From c927a3492698c254637da836762f9b1f86cffabc Mon Sep 17 00:00:00 2001

From: Viktor Dukhovni <openssl-users@dukhovni.org>

Date: Tue, 13 Dec 2022 08:49:13 +0100

Subject: [PATCH 01/18] Fix type confusion in nc_match_single()

This function assumes that if the "gen" is an OtherName, then the "base"

is a rfc822Name constraint. This assumption is not true in all cases.

If the end-entity certificate contains an OtherName SAN of any type besides

SmtpUtf8Mailbox and the CA certificate contains a name constraint of

OtherName (of any type), then "nc_email_eai" will be invoked, with the

OTHERNAME "base" being incorrectly interpreted as a ASN1_IA5STRING.

Reported by Corey Bonnell from Digicert.

CVE-2022-4203

Reviewed-by: Paul Dale <pauli@openssl.org>

Reviewed-by: Hugo Landau <hlandau@openssl.org>

Reviewed-by: Tomas Mraz <tomas@openssl.org>

---

 crypto/x509/v3_ncons.c | 45 +++++++++++++++++++++++++++++-------------

 1 file changed, 31 insertions(+), 14 deletions(-)

diff --git a/crypto/x509/v3_ncons.c b/crypto/x509/v3_ncons.c

index 70a7e8304e..5101598512 100644

--- a/crypto/x509/v3_ncons.c

+++ b/crypto/x509/v3_ncons.c

@@ -31,7 +31,8 @@ static int do_i2r_name_constraints(const X509V3_EXT_METHOD *method,

 static int print_nc_ipadd(BIO *bp, ASN1_OCTET_STRING *ip);

 static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc);

-static int nc_match_single(GENERAL_NAME *sub, GENERAL_NAME *gen);

+static int nc_match_single(int effective_type, GENERAL_NAME *sub,

+                           GENERAL_NAME *gen);

 static int nc_dn(const X509_NAME *sub, const X509_NAME *nm);

 static int nc_dns(ASN1_IA5STRING *sub, ASN1_IA5STRING *dns);

 static int nc_email(ASN1_IA5STRING *sub, ASN1_IA5STRING *eml);

@@ -472,14 +473,17 @@ static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)

 {

     GENERAL_SUBTREE *sub;

     int i, r, match = 0;

+    int effective_type = gen->type;

+

     /*

      * We need to compare not gen->type field but an "effective" type because

      * the otherName field may contain EAI email address treated specially

      * according to RFC 8398, section 6

      */

-    int effective_type = ((gen->type == GEN_OTHERNAME) &&

-                          (OBJ_obj2nid(gen->d.otherName->type_id) ==

-                           NID_id_on_SmtpUTF8Mailbox)) ? GEN_EMAIL : gen->type;

+    if (effective_type == GEN_OTHERNAME &&

+        (OBJ_obj2nid(gen->d.otherName->type_id) == NID_id_on_SmtpUTF8Mailbox)) {

+        effective_type = GEN_EMAIL;

+    }

     /*

      * Permitted subtrees: if any subtrees exist of matching the type at

@@ -488,7 +492,10 @@ static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)

     for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->permittedSubtrees); i++) {

         sub = sk_GENERAL_SUBTREE_value(nc->permittedSubtrees, i);

-        if (effective_type != sub->base->type)

+        if (effective_type != sub->base->type

+            || (effective_type == GEN_OTHERNAME &&

+                OBJ_cmp(gen->d.otherName->type_id,

+                        sub->base->d.otherName->type_id) != 0))

             continue;

         if (!nc_minmax_valid(sub))

             return X509_V_ERR_SUBTREE_MINMAX;

@@ -497,7 +504,7 @@ static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)

             continue;

         if (match == 0)

             match = 1;

-        r = nc_match_single(gen, sub->base);

+        r = nc_match_single(effective_type, gen, sub->base);

         if (r == X509_V_OK)

             match = 2;

         else if (r != X509_V_ERR_PERMITTED_VIOLATION)

