src/crypto/x509/root_cgo_darwin_amd64.go - go - Git at Google

 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

 // +build !ios

 package x509

 // This cgo implementation exists only to support side-by-side testing by
 // TestSystemRoots. It can be removed once we are confident in the no-cgo
 // implementation.

 /*
 #cgo CFLAGS: -mmacosx-version-min=10.11
 #cgo LDFLAGS: -framework CoreFoundation -framework Security

 #include <errno.h>
 #include <sys/sysctl.h>

 #include <CoreFoundation/CoreFoundation.h>
 #include <Security/Security.h>

 static Boolean isSSLPolicy(SecPolicyRef policyRef) {
 	if (!policyRef) {
 		return false;
 	}
 	CFDictionaryRef properties = SecPolicyCopyProperties(policyRef);
 	if (properties == NULL) {
 		return false;
 	}
 	Boolean isSSL = false;
 	CFTypeRef value = NULL;
 	if (CFDictionaryGetValueIfPresent(properties, kSecPolicyOid, (const void **)&value)) {
 		isSSL = CFEqual(value, kSecPolicyAppleSSL);
 	}
 	CFRelease(properties);
 	return isSSL;
 }

 // sslTrustSettingsResult obtains the final kSecTrustSettingsResult value
 // for a certificate in the user or admin domain, combining usage constraints
 // for the SSL SecTrustSettingsPolicy, ignoring SecTrustSettingsKeyUsage and
 // kSecTrustSettingsAllowedError.
 // https://developer.apple.com/documentation/security/1400261-sectrustsettingscopytrustsetting
 static SInt32 sslTrustSettingsResult(SecCertificateRef cert) {
 	CFArrayRef trustSettings = NULL;
 	OSStatus err = SecTrustSettingsCopyTrustSettings(cert, kSecTrustSettingsDomainUser, &trustSettings);

 	// According to Apple's SecTrustServer.c, "user trust settings overrule admin trust settings",
 	// but the rules of the override are unclear. Let's assume admin trust settings are applicable
 	// if and only if user trust settings fail to load or are NULL.
 	if (err != errSecSuccess || trustSettings == NULL) {
 		if (trustSettings != NULL) CFRelease(trustSettings);
 		err = SecTrustSettingsCopyTrustSettings(cert, kSecTrustSettingsDomainAdmin, &trustSettings);
 	}

 	// > no trust settings [...] means "this certificate must be verified to a known trusted certificate”
 	// (Should this cause a fallback from user to admin domain? It's unclear.)
 	if (err != errSecSuccess || trustSettings == NULL) {
 		if (trustSettings != NULL) CFRelease(trustSettings);
 		return kSecTrustSettingsResultUnspecified;
 	}

 	// > An empty trust settings array means "always trust this certificate” with an
 	// > overall trust setting for the certificate of kSecTrustSettingsResultTrustRoot.
 	if (CFArrayGetCount(trustSettings) == 0) {
 		CFRelease(trustSettings);
 		return kSecTrustSettingsResultTrustRoot;
 	}

 	// kSecTrustSettingsResult is defined as CFSTR("kSecTrustSettingsResult"),
 	// but the Go linker's internal linking mode can't handle CFSTR relocations.
 	// Create our own dynamic string instead and release it below.
 	CFStringRef _kSecTrustSettingsResult = CFStringCreateWithCString(
 		NULL, "kSecTrustSettingsResult", kCFStringEncodingUTF8);
 	CFStringRef _kSecTrustSettingsPolicy = CFStringCreateWithCString(
 		NULL, "kSecTrustSettingsPolicy", kCFStringEncodingUTF8);
 	CFStringRef _kSecTrustSettingsPolicyString = CFStringCreateWithCString(
 		NULL, "kSecTrustSettingsPolicyString", kCFStringEncodingUTF8);

 	CFIndex m; SInt32 result = 0;
 	for (m = 0; m < CFArrayGetCount(trustSettings); m++) {
 		CFDictionaryRef tSetting = (CFDictionaryRef)CFArrayGetValueAtIndex(trustSettings, m);

