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Restore error code from DecodeGeneralName

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This commit is contained in:
Eric Blankenhorn
2026-06-26 11:11:22 -05:00
parent 0cecccdf6e
commit e1a2ba3b02
6 changed files with 112 additions and 53 deletions
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doc/dox_comments/header_files/ssl.h
+9
View File
@@ -13859,6 +13859,14 @@ int wolfSSL_set_msg_callback_arg(WOLFSSL *ssl, void* arg);
\param cert a pointer to the wolfSSL_X509 structure.
\warning The returned value is a bare C string with no length. A dNSName,
rfc822Name, or uniformResourceIdentifier SAN may legally contain an embedded
NUL byte (RFC 6125 Sec. 6.3 treats such a name as an invalid presented
identifier, not a malformed certificate, so the certificate still parses),
which silently truncates the returned string. Do not use strlen or strcmp on
the result for security comparisons; use wolfSSL_X509_get_ext_d2i and the
GENERAL_NAME ASN1_STRING length instead.
_Example_
\code
WOLFSSL_X509 x509 = (WOLFSSL_X509*)XMALLOC(sizeof(WOLFSSL_X509), NULL,
@@ -13872,6 +13880,7 @@ int wolfSSL_set_msg_callback_arg(WOLFSSL *ssl, void* arg);
\sa wolfSSL_X509_get_issuer_name
\sa wolfSSL_X509_get_subject_name
\sa wolfSSL_X509_get_ext_d2i
*/
char* wolfSSL_X509_get_next_altname(WOLFSSL_X509*);
tests/api/test_asn.c
+21 -4
View File
@@ -1378,7 +1378,9 @@ int test_wc_DecodeRsaPssParams(void)
}
/* Test that DecodeAltNames rejects a SAN entry whose length exceeds the
* remaining SEQUENCE length (integer underflow on the length tracker). */
* remaining SEQUENCE length (integer underflow on the length tracker), and
* that a dNSName SAN carrying an embedded NUL is stored rather than rejected
* so verification reports a name mismatch instead of a parse error. */
int test_DecodeAltNames_length_underflow(void)
{
EXPECT_DECLS;
@@ -1481,14 +1483,29 @@ int test_DecodeAltNames_length_underflow(void)
WC_NO_ERR_TRACE(ASN_PARSE_E));
wc_FreeDecodedCert(&cert);
/* NUL in dNSName SAN must be rejected per RFC 5280 4.2.1.6. */
/* An embedded NUL in a dNSName SAN is an invalid presented identifier
* (RFC 6125 Sec. 6.3 / RFC 9525 Sec. 6.3), not a malformed certificate.
* Set the third byte of the 4-byte dNSName ("a*b*") to NUL, giving
* "a*\0*". The certificate must still parse: the entry is stored with
* its embedded NUL intact (length 4, not truncated) so that hostname
* verification reports DOMAIN_NAME_MISMATCH rather than the parser
* aborting with ASN_PARSE_E (regression from curl test 311). */
XMEMCPY(bad_san_cert, good_san_cert, sizeof(good_san_cert));
bad_san_cert[SAN_SEQ_LEN_OFFSET + 5] = 0x00;
wc_InitDecodedCert(&cert, bad_san_cert, (word32)sizeof(bad_san_cert),
NULL);
ExpectIntEQ(wc_ParseCert(&cert, CERT_TYPE, NO_VERIFY, NULL),
WC_NO_ERR_TRACE(ASN_PARSE_E));
ExpectIntEQ(wc_ParseCert(&cert, CERT_TYPE, NO_VERIFY, NULL), 0);
ExpectNotNull(cert.altNames);
if (cert.altNames != NULL) {
ExpectIntEQ(cert.altNames->type, ASN_DNS_TYPE);
ExpectIntEQ(cert.altNames->len, 4);
/* Embedded NUL preserved at offset 2: stored, not truncated. */
ExpectNotNull(cert.altNames->name);
if (cert.altNames->name != NULL) {
ExpectIntEQ(cert.altNames->name[2], 0x00);
}
}
wc_FreeDecodedCert(&cert);
#endif /* !NO_CERTS && !NO_RSA && !NO_ASN */
tests/api/test_ossl_x509.c
+67
View File
@@ -1795,6 +1795,73 @@ int test_wolfSSL_MatchDomainName_idn(void)
return EXPECT_RESULT();
}
/* Regression test mirroring curl test 311 ("HTTPS wrong subjectAltName but
* right CN"). The leaf Subject CN is the wanted host ("localhost") while its
* only dNSName SAN carries an embedded NUL ("localhost\0h"). Such a SAN is an
* invalid presented identifier (RFC 6125 Sec. 6.3 / RFC 9525 Sec. 6.3), not a
* malformed certificate, so the certificate must parse. Verification must then