@@ -511,12 +518,15 @@ static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)

     for (i = 0; i < sk_GENERAL_SUBTREE_num(nc->excludedSubtrees); i++) {

         sub = sk_GENERAL_SUBTREE_value(nc->excludedSubtrees, i);

-        if (effective_type != sub->base->type)

+        if (effective_type != sub->base->type

+            || (effective_type == GEN_OTHERNAME &&

+                OBJ_cmp(gen->d.otherName->type_id,

+                        sub->base->d.otherName->type_id) != 0))

             continue;

         if (!nc_minmax_valid(sub))

             return X509_V_ERR_SUBTREE_MINMAX;

-        r = nc_match_single(gen, sub->base);

+        r = nc_match_single(effective_type, gen, sub->base);

         if (r == X509_V_OK)

             return X509_V_ERR_EXCLUDED_VIOLATION;

         else if (r != X509_V_ERR_PERMITTED_VIOLATION)

@@ -528,15 +538,22 @@ static int nc_match(GENERAL_NAME *gen, NAME_CONSTRAINTS *nc)

 }

-static int nc_match_single(GENERAL_NAME *gen, GENERAL_NAME *base)

+static int nc_match_single(int effective_type, GENERAL_NAME *gen,

+                           GENERAL_NAME *base)

 {

     switch (gen->type) {

     case GEN_OTHERNAME:

-        /*

-         * We are here only when we have SmtpUTF8 name,

-         * so we match the value of othername with base->d.rfc822Name

-         */

-        return nc_email_eai(gen->d.otherName->value, base->d.rfc822Name);

+        switch (effective_type) {

+        case GEN_EMAIL:

+            /*

+             * We are here only when we have SmtpUTF8 name,

+             * so we match the value of othername with base->d.rfc822Name

+             */

+            return nc_email_eai(gen->d.otherName->value, base->d.rfc822Name);

+

+        default:

+            return X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE;

+        }

     case GEN_DIRNAME:

         return nc_dn(gen->d.directoryName, base->d.directoryName);

-- 

2.39.1

From fe6842f5a5dc2fb66da7fb24bf4343a3aeedd50a Mon Sep 17 00:00:00 2001

From: Tomas Mraz <tomas@openssl.org>

Date: Tue, 13 Dec 2022 19:45:09 +0100

Subject: [PATCH 02/18] Add testcase for nc_match_single type confusion

Reviewed-by: Paul Dale <pauli@openssl.org>

Reviewed-by: Hugo Landau <hlandau@openssl.org>

---

 test/certs/bad-othername-cert.pem | 20 ++++++++++++++++++++

 test/certs/nccaothername-cert.pem | 20 ++++++++++++++++++++

 test/certs/nccaothername-key.pem  | 28 ++++++++++++++++++++++++++++

 test/certs/setup.sh               | 11 +++++++++++

 test/recipes/25-test_verify.t     |  5 ++++-

 5 files changed, 83 insertions(+), 1 deletion(-)

 create mode 100644 test/certs/bad-othername-cert.pem

 create mode 100644 test/certs/nccaothername-cert.pem

 create mode 100644 test/certs/nccaothername-key.pem

diff --git a/test/certs/bad-othername-cert.pem b/test/certs/bad-othername-cert.pem

