Make internal JSON functions return error codes

Return error codes (0, ENOMEM, or EINVAL) from JSON support functions
instead of returning results directly.  This makes error handling
simpler for functions which assemble JSON objects and then return a
krb5_error_code values.  Adjust all callers.  Use shims in
export_cred.c to minimize changes there; it will be redesigned
internally in a subsequent commit.

2 files changed, 97 insertions, 75 deletions

diff --git a/src/lib/gssapi/krb5/export_cred.c b/src/lib/gssapi/krb5/export_cred.c
index 162547966..e5ffaf54a 100644
--- a/src/lib/gssapi/krb5/export_cred.c
+++ b/src/lib/gssapi/krb5/export_cred.c
@@ -44,12 +44,51 @@ add(k5_json_array array, k5_json_value v)
     return 0;
 }
 
+static inline k5_json_number
+number(long long nval)
+{
+    k5_json_number num;
+
+    return k5_json_number_create(nval, &num) ? NULL : num;
+}
+
+static inline k5_json_string
+string(const char *cstring)
+{
+    k5_json_string str;
+
+    return k5_json_string_create(cstring, &str) ? NULL : str;
+}
+
+static inline k5_json_string
+base64string(const void *data, size_t len)
+{
+    k5_json_string str;
+
+    return k5_json_string_create_base64(data, len, &str) ? NULL : str;
+}
+
+static inline k5_json_null
+null(void)
+{
+    k5_json_null n;
+
+    return k5_json_null_create(&n) ? NULL : n;
+}
+
+static inline k5_json_bool
+bool(int truth)
+{
+    k5_json_bool b;
+
+    return k5_json_bool_create(truth, &b) ? NULL : b;
+}
+
 /* Return a JSON null or string value representing str. */
 static k5_json_value
 json_optional_string(const char *str)
 {
-    return (str == NULL) ? (k5_json_value)k5_json_null_create() :
-        (k5_json_value)k5_json_string_create(str);
+    return (str == NULL) ? (k5_json_value)null() : string(str);
 }
 
 /* Return a JSON null or array value representing princ. */
@@ -60,10 +99,10 @@ json_principal(krb5_context context, krb5_principal princ)
     k5_json_string str;
 
     if (princ == NULL)
-        return k5_json_null_create();
+        return null();
     if (krb5_unparse_name(context, princ, &princname))
         return NULL;
-    str = k5_json_string_create(princname);
+    str = string(princname);
     krb5_free_unparsed_name(context, princname);
     return str;
 }
@@ -75,12 +114,11 @@ json_etypes(krb5_enctype *etypes)
     k5_json_array array;
 
     if (etypes == NULL)
-        return k5_json_null_create();
-    array = k5_json_array_create();
-    if (array == NULL)
+        return null();
+    if (k5_json_array_create(&array))
         return NULL;
     for (; *etypes != 0; etypes++) {
-        if (add(array, k5_json_number_create(*etypes)))
+        if (add(array, number(*etypes)))
             goto oom;
     }
     return array;
@@ -96,9 +134,8 @@ json_kgname(krb5_context context, krb5_gss_name_t name)
     k5_json_array array;
 
     if (name == NULL)
-        return k5_json_null_create();
-    array = k5_json_array_create();
-    if (array == NULL)
+        return null();
+    if (k5_json_array_create(&array))
         return NULL;
     if (add(array, json_principal(context, name->princ)))
         goto oom;
@@ -119,10 +156,10 @@ json_keytab(krb5_context context, krb5_keytab keytab)
     char name[1024];
 
     if (keytab == NULL)
-        return k5_json_null_create();
+        return null();
     if (krb5_kt_get_name(context, keytab, name, sizeof(name)))
         return NULL;
-    return k5_json_string_create(name);
+    return string(name);
 }
 