* report DOMAIN_NAME_MISMATCH: the SAN presence suppresses Subject CN fallback
* and the NUL name can never match the NUL-free reference host, so the
* otherwise-correct CN must not rescue it. Before the parser stored rather than
* rejected the entry, verification aborted earlier with ASN_PARSE_E. */
int test_wolfSSL_X509_check_host_embedded_nul_san(void)
{
EXPECT_DECLS;
#if !defined(NO_FILESYSTEM) && !defined(NO_CERTS) && !defined(NO_RSA) && \
defined(OPENSSL_EXTRA) && defined(WOLFSSL_CERT_GEN) && \
defined(WOLFSSL_CERT_EXT) && defined(WOLFSSL_ALT_NAMES) && \
!defined(NO_SHA256) && !defined(NO_ASN)
WOLFSSL_EVP_PKEY* priv = NULL;
WOLFSSL_X509* leaf = NULL;
const char* server_cert = "./certs/test/server-goodcn.pem";
const char host[] = "localhost";
/* dNSName "localhost" + embedded NUL + 'h', length 11. */
static const byte nulSan[] = {
'l', 'o', 'c', 'a', 'l', 'h', 'o', 's', 't', '\0', 'h'
};
byte* keyPt = NULL;
const byte* der = NULL;
int derSz = 0;
DecodedCert dCert;
int parseRet = -1;
keyPt = (byte*)server_key_der_2048;
ExpectNotNull(priv = wolfSSL_d2i_PrivateKey(EVP_PKEY_RSA, NULL,
(const unsigned char**)&keyPt, sizeof_server_key_der_2048));
/* server-goodcn.pem has CN=localhost and no SAN; add one dNSName SAN that
* carries an embedded NUL, then re-sign so the SAN is serialized. */
ExpectNotNull(leaf = wolfSSL_X509_load_certificate_file(server_cert,
WOLFSSL_FILETYPE_PEM));
ExpectIntEQ(wolfSSL_X509_add_altname_ex(leaf, (const char*)nulSan,
sizeof(nulSan), ASN_DNS_TYPE), WOLFSSL_SUCCESS);
ExpectIntGT(wolfSSL_X509_sign(leaf, priv, EVP_sha256()), 0);
/* Regression pin: the signed certificate must parse despite the embedded
* NUL (it aborted with ASN_PARSE_E before the parser stored the entry). */
ExpectNotNull(der = wolfSSL_X509_get_der(leaf, &derSz));
ExpectIntGT(derSz, 0);
if ((der != NULL) && (derSz > 0)) {
wc_InitDecodedCert(&dCert, der, (word32)derSz, NULL);
parseRet = wc_ParseCert(&dCert, CERT_TYPE, NO_VERIFY, NULL);
ExpectIntEQ(parseRet, 0);
wc_FreeDecodedCert(&dCert);
}
/* Security pin: the host must still be rejected. With parsing now
* succeeding, the only remaining failure path in check_host for a
* non-IP host is the hostname comparison, so a failure here means
* DOMAIN_NAME_MISMATCH: the SAN presence suppressed CN fallback and the
* NUL name did not match. The correct CN must not rescue the wrong SAN. */
ExpectIntEQ(wolfSSL_X509_check_host(leaf, host, XSTRLEN(host), 0, NULL),
WC_NO_ERR_TRACE(WOLFSSL_FAILURE));
wolfSSL_X509_free(leaf);
wolfSSL_EVP_PKEY_free(priv);
#endif
return EXPECT_RESULT();
}
int test_wolfSSL_X509_max_altnames(void)
{
EXPECT_DECLS;
tests/api/test_ossl_x509.h
+2
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@@ -50,6 +50,7 @@ int test_wolfSSL_X509_name_match2(void);
int test_wolfSSL_X509_name_match3(void);
int test_wolfssl_local_IsValidFQDN(void);
int test_wolfSSL_MatchDomainName_idn(void);
int test_wolfSSL_X509_check_host_embedded_nul_san(void);
int test_wolfSSL_X509_max_altnames(void);
int test_wolfSSL_X509_max_name_constraints(void);
int test_wolfSSL_X509_check_ca(void);
@@ -83,6 +84,7 @@ int test_wolfSSL_X509_cmp(void);
TEST_DECL_GROUP("ossl_x509", test_wolfSSL_X509_name_match3), \
TEST_DECL_GROUP("ossl_x509", test_wolfssl_local_IsValidFQDN), \
TEST_DECL_GROUP("ossl_x509", test_wolfSSL_MatchDomainName_idn), \
TEST_DECL_GROUP("ossl_x509", test_wolfSSL_X509_check_host_embedded_nul_san),\
TEST_DECL_GROUP("ossl_x509", test_wolfSSL_X509_max_altnames), \
TEST_DECL_GROUP("ossl_x509", test_wolfSSL_X509_max_name_constraints), \
TEST_DECL_GROUP("ossl_x509", test_wolfSSL_X509_check_ca), \
wolfcrypt/src/asn.c
+7 -26
View File
@@ -18900,31 +18900,20 @@ static int DecodeOtherName(DecodedCert* cert, const byte* input,
* @return ASN_UNKNOWN_OID_E when the OID cannot be verified.
