Add some documentation for X509_gmtime_adj()

Other very similar functions were documented, but this one was missing.

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18974)

2 files changed, 21 insertions, 17 deletions

diff --git a/doc/man3/X509_cmp_time.pod b/doc/man3/X509_cmp_time.pod
index 73ef9e3fbc..30a09f25f9 100644
--- a/doc/man3/X509_cmp_time.pod
+++ b/doc/man3/X509_cmp_time.pod
@@ -3,7 +3,7 @@
 =head1 NAME
 
 X509_cmp_time, X509_cmp_current_time, X509_cmp_timeframe,
-X509_time_adj, X509_time_adj_ex
+X509_time_adj, X509_time_adj_ex, X509_gmtime_adj
 - X509 time functions
 
 =head1 SYNOPSIS
@@ -15,36 +15,41 @@ X509_time_adj, X509_time_adj_ex
  ASN1_TIME *X509_time_adj(ASN1_TIME *asn1_time, long offset_sec, time_t *in_tm);
  ASN1_TIME *X509_time_adj_ex(ASN1_TIME *asn1_time, int offset_day, long
                              offset_sec, time_t *in_tm);
+ ASN1_TIME *X509_gmtime_adj(ASN1_TIME *asn1_time, long offset_sec);
 
 =head1 DESCRIPTION
 
-X509_cmp_time() compares the ASN1_TIME in B<asn1_time> with the time
+X509_cmp_time() compares the ASN1_TIME in I<asn1_time> with the time
 in <in_tm>.
 
 X509_cmp_current_time() compares the ASN1_TIME in
-B<asn1_time> with the current time, expressed as time_t.
+I<asn1_time> with the current time, expressed as time_t.
 
 X509_cmp_timeframe() compares the given time period with the reference time
-included in the verification parameters B<vpm> if they are not NULL and contain
+included in the verification parameters I<vpm> if they are not NULL and contain
 B<X509_V_FLAG_USE_CHECK_TIME>; else the current time is used as reference time.
 
-X509_time_adj_ex() sets the ASN1_TIME structure B<asn1_time> to the time
-B<offset_day> and B<offset_sec> after B<in_tm>.
+X509_time_adj_ex() sets the ASN1_TIME structure I<asn1_time> to the time
+I<offset_day> and I<offset_sec> after I<in_tm>.
 
-X509_time_adj() sets the ASN1_TIME structure B<asn1_time> to the time
-B<offset_sec> after B<in_tm>. This method can only handle second
+X509_time_adj() sets the ASN1_TIME structure I<asn1_time> to the time
+I<offset_sec> after I<in_tm>. This method can only handle second
 offsets up to the capacity of long, so the newer X509_time_adj_ex()
 API should be preferred.
 
-In both methods, if B<asn1_time> is NULL, a new ASN1_TIME structure
+In both methods, if I<asn1_time> is NULL, a new ASN1_TIME structure
 is allocated and returned.
 
-In all methods, if B<in_tm> is NULL, the current time, expressed as
+In all methods, if I<in_tm> is NULL, the current time, expressed as
 time_t, is used.
 
-B<asn1_time> must satisfy the ASN1_TIME format mandated by RFC 5280,
+I<asn1_time> must satisfy the ASN1_TIME format mandated by RFC 5280,
 i.e., its format must be either YYMMDDHHMMSSZ or YYYYMMDDHHMMSSZ.
 
+X509_gmtime_adj() sets the ASN1_TIME structure I<asn1_time> to the time
+I<offset_sec> after the current time. It is equivalent to calling
+X509_time_adj() with the last parameter as NULL.
+
 =head1 BUGS
 
 Unlike many standard comparison functions, X509_cmp_time() and
@@ -52,11 +57,11 @@ X509_cmp_current_time() return 0 on error.
 
 =head1 RETURN VALUES
 
-X509_cmp_time() and X509_cmp_current_time() return -1 if B<asn1_time>
-is earlier than, or equal to, B<in_tm> (resp. current time), and 1
+X509_cmp_time() and X509_cmp_current_time() return -1 if I<asn1_time>
+is earlier than, or equal to, I<in_tm> (resp. current time), and 1
 otherwise. These methods return 0 on error.
 
-X509_cmp_timeframe() returns 0 if B<vpm> is not NULL and the verification
+X509_cmp_timeframe() returns 0 if I<vpm> is not NULL and the verification
 parameters do not contain B<X509_V_FLAG_USE_CHECK_TIME>
 but do contain B<X509_V_FLAG_NO_CHECK_TIME>. Otherwise it returns
 1 if the end time is not NULL and the reference time (which has determined as
@@ -64,8 +69,8 @@ stated above) is past the end time, -1 if the start time is not NULL and the
 reference time is before, else 0 to indicate that the reference time is in range
 (implying that the end time is not before the start time if both are present).
 
-X509_time_adj() and X509_time_adj_ex() return a pointer to the updated
-ASN1_TIME structure, and NULL on error.
+X509_time_adj(), X509_time_adj_ex() and X509_gmtime_adj() return a pointer to
+the updated ASN1_TIME structure, and NULL on error.
 
 =head1 HISTORY
 
diff --git a/util/missingcrypto.txt b/util/missingcrypto.txt
index a0937d4d98..af8a57fa2c 100644
--- a/util/missingcrypto.txt
+++ b/util/missingcrypto.txt
@@ -1324,7 +1324,6 @@ X509_get_default_cert_file_env(3)
 X509_get_default_private_dir(3)
 X509_get_pubkey_parameters(3)
 X509_get_signature_type(3)
-X509_gmtime_adj(3)
 X509_issuer_and_serial_hash(3)
 X509_issuer_name_hash(3)
 X509_issuer_name_hash_old(3)