new file mode 100644

index 0000000000..cf279de5ea

--- /dev/null

+++ b/test/certs/bad-othername-cert.pem

@@ -0,0 +1,20 @@

+-----BEGIN CERTIFICATE-----

+MIIDRDCCAiygAwIBAgIBAjANBgkqhkiG9w0BAQsFADAfMR0wGwYDVQQDDBRUZXN0

+IE5DIENBIG90aGVybmFtZTAgFw0yMjEyMTMxODMzMTZaGA8yMTIyMTIxNDE4MzMx

+NlowMTEvMC0GA1UECgwmTkMgZW1haWwgaW4gb3RoZXJuYW1lIFRlc3QgQ2VydGlm

+aWNhdGUwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQDPgeoakqHk1zYt

+JZpEC0qkJPU/X0lfI+6GY2LHFY9KOSFqqmTXxrUtjQc3SdpQvBZhPuMZ8p82Jid2

+kkRHnWs0uqX9NtLO923yQalYvP6Mt3fokcYgw/C9b+I/q1PKUyN0kPB6McROguD5

+Jz2DcEufJBhbpyay1bFjEI2DAQJKDP/U7uH0EA7kH/27UMk0vfvL5uVjDvlo8i6S

+Ul8+u0cDV5ZFJW2VAJKLU3wp6IY4fZl9UqkHZuRQpMJGqAjAleWOIEpyyvfGGh0b

+75n3GJ+4YZ7CIBEgY7K0nIbKxtcDZPvmtbYg3g1tkPMTHcodFT7yEdqkBTJ5AGL7

+6U850OhjAgMBAAGjdzB1MB0GA1UdDgQWBBTBz0k+q6d4c3aM+s2IyOF/QP6zCTAf

+BgNVHSMEGDAWgBTwhghX7uNdMejZ3f4XorqOQoMqwTAJBgNVHRMEAjAAMCgGA1Ud

+EQQhMB+gHQYIKwYBBQUHCAegEQwPZm9vQGV4YW1wbGUub3JnMA0GCSqGSIb3DQEB

+CwUAA4IBAQAhxbCEVH8pq0aUMaLWaodyXdCqA0AKTFG6Mz9Rpwn89OwC8FylTEru

+t+Bqx/ZuTo8YzON8h9m7DIrQIjZKDLW/g5YbvIsxIVV9gWhAGohdsIyMKRBepSmr

+NxJQkO74RLBTamfl0WUCVM4HqroflFjBBG67CTJaQ9cH9ug3TKxaXCK1L6iQAXtq

+enILGai98Byo0LCFH4MQOhmhV1BDT2boIG/iYb5VKCTSX25vhaF+PNBhUoysjW0O

+vhQX8vrw42QRr4Qi7VfUBXzrbRTzxjOc4yqki7h2DcEdpginqe+aGyaFY+H9m/ka

+1AR5KN8h5SYKltSXknjs0pp1w4k49aHl

+-----END CERTIFICATE-----

diff --git a/test/certs/nccaothername-cert.pem b/test/certs/nccaothername-cert.pem

