From 17f32c3e0592775a2f3df6cd97792dbad327e5ab Mon Sep 17 00:00:00 2001
From: Jacob Barthelmeh <jacob@wolfssl.com>
Date: Fri, 11 Dec 2020 05:22:46 +0700
Subject: [PATCH 1/3] add strict check on name constraints with DIR alt names

---
 wolfcrypt/src/asn.c     | 58 +++++++++++++++++++++++++++++++++++++++++
 wolfssl/wolfcrypt/asn.h |  1 +
 2 files changed, 59 insertions(+)

diff --git a/wolfcrypt/src/asn.c b/wolfcrypt/src/asn.c
index 6c1d938d5..eb1491b6c 100644
--- a/wolfcrypt/src/asn.c
+++ b/wolfcrypt/src/asn.c
@@ -5090,6 +5090,8 @@ void FreeDecodedCert(DecodedCert* cert)
 #ifndef IGNORE_NAME_CONSTRAINTS
     if (cert->altEmailNames)
         FreeAltNames(cert->altEmailNames, cert->heap);
+    if (cert->altDirNames)
+        FreeAltNames(cert->altDirNames, cert->heap);
     if (cert->permittedNames)
         FreeNameSubtrees(cert->permittedNames, cert->heap);
     if (cert->excludedNames)
@@ -7684,6 +7686,26 @@ static int ConfirmNameConstraints(Signer* signer, DecodedCert* cert)
                         XMEMCMP(cert->subjectRaw, base->name,
                                                         base->nameSz) == 0) {
                         matchDir = 1;
+
+                        #ifndef WOLFSSL_NO_ASN_STRICT
+                        /* RFC 5280 section 4.2.1.10
+                           "Restrictions of the form directoryName MUST be
+                            applied to the subject field .... and to any names
+                            of type directoryName in the subjectAltName
+                            extension"
+                        */
+                        if (cert->altDirNames != NULL) {
+                            DNS_entry* cur = cert->altDirNames;
+                            while (cur != NULL) {
+                                if (XMEMCMP(cur->name, base->name, base->nameSz)
+                                        != 0) {
+                                    WOLFSSL_MSG("DIR alt name constraint err");
+                                    matchDir = 0; /* did not match */
+                                }
+                                cur = cur->next;
+                            }
+                        }
+                        #endif /* !WOLFSSL_NO_ASN_STRICT */
                     }
                     break;
                 }
@@ -7768,6 +7790,42 @@ static int DecodeAltNames(const byte* input, int sz, DecodedCert* cert)
             idx    += strLen;
         }
     #ifndef IGNORE_NAME_CONSTRAINTS
+        else if (b == (ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | ASN_DIR_TYPE)) {
+            DNS_entry* dirEntry;
+            int strLen;
+            word32 lenStartIdx = idx;
+
+            if (GetLength(input, &idx, &strLen, sz) < 0) {
+                WOLFSSL_MSG("\tfail: str length");
+                return ASN_PARSE_E;
+            }
+            length -= (idx - lenStartIdx);
+
+            dirEntry = (DNS_entry*)XMALLOC(sizeof(DNS_entry), cert->heap,
+                                        DYNAMIC_TYPE_ALTNAME);
+            if (dirEntry == NULL) {
+                WOLFSSL_MSG("\tOut of Memory");
+                return MEMORY_E;
+            }
+
+            dirEntry->type = ASN_DIR_TYPE;
+            dirEntry->name = (char*)XMALLOC(strLen + 1, cert->heap,
+                                         DYNAMIC_TYPE_ALTNAME);
+            if (dirEntry->name == NULL) {
+                WOLFSSL_MSG("\tOut of Memory");
+                XFREE(dirEntry, cert->heap, DYNAMIC_TYPE_ALTNAME);
+                return MEMORY_E;
+            }
+            dirEntry->len = strLen;
+            XMEMCPY(dirEntry->name, &input[idx], strLen);
+            dirEntry->name[strLen] = '\0';
+
+            dirEntry->next = cert->altDirNames;
+            cert->altDirNames = dirEntry;
+
+            length -= strLen;
+            idx    += strLen;
+        }
         else if (b == (ASN_CONTEXT_SPECIFIC | ASN_RFC822_TYPE)) {
             DNS_entry* emailEntry;
             int strLen;
diff --git a/wolfssl/wolfcrypt/asn.h b/wolfssl/wolfcrypt/asn.h
index edb3d0d12..26eeee647 100644
--- a/wolfssl/wolfcrypt/asn.h
+++ b/wolfssl/wolfcrypt/asn.h
@@ -769,6 +769,7 @@ struct DecodedCert {
     DNS_entry* altNames;             /* alt names list of dns entries    */
 #ifndef IGNORE_NAME_CONSTRAINTS
     DNS_entry* altEmailNames;        /* alt names list of RFC822 entries */
+    DNS_entry* altDirNames;          /* alt names list of DIR entries    */
     Base_entry* permittedNames;      /* Permitted name bases             */
     Base_entry* excludedNames;       /* Excluded name bases              */
 #endif /* IGNORE_NAME_CONSTRAINTS */