 /* Return a JSON null or string value representing rcache. */
@@ -133,11 +170,11 @@ json_rcache(krb5_context context, krb5_rcache rcache)
     k5_json_string str;
 
     if (rcache == NULL)
-        return k5_json_null_create();
+        return null();
     if (asprintf(&name, "%s:%s", krb5_rc_get_type(context, rcache),
                  krb5_rc_get_name(context, rcache)) < 0)
         return NULL;
-    str = k5_json_string_create(name);
+    str = string(name);
     free(name);
     return str;
 }
@@ -148,13 +185,11 @@ json_keyblock(krb5_keyblock *keyblock)
 {
     k5_json_array array;
 
-    array = k5_json_array_create();
-    if (array == NULL)
+    if (k5_json_array_create(&array))
         return NULL;
-    if (add(array, k5_json_number_create(keyblock->enctype)))
+    if (add(array, number(keyblock->enctype)))
         goto oom;
-    if (add(array, k5_json_string_create_base64(keyblock->contents,
-                                                keyblock->length)))
+    if (add(array, base64string(keyblock->contents, keyblock->length)))
         goto oom;
     return array;
 oom:
@@ -168,12 +203,11 @@ json_address(krb5_address *addr)
 {
     k5_json_array array;
 
-    array = k5_json_array_create();
-    if (array == NULL)
+    if (k5_json_array_create(&array))
         return NULL;
-    if (add(array, k5_json_number_create(addr->addrtype)))
+    if (add(array, number(addr->addrtype)))
         goto oom;
-    if (add(array, k5_json_string_create_base64(addr->contents, addr->length)))
+    if (add(array, base64string(addr->contents, addr->length)))
         goto oom;
     return array;
 oom:
@@ -188,9 +222,8 @@ json_addresses(krb5_address **addrs)
     k5_json_array array;
 
     if (addrs == NULL)
-        return k5_json_null_create();
-    array = k5_json_array_create();
-    if (array == NULL)
+        return null();
+    if (k5_json_array_create(&array))
         return NULL;
     for (; *addrs != NULL; addrs++) {
         if (add(array, json_address(*addrs))) {
@@ -207,12 +240,11 @@ json_authdata_element(krb5_authdata *ad)
 {
     k5_json_array array;
 
-    array = k5_json_array_create();
-    if (array == NULL)
+    if (k5_json_array_create(&array))
         return NULL;
-    if (add(array, k5_json_number_create(ad->ad_type)))
+    if (add(array, number(ad->ad_type)))
         goto oom;
-    if (add(array, k5_json_string_create_base64(ad->contents, ad->length)))
+    if (add(array, base64string(ad->contents, ad->length)))
         goto oom;
     return array;
 oom:
@@ -227,9 +259,8 @@ json_authdata(krb5_authdata **authdata)
     k5_json_array array;
 
     if (authdata == NULL)
-        return k5_json_null_create();
-    array = k5_json_array_create();
-    if (array == NULL)
+        return null();
+    if (k5_json_array_create(&array))
         return NULL;
     for (; *authdata != NULL; authdata++) {
         if (add(array, json_authdata_element(*authdata))) {
@@ -246,8 +277,7 @@ json_creds(krb5_context context, krb5_creds *creds)
 {
     k5_json_array array;
 
