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open62541/plugins/crypto/openssl/certificategroup.c

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/* This work is licensed under a Creative Commons CCZero 1.0 Universal License.
* See http://creativecommons.org/publicdomain/zero/1.0/ for more information.
*
* Copyright 2020 (c) Wind River Systems, Inc.
* Copyright 2020 (c) basysKom GmbH
* Copyright 2024 (c) Fraunhofer IOSB (Author: Noel Graf)
* Copyright 2024 (c) Siemens AG (Authors: Tin Raic, Thomas Zeschg)
*/
#include <open62541/util.h>
#include <open62541/plugin/certificategroup_default.h>
#include <open62541/plugin/log_stdout.h>
#if defined(UA_ENABLE_ENCRYPTION_OPENSSL) || defined(UA_ENABLE_ENCRYPTION_LIBRESSL)
#include <openssl/x509.h>
#include <openssl/x509_vfy.h>
#include <openssl/x509v3.h>
#include <openssl/pem.h>
#include "libc_time.h"
#include "securitypolicy_common.h"
#define SHA1_DIGEST_LENGTH 20
/* Configuration parameters */
#define MEMORYCERTSTORE_PARAMETERSSIZE 2
#define MEMORYCERTSTORE_PARAMINDEX_MAXTRUSTLISTSIZE 0
#define MEMORYCERTSTORE_PARAMINDEX_MAXREJECTEDLISTSIZE 1
static const struct {
UA_QualifiedName name;
const UA_DataType *type;
UA_Boolean required;
} MemoryCertStoreParameters[MEMORYCERTSTORE_PARAMETERSSIZE] = {
{{0, UA_STRING_STATIC("maxTrustListSize")}, &UA_TYPES[UA_TYPES_UINT16], false},
{{0, UA_STRING_STATIC("maxRejectedListSize")}, &UA_TYPES[UA_TYPES_STRING], false}
};
struct MemoryCertStore;
typedef struct MemoryCertStore MemoryCertStore;
struct MemoryCertStore {
UA_TrustListDataType trustList;
size_t rejectedCertificatesSize;
UA_ByteString *rejectedCertificates;
UA_UInt32 maxTrustListSize;
UA_UInt32 maxRejectedListSize;
UA_Boolean reloadRequired;
STACK_OF(X509) *trustedCertificates;
STACK_OF(X509) *issuerCertificates;
STACK_OF(X509_CRL) *crls;
UA_CertificateGroup *cg;
};
static UA_Boolean
openSSLCheckCA(X509 *cert);
static UA_StatusCode
MemoryCertStore_removeFromTrustList(UA_CertificateGroup *certGroup, const UA_TrustListDataType *trustList) {
/* Check parameter */
if(certGroup == NULL || trustList == NULL) {
return UA_STATUSCODE_BADINTERNALERROR;
}
MemoryCertStore *context = (MemoryCertStore *)certGroup->context;
context->reloadRequired = true;
return UA_TrustListDataType_remove(trustList, &context->trustList);
}
static UA_StatusCode
MemoryCertStore_getTrustList(UA_CertificateGroup *certGroup, UA_TrustListDataType *trustList) {
/* Check parameter */
if(certGroup == NULL || trustList == NULL) {
return UA_STATUSCODE_BADINTERNALERROR;
}
MemoryCertStore *context = (MemoryCertStore *)certGroup->context;
return UA_TrustListDataType_copy(&context->trustList, trustList);
}
static UA_StatusCode
MemoryCertStore_setTrustList(UA_CertificateGroup *certGroup, const UA_TrustListDataType *trustList) {
/* Check parameter */
if(certGroup == NULL || trustList == NULL) {
return UA_STATUSCODE_BADINTERNALERROR;
}
MemoryCertStore *context = (MemoryCertStore *)certGroup->context;
if(context->maxTrustListSize != 0 && UA_TrustListDataType_getSize(trustList) > context->maxTrustListSize) {
return UA_STATUSCODE_BADINTERNALERROR;
}
context->reloadRequired = true;
UA_TrustListDataType_clear(&context->trustList);
return UA_TrustListDataType_add(trustList, &context->trustList);
}
static UA_StatusCode
MemoryCertStore_addToTrustList(UA_CertificateGroup *certGroup, const UA_TrustListDataType *trustList) {
/* Check parameter */
if(certGroup == NULL || trustList == NULL) {
return UA_STATUSCODE_BADINTERNALERROR;
}
MemoryCertStore *context = (MemoryCertStore *)certGroup->context;
if(context->maxTrustListSize != 0 && UA_TrustListDataType_getSize(&context->trustList) + UA_TrustListDataType_getSize(trustList) > context->maxTrustListSize) {
return UA_STATUSCODE_BADINTERNALERROR;
}
context->reloadRequired = true;
return UA_TrustListDataType_add(trustList, &context->trustList);
}
static UA_StatusCode
MemoryCertStore_getRejectedList(UA_CertificateGroup *certGroup, UA_ByteString **rejectedList, size_t *rejectedListSize) {
/* Check parameter */
if(certGroup == NULL || rejectedList == NULL || rejectedListSize == NULL) {
return UA_STATUSCODE_BADINTERNALERROR;
}
MemoryCertStore *context = (MemoryCertStore *)certGroup->context;
UA_StatusCode retval = UA_Array_copy(context->rejectedCertificates, context->rejectedCertificatesSize,
(void**)rejectedList, &UA_TYPES[UA_TYPES_BYTESTRING]);
if(retval == UA_STATUSCODE_GOOD)
*rejectedListSize = context->rejectedCertificatesSize;
return retval;
}
static UA_StatusCode
openSSLCheckCrlMatch(X509 *cert, X509_CRL *crl) {
X509_NAME *certSubject = X509_get_subject_name(cert);
if(!certSubject)
return UA_STATUSCODE_BADINTERNALERROR;
X509_NAME *crlIssuer = X509_CRL_get_issuer(crl);
if(!crlIssuer) {
return UA_STATUSCODE_BADINTERNALERROR;
}
if(X509_NAME_cmp(certSubject, crlIssuer) == 0)
return UA_STATUSCODE_GOOD;
return UA_STATUSCODE_BADNOMATCH;
}
static UA_StatusCode
openSSLFindCrls(UA_CertificateGroup *certGroup, const UA_ByteString *certificate,
const UA_ByteString *crlList, const size_t crlListSize,
UA_ByteString **crls, size_t *crlsSize) {
UA_StatusCode retval = UA_STATUSCODE_GOOD;
X509 *cert = UA_OpenSSL_LoadCertificate(certificate);
if(!cert)
return UA_STATUSCODE_BADINTERNALERROR;
/* Check if the certificate is a CA certificate.
