asn: MatchBaseName fixes

Author: rizlik

tests/api/test_asn.c

@@ -21,6 +21,8 @@
 
 #include <tests/unit.h>
 
+#include <wolfssl/internal.h>
+
 #include <tests/api/test_asn.h>
 
 #if defined(WC_ENABLE_ASYM_KEY_EXPORT) && defined(HAVE_ED25519)
@@ -638,3 +640,150 @@ int test_wc_IndexSequenceOf(void)
 
     return EXPECT_RESULT();
 }
+
+int test_wolfssl_local_MatchBaseName(void)
+{
+    EXPECT_DECLS;
+
+#if !defined(NO_CERTS) && !defined(NO_ASN) && !defined(IGNORE_NAME_CONSTRAINTS)
+    /*
+     * Tests for DNS type (ASN_DNS_TYPE = 0x02)
+     */
+
+    /* Positive tests - should match */
+    /* Exact match */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "domain.com", 10, "domain.com", 10), 1);
+    /* Case insensitive match */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "DOMAIN.COM", 10, "domain.com", 10), 1);
+    /* Subdomain match (RFC 5280: adding labels to the left) */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "sub.domain.com", 14, "domain.com", 10), 1);
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "a.b.domain.com", 14, "domain.com", 10), 1);
+    /* Leading dot constraint with subdomain (not RFC 5280 compliant for DNS,
+     * but kept for backwards compatibility) */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "sub.domain.com", 14, ".domain.com", 11), 1);
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "a.b.domain.com", 14, ".domain.com", 11), 1);
+
+    /* Negative tests - should NOT match */
+    /* Bug #3: fakedomain.com should NOT match domain.com (no dot boundary) */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "fakedomain.com", 14, "domain.com", 10), 0);
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "notdomain.com", 13, "domain.com", 10), 0);
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "xexample.com", 12, "example.com", 11), 0);
+    /* Bug #3: fakedomain.com should NOT match .domain.com */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "fakedomain.com", 14, ".domain.com", 11), 0);
+    /* domain.com should NOT match .domain.com (leading dot requires subdomain) */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "domain.com", 10, ".domain.com", 11), 0);
+    /* Different domain */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "other.com", 9, "domain.com", 10), 0);
+    /* Name starting with dot */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                ".domain.com", 11, "domain.com", 10), 0);
+
+    /*
+     * Tests for email type (ASN_RFC822_TYPE = 0x01)
+     */
+
+    /* Positive tests - should match */
+    /* Exact email match */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "[email protected]", 15, "[email protected]", 15), 1);
+    /* Email with domain constraint (leading dot) - subdomain present */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "[email protected]", 19, ".domain.com", 11), 1);
+    /* Email with domain constraint (no leading dot) - exact domain */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "[email protected]", 15, "domain.com", 10), 1);
+
+    /* Negative tests - should NOT match */
+    /* Bug #2: [email protected] should NOT match .domain.com (subdomain required) */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "[email protected]", 15, ".domain.com", 11), 0);
+    /* Bug #2: [email protected] should NOT match domain.com (exact domain only) */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "[email protected]", 19, "domain.com", 10), 0);
+    /* Bug #1: @ at start is invalid */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "@domain.com", 11, ".domain.com", 11), 0);
+    /* Bug #1: @ at end is invalid */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "user@", 5, ".domain.com", 11), 0);
+    /* Bug #1: double @ is invalid */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "user@@domain.com", 16, ".domain.com", 11), 0);
+    /* Bug #1: multiple @ is invalid */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "user@[email protected]", 21, ".domain.com", 11), 0);
+    /* No @ in email name */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "userdomain.com", 14, ".domain.com", 11), 0);
+    /* Email domain doesn't match constraint */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "[email protected]", 14, ".domain.com", 11), 0);
+    /* Email suffix without dot boundary (fakedomain) */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "[email protected]", 19, ".domain.com", 11), 0);
+    /* Base constraint with invalid @ position */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "[email protected]", 15, "@domain.com", 11), 0);
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_RFC822_TYPE,
+                "[email protected]", 15, "user@", 5), 0);
+
+    /*
+     * Tests for directory type (ASN_DIR_TYPE = 0x04)
+     */
+
+    /* Positive tests - should match */
+    /* Exact match */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DIR_TYPE,
+                "CN=test", 7, "CN=test", 7), 1);
+    /* Prefix match (name longer than base) */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DIR_TYPE,
+                "CN=test,O=org", 13, "CN=test", 7), 1);
+
+    /* Negative tests - should NOT match */
+    /* Different content */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DIR_TYPE,
+                "CN=other", 8, "CN=test", 7), 0);
+    /* Case sensitive for directory */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DIR_TYPE,
+                "CN=TEST", 7, "CN=test", 7), 0);
+
+    /*
+     * Edge cases and error handling
+     */
+
+    /* NULL pointers */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                NULL, 10, "domain.com", 10), 0);
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "domain.com", 10, NULL, 10), 0);
+    /* Empty/zero size */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "", 0, "domain.com", 10), 0);
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "domain.com", 10, "", 0), 0);
+    /* Invalid type */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(0xFF,
+                "domain.com", 10, "domain.com", 10), 0);
+    /* Name starting with dot */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                ".", 1, ".", 1), 0);
+    /* Name shorter than base */
+    ExpectIntEQ(wolfssl_local_MatchBaseName(ASN_DNS_TYPE,
+                "a.com", 5, "domain.com", 10), 0);
+
+#endif /* !NO_CERTS && !NO_ASN && !IGNORE_NAME_CONSTRAINTS */
+
+    return EXPECT_RESULT();
+}