 		// First, check if this trust setting is constrained to a non-SSL policy.
 		SecPolicyRef policyRef;
 		if (CFDictionaryGetValueIfPresent(tSetting, _kSecTrustSettingsPolicy, (const void**)&policyRef)) {
 			if (!isSSLPolicy(policyRef)) {
 				continue;
 			}
 		}

 		if (CFDictionaryContainsKey(tSetting, _kSecTrustSettingsPolicyString)) {
 			// Restricted to a hostname, not a root.
 			continue;
 		}

 		CFNumberRef cfNum;
 		if (CFDictionaryGetValueIfPresent(tSetting, _kSecTrustSettingsResult, (const void**)&cfNum)) {
 			CFNumberGetValue(cfNum, kCFNumberSInt32Type, &result);
 		} else {
 			// > If this key is not present, a default value of
 			// > kSecTrustSettingsResultTrustRoot is assumed.
 			result = kSecTrustSettingsResultTrustRoot;
 		}

 		// If multiple dictionaries match, we are supposed to "OR" them,
 		// the semantics of which are not clear. Since TrustRoot and TrustAsRoot
 		// are mutually exclusive, Deny should probably override, and Invalid and
 		// Unspecified be overridden, approximate this by stopping at the first
 		// TrustRoot, TrustAsRoot or Deny.
 		if (result == kSecTrustSettingsResultTrustRoot) {
 			break;
 		} else if (result == kSecTrustSettingsResultTrustAsRoot) {
 			break;
 		} else if (result == kSecTrustSettingsResultDeny) {
 			break;
 		}
 	}

 	// If trust settings are present, but none of them match the policy...
 	// the docs don't tell us what to do.
 	//
 	// "Trust settings for a given use apply if any of the dictionaries in the
 	// certificate’s trust settings array satisfies the specified use." suggests
 	// that it's as if there were no trust settings at all, so we should probably
 	// fallback to the admin trust settings. TODO.
 	if (result == 0) {
 		result = kSecTrustSettingsResultUnspecified;
 	}

 	CFRelease(_kSecTrustSettingsPolicy);
 	CFRelease(_kSecTrustSettingsPolicyString);
 	CFRelease(_kSecTrustSettingsResult);
 	CFRelease(trustSettings);

 	return result;
 }

 // isRootCertificate reports whether Subject and Issuer match.
 static Boolean isRootCertificate(SecCertificateRef cert, CFErrorRef *errRef) {
 	CFDataRef subjectName = SecCertificateCopyNormalizedSubjectContent(cert, errRef);
 	if (*errRef != NULL) {
 		return false;
 	}
 	CFDataRef issuerName = SecCertificateCopyNormalizedIssuerContent(cert, errRef);
 	if (*errRef != NULL) {
 		CFRelease(subjectName);
 		return false;
 	}
 	Boolean equal = CFEqual(subjectName, issuerName);
 	CFRelease(subjectName);
 	CFRelease(issuerName);
 	return equal;
 }

 // CopyPEMRoots fetches the system's list of trusted X.509 root certificates
 // for the kSecTrustSettingsPolicy SSL.
 //
 // On success it returns 0 and fills pemRoots with a CFDataRef that contains the extracted root
 // certificates of the system. On failure, the function returns -1.
 // Additionally, it fills untrustedPemRoots with certs that must be removed from pemRoots.
 //
 // Note: The CFDataRef returned in pemRoots and untrustedPemRoots must
 // be released (using CFRelease) after we've consumed its content.
 static int CopyPEMRoots(CFDataRef *pemRoots, CFDataRef *untrustedPemRoots, bool debugDarwinRoots) {
 	int i;

 	if (debugDarwinRoots) {
 		fprintf(stderr, "crypto/x509: kSecTrustSettingsResultInvalid = %d\n", kSecTrustSettingsResultInvalid);
 		fprintf(stderr, "crypto/x509: kSecTrustSettingsResultTrustRoot = %d\n", kSecTrustSettingsResultTrustRoot);
 		fprintf(stderr, "crypto/x509: kSecTrustSettingsResultTrustAsRoot = %d\n", kSecTrustSettingsResultTrustAsRoot);
 		fprintf(stderr, "crypto/x509: kSecTrustSettingsResultDeny = %d\n", kSecTrustSettingsResultDeny);
 		fprintf(stderr, "crypto/x509: kSecTrustSettingsResultUnspecified = %d\n", kSecTrustSettingsResultUnspecified);
 	}

