
> Thanks.

I didn't realize that the strlen() comparison was meant to check for 
embedded NULs. I'll send v2 shortly that keeps this check.

Cheers, Beat


>> Signed-off-by: Beat Bolli <dev+git@drbeat.li>
>> ---
>>   imap-send.c | 5 +----
>>   1 file changed, 1 insertion(+), 4 deletions(-)
>>
>> diff --git a/imap-send.c b/imap-send.c
>> index 2a904314dd..2bb0003f08 100644
>> --- a/imap-send.c
>> +++ b/imap-send.c
>> @@ -253,8 +253,6 @@ static int verify_hostname(X509 *cert, const char *hostname)
>>   			ASN1_STRING *subj_alt_str = GENERAL_NAME_get0_value(subj_alt_name, &ntype);
>>   
>>   			if (ntype == GEN_DNS &&
>> -			    strlen((const char *)ASN1_STRING_get0_data(subj_alt_str)) ==
>> -				    ASN1_STRING_length(subj_alt_str) &&
>>   			    host_matches(hostname, (const char *)ASN1_STRING_get0_data(subj_alt_str)))
>>   				found = 1;
>>   		}
>> @@ -270,8 +268,7 @@ static int verify_hostname(X509 *cert, const char *hostname)
>>   	    (cname_entry = X509_NAME_get_entry(subj, i)) == NULL ||
>>   	    (cname = X509_NAME_ENTRY_get_data(cname_entry)) == NULL)
>>   		return error("cannot get certificate common name");
>> -	if (strlen((const char *)ASN1_STRING_get0_data(cname)) == ASN1_STRING_length(cname) &&
>> -	    host_matches(hostname, (const char *)ASN1_STRING_get0_data(cname)))
>> +	if (host_matches(hostname, (const char *)ASN1_STRING_get0_data(cname)))
>>   		return 0;
>>   	return error("certificate owner '%s' does not match hostname '%s'",
>>   		     ASN1_STRING_get0_data(cname), hostname);