Fix printing empty names in certificates

The empty-issuer-cert.pem certificate was created with:

    wolfssl genkey rsa -size 2048 -out mykey -outform pem -output KEY
    wolfssl req -new -days 3650 -key mykey.priv -out empty-issuer-cert.pem -x509

Prior to this fix this command would error printing the certificate:

    wolfssl x509 -inform pem -in empty-issuer-cert.pem -text

Author: holtrop-wolfssl

certs/empty-issuer-cert.pem

@@ -0,0 +1,17 @@
+-----BEGIN CERTIFICATE-----
+MIICnTCCAYWgAwIBAgIQToFDJ79b/2ZHXVCCCNt8VTANBgkqhkiG9w0BAQsFADAA
+MB4XDTI1MDYxMjIwMTE0N1oXDTM1MDYxMDIwMTE0N1owADCCASIwDQYJKoZIhvcN
+AQEBBQADggEPADCCAQoCggEBAOI/4VVa7Pk0NWS7BQGM4ZbuTapoza4baS9+TRbT
+QUqgN28gChSw/kHNp4BU/KQhKN/Mp0NN2vmYzRVDB25L1HWph8TqCO+Kqa6XYvnN
+CgMEYyumWYWJr2u6hjpF19QeiZ26ezgnDbpkFiysdzn7+MG+PjtRj3mcnaKb1PjK
+1P2j9pcrhc/WLo39y+OF2+3nW7JeqJHgAdXgeTLPaFyf91ktaWSLmc3pLqlurLup
+pcClP6CKkLClz2Re3eM2/qdTEDO1pU8DRPc5v8qHxuX4K4DD0HYwWXFWDW8Ce+Ta
+3o2hrM3mKtQH4n2xoJhJKXlcyrOu++SE4iyaSnooYLxkIqsCAwEAAaMTMBEwDwYD
+VR0TAQH/BAUwAwEB/zANBgkqhkiG9w0BAQsFAAOCAQEAhBolr3oHIKUrKp0eC1AO
+1+byE+vjuDIs0JBtAQ6TD4VTb9E2YavckOXcs0deHM7FUY2TcZ01A0msqtTYYyJ4
+9D325+jrh4FIACrOOyVblWaO+lentmBhexzEXPWS6EhYTDTeZvY1AzDRTkBKm245
+yqeqALL9K5KWdKesQurmt2FKzlc0WSQJmyfVf0IUdHgF05yjECOksYQdFDpeewNF
++1IKwHKemEtnIYatGv0w7XNeUrGTsgVa9vk0Uzg+wIh9+ZeJpOS21010ph6BkaeC
+8Y1+kK7bZc0kBw5V20w16QtbE2MZucjlNLzjvAW5rVFNlBaiO7WIHPTvJfk38hq9
+zw==
+-----END CERTIFICATE-----

certs/include.am

@@ -30,6 +30,7 @@ EXTRA_DIST += \
              certs/ecc-keyPkcs8.der \
              certs/ecc-client-key.pem \
              certs/ecc-client-keyPub.pem \
+             certs/empty-issuer-cert.pem \
              certs/client-ecc-cert.pem \
              certs/client-ca.pem \
              certs/dh2048.pem \

src/x509.c

@@ -13874,7 +13874,7 @@ int wolfSSL_X509_NAME_print_ex(WOLFSSL_BIO* bio, WOLFSSL_X509_NAME* name,
 
     WOLFSSL_ENTER("wolfSSL_X509_NAME_print_ex");
 
-    if ((name == NULL) || (name->sz == 0) || (bio == NULL))
+    if ((name == NULL) || (bio == NULL))
         return WOLFSSL_FAILURE;
 
     XMEMSET(eqStr, 0, sizeof(eqStr));

tests/api.c

@@ -22154,7 +22154,7 @@ static int test_wolfSSL_X509_NAME_print_ex(void)
     ExpectIntEQ(X509_NAME_print_ex(NULL, NULL, 0, 0), WOLFSSL_FAILURE);
     ExpectIntEQ(X509_NAME_print_ex(membio, NULL, 0, 0), WOLFSSL_FAILURE);
     ExpectIntEQ(X509_NAME_print_ex(NULL, name, 0, 0), WOLFSSL_FAILURE);
-    ExpectIntEQ(X509_NAME_print_ex(membio, empty, 0, 0), WOLFSSL_FAILURE);
+    ExpectIntEQ(X509_NAME_print_ex(membio, empty, 0, 0), WOLFSSL_SUCCESS);
     ExpectIntEQ(X509_NAME_print_ex(membio, name, 0, 0), WOLFSSL_SUCCESS);
     wolfSSL_X509_NAME_free(empty);
     BIO_free(membio);
@@ -22178,6 +22178,23 @@ static int test_wolfSSL_X509_NAME_print_ex(void)
     BIO_free(bio);
     name = NULL;
 
+    /* Test with empty issuer cert. */
+    ExpectNotNull(bio = BIO_new(BIO_s_file()));
+    ExpectIntGT(BIO_read_filename(bio, noIssuerCertFile), 0);
+    ExpectNotNull(PEM_read_bio_X509(bio, &x509, NULL, NULL));
+    ExpectNotNull(name = X509_get_subject_name(x509));
+
+    ExpectNotNull(membio = BIO_new(BIO_s_mem()));
+    ExpectIntEQ(X509_NAME_print_ex(membio, name, 0, 0), WOLFSSL_SUCCESS);
+    /* Should be empty string "" */
+    ExpectIntEQ((memSz = BIO_get_mem_data(membio, &mem)), 0);
+
+    BIO_free(membio);
+    membio = NULL;
+    X509_free(x509);
+    BIO_free(bio);
+    name = NULL;
+
     /* Test normal case without escaped characters */
     {
         /* Create name: "/C=US/CN=wolfssl.com" */

wolfssl/test.h

@@ -527,6 +527,7 @@ err_sys_with_errno(const char* msg)
 #define cliEd448CertFile  "certs/ed448/client-ed448.pem"
 #define cliEd448KeyFile   "certs/ed448/client-ed448-priv.pem"
 #define caEd448CertFile   "certs/ed448/ca-ed448.pem"
+#define noIssuerCertFile  "certs/empty-issuer-cert.pem"
 #define caCertFolder      "certs/"
 #ifdef HAVE_WNR
     /* Whitewood netRandom default config file */
@@ -590,6 +591,7 @@ err_sys_with_errno(const char* msg)
 #define cliEd448CertFile  "./certs/ed448/client-ed448.pem"
 #define cliEd448KeyFile   "./certs/ed448/client-ed448-priv.pem"
 #define caEd448CertFile   "./certs/ed448/ca-ed448.pem"
+#define noIssuerCertFile  "./certs/empty-issuer-cert.pem"
 #define caCertFolder      "./certs/"
 #ifdef HAVE_WNR
     /* Whitewood netRandom default config file */