* Only a CA certificate can have a CRL. */
if(!openSSLCheckCA(cert)) {
UA_LOG_WARNING(certGroup->logging, UA_LOGCATEGORY_SERVER,
"The certificate is not a CA certificate and therefore does not have a CRL.");
X509_free(cert);
return UA_STATUSCODE_GOOD;
}
UA_Boolean foundMatch = false;
for(size_t i = 0; i < crlListSize; i++) {
X509_CRL *crl = UA_OpenSSL_LoadCrl(&crlList[i]);
if(!crl) {
X509_free(cert);
return UA_STATUSCODE_BADINTERNALERROR;
}
retval = openSSLCheckCrlMatch(cert, crl);
X509_CRL_free(crl);
if(retval != UA_STATUSCODE_GOOD) {
continue;
}
/* Continue the search, as a certificate may be associated with multiple CRLs. */
foundMatch = true;
retval = UA_Array_appendCopy((void **)crls, crlsSize, &crlList[i],
&UA_TYPES[UA_TYPES_BYTESTRING]);
if(retval != UA_STATUSCODE_GOOD) {
X509_free(cert);
return retval;
}
}
X509_free(cert);
if(!foundMatch)
return UA_STATUSCODE_BADNOMATCH;
return UA_STATUSCODE_GOOD;
}
static UA_StatusCode
MemoryCertStore_getCertificateCrls(UA_CertificateGroup *certGroup, const UA_ByteString *certificate,
const UA_Boolean isTrusted, UA_ByteString **crls,
size_t *crlsSize) {
/* Check parameter */
if(certGroup == NULL || certificate == NULL || crls == NULL) {
return UA_STATUSCODE_BADINTERNALERROR;
}
MemoryCertStore *context = (MemoryCertStore *)certGroup->context;
if(isTrusted) {
return openSSLFindCrls(certGroup, certificate,
context->trustList.trustedCrls,
context->trustList.trustedCrlsSize, crls,
crlsSize);
}
return openSSLFindCrls(certGroup, certificate,
context->trustList.issuerCrls,
context->trustList.issuerCrlsSize, crls,
crlsSize);
}
static UA_StatusCode
MemoryCertStore_addToRejectedList(UA_CertificateGroup *certGroup, const UA_ByteString *certificate) {
/* Check parameter */
if(certGroup == NULL || certificate == NULL) {
return UA_STATUSCODE_BADINTERNALERROR;
}
MemoryCertStore *context = (MemoryCertStore *)certGroup->context;
/* check duplicate certificate */
for(size_t i = 0; i < context->rejectedCertificatesSize; i++) {
if(UA_ByteString_equal(certificate, &context->rejectedCertificates[i]))
return UA_STATUSCODE_GOOD; /* certificate already exist */
}
/* Store rejected certificate */
if(context->maxRejectedListSize == 0 || context->rejectedCertificatesSize < context->maxRejectedListSize) {
return UA_Array_appendCopy((void**)&context->rejectedCertificates, &context->rejectedCertificatesSize,
certificate, &UA_TYPES[UA_TYPES_BYTESTRING]);
}
UA_Array_delete(context->rejectedCertificates, context->rejectedCertificatesSize, &UA_TYPES[UA_TYPES_BYTESTRING]);
context->rejectedCertificates = NULL;
context->rejectedCertificatesSize = 0;
return UA_Array_appendCopy((void**)&context->rejectedCertificates, &context->rejectedCertificatesSize,
certificate, &UA_TYPES[UA_TYPES_BYTESTRING]);
}
static void
MemoryCertStore_clear(UA_CertificateGroup *certGroup) {
/* check parameter */
if(certGroup == NULL) {
return;
}
UA_NodeId_clear(&certGroup->certificateGroupId);
MemoryCertStore *context = (MemoryCertStore *)certGroup->context;
if(context) {
UA_TrustListDataType_clear(&context->trustList);
UA_Array_delete(context->rejectedCertificates, context->rejectedCertificatesSize, &UA_TYPES[UA_TYPES_BYTESTRING]);
context->rejectedCertificates = NULL;
context->rejectedCertificatesSize = 0;
sk_X509_pop_free (context->trustedCertificates, X509_free);
sk_X509_pop_free (context->issuerCertificates, X509_free);
sk_X509_CRL_pop_free (context->crls, X509_CRL_free);
UA_free(context);
certGroup->context = NULL;
}
}
static UA_StatusCode
reloadCertificates(UA_CertificateGroup *certGroup) {
/* Check parameter */
if(certGroup == NULL) {
return UA_STATUSCODE_BADINTERNALERROR;
}
MemoryCertStore *context = (MemoryCertStore *)certGroup->context;
sk_X509_pop_free(context->trustedCertificates, X509_free);
context->trustedCertificates = sk_X509_new_null();
if(context->trustedCertificates == NULL) {
return UA_STATUSCODE_BADOUTOFMEMORY;
}
for(size_t i = 0; i < context->trustList.trustedCertificatesSize; i++) {
X509 *cert = UA_OpenSSL_LoadCertificate(&context->trustList.trustedCertificates[i]);
if(cert == NULL)
return UA_STATUSCODE_BADINTERNALERROR;
sk_X509_push(context->trustedCertificates, cert);
}
sk_X509_pop_free(context->issuerCertificates, X509_free);
context->issuerCertificates = sk_X509_new_null();
if(context->issuerCertificates == NULL) {
return UA_STATUSCODE_BADOUTOFMEMORY;
}
for(size_t i = 0; i < context->trustList.issuerCertificatesSize; i++) {
X509 *cert = UA_OpenSSL_LoadCertificate(&context->trustList.issuerCertificates[i]);
if(cert == NULL)
return UA_STATUSCODE_BADINTERNALERROR;
sk_X509_push(context->issuerCertificates, cert);