new file mode 100644

index 0000000000..f9b9b07b80

--- /dev/null

+++ b/test/certs/nccaothername-cert.pem

@@ -0,0 +1,20 @@

+-----BEGIN CERTIFICATE-----

+MIIDPjCCAiagAwIBAgIBAjANBgkqhkiG9w0BAQsFADASMRAwDgYDVQQDDAdSb290

+IENBMCAXDTIyMTIxMzE4MTgwM1oYDzIxMjIxMjE0MTgxODAzWjAfMR0wGwYDVQQD

+DBRUZXN0IE5DIENBIG90aGVybmFtZTCCASIwDQYJKoZIhvcNAQEBBQADggEPADCC

+AQoCggEBAN0Dx+ei8CgtRKnDcYiLwX4vrA48at/o/zfX24X/WZZM1o9HUKo1FQBN

+vhESJu+gqPxuIePrk+/L25XdRqwCKk8wkWX0XIz18q5orOHUUFAWNK3g0FDj6N8H

+d8urNIbDJ44FCx+/0n8Ppiht/EYN3aVOW5enqbgZ+EEt+3AUG6ibieRdGri9g4oh

+IIx60MmVHLbuT/TcVZxaeWyTl6iWmsYosUyqlhTtu1uGtbVtkCAhBYloVvz4J5eA

+mVu/JuJbsNxbxVeO9Q8Kj6nb4jPPdGvZ3JPcabbWrz5LwaereBf5IPrXEVdQTlYB

+gI0pTz2CEDHSIrd7jzRUX/9EC2gMk6UCAwEAAaOBjzCBjDAPBgNVHRMBAf8EBTAD

+AQH/MAsGA1UdDwQEAwIBBjAdBgNVHQ4EFgQU8IYIV+7jXTHo2d3+F6K6jkKDKsEw

+HwYDVR0jBBgwFoAUjvUlrx6ba4Q9fICayVOcTXL3o1IwLAYDVR0eBCUwI6EhMB+g

+HQYIKwYBBQUHCAegEQwPZm9vQGV4YW1wbGUub3JnMA0GCSqGSIb3DQEBCwUAA4IB

+AQDPI5uZd8DhSNKMvYF5bxOshd6h6UJ7YzZS7K6fhiygltdqzkHQ/5+4yiuUkDe4

+hOZlH8MCfXQy5jVZDTk24yNchpdfie5Bswn4SmQVQh3QyzOLxizoh0rLCf2PHueu

+dNVNhfiiJNJ5kd8MIuVG7CPK68dP0QrVR+DihROuJgvGB3ClKttLrgle19t4PFRR

+2wW6hJT9aXEjzLNyN1QFZKoShuiGX4xwjZh7VyKkV64p8hjojhcLk6dQkel+Jw4y

+OP26XbVfM8/6KG8f6WAZ8P0qJwHlhmi0EvRTnEpAM8WuenOeZH6ERZ9uZbRGh6xx

+LKQu2Aw2+bOEZ2vUtz0dBhX8

+-----END CERTIFICATE-----

diff --git a/test/certs/nccaothername-key.pem b/test/certs/nccaothername-key.pem

new file mode 100644

index 0000000000..d3e300ac2f

--- /dev/null

+++ b/test/certs/nccaothername-key.pem

@@ -0,0 +1,28 @@

+-----BEGIN PRIVATE KEY-----

+MIIEvwIBADANBgkqhkiG9w0BAQEFAASCBKkwggSlAgEAAoIBAQDdA8fnovAoLUSp

+w3GIi8F+L6wOPGrf6P8319uF/1mWTNaPR1CqNRUATb4REibvoKj8biHj65Pvy9uV

+3UasAipPMJFl9FyM9fKuaKzh1FBQFjSt4NBQ4+jfB3fLqzSGwyeOBQsfv9J/D6Yo

+bfxGDd2lTluXp6m4GfhBLftwFBuom4nkXRq4vYOKISCMetDJlRy27k/03FWcWnls

+k5eolprGKLFMqpYU7btbhrW1bZAgIQWJaFb8+CeXgJlbvybiW7DcW8VXjvUPCo+p

+2+Izz3Rr2dyT3Gm21q8+S8Gnq3gX+SD61xFXUE5WAYCNKU89ghAx0iK3e480VF//

+RAtoDJOlAgMBAAECggEAMFSJlCyEFlER3Qq9asXe9eRgXEuXdmfZ2aEVIuf8M/sR

+B0tpxxKtCUA24j5FL+0CzxKZTCFBnDRIzCyTbf1aOa9t+CzXyUZmP3/p4EdgmabF

+dcl93FZ+X7kfF/VUGu0Vmv+c12BH3Fu0cs5cVohlMecg7diu6zCYok43F+L5ymRy

+2mTcKkGc0ShWizj8Z9R3WJGssZOlxbxa/Zr4rZwRC24UVhfN8AfGWYx/StyQPQIw

+gtbbtOmwbyredQmY4jwNqgrnfZS9bkWwJbRuCmD5l7lxubBgcHQpoM+DQVeOLZIq

+uksFXeNfal9G5Bo747MMzpD7dJMCGmX+gbMY5oZF+QKBgQDs2MbY4nbxi+fV+KuV

+zUvis8m8Lpzf3T6NLkgSkUPRN9tGr95iLIrB/bRPJg5Ne02q/cT7d86B9rpE42w7

+eeIF9fANezX2AF8LUqNZhIR23J3tfB/eqGlJRZeMNia+lD09a7SWGwrS7sufY1I+