 	// Get certificates from all domains, not just System, this lets
 	// the user add CAs to their "login" keychain, and Admins to add
 	// to the "System" keychain
 	SecTrustSettingsDomain domains[] = { kSecTrustSettingsDomainSystem,
 		kSecTrustSettingsDomainAdmin, kSecTrustSettingsDomainUser };

 	int numDomains = sizeof(domains)/sizeof(SecTrustSettingsDomain);
 	if (pemRoots == NULL || untrustedPemRoots == NULL) {
 		return -1;
 	}

 	CFMutableDataRef combinedData = CFDataCreateMutable(kCFAllocatorDefault, 0);
 	CFMutableDataRef combinedUntrustedData = CFDataCreateMutable(kCFAllocatorDefault, 0);
 	for (i = 0; i < numDomains; i++) {
 		int j;
 		CFArrayRef certs = NULL;
 		OSStatus err = SecTrustSettingsCopyCertificates(domains[i], &certs);
 		if (err != noErr) {
 			continue;
 		}

 		CFIndex numCerts = CFArrayGetCount(certs);
 		for (j = 0; j < numCerts; j++) {
 			SecCertificateRef cert = (SecCertificateRef)CFArrayGetValueAtIndex(certs, j);
 			if (cert == NULL) {
 				continue;
 			}

 			SInt32 result;
 			if (domains[i] == kSecTrustSettingsDomainSystem) {
 				// Certs found in the system domain are always trusted. If the user
 				// configures "Never Trust" on such a cert, it will also be found in the
 				// admin or user domain, causing it to be added to untrustedPemRoots. The
 				// Go code will then clean this up.
 				result = kSecTrustSettingsResultTrustRoot;
 			} else {
 				result = sslTrustSettingsResult(cert);
 				if (debugDarwinRoots) {
 					CFErrorRef errRef = NULL;
 					CFStringRef summary = SecCertificateCopyShortDescription(NULL, cert, &errRef);
 					if (errRef != NULL) {
 						fprintf(stderr, "crypto/x509: SecCertificateCopyShortDescription failed\n");
 						CFRelease(errRef);
 						continue;
 					}

 					CFIndex length = CFStringGetLength(summary);
 					CFIndex maxSize = CFStringGetMaximumSizeForEncoding(length, kCFStringEncodingUTF8) + 1;
 					char *buffer = malloc(maxSize);
 					if (CFStringGetCString(summary, buffer, maxSize, kCFStringEncodingUTF8)) {
 						fprintf(stderr, "crypto/x509: %s returned %d\n", buffer, (int)result);
 					}
 					free(buffer);
 					CFRelease(summary);
 				}
 			}

 			CFMutableDataRef appendTo;
 			// > Note the distinction between the results kSecTrustSettingsResultTrustRoot
 			// > and kSecTrustSettingsResultTrustAsRoot: The former can only be applied to
 			// > root (self-signed) certificates; the latter can only be applied to
 			// > non-root certificates.
 			if (result == kSecTrustSettingsResultTrustRoot) {
 				CFErrorRef errRef = NULL;
 				if (!isRootCertificate(cert, &errRef) || errRef != NULL) {
 					if (errRef != NULL) CFRelease(errRef);
 					continue;
 				}

 				appendTo = combinedData;
 			} else if (result == kSecTrustSettingsResultTrustAsRoot) {
 				CFErrorRef errRef = NULL;
 				if (isRootCertificate(cert, &errRef) || errRef != NULL) {
 					if (errRef != NULL) CFRelease(errRef);
 					continue;
 				}

 				appendTo = combinedData;
 			} else if (result == kSecTrustSettingsResultDeny) {
 				appendTo = combinedUntrustedData;
 			} else if (result == kSecTrustSettingsResultUnspecified) {
 				// Certificates with unspecified trust should probably be added to a pool of
 				// intermediates for chain building, or checked for transitive trust and
 				// added to the root pool (which is an imprecise approximation because it
 				// cuts chains short) but we don't support either at the moment. TODO.
 				continue;
 			} else {
 				continue;
 			}