From f00263889b97ba4a0d5894d41735de191b0ec316 Mon Sep 17 00:00:00 2001
From: Jacob Barthelmeh <jacob@wolfssl.com>
Date: Fri, 11 Dec 2020 08:20:48 +0700
Subject: [PATCH 2/3] add test case

---
 certs/test/cert-ext-ndir.cfg |  23 ++++++++++
 certs/test/cert-ext-ndir.der | Bin 0 -> 1260 bytes
 certs/test/gen-ext-certs.sh  |  34 +++++++++++++-
 certs/test/include.am        |   2 +
 tests/api.c                  |  85 +++++++++++++++++++++++++++++++++++
 wolfcrypt/src/asn.c          |  11 ++++-
 6 files changed, 153 insertions(+), 2 deletions(-)
 create mode 100644 certs/test/cert-ext-ndir.cfg
 create mode 100644 certs/test/cert-ext-ndir.der

diff --git a/certs/test/cert-ext-ndir.cfg b/certs/test/cert-ext-ndir.cfg
new file mode 100644
index 000000000..0757874d8
--- /dev/null
+++ b/certs/test/cert-ext-ndir.cfg
@@ -0,0 +1,23 @@
+[ req ]
+distinguished_name = req_distinguished_name
+prompt             = no
+x509_extensions    = constraints
+
+[ req_distinguished_name ]
+C             = US
+ST            = Montana
+L             = Bozeman
+O             = Sawtooth
+OU            = Consulting
+CN            = www.wolfssl.com
+emailAddress  = info@wolfsssl.com
+
+[constraints]
+subjectKeyIdentifier=hash
+authorityKeyIdentifier=keyid:always,issuer:always
+basicConstraints=CA:TRUE
+nameConstraints=critical,permitted;dirName:dir_name
+
+[dir_name]
+countryName = US
+
diff --git a/certs/test/cert-ext-ndir.der b/certs/test/cert-ext-ndir.der
new file mode 100644
index 0000000000000000000000000000000000000000..63f566bfc02ba2e783f5231f39c4d8094570edbb
GIT binary patch
literal 1260
zcmXqLVtHZE#C%}^GZP~dlSqAq)Q_^4&D+ao6`4nB$Uj^XQ&4Nb%f_kI=F#?@mywa1
zmBFBKsv)-lCmVAp3!5-gXt1Gx0UwCN!NcyGpI4HYmk1MK=V5osuS(5L%rg`;;0LMU
z;^7EREHBB=FUc?zHV^~}ar1CF=jRod=9FaSr5j2Zh=Bx|dHBoA%k|3hbJB{7bM%t)
za}5;?<lxTWWE2z3%uCC6fGB{dFpv}HH8L<XGBh+WFfuT(j1uQHGB&U@Fo$vnt-G5T
zm5_s&k(GhDiIJbdpox)-sfm%1VL#6)U6D<4El$yAE#$pE`IZWN+-5re{;68#8JE}G
zV@`Xg_3_4r+C26UZh;w!z73~^6rP{)zvo(evZ&nX)u{=)GlK+}^;dkJdh}y=QkeAn
z^!z0Pj#Jli&3?S}z=lf&WdR1!D_(Hu)Vy83sH)dOQ)bQax1VaJZkXCs>ltHlwp{i7
z-iFfPDK@sJlB4H~ZoMoktS@=d=60FYnH{w!pB}n?%OU@U;+<k?C*9yV|D^uZuC6k(
zpK-6HhBf_MmWW0B%8xx;GfrpJ7b<9fU6A}WOn<T3rS16}qr|UU%;fktIU@hxVPQ`W
zG4AEQ=?p=J>B@dH-UhnL?qs>i{pN<oX79ak%_^Cg85tNCH!<oMG%;!z$g(kq%JQ*@
zv52Vmr3;oER+F`VYn;4!$qiY9r!TG=G+qVCE3-77HE2B5fK|=H#@S06XAIWl(1bk?
z@_@W0%))BG%*goPKoP`~V`Ti#B5okMK-fTV3BLg^O0GmsQQY7Z#mHdNy6nkEZY#}~
z`^tDP*H2ktz2cCp&u(8a*N(QeVc)mMaNXNooW~m)6xtQq9<=1kYo<FKx9%u$Xx=<p
ze)ghcWQ_cpsdtW>9ZTIYJ6Sd>QJE=isY}<T3)b3VN|z3@Y<J^7S=(a$@w0Nl3dyW*
z4gGH0Bx+{0%8S~ct4uv5x$y1gg}yI^E?N9ao|Sz0)rDVcX4vz&tXI?Xi2G@>Y3AI_
zFo*ZX+%Glaf+xARZtZUVebMDv_M7^HVwtxE6ymn7cG!LY>(@&@8+$UX)?IyEds+LE
zo13)VA$3;I@H4k3KD#a$@<DsQfL!R~r5chd^OKWOujFJItIu-SmRM7J=*J$Gv{<h@
E0GD98egFUf

