Add malloc failure checks

Add some missing checks for memory allocation failures in ca app.
Reviewed-by: NTim Hudson <tjh@openssl.org>

apps/ca.c

@@ -2809,6 +2809,11 @@ int unpack_revinfo(ASN1_TIME **prevtm, int *preason, ASN1_OBJECT **phold,
     ASN1_GENERALIZEDTIME *comp_time = NULL;
     tmp = BUF_strdup(str);
 
+    if(!tmp) {
+        BIO_printf(bio_err, "memory allocation failure\n");
+        goto err;
+    }
+
     p = strchr(tmp, ',');
 
     rtime_str = tmp;
@@ -2826,6 +2831,10 @@ int unpack_revinfo(ASN1_TIME **prevtm, int *preason, ASN1_OBJECT **phold,
 
     if (prevtm) {
         *prevtm = ASN1_UTCTIME_new();
+        if(!*prevtm) {
+            BIO_printf(bio_err, "memory allocation failure\n");
+            goto err;
+        }
         if (!ASN1_UTCTIME_set_string(*prevtm, rtime_str)) {
             BIO_printf(bio_err, "invalid revocation date %s\n", rtime_str);
             goto err;
@@ -2866,6 +2875,10 @@ int unpack_revinfo(ASN1_TIME **prevtm, int *preason, ASN1_OBJECT **phold,
                 goto err;
             }
             comp_time = ASN1_GENERALIZEDTIME_new();
+            if(!comp_time) {
+                BIO_printf(bio_err, "memory allocation failure\n");
+                goto err;
+            }
             if (!ASN1_GENERALIZEDTIME_set_string(comp_time, arg_str)) {
                 BIO_printf(bio_err, "invalid compromised time %s\n", arg_str);
                 goto err;