}
sk_X509_CRL_pop_free(context->crls, X509_CRL_free);
context->crls = sk_X509_CRL_new_null();
if(context->crls == NULL) {
return UA_STATUSCODE_BADOUTOFMEMORY;
}
for(size_t i = 0; i < context->trustList.trustedCrlsSize; i++) {
X509_CRL * crl = NULL;
BIO * bio = NULL;
bio = BIO_new_mem_buf((void *)context->trustList.trustedCrls[i].data,
(int)context->trustList.trustedCrls[i].length);
/* Try to load DER encoded CRL */
crl = d2i_X509_CRL_bio(bio, NULL);
if (crl == NULL) {
/* Try to load PEM encoded CRL */
BIO_reset(bio);
crl = PEM_read_bio_X509_CRL(bio, NULL, NULL, NULL);
}
BIO_free(bio);
if (crl == NULL) {
return UA_STATUSCODE_BADINTERNALERROR;
}
sk_X509_CRL_push(context->crls, crl);
}
for(size_t i = 0; i < context->trustList.issuerCrlsSize; i++) {
X509_CRL * crl = NULL;
BIO * bio = NULL;
bio = BIO_new_mem_buf((void *)context->trustList.issuerCrls[i].data,
(int)context->trustList.issuerCrls[i].length);
/* Try to load DER encoded Issuer CRL */
crl = d2i_X509_CRL_bio(bio, NULL);
if (crl == NULL) {
/* Try to load PEM encoded Issuer CRL */
BIO_reset(bio);
crl = PEM_read_bio_X509_CRL(bio, NULL, NULL, NULL);
}
BIO_free(bio);
if (crl == NULL) {
return UA_STATUSCODE_BADINTERNALERROR;
}
sk_X509_CRL_push(context->crls, crl);
}
return UA_STATUSCODE_GOOD;
}
/* Find binary substring. Taken and adjusted from
* http://tungchingkai.blogspot.com/2011/07/binary-strstr.html */
static const unsigned char *
bstrchr(const unsigned char *s, const unsigned char ch, size_t l) {
/* find first occurrence of c in char s[] for length l*/
for(; l > 0; ++s, --l) {
if(*s == ch)
return s;
}
return NULL;
}
static const unsigned char *
UA_Bstrstr(const unsigned char *s1, size_t l1, const unsigned char *s2, size_t l2) {
/* find first occurrence of s2[] in s1[] for length l1*/
const unsigned char *ss1 = s1;
const unsigned char *ss2 = s2;
/* handle special case */
if(l1 == 0)
return (NULL);
if(l2 == 0)
return s1;
/* match prefix */
for (; (s1 = bstrchr(s1, *s2, (uintptr_t)ss1-(uintptr_t)s1+(uintptr_t)l1)) != NULL &&
(uintptr_t)ss1-(uintptr_t)s1+(uintptr_t)l1 != 0; ++s1) {
/* match rest of prefix */
const unsigned char *sc1, *sc2;
for (sc1 = s1, sc2 = s2; ;)
if (++sc2 >= ss2+l2)
return s1;
else if (*++sc1 != *sc2)
break;
}
return NULL;
}
static const unsigned char openssl_PEM_PRE[28] = "-----BEGIN CERTIFICATE-----";
/* Extract the leaf certificate from a bytestring that may contain an entire chain */
static X509 *
openSSLLoadLeafCertificate(UA_ByteString cert, size_t *offset) {
if(cert.length <= *offset)
return NULL;
cert.length -= *offset;
cert.data += *offset;
/* Detect DER encoding. Extract the encoding length and cut. */
if(cert.length >= 4 && cert.data[0] == 0x30 && cert.data[1] == 0x82) {
/* The certificate length is encoded after the magic bytes */
size_t certLen = 4; /* Magic numbers + length bytes */
certLen += (size_t)(((uint16_t)cert.data[2]) << 8);
certLen += cert.data[3];
if(certLen > cert.length)
return NULL;
cert.length = certLen;
*offset += certLen;
const UA_Byte *dataPtr = cert.data;
return d2i_X509(NULL, &dataPtr, (long)cert.length);
}
/* Assume PEM encoding. Detect multiple certificates and cut. */
if(cert.length > 27 * 4) {
const unsigned char *match =
UA_Bstrstr(openssl_PEM_PRE, 27, &cert.data[27*2], cert.length - (27*2));
if(match)
cert.length = (uintptr_t)(match - cert.data);
}
*offset += cert.length;
BIO *bio = BIO_new_mem_buf((void *) cert.data, (int)cert.length);
X509 *result = PEM_read_bio_X509(bio, NULL, NULL, NULL);
BIO_free(bio);
return result;
}
/* The bytestring might contain an entire certificate chain. The first
* stack-element is the leaf certificate itself. The remaining ones are
* potential issuer certificates. */
static STACK_OF(X509) *
openSSLLoadCertificateStack(const UA_ByteString cert) {
size_t offset = 0;
X509 *x509 = NULL;
STACK_OF(X509) *result = sk_X509_new_null();
if(!result)
return NULL;
while((x509 = openSSLLoadLeafCertificate(cert, &offset))) {
sk_X509_push(result, x509);
}
return result;
}
/* Return the first matching issuer candidate AFTER prev */
static X509 *
openSSLFindNextIssuer(MemoryCertStore *ctx, STACK_OF(X509) *stack, X509 *x509, X509 *prev) {
/* First check issuers from the stack - provided in the same bytestring as
* the certificate. This can also return x509 itself. */
X509_NAME *in = X509_get_issuer_name(x509);
do {
int size = sk_X509_num(stack);
for(int i = 0; i < size; i++) {
X509 *candidate = sk_X509_value(stack, i);
if(prev) {
if(prev == candidate)
prev = NULL; /* This was the last issuer we tried to verify */
continue;
}
/* This checks subject/issuer name and the key usage of the issuer.