literal 0
HcmV?d00001

diff --git a/certs/test/gen-ext-certs.sh b/certs/test/gen-ext-certs.sh
index 10b887133..65ce2124c 100755
--- a/certs/test/gen-ext-certs.sh
+++ b/certs/test/gen-ext-certs.sh
@@ -2,8 +2,9 @@
 
 TMP="/tmp/`basename $0`"
 
+KEY=certs/server-key.der
 gen_cert() {
-    openssl req -x509 -keyform DER -key certs/server-key.der \
+    openssl req -x509 -keyform DER -key $KEY \
       -days 1000 -new -outform DER -out $OUT -config $CONFIG \
         >$TMP 2>&1
 
@@ -96,3 +97,34 @@ nsComment        = "Testing Netscape Certificate Type"
 EOF
 gen_cert
 
+KEY=certs/ca-key.der
+OUT=certs/test/cert-ext-ndir.der
+KEYFILE=certs/ca-key.der
+CONFIG=certs/test/cert-ext-ndir.cfg
+tee >$CONFIG <<EOF
+[ req ]
+distinguished_name = req_distinguished_name
+prompt             = no
+x509_extensions    = constraints
+
+[ req_distinguished_name ]
+C             = US
+ST            = Montana
+L             = Bozeman
+O             = Sawtooth
+OU            = Consulting
+CN            = www.wolfssl.com
+emailAddress  = info@wolfsssl.com
+
+[constraints]
+subjectKeyIdentifier=hash
+authorityKeyIdentifier=keyid:always,issuer:always
+basicConstraints=CA:TRUE
+nameConstraints=critical,permitted;dirName:dir_name
+
+[dir_name]
+countryName = US
+
+EOF
+gen_cert
+
diff --git a/certs/test/include.am b/certs/test/include.am
index 6f37df6d2..ca9822032 100644
--- a/certs/test/include.am
+++ b/certs/test/include.am
@@ -9,6 +9,8 @@ EXTRA_DIST += \
          certs/test/cert-ext-nc.der \
          certs/test/cert-ext-nct.cfg \
          certs/test/cert-ext-nct.der \
+         certs/test/cert-ext-ndir.cfg \
+         certs/test/cert-ext-ndir.der \
          certs/test/cert-ext-ns.der \
          certs/test/gen-ext-certs.sh \
          certs/test/server-duplicate-policy.pem \
diff --git a/tests/api.c b/tests/api.c
index 4a6b5ffcd..9e81ac409 100644
--- a/tests/api.c
+++ b/tests/api.c
@@ -1267,6 +1267,90 @@ static void test_wolfSSL_CertManagerNameConstraint(void)
 #endif
 }
 