 			CFDataRef data = NULL;
 			err = SecItemExport(cert, kSecFormatX509Cert, kSecItemPemArmour, NULL, &data);
 			if (err != noErr) {
 				continue;
 			}
 			if (data != NULL) {
 				CFDataAppendBytes(appendTo, CFDataGetBytePtr(data), CFDataGetLength(data));
 				CFRelease(data);
 			}
 		}
 		CFRelease(certs);
 	}
 	*pemRoots = combinedData;
 	*untrustedPemRoots = combinedUntrustedData;
 	return 0;
 }
 */
 import "C"
 import (
 	"errors"
 	"unsafe"
 )

 func init() {
 	loadSystemRootsWithCgo = _loadSystemRootsWithCgo
 }

 func _loadSystemRootsWithCgo() (*CertPool, error) {
 	var data, untrustedData C.CFDataRef
 	err := C.CopyPEMRoots(&data, &untrustedData, C.bool(debugDarwinRoots))
 	if err == -1 {
 		return nil, errors.New("crypto/x509: failed to load darwin system roots with cgo")
 	}
 	defer C.CFRelease(C.CFTypeRef(data))
 	defer C.CFRelease(C.CFTypeRef(untrustedData))

 	buf := C.GoBytes(unsafe.Pointer(C.CFDataGetBytePtr(data)), C.int(C.CFDataGetLength(data)))
 	roots := NewCertPool()
 	roots.AppendCertsFromPEM(buf)

 	if C.CFDataGetLength(untrustedData) == 0 {
 		return roots, nil
 	}

 	buf = C.GoBytes(unsafe.Pointer(C.CFDataGetBytePtr(untrustedData)), C.int(C.CFDataGetLength(untrustedData)))
 	untrustedRoots := NewCertPool()
 	untrustedRoots.AppendCertsFromPEM(buf)

 	trustedRoots := NewCertPool()
 	for _, c := range roots.certs {
 		if !untrustedRoots.contains(c) {
 			trustedRoots.AddCert(c)
 		}
 	}
 	return trustedRoots, nil
 }
	// Copyright 2011 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	// +build !ios

	package x509

	// This cgo implementation exists only to support side-by-side testing by
	// TestSystemRoots. It can be removed once we are confident in the no-cgo
	// implementation.

	/*
	#cgo CFLAGS: -mmacosx-version-min=10.11
	#cgo LDFLAGS: -framework CoreFoundation -framework Security

	#include <errno.h>
	#include <sys/sysctl.h>

	#include <CoreFoundation/CoreFoundation.h>
	#include <Security/Security.h>

	static Boolean isSSLPolicy(SecPolicyRef policyRef) {
	if (!policyRef) {
	return false;
	}
	CFDictionaryRef properties = SecPolicyCopyProperties(policyRef);
	if (properties == NULL) {
	return false;
	}
	Boolean isSSL = false;
	CFTypeRef value = NULL;
	if (CFDictionaryGetValueIfPresent(properties, kSecPolicyOid, (const void **)&value)) {
	isSSL = CFEqual(value, kSecPolicyAppleSSL);
	}
	CFRelease(properties);
	return isSSL;
	}

	// sslTrustSettingsResult obtains the final kSecTrustSettingsResult value
	// for a certificate in the user or admin domain, combining usage constraints
	// for the SSL SecTrustSettingsPolicy, ignoring SecTrustSettingsKeyUsage and
	// kSecTrustSettingsAllowedError.
	// https://developer.apple.com/documentation/security/1400261-sectrustsettingscopytrustsetting
	static SInt32 sslTrustSettingsResult(SecCertificateRef cert) {
	CFArrayRef trustSettings = NULL;
	OSStatus err = SecTrustSettingsCopyTrustSettings(cert, kSecTrustSettingsDomainUser, &trustSettings);