-    array = k5_json_array_create();
-    if (array == NULL)
+    if (k5_json_array_create(&array))
         return NULL;
     if (add(array, json_principal(context, creds->client)))
         goto eom;
@@ -255,25 +285,24 @@ json_creds(krb5_context context, krb5_creds *creds)
         goto eom;
     if (add(array, json_keyblock(&creds->keyblock)))
         goto eom;
-    if (add(array, k5_json_number_create(creds->times.authtime)))
+    if (add(array, number(creds->times.authtime)))
         goto eom;
-    if (add(array, k5_json_number_create(creds->times.starttime)))
+    if (add(array, number(creds->times.starttime)))
         goto eom;
-    if (add(array, k5_json_number_create(creds->times.endtime)))
+    if (add(array, number(creds->times.endtime)))
         goto eom;
-    if (add(array, k5_json_number_create(creds->times.renew_till)))
+    if (add(array, number(creds->times.renew_till)))
         goto eom;
-    if (add(array, k5_json_bool_create(creds->is_skey)))
+    if (add(array, bool(creds->is_skey)))
         goto eom;
-    if (add(array, k5_json_number_create(creds->ticket_flags)))
+    if (add(array, number(creds->ticket_flags)))
         goto eom;
     if (add(array, json_addresses(creds->addresses)))
         goto eom;
-    if (add(array, k5_json_string_create_base64(creds->ticket.data,
-                                                creds->ticket.length)))
+    if (add(array, base64string(creds->ticket.data, creds->ticket.length)))
         goto eom;
-    if (add(array, k5_json_string_create_base64(creds->second_ticket.data,
-                                                creds->second_ticket.length)))
+    if (add(array, base64string(creds->second_ticket.data,
+                                creds->second_ticket.length)))
         goto eom;
     if (add(array, json_authdata(creds->authdata)))
         goto eom;
@@ -294,8 +323,7 @@ json_ccache_contents(krb5_context context, krb5_ccache ccache)
     k5_json_array array;
     int st;
 
-    array = k5_json_array_create();
-    if (array == NULL)
+    if (k5_json_array_create(&array))
         return NULL;
 
     /* Put the principal in the first array entry. */
@@ -334,13 +362,13 @@ json_ccache(krb5_context context, krb5_ccache ccache)
     k5_json_string str;
 
     if (ccache == NULL)
-        return k5_json_null_create();
+        return null();
     if (strcmp(krb5_cc_get_type(context, ccache), "MEMORY") == 0) {
         return json_ccache_contents(context, ccache);
     } else {
         if (krb5_cc_get_full_name(context, ccache, &name))
             return NULL;
-        str = k5_json_string_create(name);
+        str = string(name);
         free(name);
         return str;
     }
@@ -352,18 +380,17 @@ json_kgcred(krb5_context context, krb5_gss_cred_id_t cred)
 {
     k5_json_array array;
 
-    array = k5_json_array_create();
-    if (array == NULL)
+    if (k5_json_array_create(&array))
         return NULL;
-    if (add(array, k5_json_number_create(cred->usage)))
+    if (add(array, number(cred->usage)))
         goto oom;
     if (add(array, json_kgname(context, cred->name)))
         goto oom;
     if (add(array, json_principal(context, cred->impersonator)))
         goto oom;
-    if (add(array, k5_json_bool_create(cred->default_identity)))
+    if (add(array, bool(cred->default_identity)))
         goto oom;
-    if (add(array, k5_json_bool_create(cred->iakerb_mech)))
+    if (add(array, bool(cred->iakerb_mech)))
         goto oom;
     /* Don't marshal cred->destroy_ccache. */
     if (add(array, json_keytab(context, cred->keytab)))
@@ -374,11 +401,11 @@ json_kgcred(krb5_context context, krb5_gss_cred_id_t cred)
         goto oom;
     if (add(array, json_keytab(context, cred->client_keytab)))
         goto oom;
-    if (add(array, k5_json_bool_create(cred->have_tgt)))
+    if (add(array, bool(cred->have_tgt)))
         goto oom;
-    if (add(array, k5_json_number_create(cred->expire)))
+    if (add(array, number(cred->expire)))
         goto oom;
-    if (add(array, k5_json_number_create(cred->refresh_time)))
+    if (add(array, number(cred->refresh_time)))
         goto oom;
     if (add(array, json_etypes(cred->req_enctypes)))
         goto oom;
@@ -414,16 +441,14 @@ krb5_gss_export_cred(OM_uint32 *minor_status, gss_cred_id_t cred_handle,
         return status;
     cred = (krb5_gss_cred_id_t)cred_handle;
 