+
+static void test_wolfSSL_CertManagerNameConstraint2(void)
+{
+#if !defined(NO_FILESYSTEM) && !defined(NO_CERTS) && \
+    !defined(NO_WOLFSSL_CM_VERIFY) && !defined(NO_RSA) && \
+    defined(OPENSSL_EXTRA) && defined(WOLFSSL_CERT_GEN) && \
+    defined(WOLFSSL_CERT_EXT) && defined(WOLFSSL_ALT_NAMES)
+    const char* ca_cert = "./certs/test/cert-ext-ndir.der";
+    const char* server_cert = "./certs/server-cert.pem";
+    WOLFSSL_CERT_MANAGER* cm;
+    WOLFSSL_X509 *x509, *ca;
+
+    const unsigned char *der;
+    const unsigned char *pt;
+    WOLFSSL_EVP_PKEY *priv;
+    WOLFSSL_X509_NAME* name;
+    int   derSz;
+
+    /* C=US*/
+    char altName[] = {
+        0x30, 0x0D, 0x31, 0x0B, 0x30, 0x09,
+        0x06, 0x03, 0x55, 0x04, 0x06, 0x13, 0x02, 0x55, 0x53
+    };
+
+    /* C=ID */
+    char altNameFail[] = {
+        0x30, 0x0D, 0x31, 0x0B, 0x30, 0x09,
+        0x06, 0x03, 0x55, 0x04, 0x06, 0x13, 0x02, 0x49, 0x44
+    };
+
+    /* load in CA private key for signing */
+    pt = ca_key_der_2048;
+    AssertNotNull(priv = wolfSSL_d2i_PrivateKey(EVP_PKEY_RSA, NULL, &pt,
+                                                sizeof_ca_key_der_2048));
+
+    AssertNotNull(cm = wolfSSL_CertManagerNew());
+    AssertNotNull(ca = wolfSSL_X509_load_certificate_file(ca_cert,
+                WOLFSSL_FILETYPE_ASN1));
+    AssertNotNull((der = wolfSSL_X509_get_der(ca, &derSz)));
+    AssertIntEQ(wolfSSL_CertManagerLoadCABuffer(cm, der, derSz,
+                WOLFSSL_FILETYPE_ASN1), WOLFSSL_SUCCESS);
+
+    AssertNotNull(x509 = wolfSSL_X509_load_certificate_file(server_cert,
+                WOLFSSL_FILETYPE_PEM));
+    AssertNotNull(name = wolfSSL_X509_get_subject_name(ca));
+    AssertIntEQ(wolfSSL_X509_set_issuer_name(x509, name), WOLFSSL_SUCCESS);
+    wolfSSL_X509_sign(x509, priv, EVP_sha256());
+    AssertNotNull((der = wolfSSL_X509_get_der(x509, &derSz)));
+    AssertIntEQ(wolfSSL_CertManagerVerifyBuffer(cm, der, derSz,
+                WOLFSSL_FILETYPE_ASN1), WOLFSSL_SUCCESS);
+
+    /* add in matching DIR alt name and resign */
+    wolfSSL_X509_add_altname_ex(x509, altName, sizeof(altName), ASN_DIR_TYPE);