tests/api/test_asn.h

@@ -27,10 +27,12 @@
 int test_SetAsymKeyDer(void);
 int test_GetSetShortInt(void);
 int test_wc_IndexSequenceOf(void);
+int test_wolfssl_local_MatchBaseName(void);
 
 #define TEST_ASN_DECLS                                              \
     TEST_DECL_GROUP("asn", test_SetAsymKeyDer),                     \
     TEST_DECL_GROUP("asn", test_GetSetShortInt),                    \
-    TEST_DECL_GROUP("asn", test_wc_IndexSequenceOf)
+    TEST_DECL_GROUP("asn", test_wc_IndexSequenceOf),                \
+    TEST_DECL_GROUP("asn", test_wolfssl_local_MatchBaseName)
 
 #endif /* WOLFCRYPT_TEST_ASN_H */

wolfcrypt/src/asn.c

@@ -19315,8 +19315,9 @@ int ConfirmSignature(SignatureCtx* sigCtx,
 
 #ifndef IGNORE_NAME_CONSTRAINTS
 
-static int MatchBaseName(int type, const char* name, int nameSz,
-                         const char* base, int baseSz)
+WOLFSSL_TEST_VIS int wolfssl_local_MatchBaseName(int type, const char* name,
+                                                 int nameSz, const char* base,
+                                                 int baseSz)
 {
     if (base == NULL || baseSz <= 0 || name == NULL || nameSz <= 0 ||
             name[0] == '.' || nameSz < baseSz ||
@@ -19333,6 +19334,8 @@ static int MatchBaseName(int type, const char* name, int nameSz,
     if (type == ASN_RFC822_TYPE) {
         const char* p = NULL;
         int count = 0;
+        int baseIsEmail = 0;
+        int atPos = -1;
 
         if (base[0] != '.') {
             p = base;
@@ -19344,39 +19347,61 @@ static int MatchBaseName(int type, const char* name, int nameSz,
                 p++;
             }
 
-            /* No '@' in base, reset p to NULL */
-            if (count >= baseSz)
-                p = NULL;
+            if (count < baseSz) {
+                /* '@' found in base - validate it's not at start/end and only one */
+                if (count == 0 || count == baseSz - 1)
+                    return 0; /* '@' at start or end of base is invalid */
+                baseIsEmail = 1;
+            }
         }
 