-    array = k5_json_array_create();
-    if (array == NULL)
+    if (k5_json_array_create(&array))
         goto oom;
-    if (add(array, k5_json_string_create(CRED_EXPORT_MAGIC)))
+    if (add(array, string(CRED_EXPORT_MAGIC)))
         goto oom;
     if (add(array, json_kgcred(context, cred)))
         goto oom;
 
-    str = k5_json_encode(array);
-    if (str == NULL)
+    if (k5_json_encode(array, &str))
         goto oom;
     d = string2data(str);
     if (data_to_gss(&d, token))
diff --git a/src/lib/gssapi/krb5/import_cred.c b/src/lib/gssapi/krb5/import_cred.c
index ad9a1110e..973b9d015 100644
--- a/src/lib/gssapi/krb5/import_cred.c
+++ b/src/lib/gssapi/krb5/import_cred.c
@@ -205,8 +205,7 @@ json_to_keyblock(k5_json_value v, krb5_keyblock *keyblock)
     s = check_element(array, 1, K5_JSON_TID_STRING);
     if (s == NULL)
         return -1;
-    keyblock->contents = k5_json_string_unbase64(s, &len);
-    if (keyblock->contents == NULL)
+    if (k5_json_string_unbase64(s, &keyblock->contents, &len))
         return -1;
     keyblock->length = len;
     keyblock->magic = KV5M_KEYBLOCK;
@@ -241,8 +240,7 @@ json_to_address(k5_json_value v, krb5_address **addr_out)
     if (addr == NULL)
         return -1;
     addr->addrtype = k5_json_number_value(n);
-    addr->contents = k5_json_string_unbase64(s, &len);
-    if (addr->contents == NULL) {
+    if (k5_json_string_unbase64(s, &addr->contents, &len)) {
         free(addr);
         return -1;
     }
@@ -311,8 +309,7 @@ json_to_authdata_element(k5_json_value v, krb5_authdata **ad_out)
     if (ad == NULL)
         return -1;
     ad->ad_type = k5_json_number_value(n);
-    ad->contents = k5_json_string_unbase64(s, &len);
-    if (ad->contents == NULL) {
+    if (k5_json_string_unbase64(s, &ad->contents, &len)) {
         free(ad);
         return -1;
     }
@@ -361,6 +358,7 @@ json_to_creds(krb5_context context, k5_json_value v, krb5_creds *creds)
     k5_json_number n;
     k5_json_bool b;
     k5_json_string s;
+    unsigned char *data;
     size_t len;
 
     memset(creds, 0, sizeof(*creds));
@@ -418,17 +416,17 @@ json_to_creds(krb5_context context, k5_json_value v, krb5_creds *creds)
     s = check_element(array, 10, K5_JSON_TID_STRING);
     if (s == NULL)
         goto invalid;
-    creds->ticket.data = k5_json_string_unbase64(s, &len);
-    if (creds->ticket.data == NULL)
+    if (k5_json_string_unbase64(s, &data, &len))
         goto invalid;
+    creds->ticket.data = (char *)data;
     creds->ticket.length = len;
 
     s = check_element(array, 11, K5_JSON_TID_STRING);
     if (s == NULL)
         goto invalid;
-    creds->second_ticket.data = k5_json_string_unbase64(s, &len);
-    if (creds->second_ticket.data == NULL)
+    if (k5_json_string_unbase64(s, &data, &len))
         goto invalid;
+    creds->second_ticket.data = (char *)data;
     creds->second_ticket.length = len;
 
     if (json_to_authdata(context, k5_json_array_get(array, 12),
@@ -620,8 +618,7 @@ krb5_gss_import_cred(OM_uint32 *minor_status, gss_buffer_t token,
         *minor_status = ret;
         goto cleanup;
     }
-    v = k5_json_decode(copy);
-    if (v == NULL)
+    if (k5_json_decode(copy, &v))
         goto invalid;
 
     /* Decode the CRED_EXPORT_MAGIC array wrapper. */