* @return MEMORY_E when dynamic memory allocation fails.
*/
/* Reject IA5String SAN content that cannot legally appear in
* dNSName / rfc822Name / URI per RFC 5280 4.2.1.6. Currently just NUL. */
static int DecodeGeneralNameCheckChars(const byte* input, int len)
{
int i;
for (i = 0; i < len; i++) {
if (input[i] == 0) {
return ASN_PARSE_E;
}
}
return 0;
}
static int DecodeGeneralName(const byte* input, word32* inOutIdx, byte tag,
int len, DecodedCert* cert)
{
int ret = 0;
word32 idx = *inOutIdx;
/* GeneralName choice: dnsName */
/* GeneralName choice: dnsName.
* An embedded NUL makes a dNSName an invalid presented identifier
* (RFC 6125 Sec. 6.3 / RFC 9525 Sec. 6.3), not a malformed certificate.
* Store it so its presence still suppresses Subject CN fallback, but
* length-based matching in MatchDomainName never matches a NUL-free
* reference hostname. The result is DOMAIN_NAME_MISMATCH at verification
* time rather than ASN_PARSE_E at parse time. */
if (tag == (ASN_CONTEXT_SPECIFIC | ASN_DNS_TYPE)) {
ret = DecodeGeneralNameCheckChars(input + idx, len);
if (ret != 0) {
return ret;
}
ret = SetDNSEntry(cert->heap, (const char*)(input + idx), len,
ASN_DNS_TYPE, &cert->altNames);
if (ret == 0) {
@@ -18952,10 +18941,6 @@ static int DecodeGeneralName(const byte* input, word32* inOutIdx, byte tag,
}
/* GeneralName choice: rfc822Name */
else if (tag == (ASN_CONTEXT_SPECIFIC | ASN_RFC822_TYPE)) {
ret = DecodeGeneralNameCheckChars(input + idx, len);
if (ret != 0) {
return ret;
}
ret = SetDNSEntry(cert->heap, (const char*)(input + idx), len,
ASN_RFC822_TYPE, &cert->altEmailNames);
if (ret == 0) {
@@ -18964,10 +18949,6 @@ static int DecodeGeneralName(const byte* input, word32* inOutIdx, byte tag,
}
/* GeneralName choice: uniformResourceIdentifier */
else if (tag == (ASN_CONTEXT_SPECIFIC | ASN_URI_TYPE)) {
ret = DecodeGeneralNameCheckChars(input + idx, len);
if (ret != 0) {
return ret;
}
WOLFSSL_MSG("\tPutting URI into list but not using");
#ifndef WOLFSSL_NO_ASN_STRICT
wolfcrypt/src/asn_orig.c
+6 -23
View File
@@ -3125,19 +3125,6 @@ static int DecodeConstructedOtherName(DecodedCert* cert, const byte* input,
return ret;
}
/* Reject IA5String SAN content that cannot legally appear in
* dNSName / rfc822Name / URI per RFC 5280 4.2.1.6. Currently just NUL. */
static int DecodeGeneralNameCheckChars(const byte* input, int len)
{
int i;
for (i = 0; i < len; i++) {
if (input[i] == 0) {
return ASN_PARSE_E;
}
}
return 0;
}
static int DecodeAltNames(const byte* input, word32 sz, DecodedCert* cert)
{
word32 idx = 0;
@@ -3200,9 +3187,12 @@ static int DecodeAltNames(const byte* input, word32 sz, DecodedCert* cert)
if ((word32)strLen + idx > sz) {
return BUFFER_E;
}
if (DecodeGeneralNameCheckChars(&input[idx], strLen) != 0) {
return ASN_PARSE_E;
}
/* An embedded NUL makes a dNSName an invalid presented identifier
* (RFC 6125 Sec. 6.3), not a malformed certificate. Store it so
* its presence still suppresses Subject CN fallback; length-based
* matching in MatchDomainName never matches a NUL-free hostname,
* giving DOMAIN_NAME_MISMATCH at verification rather than
* ASN_PARSE_E at parse time. */
dnsEntry = AltNameNew(cert->heap);
if (dnsEntry == NULL) {
@@ -3292,9 +3282,6 @@ static int DecodeAltNames(const byte* input, word32 sz, DecodedCert* cert)
if ((word32)strLen + idx > sz) {
return BUFFER_E;
}
if (DecodeGeneralNameCheckChars(&input[idx], strLen) != 0) {
return ASN_PARSE_E;
}
emailEntry = AltNameNew(cert->heap);
if (emailEntry == NULL) {
@@ -3341,10 +3328,6 @@ static int DecodeAltNames(const byte* input, word32 sz, DecodedCert* cert)
return BUFFER_E;
}
if (DecodeGeneralNameCheckChars(&input[idx], strLen) != 0) {
return ASN_PARSE_E;
}
#ifndef WOLFSSL_NO_ASN_STRICT
/* Verify RFC 5280 Sec 4.2.1.6 rule:
"The name MUST NOT be a relative URI"