	// According to Apple's SecTrustServer.c, "user trust settings overrule admin trust settings",
	// but the rules of the override are unclear. Let's assume admin trust settings are applicable
	// if and only if user trust settings fail to load or are NULL.
	if (err != errSecSuccess \|\| trustSettings == NULL) {
	if (trustSettings != NULL) CFRelease(trustSettings);
	err = SecTrustSettingsCopyTrustSettings(cert, kSecTrustSettingsDomainAdmin, &trustSettings);
	}

	// > no trust settings [...] means "this certificate must be verified to a known trusted certificate”
	// (Should this cause a fallback from user to admin domain? It's unclear.)
	if (err != errSecSuccess \|\| trustSettings == NULL) {
	if (trustSettings != NULL) CFRelease(trustSettings);
	return kSecTrustSettingsResultUnspecified;
	}

	// > An empty trust settings array means "always trust this certificate” with an
	// > overall trust setting for the certificate of kSecTrustSettingsResultTrustRoot.
	if (CFArrayGetCount(trustSettings) == 0) {
	CFRelease(trustSettings);
	return kSecTrustSettingsResultTrustRoot;
	}

	// kSecTrustSettingsResult is defined as CFSTR("kSecTrustSettingsResult"),
	// but the Go linker's internal linking mode can't handle CFSTR relocations.
	// Create our own dynamic string instead and release it below.
	CFStringRef _kSecTrustSettingsResult = CFStringCreateWithCString(
	NULL, "kSecTrustSettingsResult", kCFStringEncodingUTF8);
	CFStringRef _kSecTrustSettingsPolicy = CFStringCreateWithCString(
	NULL, "kSecTrustSettingsPolicy", kCFStringEncodingUTF8);
	CFStringRef _kSecTrustSettingsPolicyString = CFStringCreateWithCString(
	NULL, "kSecTrustSettingsPolicyString", kCFStringEncodingUTF8);

	CFIndex m; SInt32 result = 0;
	for (m = 0; m < CFArrayGetCount(trustSettings); m++) {
	CFDictionaryRef tSetting = (CFDictionaryRef)CFArrayGetValueAtIndex(trustSettings, m);

	// First, check if this trust setting is constrained to a non-SSL policy.
	SecPolicyRef policyRef;
	if (CFDictionaryGetValueIfPresent(tSetting, _kSecTrustSettingsPolicy, (const void**)&policyRef)) {
	if (!isSSLPolicy(policyRef)) {
	continue;
	}
	}

	if (CFDictionaryContainsKey(tSetting, _kSecTrustSettingsPolicyString)) {
	// Restricted to a hostname, not a root.
	continue;
	}

	CFNumberRef cfNum;
	if (CFDictionaryGetValueIfPresent(tSetting, _kSecTrustSettingsResult, (const void**)&cfNum)) {
	CFNumberGetValue(cfNum, kCFNumberSInt32Type, &result);
	} else {
	// > If this key is not present, a default value of
	// > kSecTrustSettingsResultTrustRoot is assumed.
	result = kSecTrustSettingsResultTrustRoot;
	}

	// If multiple dictionaries match, we are supposed to "OR" them,
	// the semantics of which are not clear. Since TrustRoot and TrustAsRoot
	// are mutually exclusive, Deny should probably override, and Invalid and
	// Unspecified be overridden, approximate this by stopping at the first
	// TrustRoot, TrustAsRoot or Deny.
	if (result == kSecTrustSettingsResultTrustRoot) {
	break;
	} else if (result == kSecTrustSettingsResultTrustAsRoot) {
	break;
	} else if (result == kSecTrustSettingsResultDeny) {
	break;
	}
	}

	// If trust settings are present, but none of them match the policy...
	// the docs don't tell us what to do.
	//
	// "Trust settings for a given use apply if any of the dictionaries in the
	// certificate’s trust settings array satisfies the specified use." suggests
	// that it's as if there were no trust settings at all, so we should probably
	// fallback to the admin trust settings. TODO.
	if (result == 0) {
	result = kSecTrustSettingsResultUnspecified;
	}