+    wolfSSL_X509_sign(x509, priv, EVP_sha256());
+
+    AssertNotNull((der = wolfSSL_X509_get_der(x509, &derSz)));
+    AssertIntEQ(wolfSSL_CertManagerVerifyBuffer(cm, der, derSz,
+                WOLFSSL_FILETYPE_ASN1), WOLFSSL_SUCCESS);
+    wolfSSL_X509_free(x509);
+
+    /* check verify fail */
+    AssertNotNull(x509 = wolfSSL_X509_load_certificate_file(server_cert,
+                WOLFSSL_FILETYPE_PEM));
+    AssertNotNull(name = wolfSSL_X509_get_subject_name(ca));
+    AssertIntEQ(wolfSSL_X509_set_issuer_name(x509, name), WOLFSSL_SUCCESS);
+
+    /* add in miss matching DIR alt name and resign */
+    wolfSSL_X509_add_altname_ex(x509, altNameFail, sizeof(altNameFail),
+            ASN_DIR_TYPE);
+
+
+    wolfSSL_X509_sign(x509, priv, EVP_sha256());
+    AssertNotNull((der = wolfSSL_X509_get_der(x509, &derSz)));
+    AssertIntEQ(wolfSSL_CertManagerVerifyBuffer(cm, der, derSz,
+                WOLFSSL_FILETYPE_ASN1), ASN_NAME_INVALID_E);
+    wolfSSL_CertManagerFree(cm);
+
+    wolfSSL_X509_free(x509);
+    wolfSSL_X509_free(ca);
+    wolfSSL_X509_MAME_free(name);
+    wolfSSL_EVP_PKEY_free(priv);
+#endif
+}
+
 static void test_wolfSSL_CertManagerCRL(void)
 {
 #if !defined(NO_FILESYSTEM) && !defined(NO_CERTS) && defined(HAVE_CRL) && \
@@ -39246,6 +39330,7 @@ void ApiTest(void)
     test_wolfSSL_CertManagerGetCerts();
     test_wolfSSL_CertManagerSetVerify();
     test_wolfSSL_CertManagerNameConstraint();
+    test_wolfSSL_CertManagerNameConstraint2();
     test_wolfSSL_CertManagerCRL();
     test_wolfSSL_CTX_load_verify_locations_ex();
     test_wolfSSL_CTX_load_verify_buffer_ex();
diff --git a/wolfcrypt/src/asn.c b/wolfcrypt/src/asn.c
index eb1491b6c..d509e89c6 100644
--- a/wolfcrypt/src/asn.c
+++ b/wolfcrypt/src/asn.c
@@ -7799,6 +7799,11 @@ static int DecodeAltNames(const byte* input, int sz, DecodedCert* cert)
                 WOLFSSL_MSG("\tfail: str length");
                 return ASN_PARSE_E;
             }
+
+            if (GetSequence(input, &idx, &strLen, sz) < 0) {
+                WOLFSSL_MSG("\tfail: seq length");
+                return ASN_PARSE_E;
+            }
             length -= (idx - lenStartIdx);
 