* It does not verify the validity period and if the issuer key was
* used for the signature. We check that afterwards. */
if(X509_NAME_cmp(in, X509_get_subject_name(candidate)) == 0)
return candidate;
}
/* Switch from the stack that came with the cert to the issuer list and
* then to the trust list. */
if(stack == ctx->trustedCertificates)
stack = NULL;
else if(stack == ctx->issuerCertificates)
stack = ctx->trustedCertificates;
else
stack = ctx->issuerCertificates;
} while(stack);
return NULL;
}
/* Is the certificate a CA? */
static UA_Boolean
openSSLCheckCA(X509 *cert) {
uint32_t flags = X509_get_extension_flags(cert);
/* The basic constraints must be set with the CA flag true */
if(!(flags & EXFLAG_CA))
return false;
/* The Key Usage extension must be set */
if(!(flags & EXFLAG_KUSAGE))
return false;
/* The Key Usage must include cert signing and CRL issuing */
uint32_t usage = X509_get_key_usage(cert);
if(!(usage & KU_KEY_CERT_SIGN) || !(usage & KU_CRL_SIGN))
return false;
return true;
}
static UA_StatusCode
openSSLCheckRevoked(MemoryCertStore *ctx, X509 *cert) {
const ASN1_INTEGER *sn = X509_get0_serialNumber(cert);
const X509_NAME *in = X509_get_issuer_name(cert);
int size = sk_X509_CRL_num(ctx->crls);
if(size == 0) {
UA_LOG_WARNING(ctx->cg->logging, UA_LOGCATEGORY_SECURITYPOLICY,
"Zero revocation lists have been loaded. "
"This seems intentional - omitting the check.");
return UA_STATUSCODE_GOOD;
}
/* Loop over the crl and match the Issuer Name */
UA_StatusCode res = UA_STATUSCODE_BADCERTIFICATEREVOCATIONUNKNOWN;
for(int i = 0; i < size; i++) {
/* The crl contains a list of serial numbers from the same issuer */
X509_CRL *crl = sk_X509_CRL_value(ctx->crls, i);
if(X509_NAME_cmp(in, X509_CRL_get_issuer(crl)) != 0)
continue;
STACK_OF(X509_REVOKED) *rs = X509_CRL_get_REVOKED(crl);
int rsize = sk_X509_REVOKED_num(rs);
for(int j = 0; j < rsize; j++) {
X509_REVOKED *r = sk_X509_REVOKED_value(rs, j);
if(ASN1_INTEGER_cmp(sn, X509_REVOKED_get0_serialNumber(r)) == 0)
return UA_STATUSCODE_BADCERTIFICATEREVOKED;
}
res = UA_STATUSCODE_GOOD; /* There was at least one crl that did not revoke (so far) */
}
return res;
}
#define UA_OPENSSL_MAX_CHAIN_LENGTH 10
static UA_StatusCode
openSSL_verifyChain(MemoryCertStore *ctx, STACK_OF(X509) *stack, X509 **old_issuers,
X509 *cert, int depth) {
/* Maxiumum chain length */
if(depth == UA_OPENSSL_MAX_CHAIN_LENGTH)
return UA_STATUSCODE_BADCERTIFICATECHAININCOMPLETE;
/* Verification Step: Validity Period */
ASN1_TIME *notBefore = X509_get_notBefore(cert);
ASN1_TIME *notAfter = X509_get_notAfter(cert);
if(X509_cmp_current_time(notBefore) != -1 || X509_cmp_current_time(notAfter) != 1)
return (depth == 0) ? UA_STATUSCODE_BADCERTIFICATETIMEINVALID :
UA_STATUSCODE_BADCERTIFICATEISSUERTIMEINVALID;
/* Return the most specific error code. BADCERTIFICATECHAININCOMPLETE is
* returned only if all possible chains are incomplete. */
X509 *issuer = NULL;
UA_StatusCode ret = UA_STATUSCODE_BADCERTIFICATECHAININCOMPLETE;
while(ret != UA_STATUSCODE_GOOD) {
/* Find the issuer. We jump back here to find a different path if a
* subsequent check fails. */
issuer = openSSLFindNextIssuer(ctx, stack, cert, issuer);
if(!issuer)
break;
/* Verification Step: Certificate Usage
* Can the issuer act as CA? Omit for self-signed leaf certificates. */
if((depth > 0 || issuer != cert) && !openSSLCheckCA(issuer)) {
ret = UA_STATUSCODE_BADCERTIFICATEISSUERUSENOTALLOWED;
continue;
}
/* Verification Step: Signature */
int opensslRet = X509_verify(cert, X509_get0_pubkey(issuer));
if(opensslRet == -1) {
return UA_STATUSCODE_BADCERTIFICATEINVALID; /* Ill-formed signature */
} else if(opensslRet == 0) {
ret = UA_STATUSCODE_BADCERTIFICATEINVALID; /* Wrong issuer, try again */
continue;
}
/* The certificate is self-signed. We have arrived at the top of the
* chain. We check whether the certificate is trusted below. This is the
* only place where we return UA_STATUSCODE_BADCERTIFICATEUNTRUSTED.