	CFRelease(_kSecTrustSettingsPolicy);
	CFRelease(_kSecTrustSettingsPolicyString);
	CFRelease(_kSecTrustSettingsResult);
	CFRelease(trustSettings);

	return result;
	}

	// isRootCertificate reports whether Subject and Issuer match.
	static Boolean isRootCertificate(SecCertificateRef cert, CFErrorRef *errRef) {
	CFDataRef subjectName = SecCertificateCopyNormalizedSubjectContent(cert, errRef);
	if (*errRef != NULL) {
	return false;
	}
	CFDataRef issuerName = SecCertificateCopyNormalizedIssuerContent(cert, errRef);
	if (*errRef != NULL) {
	CFRelease(subjectName);
	return false;
	}
	Boolean equal = CFEqual(subjectName, issuerName);
	CFRelease(subjectName);
	CFRelease(issuerName);
	return equal;
	}

	// CopyPEMRoots fetches the system's list of trusted X.509 root certificates
	// for the kSecTrustSettingsPolicy SSL.
	//
	// On success it returns 0 and fills pemRoots with a CFDataRef that contains the extracted root
	// certificates of the system. On failure, the function returns -1.
	// Additionally, it fills untrustedPemRoots with certs that must be removed from pemRoots.
	//
	// Note: The CFDataRef returned in pemRoots and untrustedPemRoots must
	// be released (using CFRelease) after we've consumed its content.
	static int CopyPEMRoots(CFDataRef pemRoots, CFDataRef untrustedPemRoots, bool debugDarwinRoots) {
	int i;

	if (debugDarwinRoots) {
	fprintf(stderr, "crypto/x509: kSecTrustSettingsResultInvalid = %d\n", kSecTrustSettingsResultInvalid);
	fprintf(stderr, "crypto/x509: kSecTrustSettingsResultTrustRoot = %d\n", kSecTrustSettingsResultTrustRoot);
	fprintf(stderr, "crypto/x509: kSecTrustSettingsResultTrustAsRoot = %d\n", kSecTrustSettingsResultTrustAsRoot);
	fprintf(stderr, "crypto/x509: kSecTrustSettingsResultDeny = %d\n", kSecTrustSettingsResultDeny);
	fprintf(stderr, "crypto/x509: kSecTrustSettingsResultUnspecified = %d\n", kSecTrustSettingsResultUnspecified);
	}

	// Get certificates from all domains, not just System, this lets
	// the user add CAs to their "login" keychain, and Admins to add
	// to the "System" keychain
	SecTrustSettingsDomain domains[] = { kSecTrustSettingsDomainSystem,
	kSecTrustSettingsDomainAdmin, kSecTrustSettingsDomainUser };

	int numDomains = sizeof(domains)/sizeof(SecTrustSettingsDomain);
	if (pemRoots == NULL \|\| untrustedPemRoots == NULL) {
	return -1;
	}

	CFMutableDataRef combinedData = CFDataCreateMutable(kCFAllocatorDefault, 0);
	CFMutableDataRef combinedUntrustedData = CFDataCreateMutable(kCFAllocatorDefault, 0);
	for (i = 0; i < numDomains; i++) {
	int j;
	CFArrayRef certs = NULL;
	OSStatus err = SecTrustSettingsCopyCertificates(domains[i], &certs);
	if (err != noErr) {
	continue;
	}

	CFIndex numCerts = CFArrayGetCount(certs);
	for (j = 0; j < numCerts; j++) {
	SecCertificateRef cert = (SecCertificateRef)CFArrayGetValueAtIndex(certs, j);
	if (cert == NULL) {
	continue;
	}

	SInt32 result;
	if (domains[i] == kSecTrustSettingsDomainSystem) {
	// Certs found in the system domain are always trusted. If the user
	// configures "Never Trust" on such a cert, it will also be found in the
	// admin or user domain, causing it to be added to untrustedPemRoots. The
	// Go code will then clean this up.
	result = kSecTrustSettingsResultTrustRoot;
	} else {
	result = sslTrustSettingsResult(cert);
	if (debugDarwinRoots) {
	CFErrorRef errRef = NULL;
	CFStringRef summary = SecCertificateCopyShortDescription(NULL, cert, &errRef);
	if (errRef != NULL) {
	fprintf(stderr, "crypto/x509: SecCertificateCopyShortDescription failed\n");
	CFRelease(errRef);
	continue;
	}