-        if (p == NULL) {
-            /* Base isn't an email address, it is a domain name,
-             * wind the name forward one character past its '@'. */
-            p = name;
-            count = 0;
-            while (*p != '@' && count < baseSz) {
-                count++;
-                p++;
+        /* verify that name is a valid email address, store @ position */
+        p = name;
+        count = 0;
+        while (count < nameSz) {
+            if (*p == '@') {
+                if (atPos >= 0)
+                    return 0; /* Multiple '@' in name is invalid */
+                atPos = count;
             }
+            count++;
+            p++;
+        }
 
-            if (count < baseSz && *p == '@') {
-                name = p + 1;
-                nameSz -= count + 1;
-            }
+        /* Validate '@' exists and is not at start or end */
+        if (atPos < 0 || atPos == 0 || atPos == nameSz - 1)
+            return 0;
+
+        if (!baseIsEmail) {
+            /* Base isn't an email address but a domain or host.
+             * wind the name forward one character past its '@'. */
+            name = name + atPos + 1;
+            nameSz -= atPos + 1;
         }
     }
 
     /* RFC 5280 section 4.2.1.10
      * "...Any DNS name that can be constructed by simply adding zero or more
      *  labels to the left-hand side of the name satisfies the name constraint."
      * i.e www.host.example.com works for host.example.com name constraint and
-     * host1.example.com does not. */
+     * host1.example.com does not.
+     *
+     * Note: For DNS type, RFC 5280 does not allow leading dot in constraint.
+     * However, we accept it here for backwards compatibility. */
     if (type == ASN_DNS_TYPE || (type == ASN_RFC822_TYPE && base[0] == '.')) {
         int szAdjust = nameSz - baseSz;
+        /* Check dot boundary: if there's a prefix and base doesn't start with
+         * '.', the character before the matched suffix must be '.'.
+         * When base starts with '.', the dot is included in the comparison. */
+        if (szAdjust > 0 && base[0] != '.' && name[szAdjust - 1] != '.')
+            return 0;
         name += szAdjust;
         nameSz -= szAdjust;
     }
 
+    if (nameSz != baseSz)
+        return 0;
+
     while (nameSz > 0) {
         if (XTOLOWER((unsigned char)*name) !=
                                                XTOLOWER((unsigned char)*base))
@@ -19408,8 +19433,8 @@ static int PermittedListOk(DNS_entry* name, Base_entry* dnsList, byte nameType)
         if (current->type == nameType) {
             need = 1; /* restriction on permitted names is set for this type */
             if (name->len >= current->nameSz &&
-                MatchBaseName(nameType, name->name, name->len,
-                              current->name, current->nameSz)) {
+                wolfssl_local_MatchBaseName(nameType, name->name, name->len,
+                                            current->name, current->nameSz)) {
                 match = 1; /* found the current name in the permitted list*/
                 break;
             }
@@ -19439,8 +19464,8 @@ static int IsInExcludedList(DNS_entry* name, Base_entry* dnsList, byte nameType)
     while (current != NULL) {
         if (current->type == nameType) {
             if (name->len >= current->nameSz &&
-                MatchBaseName(nameType, name->name, name->len,
-                              current->name, current->nameSz)) {
+                wolfssl_local_MatchBaseName(nameType, name->name, name->len,
+                                            current->name, current->nameSz)) {
                 ret = 1;
                 break;
             }

wolfssl/internal.h

@@ -2218,6 +2218,11 @@ WOLFSSL_LOCAL int  CheckForAltNames(DecodedCert* dCert, const char* domain,
                                     unsigned int flags, byte isIP);
 WOLFSSL_LOCAL int  CheckIPAddr(DecodedCert* dCert, const char* ipasc);
 WOLFSSL_LOCAL void CopyDecodedName(WOLFSSL_X509_NAME* name, DecodedCert* dCert, int nameType);
+#ifndef IGNORE_NAME_CONSTRAINTS
+WOLFSSL_TEST_VIS int  wolfssl_local_MatchBaseName(int type, const char* name,
+                                                  int nameSz, const char* base,
+                                                  int baseSz);
+#endif
 #endif
 WOLFSSL_LOCAL int  SetupTicket(WOLFSSL* ssl);
 WOLFSSL_LOCAL int  CreateTicket(WOLFSSL* ssl);