* This signals that the chain is complete (but can be still
* untrusted).
*
* Break here as we have reached the end of the chain. Omit the
* Revocation Check for self-signed certificates. */
if(cert == issuer || X509_cmp(cert, issuer) == 0) {
ret = UA_STATUSCODE_BADCERTIFICATEUNTRUSTED;
break;
}
/* Verification Step: Revocation Check */
ret = openSSLCheckRevoked(ctx, cert);
if(depth > 0) {
if(ret == UA_STATUSCODE_BADCERTIFICATEREVOKED)
ret = UA_STATUSCODE_BADCERTIFICATEISSUERREVOKED;
if(ret == UA_STATUSCODE_BADCERTIFICATEREVOCATIONUNKNOWN)
ret = UA_STATUSCODE_BADCERTIFICATEISSUERREVOCATIONUNKNOWN;
}
if(ret != UA_STATUSCODE_GOOD)
continue;
/* Detect (endless) loops of issuers. The last one can be skipped by the
* check for self-signed just before. */
for(int i = 0; i < depth; i++) {
if(old_issuers[i] == issuer)
return UA_STATUSCODE_BADCERTIFICATECHAININCOMPLETE;
}
old_issuers[depth] = issuer;
/* We have found the issuer certificate used for the signature. Recurse
* to the next certificate in the chain (verify the current issuer). */
ret = openSSL_verifyChain(ctx, stack, old_issuers, issuer, depth + 1);
}
/* Is the certificate in the trust list? If yes, then we are done. */
if(ret == UA_STATUSCODE_BADCERTIFICATEUNTRUSTED) {
for(int i = 0; i < sk_X509_num(ctx->trustedCertificates); i++) {
if(X509_cmp(cert, sk_X509_value(ctx->trustedCertificates, i)) == 0)
return UA_STATUSCODE_GOOD;
}
}
return ret;
}
/* This follows Part 6, 6.1.3 Determining if a Certificate is trusted.
* It defines a sequence of steps for certificate verification. */
static UA_StatusCode
verifyCertificate(UA_CertificateGroup *certGroup, const UA_ByteString *certificate) {
/* Check parameter */
if (certGroup == NULL || certGroup->context == NULL) {
return UA_STATUSCODE_BADINTERNALERROR;
}
UA_StatusCode ret = UA_STATUSCODE_GOOD;
MemoryCertStore *context = (MemoryCertStore *)certGroup->context;
if(context->reloadRequired) {
ret = reloadCertificates(certGroup);
if(ret != UA_STATUSCODE_GOOD)
return ret;
context->reloadRequired = false;
}
/* Verification Step: Certificate Structure */
STACK_OF(X509) *stack = openSSLLoadCertificateStack(*certificate);
if(!stack || sk_X509_num(stack) < 1) {
sk_X509_pop_free(stack, X509_free);
return UA_STATUSCODE_BADCERTIFICATEINVALID;
}
/* Verification Step: Certificate Usage
* Check whether the certificate is a User certificate or a CA certificate.
* Refer the test case CTT/Security/Security Certificate Validation/029.js
* for more details. */
X509 *leaf = sk_X509_value(stack, 0);
if(openSSLCheckCA(leaf)) {
sk_X509_pop_free(stack, X509_free);
return UA_STATUSCODE_BADCERTIFICATEUSENOTALLOWED;
}
/* These steps are performed outside of this method.
* Because we need the server or client context.