	CFIndex length = CFStringGetLength(summary);
	CFIndex maxSize = CFStringGetMaximumSizeForEncoding(length, kCFStringEncodingUTF8) + 1;
	char *buffer = malloc(maxSize);
	if (CFStringGetCString(summary, buffer, maxSize, kCFStringEncodingUTF8)) {
	fprintf(stderr, "crypto/x509: %s returned %d\n", buffer, (int)result);
	}
	free(buffer);
	CFRelease(summary);
	}
	}

	CFMutableDataRef appendTo;
	// > Note the distinction between the results kSecTrustSettingsResultTrustRoot
	// > and kSecTrustSettingsResultTrustAsRoot: The former can only be applied to
	// > root (self-signed) certificates; the latter can only be applied to
	// > non-root certificates.
	if (result == kSecTrustSettingsResultTrustRoot) {
	CFErrorRef errRef = NULL;
	if (!isRootCertificate(cert, &errRef) \|\| errRef != NULL) {
	if (errRef != NULL) CFRelease(errRef);
	continue;
	}

	appendTo = combinedData;
	} else if (result == kSecTrustSettingsResultTrustAsRoot) {
	CFErrorRef errRef = NULL;
	if (isRootCertificate(cert, &errRef) \|\| errRef != NULL) {
	if (errRef != NULL) CFRelease(errRef);
	continue;
	}

	appendTo = combinedData;
	} else if (result == kSecTrustSettingsResultDeny) {
	appendTo = combinedUntrustedData;
	} else if (result == kSecTrustSettingsResultUnspecified) {
	// Certificates with unspecified trust should probably be added to a pool of
	// intermediates for chain building, or checked for transitive trust and
	// added to the root pool (which is an imprecise approximation because it
	// cuts chains short) but we don't support either at the moment. TODO.
	continue;
	} else {
	continue;
	}

	CFDataRef data = NULL;
	err = SecItemExport(cert, kSecFormatX509Cert, kSecItemPemArmour, NULL, &data);
	if (err != noErr) {
	continue;
	}
	if (data != NULL) {
	CFDataAppendBytes(appendTo, CFDataGetBytePtr(data), CFDataGetLength(data));
	CFRelease(data);
	}
	}
	CFRelease(certs);
	}
	*pemRoots = combinedData;
	*untrustedPemRoots = combinedUntrustedData;
	return 0;
	}
	*/
	import "C"
	import (
	"errors"
	"unsafe"
	)

	func init() {
	loadSystemRootsWithCgo = _loadSystemRootsWithCgo
	}

	func _loadSystemRootsWithCgo() (*CertPool, error) {
	var data, untrustedData C.CFDataRef
	err := C.CopyPEMRoots(&data, &untrustedData, C.bool(debugDarwinRoots))
	if err == -1 {
	return nil, errors.New("crypto/x509: failed to load darwin system roots with cgo")
	}
	defer C.CFRelease(C.CFTypeRef(data))
	defer C.CFRelease(C.CFTypeRef(untrustedData))

	buf := C.GoBytes(unsafe.Pointer(C.CFDataGetBytePtr(data)), C.int(C.CFDataGetLength(data)))
	roots := NewCertPool()
	roots.AppendCertsFromPEM(buf)

	if C.CFDataGetLength(untrustedData) == 0 {
	return roots, nil
	}

	buf = C.GoBytes(unsafe.Pointer(C.CFDataGetBytePtr(untrustedData)), C.int(C.CFDataGetLength(untrustedData)))
	untrustedRoots := NewCertPool()
	untrustedRoots.AppendCertsFromPEM(buf)

	trustedRoots := NewCertPool()
	for _, c := range roots.certs {
	if !untrustedRoots.contains(c) {
	trustedRoots.AddCert(c)
	}
	}
	return trustedRoots, nil
	}