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author | Cherry Zhang <cherryyz@google.com> | 2020-10-28 09:12:20 -0400 |
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committer | Cherry Zhang <cherryyz@google.com> | 2020-10-28 09:12:20 -0400 |
commit | a16e30d162c1c7408db7821e7b9513cefa09c6ca (patch) | |
tree | af752ba9ba44c547df39bb0af9bff79f610ba9d5 /src/crypto/x509/root_cgo_darwin.go | |
parent | 91e4d2d57bc341dd82c98247117114c851380aef (diff) | |
parent | cf6cfba4d5358404dd890f6025e573a4b2156543 (diff) | |
download | go-git-dev.link.tar.gz |
[dev.link] all: merge branch 'master' into dev.linkdev.link
Clean merge.
Change-Id: Ia7b2808bc649790198d34c226a61d9e569084dc5
Diffstat (limited to 'src/crypto/x509/root_cgo_darwin.go')
-rw-r--r-- | src/crypto/x509/root_cgo_darwin.go | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/src/crypto/x509/root_cgo_darwin.go b/src/crypto/x509/root_cgo_darwin.go new file mode 100644 index 0000000000..15c72cc0c8 --- /dev/null +++ b/src/crypto/x509/root_cgo_darwin.go @@ -0,0 +1,322 @@ +// 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 +} |