             dirEntry = (DNS_entry*)XMALLOC(sizeof(DNS_entry), cert->heap,
@@ -12717,7 +12722,11 @@ int FlattenAltNames(byte* output, word32 outputSz, const DNS_entry* names)
 
     curName = names;
     do {
-        output[idx++] = ASN_CONTEXT_SPECIFIC | curName->type;
+        output[idx] = ASN_CONTEXT_SPECIFIC | curName->type;
+        if (curName->type == ASN_DIR_TYPE) {
+            output[idx] |= ASN_CONSTRUCTED;
+        }
+        idx++;
         idx += SetLength(curName->len, output + idx);
         XMEMCPY(output + idx, curName->name, curName->len);
         idx += curName->len;

From 04e22b0747a41bf56ca0dfce3d15e208720c7ef9 Mon Sep 17 00:00:00 2001
From: Jacob Barthelmeh <jacob@wolfssl.com>
Date: Fri, 11 Dec 2020 10:00:11 +0700
Subject: [PATCH 3/3] add restriction to excluded DIR name constraint

---
 certs/test/cert-ext-ndir-exc.cfg |  24 +++++++++++++++++++
 certs/test/cert-ext-ndir-exc.der | Bin 0 -> 1281 bytes
 certs/test/gen-ext-certs.sh      |  32 ++++++++++++++++++++++++++
 certs/test/include.am            |   2 ++
 tests/api.c                      |  38 ++++++++++++++++++++++++++++---
 wolfcrypt/src/asn.c              |  19 ++++++++++++++++
 6 files changed, 112 insertions(+), 3 deletions(-)
 create mode 100644 certs/test/cert-ext-ndir-exc.cfg
 create mode 100644 certs/test/cert-ext-ndir-exc.der

diff --git a/certs/test/cert-ext-ndir-exc.cfg b/certs/test/cert-ext-ndir-exc.cfg
new file mode 100644
index 000000000..8d66b8a07
--- /dev/null
+++ b/certs/test/cert-ext-ndir-exc.cfg
@@ -0,0 +1,24 @@
+[ req ]
+distinguished_name = req_distinguished_name
+prompt             = no
+x509_extensions    = constraints
+
+[ req_distinguished_name ]
+C             = US
+ST            = Montana
+L             = Bozeman
+O             = Sawtooth
+OU            = Consulting
+CN            = www.wolfssl.com
+emailAddress  = info@wolfsssl.com
+
+[constraints]
+subjectKeyIdentifier=hash
+authorityKeyIdentifier=keyid:always,issuer:always
+basicConstraints=CA:TRUE
+nameConstraints=critical,excluded;dirName:dir_name_exclude
+
+[dir_name_exclude]
+countryName = US
+stateOrProvinceName = California
+
diff --git a/certs/test/cert-ext-ndir-exc.der b/certs/test/cert-ext-ndir-exc.der
new file mode 100644
index 0000000000000000000000000000000000000000..19afbab840a90d09b8b50c8658fb48465f70ec88
GIT binary patch
literal 1281
zcmXqLV)<*(#QbytGZP~dlZb}T2I*f+%_<A+SLJ!+J@@Qzj(BIl%f_kI=F#?@mywa1
zmBFBKsv)-lCmVAp3!5-gXt1Gx0UwCN!NcyGpI4HYmk1MK=V5osuS(5L%rg`;;0LMU
z;^7EREHBB=FUc?zHV^~}ar1CF=jRod=9FaSr5j2Zh=Bx|dHBoA%k|3hbJB{7bM%t)
za}5;?<lxTWWE2z3%uCC6fGB{dFpv}HH8L<XGBh+WGBq|fiW28FGB&U@Fo$vnt-G5T
zm5_s&k(GhDiIJbdpox)-sfm%1VL#6)U6D<4El$yAE#$pE`IZWN+-5re{;68#8JE}G
zV@`Xg_3_4r+C26UZh;w!z73~^6rP{)zvo(evZ&nX)u{=)GlK+}^;dkJdh}y=QkeAn
z^!z0Pj#Jli&3?S}z=lf&WdR1!D_(Hu)Vy83sH)dOQ)bQax1VaJZkXCs>ltHlwp{i7
z-iFfPDK@sJlB4H~ZoMoktS@=d=60FYnH{w!pB}n?%OU@U;+<k?C*9yV|D^uZuC6k(
zpK-6HhBf_MmWW0B%8xx;GfrpJ7b<9fU6A}WOn<T3rS16}qr|UU%;fktIU@hxVPQ`W
zG4AEQ=?p=J>B@dH-UhnL?qs>i{pN<oX79ak%_^Cg85tNCH!(UIG%?y5$g(kq%JQ*@
zv52Vmr3;oER+F`VYn;4!$qiY9r!TG=G+qVCE3-77HE2B5fK|=H#@S06XAIWl(1bk?
z@_@W0%))BG%*goPzzoEbV`Ti#qGO=7P{TlNiHd;|YOaK4FAg3q=fs@MwEUvH%tYj5
z#tlwpj0`iJl%8xqw^y%t#p~k%%JI_C4qH7U+jY<Ad3KeYX5r)KUAWqOS|QI{{q_@Q
zSz{*z&TH>{XcGAEBAc?&oxAZhiuX${CM>?1K5N3)=RzmW-I!A-EOo=;{jU^e!T$aI
z@^kMh*`9p3A?4T^(+w)sk+}-*+&FqZo(@Pf4Av@LdHV6%)IGNX6%u-Tzi&<M@Y<-a
zeC+XWju!o5X34tX#*ilE$IDY69|^NR&^Gz%_N#kqZa?-E%y|9sW^-Kr*@;o>i$2^t
zqPAM|o}~OEhkHK?Qf9H&uh<$msW!&#_Ju3+;#W_~30-^c+_`J5sy-Gk-mHp>R+?B5
VU~_ht*1hYB%n#J=t}x$v2ms7j#8UtO