+JQGcHx77ntt+eQT1MUJ1skF06QKBgQDu4z+TW4QIA5ItxIReVdcfh5e3xLkzDEVP

+3KNo9tpXxvPwqapdeBh6c9z4Lqe3MKr5UPlDvVW+o40t6OjKxDCXczB8+JAM0OyX

+8V+K3zXXUxRgieSd3oMncTylSWIvouPP3aW37B67TKdRlRHgaBrpJT2wdk3kYR4t

+62J1eDdjXQKBgQDMsY0pZI/nskJrar7geM1c4IU5Xg+2aj/lRFqFsYYrC1s3fEd2

+EYjan6l1vi4eSLKXVTspGiIfsFzLrMGdpXjyLduJyzKXqTp7TrBebWkOUR0sYloo

+1OQprzuKskJJ81P6AVvRXw27vyW8Wtp5WwJJK5xbWq/YXj8qqagGkEiCAQKBgQCc

+RK3XAFurPmLGa7JHX5Hc/z8BKMAZo6JHrsZ6qFiGaRA0U1it0hz5JYfcFfECheSi

+ORUF+fn4PlbhPGXkFljPCbwjVBovOBA9CNl+J6u50pAW4r1ZhDB5gbqxSQLgtIaf

++JcqbFxiG6+sT36lNJS+BO2I3KrxhZJPaZY7z8szxQKBgQDRy70XzwOk8jXayiF2

+ej2IN7Ow9cgSE4tLEwR/vCjxvOlWhA3jC3wxoggshGJkpbP3DqLkQtwQm0h1lM8J

+QNtFwKzjtpf//bTlfFq08/YxWimTPMqzcV2PgRacB8P3yf1r8T7M4fA5TORCDWpW

+5FtOCFEmwQHTR8lu4c63qfxkEQ==

+-----END PRIVATE KEY-----

diff --git a/test/certs/setup.sh b/test/certs/setup.sh

index b9766aab20..2240cd9df0 100755

--- a/test/certs/setup.sh

+++ b/test/certs/setup.sh

@@ -388,6 +388,17 @@ REQMASK=MASK:0x800 ./mkcert.sh req badalt7-key "O = Bad NC Test Certificate 7" \

     "email.1 = good@good.org" "email.2 = any@good.com" \

     "IP = 127.0.0.1" "IP = 192.168.0.1"

+# Certs for CVE-2022-4203 testcase

+

+NC="excluded;otherName:SRVName;UTF8STRING:foo@example.org" ./mkcert.sh genca \

+    "Test NC CA othername" nccaothername-key nccaothername-cert \

+    root-key root-cert

+

+./mkcert.sh req alt-email-key "O = NC email in othername Test Certificate" | \

+    ./mkcert.sh geneealt bad-othername-key bad-othername-cert \

+    nccaothername-key nccaothername-cert \

+    "otherName.1 = SRVName;UTF8STRING:foo@example.org"

+

 # RSA-PSS signatures

 # SHA1

 ./mkcert.sh genee PSS-SHA1 ee-key ee-pss-sha1-cert ca-key ca-cert \

diff --git a/test/recipes/25-test_verify.t b/test/recipes/25-test_verify.t

index 4613489f57..e6a2bca731 100644

--- a/test/recipes/25-test_verify.t

+++ b/test/recipes/25-test_verify.t

@@ -29,7 +29,7 @@ sub verify {

     run(app([@args]));

 }

-plan tests => 162;

+plan tests => 163;

 # Canonical success

 ok(verify("ee-cert", "sslserver", ["root-cert"], ["ca-cert"]),

@@ -402,6 +402,9 @@ ok(!verify("badalt9-cert", "", ["root-cert"], ["ncca1-cert", "ncca3-cert"], ),

 ok(!verify("badalt10-cert", "", ["root-cert"], ["ncca1-cert", "ncca3-cert"], ),

    "Name constraints nested DNS name excluded");

+ok(!verify("bad-othername-cert", "", ["root-cert"], ["nccaothername-cert"], ),

+   "CVE-2022-4203 type confusion test");

+

 #Check that we get the expected failure return code

 with({ exit_checker => sub { return shift == 2; } },

      sub {

-- 

2.39.1