* - Security Policy
* - Host Name
* - URI */
/* Verification Step: Build Certificate Chain
* We perform the checks for each certificate inside. */
X509 *old_issuers[UA_OPENSSL_MAX_CHAIN_LENGTH];
ret = openSSL_verifyChain(context, stack, old_issuers, leaf, 0);
sk_X509_pop_free(stack, X509_free);
return ret;
}
static UA_StatusCode
MemoryCertStore_verifyCertificate(UA_CertificateGroup *certGroup,
const UA_ByteString *certificate) {
/* Check parameter */
if(certGroup == NULL || certificate == NULL) {
return UA_STATUSCODE_BADINVALIDARGUMENT;
}
UA_StatusCode retval = verifyCertificate(certGroup, certificate);
if(retval != UA_STATUSCODE_GOOD) {
if(MemoryCertStore_addToRejectedList(certGroup, certificate) != UA_STATUSCODE_GOOD) {
UA_LOG_WARNING(certGroup->logging, UA_LOGCATEGORY_SECURITYPOLICY,
"Could not append certificate to rejected list");
}
}
return retval;
}
UA_StatusCode
UA_CertificateGroup_Memorystore(UA_CertificateGroup *certGroup,
UA_NodeId *certificateGroupId,
const UA_TrustListDataType *trustList,
const UA_Logger *logger,
const UA_KeyValueMap *params) {
if(certGroup == NULL || certificateGroupId == NULL) {
return UA_STATUSCODE_BADINTERNALERROR;
}
UA_StatusCode retval = UA_STATUSCODE_GOOD;
/* Clear if the plugin is already initialized */
if(certGroup->clear)
certGroup->clear(certGroup);
UA_NodeId_copy(certificateGroupId, &certGroup->certificateGroupId);
certGroup->logging = logger;
certGroup->getTrustList = MemoryCertStore_getTrustList;
certGroup->setTrustList = MemoryCertStore_setTrustList;
certGroup->addToTrustList = MemoryCertStore_addToTrustList;
certGroup->removeFromTrustList = MemoryCertStore_removeFromTrustList;
certGroup->getRejectedList = MemoryCertStore_getRejectedList;
certGroup->getCertificateCrls = MemoryCertStore_getCertificateCrls;
certGroup->verifyCertificate = MemoryCertStore_verifyCertificate;
certGroup->clear = MemoryCertStore_clear;
/* Set PKI Store context data */
MemoryCertStore *context = (MemoryCertStore *)UA_calloc(1, sizeof(MemoryCertStore));
if(!context) {
retval = UA_STATUSCODE_BADOUTOFMEMORY;
goto cleanup;
}
context->cg = certGroup;
certGroup->context = context;
/* Default values */
context->maxTrustListSize = 65535;
context->maxRejectedListSize = 100;
if(params) {
const UA_UInt32 *maxTrustListSize = (const UA_UInt32*)
UA_KeyValueMap_getScalar(params, MemoryCertStoreParameters[MEMORYCERTSTORE_PARAMINDEX_MAXTRUSTLISTSIZE].name,
&UA_TYPES[UA_TYPES_UINT32]);
const UA_UInt32 *maxRejectedListSize = (const UA_UInt32*)
UA_KeyValueMap_getScalar(params, MemoryCertStoreParameters[MEMORYCERTSTORE_PARAMINDEX_MAXREJECTEDLISTSIZE].name,
&UA_TYPES[UA_TYPES_UINT32]);
if(maxTrustListSize) {
context->maxTrustListSize = *maxTrustListSize;
}
if(maxRejectedListSize) {
context->maxRejectedListSize = *maxRejectedListSize;
}
}
UA_TrustListDataType_add(trustList, &context->trustList);
reloadCertificates(certGroup);
return UA_STATUSCODE_GOOD;
cleanup:
certGroup->clear(certGroup);
return retval;
}
UA_StatusCode
UA_CertificateUtils_verifyApplicationURI(UA_RuleHandling ruleHandling,
const UA_ByteString *certificate,
const UA_String *applicationURI) {
const unsigned char * pData;
X509 * certificateX509;
UA_String subjectURI = UA_STRING_NULL;
GENERAL_NAMES * pNames;
int i;
UA_StatusCode ret;
pData = certificate->data;
if (pData == NULL) {
return UA_STATUSCODE_BADSECURITYCHECKSFAILED;
}
certificateX509 = UA_OpenSSL_LoadCertificate(certificate);
if (certificateX509 == NULL) {
return UA_STATUSCODE_BADSECURITYCHECKSFAILED;
}
pNames = (GENERAL_NAMES *) X509_get_ext_d2i(certificateX509, NID_subject_alt_name,
NULL, NULL);
if (pNames == NULL) {
X509_free (certificateX509);
return UA_STATUSCODE_BADSECURITYCHECKSFAILED;
}
UA_String_init(&subjectURI);
for (i = 0; i < sk_GENERAL_NAME_num (pNames); i++) {
GENERAL_NAME * value = sk_GENERAL_NAME_value (pNames, i);
if (value->type == GEN_URI) {
subjectURI.length = (size_t) (value->d.ia5->length);
subjectURI.data = (UA_Byte *) UA_malloc (subjectURI.length);
if (subjectURI.data == NULL) {
X509_free (certificateX509);
sk_GENERAL_NAME_pop_free(pNames, GENERAL_NAME_free);
return UA_STATUSCODE_BADSECURITYCHECKSFAILED;
}
(void) memcpy (subjectURI.data, value->d.ia5->data, subjectURI.length);
break;
}
}
ret = UA_STATUSCODE_GOOD;
if (UA_Bstrstr (subjectURI.data, subjectURI.length,
applicationURI->data, applicationURI->length) == NULL) {
ret = UA_STATUSCODE_BADCERTIFICATEURIINVALID;
}
