Commit 51e8f70ba3 for openssl.org

commit 51e8f70ba30b92e8faddbb0620666b835fed5a41
Author: Norbert Pocs <norbertp@openssl.org>
Date:   Thu Dec 11 12:38:16 2025 +0100

    Harden ASN1_mbstring_ncopy

    Reported by Murali Aniruddhan

    Signed-off-by: Norbert Pocs <norbertp@openssl.org>

    Reviewed-by: Nikola Pajkovsky <nikolap@openssl.org>
    Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
    (Merged from https://github.com/openssl/openssl/pull/29376)

diff --git a/crypto/asn1/a_mbstr.c b/crypto/asn1/a_mbstr.c
index b7a5284fa5..7be233db5e 100644
--- a/crypto/asn1/a_mbstr.c
+++ b/crypto/asn1/a_mbstr.c
@@ -123,7 +123,10 @@ int ASN1_mbstring_ncopy(ASN1_STRING **out, const unsigned char *in, int len,
         return -1;
     }

-    /* Now work out output format and string type */
+    /*
+     * Now work out output format and string type.
+     * These checks should be in sync with the checks in type_str.
+     */
     outform = MBSTRING_ASC;
     if (mask & B_ASN1_NUMERICSTRING)
         str_type = V_ASN1_NUMERICSTRING;
@@ -191,7 +194,11 @@ int ASN1_mbstring_ncopy(ASN1_STRING **out, const unsigned char *in, int len,

     case MBSTRING_UTF8:
         outlen = 0;
-        traverse_string(in, len, inform, out_utf8, &outlen);
+        ret = traverse_string(in, len, inform, out_utf8, &outlen);
+        if (ret < 0) {
+            ERR_raise(ERR_LIB_ASN1, ASN1_R_INVALID_UTF8STRING);
+            return -1;
+        }
         cpyfunc = cpy_utf8;
         break;
     }
@@ -286,9 +293,29 @@ static int out_utf8(unsigned long value, void *arg)

 static int type_str(unsigned long value, void *arg)
 {
-    unsigned long types = *((unsigned long *)arg);
+    unsigned long usable_types = *((unsigned long *)arg);
+    unsigned long types = usable_types;
     const int native = value > INT_MAX ? INT_MAX : ossl_fromascii(value);

+    /*
+     * Clear out all the types which are not checked later. If any of those
+     * is present in the mask, then the UTF8 type will be added and checked
+     * below.
+     */
+    types &= B_ASN1_NUMERICSTRING | B_ASN1_PRINTABLESTRING
+        | B_ASN1_IA5STRING | B_ASN1_T61STRING | B_ASN1_BMPSTRING
+        | B_ASN1_UNIVERSALSTRING | B_ASN1_UTF8STRING;
+
+    /*
+     * If any other types were in the input mask, they're effectively treated
+     * as UTF8
+     */
+    if (types != usable_types)
+        types |= B_ASN1_UTF8STRING;
+
+    /*
+     * These checks should be in sync with ASN1_mbstring_ncopy.
+     */
     if ((types & B_ASN1_NUMERICSTRING) && !(ossl_isdigit(native) || native == ' '))
         types &= ~B_ASN1_NUMERICSTRING;
     if ((types & B_ASN1_PRINTABLESTRING) && !ossl_isasn1print(native))
@@ -356,6 +383,8 @@ static int cpy_utf8(unsigned long value, void *arg)
     p = arg;
     /* We already know there is enough room so pass 0xff as the length */
     ret = UTF8_putc(*p, 0xff, value);
+    if (ret < 0)
+        return ret;
     *p += ret;
     return 1;
 }
diff --git a/test/asn1_internal_test.c b/test/asn1_internal_test.c
index e08e2a11be..56af2b369b 100644
--- a/test/asn1_internal_test.c
+++ b/test/asn1_internal_test.c
@@ -554,6 +554,22 @@ err:
     return ret;
 }

+static int test_mbstring_ncopy(void)
+{
+    ASN1_STRING *str = NULL;
+    const unsigned char in[] = { 0xFF, 0xFE, 0xFF, 0xFE };
+    int inlen = 4;
+    int inform = MBSTRING_UNIV;
+
+    if (!TEST_int_eq(ASN1_mbstring_ncopy(&str, in, inlen, inform, B_ASN1_GENERALSTRING, 0, 0), -1)
+        || !TEST_int_eq(ASN1_mbstring_ncopy(&str, in, inlen, inform, B_ASN1_VISIBLESTRING, 0, 0), -1)
+        || !TEST_int_eq(ASN1_mbstring_ncopy(&str, in, inlen, inform, B_ASN1_VIDEOTEXSTRING, 0, 0), -1)
+        || !TEST_int_eq(ASN1_mbstring_ncopy(&str, in, inlen, inform, B_ASN1_GENERALIZEDTIME, 0, 0), -1))
+        return 0;
+
+    return 1;
+}
+
 int setup_tests(void)
 {
     ADD_TEST(test_tbl_standard);
@@ -565,5 +581,6 @@ int setup_tests(void)
     ADD_TEST(test_obj_nid_undef);
     ADD_TEST(posix_time_test);
     ADD_TEST(test_asn1_time_tm_conversions);
+    ADD_TEST(test_mbstring_ncopy);
     return 1;
 }