2 files changed, 47 insertions, 20 deletions

diff --git a/src/lib/libcrypto/man/X509_NAME_get_index_by_NID.3 b/src/lib/libcrypto/man/X509_NAME_get_index_by_NID.3
index 71dd98ce46..19a123a4ac 100644
--- a/src/lib/libcrypto/man/X509_NAME_get_index_by_NID.3
+++ b/src/lib/libcrypto/man/X509_NAME_get_index_by_NID.3
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: X509_NAME_get_index_by_NID.3,v 1.13 2022/07/02 17:09:09 jsing Exp $
+.\"     $OpenBSD: X509_NAME_get_index_by_NID.3,v 1.14 2023/05/02 14:13:05 beck Exp $
 .\"     OpenSSL aebb9aac Jul 19 09:27:53 2016 -0400
 .\"
 .\" This file was written by Dr. Stephen Henson <steve@openssl.org>.
@@ -49,7 +49,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 .\" OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: July 2 2022 $
+.Dd $Mdocdate: May 2 2023 $
 .Dt X509_NAME_GET_INDEX_BY_NID 3
 .Os
 .Sh NAME
@@ -136,22 +136,32 @@ run from 0 to
 .Fn X509_NAME_get_text_by_NID
 and
 .Fn X509_NAME_get_text_by_OBJ
-retrieve the "text" from the first entry in
+retrieve the bytes encoded as UTF-8 from the first entry in
 .Fa name
 which matches
 .Fa nid
 or
 .Fa obj .
-At most
-.Fa len
-bytes will be written and the text written to
-.Fa buf
-will be NUL terminated.
 If
 .Fa buf
 is
 .Dv NULL ,
 nothing is written, but the return value is calculated as usual.
+If
+.Fa buf
+is not
+.Dv NULL ,
+no more than
+.Fa len
+bytes will be written and the text written to
+.Fa buf
+will be NUL terminated.
+.Pp
+Nothing is written and it is a failure if
+.Fa len
+is not large enough to hold the NUL byte terminated UTF-8 encoding of
+the text, or if the UTF-8 encoding ot the text would contins a NUL
+byte.
 .Pp
 All relevant
 .Dv NID_*
@@ -189,8 +199,8 @@ if the index is invalid.
 .Fn X509_NAME_get_text_by_NID
 and
 .Fn X509_NAME_get_text_by_OBJ
-return the length of the output string written, not counting the
-terminating NUL, or -1 if no match is found.
+return the length of the output UTF-8 string written, not counting the
+terminating NUL, or -1 in the case of an error or no match being found.
 .Pp
 In some cases of failure of
 .Fn X509_NAME_get_index_by_NID
diff --git a/src/lib/libcrypto/x509/x509name.c b/src/lib/libcrypto/x509/x509name.c
index a6e4dbef89..3c9e224c1b 100644
--- a/src/lib/libcrypto/x509/x509name.c
+++ b/src/lib/libcrypto/x509/x509name.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: x509name.c,v 1.31 2023/02/16 08:38:17 tb Exp $ */
+/* $OpenBSD: x509name.c,v 1.32 2023/05/02 14:13:05 beck Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -66,6 +66,7 @@
 #include <openssl/stack.h>
 #include <openssl/x509.h>
 
+#include "bytestring.h"
 #include "x509_local.h"
 
 int
@@ -84,21 +85,37 @@ int
 X509_NAME_get_text_by_OBJ(X509_NAME *name, const ASN1_OBJECT *obj, char *buf,
     int len)
 {
-        int i;
+        unsigned char *text = NULL;
         ASN1_STRING *data;
+        int i, text_len;
+        int ret = -1;
+        CBS cbs;
 
         i = X509_NAME_get_index_by_OBJ(name, obj, -1);
         if (i < 0)
-                return (-1);
+                goto err;
         data = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(name, i));
-        i = (data->length > (len - 1)) ? (len - 1) : data->length;
-        if (buf == NULL)
-                return (data->length);
-        if (i >= 0) {
-                memcpy(buf, data->data, i);
-                buf[i] = '\0';
+        /*
+         * Fail if we cannot encode as UTF-8, or if the UTF-8 encoding of the
+         * string contains a 0 byte, because mortal callers seldom handle the
+         * length difference correctly
+         */
+        if ((text_len = ASN1_STRING_to_UTF8(&text, data)) < 0)
+                goto err;
+        CBS_init(&cbs, text, text_len);
+        if (CBS_contains_zero_byte(&cbs))
+                goto err;
+        /* We still support the "pass NULL to find out how much" API */
+        if (buf != NULL) {
+                if (!CBS_write_bytes(&cbs, buf, len - 1, NULL))
+                        goto err;
+                /* It must be a C string */
+                buf[text_len] = '\0';
         }
-        return (i);
+        ret = text_len;
+ err:
+        free(text);
+        return (ret);
 }
 LCRYPTO_ALIAS(X509_NAME_get_text_by_OBJ);