if(ret != UA_STATUSCODE_GOOD && ruleHandling == UA_RULEHANDLING_DEFAULT) {
UA_LOG_WARNING(UA_Log_Stdout, UA_LOGCATEGORY_SERVER,
"The certificate's application URI could not be verified. StatusCode %s",
UA_StatusCode_name(ret));
ret = UA_STATUSCODE_GOOD;
}
X509_free (certificateX509);
sk_GENERAL_NAME_pop_free(pNames, GENERAL_NAME_free);
UA_String_clear (&subjectURI);
return ret;
}
UA_StatusCode
UA_CertificateUtils_getExpirationDate(UA_ByteString *certificate,
UA_DateTime *expiryDateTime) {
X509 *x509 = UA_OpenSSL_LoadCertificate(certificate);
if(!x509)
return UA_STATUSCODE_BADSECURITYCHECKSFAILED;
/* Get the certificate Expiry date */
ASN1_TIME *not_after = X509_get_notAfter(x509);
struct tm dtTime;
ASN1_TIME_to_tm(not_after, &dtTime);
X509_free(x509);
struct mytm dateTime;
memset(&dateTime, 0, sizeof(struct mytm));
dateTime.tm_year = dtTime.tm_year;
dateTime.tm_mon = dtTime.tm_mon;
dateTime.tm_mday = dtTime.tm_mday;
dateTime.tm_hour = dtTime.tm_hour;
dateTime.tm_min = dtTime.tm_min;
dateTime.tm_sec = dtTime.tm_sec;
long long sec_epoch = __tm_to_secs(&dateTime);
*expiryDateTime = UA_DATETIME_UNIX_EPOCH;
*expiryDateTime += sec_epoch * UA_DATETIME_SEC;
return UA_STATUSCODE_GOOD;
}
UA_StatusCode
UA_CertificateUtils_getSubjectName(UA_ByteString *certificate,
UA_String *subjectName) {
X509 *x509 = UA_OpenSSL_LoadCertificate(certificate);
if(!x509)
return UA_STATUSCODE_BADSECURITYCHECKSFAILED;
X509_NAME *sn = X509_get_subject_name(x509);
char buf[1024];
*subjectName = UA_STRING_ALLOC(X509_NAME_oneline(sn, buf, 1024));
X509_free(x509);
return UA_STATUSCODE_GOOD;
}
UA_StatusCode
UA_CertificateUtils_getThumbprint(UA_ByteString *certificate,
UA_String *thumbprint) {
if(certificate == NULL || thumbprint->length != (SHA1_DIGEST_LENGTH * 2))
return UA_STATUSCODE_BADINTERNALERROR;
X509 *cert = UA_OpenSSL_LoadCertificate(certificate);
if(!cert)
return UA_STATUSCODE_BADSECURITYCHECKSFAILED;
unsigned char digest[SHA1_DIGEST_LENGTH];
unsigned int digestLen;
if(X509_digest(cert, EVP_sha1(), digest, &digestLen) != 1) {
X509_free(cert);
return UA_STATUSCODE_BADINTERNALERROR;
}
UA_String thumb = UA_STRING_NULL;
thumb.length = (SHA1_DIGEST_LENGTH * 2) + 1;
thumb.data = (UA_Byte*)malloc(sizeof(UA_Byte) * thumb.length);
/* Create a string containing a hex representation */
char *p = (char*)thumb.data;
for(size_t i = 0; i < digestLen; i++) {
p += sprintf(p, "%.2X", digest[i]);
}
memcpy(thumbprint->data, thumb.data, thumbprint->length);
X509_free(cert);
free(thumb.data);
return UA_STATUSCODE_GOOD;
}
UA_StatusCode
UA_CertificateUtils_getKeySize(UA_ByteString *certificate,
size_t *keySize){
if(certificate == NULL)
return UA_STATUSCODE_BADINTERNALERROR;
X509 *cert = UA_OpenSSL_LoadCertificate(certificate);
if(!cert)
return UA_STATUSCODE_BADSECURITYCHECKSFAILED;
EVP_PKEY *pkey = X509_get_pubkey(cert);
if(!pkey) {
X509_free(cert);
return UA_STATUSCODE_BADINTERNALERROR;
}
if(EVP_PKEY_base_id(pkey) == EVP_PKEY_RSA) {
#if (OPENSSL_VERSION_NUMBER >= 0x30000000L)
*keySize = EVP_PKEY_get_size(pkey) * 8;
#else
*keySize = RSA_size(get_pkey_rsa(pkey)) * 8;
#endif
} else if(EVP_PKEY_base_id(pkey) == EVP_PKEY_EC) {
#if (OPENSSL_VERSION_NUMBER >= 0x30000000L)
*keySize = EVP_PKEY_get_size(pkey) * 8;
#else
*keySize = ECDSA_size(EVP_PKEY_get0_EC_KEY(pkey)) * 8;
#endif
} else {
EVP_PKEY_free(pkey);
X509_free(cert);
return UA_STATUSCODE_BADINTERNALERROR; /* Unsupported key type */
}
EVP_PKEY_free(pkey);
X509_free(cert);
return UA_STATUSCODE_GOOD;
}
UA_StatusCode
UA_CertificateUtils_comparePublicKeys(const UA_ByteString *certificate1,
const UA_ByteString *certificate2) {
if(certificate1 == NULL || certificate2 == NULL)
return UA_STATUSCODE_BADINTERNALERROR;
BIO *dataBio1 = BIO_new_mem_buf(certificate1->data, certificate1->length);
if(!dataBio1)
return UA_STATUSCODE_BADINTERNALERROR;
BIO *dataBio2 = BIO_new_mem_buf(certificate2->data, certificate2->length);
if(!dataBio2) {
BIO_free(dataBio1);
return UA_STATUSCODE_BADINTERNALERROR;
}
X509 *cert1 = NULL;
X509 *cert2 = NULL;
X509_REQ *csr1 = NULL;
X509_REQ *csr2 = NULL;
/* Try to read the certificate as PEM first */
cert1 = PEM_read_bio_X509(dataBio1, NULL, 0, NULL);
if(!cert1) {
/* If PEM read fails, reset BIO and try reading as DER */
BIO_reset(dataBio1);
cert1 = d2i_X509_bio(dataBio1, NULL);
}
/* Try to read as a csr */
if(!cert1) {
BIO_reset(dataBio1);
csr1 = PEM_read_bio_X509_REQ(dataBio1, NULL, 0, NULL);
if(!csr1) {
BIO_reset(dataBio1);