literal 0
HcmV?d00001

diff --git a/certs/test/gen-ext-certs.sh b/certs/test/gen-ext-certs.sh
index 65ce2124c..e418157ab 100755
--- a/certs/test/gen-ext-certs.sh
+++ b/certs/test/gen-ext-certs.sh
@@ -128,3 +128,35 @@ countryName = US
 EOF
 gen_cert
 
+OUT=certs/test/cert-ext-ndir-exc.der
+KEYFILE=certs/ca-key.der
+CONFIG=certs/test/cert-ext-ndir-exc.cfg
+tee >$CONFIG <<EOF
+[ req ]
+distinguished_name = req_distinguished_name
+prompt             = no
+x509_extensions    = constraints
+
+[ req_distinguished_name ]
+C             = US
+ST            = Montana
+L             = Bozeman
+O             = Sawtooth
+OU            = Consulting
+CN            = www.wolfssl.com
+emailAddress  = info@wolfsssl.com
+
+[constraints]
+subjectKeyIdentifier=hash
+authorityKeyIdentifier=keyid:always,issuer:always
+basicConstraints=CA:TRUE
+nameConstraints=critical,excluded;dirName:dir_name_exclude
+
+[dir_name_exclude]
+countryName = US
+stateOrProvinceName = California
+
+EOF
+gen_cert
+
+
diff --git a/certs/test/include.am b/certs/test/include.am
index ca9822032..588603380 100644
--- a/certs/test/include.am
+++ b/certs/test/include.am
@@ -12,6 +12,8 @@ EXTRA_DIST += \
          certs/test/cert-ext-ndir.cfg \
          certs/test/cert-ext-ndir.der \
          certs/test/cert-ext-ns.der \
+         certs/test/cert-ext-ndir-exc.cfg \
+         certs/test/cert-ext-ndir-exc.der \
          certs/test/gen-ext-certs.sh \
          certs/test/server-duplicate-policy.pem \
          certs/test/cert-ext-joi.pem
diff --git a/tests/api.c b/tests/api.c
index 9e81ac409..d361e8caf 100644
--- a/tests/api.c
+++ b/tests/api.c
@@ -1274,7 +1274,8 @@ static void test_wolfSSL_CertManagerNameConstraint2(void)
     !defined(NO_WOLFSSL_CM_VERIFY) && !defined(NO_RSA) && \
     defined(OPENSSL_EXTRA) && defined(WOLFSSL_CERT_GEN) && \
     defined(WOLFSSL_CERT_EXT) && defined(WOLFSSL_ALT_NAMES)
-    const char* ca_cert = "./certs/test/cert-ext-ndir.der";
+    const char* ca_cert  = "./certs/test/cert-ext-ndir.der";
+    const char* ca_cert2 = "./certs/test/cert-ext-ndir-exc.der";
     const char* server_cert = "./certs/server-cert.pem";
     WOLFSSL_CERT_MANAGER* cm;
     WOLFSSL_X509 *x509, *ca;
@@ -1297,6 +1298,15 @@ static void test_wolfSSL_CertManagerNameConstraint2(void)
         0x06, 0x03, 0x55, 0x04, 0x06, 0x13, 0x02, 0x49, 0x44
     };
 