csr1 = d2i_X509_REQ_bio(dataBio1, NULL);
}
}
if(!cert1 && !csr1) {
BIO_free(dataBio1);
BIO_free(dataBio2);
return UA_STATUSCODE_BADINTERNALERROR;
}
cert2 = PEM_read_bio_X509(dataBio2, NULL, 0, NULL);
if(!cert2) {
/* If PEM read fails, reset BIO and try reading as DER */
BIO_reset(dataBio2);
cert2 = d2i_X509_bio(dataBio2, NULL);
}
/* Try to load as a csr */
if(!cert2) {
BIO_reset(dataBio2);
csr2 = PEM_read_bio_X509_REQ(dataBio2, NULL, 0, NULL);
if(!csr2) {
BIO_reset(dataBio2);
csr2 = d2i_X509_REQ_bio(dataBio2, NULL);
}
}
if(!cert2 && !csr2) {
X509_free(cert1);
X509_REQ_free(csr1);
BIO_free(dataBio1);
BIO_free(dataBio2);
return UA_STATUSCODE_BADINTERNALERROR;
}
BIO_free(dataBio1);
BIO_free(dataBio2);
EVP_PKEY *pkey1 = cert1 ? X509_get_pubkey(cert1) : X509_REQ_get_pubkey(csr1);
EVP_PKEY *pkey2 = cert2 ? X509_get_pubkey(cert2) : X509_REQ_get_pubkey(csr2);
X509_free(cert1);
X509_free(cert2);
X509_REQ_free(csr1);
X509_REQ_free(csr2);
if(!pkey1 || !pkey2) {
EVP_PKEY_free(pkey1);
EVP_PKEY_free(pkey2);
return UA_STATUSCODE_BADINTERNALERROR;
}
UA_StatusCode retval = UA_STATUSCODE_GOOD;
#if (OPENSSL_VERSION_NUMBER >= 0x30000000L)
int isEqual = EVP_PKEY_eq(pkey1, pkey2);
if(isEqual == 0)
retval = UA_STATUSCODE_BADNOMATCH;
if(isEqual < 0)
retval = UA_STATUSCODE_BADINTERNALERROR;
#else
int isEqual = EVP_PKEY_cmp(pkey1, pkey2);
if(isEqual == 0)
retval = UA_STATUSCODE_BADNOMATCH;
if(isEqual < 0)
retval = UA_STATUSCODE_BADINTERNALERROR;
#endif
EVP_PKEY_free(pkey1);
EVP_PKEY_free(pkey2);
return retval;
}
UA_StatusCode
UA_CertificateUtils_checkKeyPair(const UA_ByteString *certificate,
const UA_ByteString *privateKey) {
if(certificate == NULL || privateKey == NULL)
return UA_STATUSCODE_BADINTERNALERROR;
X509 *cert = UA_OpenSSL_LoadCertificate(certificate);
if(!cert)
return UA_STATUSCODE_BADSECURITYCHECKSFAILED;
EVP_PKEY *pkey = UA_OpenSSL_LoadPrivateKey(privateKey);
if(!pkey) {
X509_free(cert);
return UA_STATUSCODE_BADSECURITYCHECKSFAILED;
}
/* Verify if the private key matches the public key in the certificate */
if(X509_check_private_key(cert, pkey) != 1) {
X509_free(cert);
EVP_PKEY_free(pkey);
return UA_STATUSCODE_BADSECURITYCHECKSFAILED;
}
X509_free(cert);
EVP_PKEY_free(pkey);
return UA_STATUSCODE_GOOD;
}
UA_StatusCode
UA_CertificateUtils_checkCA(const UA_ByteString *certificate) {
if(certificate == NULL)
return UA_STATUSCODE_BADINTERNALERROR;
X509 *certificateX509 = UA_OpenSSL_LoadCertificate(certificate);
if(!certificateX509)
return UA_STATUSCODE_BADSECURITYCHECKSFAILED;
UA_StatusCode retval = openSSLCheckCA(certificateX509) ?
UA_STATUSCODE_GOOD : UA_STATUSCODE_BADNOMATCH;
X509_free(certificateX509);
return retval;
}
static int
privateKeyPasswordCallback(char *buf, int size, int rwflag, void *userdata) {
(void) rwflag;
UA_ByteString *pw = (UA_ByteString*)userdata;
if(pw->length <= (size_t)size)
memcpy(buf, pw->data, pw->length);
return (int)pw->length;
}
UA_StatusCode
UA_CertificateUtils_decryptPrivateKey(const UA_ByteString privateKey,
const UA_ByteString password,
UA_ByteString *outDerKey) {
if(!outDerKey)
return UA_STATUSCODE_BADINTERNALERROR;
if (privateKey.length == 0) {
*outDerKey = UA_BYTESTRING_NULL;
return UA_STATUSCODE_BADINVALIDARGUMENT;
}
EVP_PKEY *pkey = NULL;
const unsigned char * in = privateKey.data;
/* Check if input is already in DER format */
pkey = d2i_AutoPrivateKey(NULL, &in, privateKey.length);
if (pkey != NULL) {
EVP_PKEY_free(pkey);
return UA_ByteString_copy(&privateKey, outDerKey);
}
/* Decrypt */
BIO *bio = BIO_new_mem_buf((void*)privateKey.data, (int)privateKey.length);
pkey = PEM_read_bio_PrivateKey(bio, NULL,
privateKeyPasswordCallback,
(void*)(uintptr_t)&password);
BIO_free(bio);
if(!pkey)
return UA_STATUSCODE_BADSECURITYCHECKSFAILED;
/* Write DER encoded, allocates the new memory */
unsigned char *data = NULL;
const int numBytes = i2d_PrivateKey(pkey, &data);
EVP_PKEY_free(pkey);
if(!data)
return UA_STATUSCODE_BADOUTOFMEMORY;
/* Copy to the data to outDerKey
* Passing the data pointer directly causes a heap corruption on Windows
* when outDerKey is cleared.
*/
UA_ByteString temp = UA_BYTESTRING_NULL;
temp.data = data;
temp.length = (size_t)numBytes;
const UA_StatusCode success = UA_ByteString_copy(&temp, outDerKey);
/* OPENSSL_clear_free() is not supported by the LibreSSL version in the CI */
OPENSSL_cleanse(data, numBytes);
OPENSSL_free(data);
return success;
}
#endif
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