+    /* C=US ST=California*/
+    char altNameExc[] = {
+        0x30, 0x22,
+        0x31, 0x0B,
+        0x30, 0x09, 0x06, 0x03, 0x55, 0x04, 0x06, 0x13, 0x02, 0x55, 0x53,
+        0x31, 0x13,
+        0x30, 0x11, 0x06, 0x03, 0x55, 0x04, 0x08, 0x0C, 0x0A,
+        0x43, 0x61, 0x6c, 0x69, 0x66, 0x6f, 0x72, 0x6e, 0x69, 0x61
+    };
     /* load in CA private key for signing */
     pt = ca_key_der_2048;
     AssertNotNull(priv = wolfSSL_d2i_PrivateKey(EVP_PKEY_RSA, NULL, &pt,
@@ -1337,7 +1347,6 @@ static void test_wolfSSL_CertManagerNameConstraint2(void)
     wolfSSL_X509_add_altname_ex(x509, altNameFail, sizeof(altNameFail),
             ASN_DIR_TYPE);
 
-
     wolfSSL_X509_sign(x509, priv, EVP_sha256());
     AssertNotNull((der = wolfSSL_X509_get_der(x509, &derSz)));
     AssertIntEQ(wolfSSL_CertManagerVerifyBuffer(cm, der, derSz,
@@ -1346,7 +1355,30 @@ static void test_wolfSSL_CertManagerNameConstraint2(void)
 
     wolfSSL_X509_free(x509);
     wolfSSL_X509_free(ca);
-    wolfSSL_X509_MAME_free(name);
+
+    /* now test with excluded name constraint */
+    AssertNotNull(cm = wolfSSL_CertManagerNew());
+    AssertNotNull(ca = wolfSSL_X509_load_certificate_file(ca_cert2,
+                WOLFSSL_FILETYPE_ASN1));
+    AssertNotNull((der = wolfSSL_X509_get_der(ca, &derSz)));
+    AssertIntEQ(wolfSSL_CertManagerLoadCABuffer(cm, der, derSz,
+                WOLFSSL_FILETYPE_ASN1), WOLFSSL_SUCCESS);
+
+    AssertNotNull(x509 = wolfSSL_X509_load_certificate_file(server_cert,
+                WOLFSSL_FILETYPE_PEM));
+    wolfSSL_X509_add_altname_ex(x509, altNameExc, sizeof(altNameExc),
+            ASN_DIR_TYPE);
+    AssertNotNull(name = wolfSSL_X509_get_subject_name(ca));
+    AssertIntEQ(wolfSSL_X509_set_issuer_name(x509, name), WOLFSSL_SUCCESS);
+
+    wolfSSL_X509_sign(x509, priv, EVP_sha256());
+    AssertNotNull((der = wolfSSL_X509_get_der(x509, &derSz)));
+    AssertIntEQ(wolfSSL_CertManagerVerifyBuffer(cm, der, derSz,
+                WOLFSSL_FILETYPE_ASN1), ASN_NAME_INVALID_E);
+    wolfSSL_CertManagerFree(cm);
+    wolfSSL_X509_free(x509);
+    wolfSSL_X509_free(ca);
+
     wolfSSL_EVP_PKEY_free(priv);
 #endif
 }
diff --git a/wolfcrypt/src/asn.c b/wolfcrypt/src/asn.c
index d509e89c6..7815cca3f 100644
--- a/wolfcrypt/src/asn.c
+++ b/wolfcrypt/src/asn.c
@@ -7628,6 +7628,25 @@ static int ConfirmNameConstraints(Signer* signer, DecodedCert* cert)
                                                         base->nameSz) == 0) {
                         return 0;
                     }
+                    #ifndef WOLFSSL_NO_ASN_STRICT
+                    /* RFC 5280 section 4.2.1.10
+                       "Restrictions of the form directoryName MUST be
+                        applied to the subject field .... and to any names
+                        of type directoryName in the subjectAltName
+                        extension"
+                    */
+                    if (cert->altDirNames != NULL) {
+                        DNS_entry* cur = cert->altDirNames;
+                        while (cur != NULL) {
+                            if (XMEMCMP(cur->name, base->name, base->nameSz)
+                                    == 0) {
+                                WOLFSSL_MSG("DIR alt name constraint err");
+                                return 0;
+                            }
+                            cur = cur->next;
+                        }
+                    }
+                    #endif /* !WOLFSSL_NO_ASN_STRICT */
                     break;
                 }
             }; /* switch */