diff --git a/src/crypto/x509/internal/macOS/corefoundation.go b/src/crypto/x509/internal/macOS/corefoundation.go
new file mode 100644
index 0000000000000..359694fabf269
--- /dev/null
+++ b/src/crypto/x509/internal/macOS/corefoundation.go
@@ -0,0 +1,141 @@
+// Copyright 2020 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 darwin,amd64
+
+// Package macOS provides cgo-less wrappers for Core Foundation and
+// Security.framework, similarly to how package syscall provides access to
+// libSystem.dylib.
+package macOS
+
+import (
+	"errors"
+	"reflect"
+	"runtime"
+	"unsafe"
+)
+
+// CFRef is an opaque reference to a Core Foundation object. It is a pointer,
+// but to memory not owned by Go, so not an unsafe.Pointer.
+type CFRef uintptr
+
+// CFDataToSlice returns a copy of the contents of data as a bytes slice.
+func CFDataToSlice(data CFRef) []byte {
+	length := CFDataGetLength(data)
+	ptr := CFDataGetBytePtr(data)
+	src := (*[1 << 20]byte)(unsafe.Pointer(ptr))[:length:length]
+	out := make([]byte, length)
+	copy(out, src)
+	return out
+}
+
+type CFString CFRef
+
+const kCFAllocatorDefault = 0
+const kCFStringEncodingUTF8 = 0x08000100
+
+//go:linkname x509_CFStringCreateWithBytes x509_CFStringCreateWithBytes
+//go:cgo_import_dynamic x509_CFStringCreateWithBytes CFStringCreateWithBytes "/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation"
+
+// StringToCFString returns a copy of the UTF-8 contents of s as a new CFString.
+func StringToCFString(s string) CFString {
+	p := unsafe.Pointer((*reflect.StringHeader)(unsafe.Pointer(&s)).Data)
+	ret := syscall(funcPC(x509_CFStringCreateWithBytes_trampoline), kCFAllocatorDefault, uintptr(p),
+		uintptr(len(s)), uintptr(kCFStringEncodingUTF8), 0 /* isExternalRepresentation */, 0)
+	runtime.KeepAlive(p)
+	return CFString(ret)
+}
+func x509_CFStringCreateWithBytes_trampoline()
+
+//go:linkname x509_CFDictionaryGetValueIfPresent x509_CFDictionaryGetValueIfPresent
+//go:cgo_import_dynamic x509_CFDictionaryGetValueIfPresent CFDictionaryGetValueIfPresent "/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation"
+
+func CFDictionaryGetValueIfPresent(dict CFRef, key CFString) (value CFRef, ok bool) {
+	ret := syscall(funcPC(x509_CFDictionaryGetValueIfPresent_trampoline), uintptr(dict), uintptr(key),
+		uintptr(unsafe.Pointer(&value)), 0, 0, 0)
+	if ret == 0 {
+		return 0, false
+	}
+	return value, true
+}
+func x509_CFDictionaryGetValueIfPresent_trampoline()
+
+const kCFNumberSInt32Type = 3
+
+//go:linkname x509_CFNumberGetValue x509_CFNumberGetValue
+//go:cgo_import_dynamic x509_CFNumberGetValue CFNumberGetValue "/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation"
+
+func CFNumberGetValue(num CFRef) (int32, error) {
+	var value int32
+	ret := syscall(funcPC(x509_CFNumberGetValue_trampoline), uintptr(num), uintptr(kCFNumberSInt32Type),
+		uintptr(unsafe.Pointer(&value)), 0, 0, 0)
+	if ret == 0 {
+		return 0, errors.New("CFNumberGetValue call failed")
+	}
+	return value, nil
+}
+func x509_CFNumberGetValue_trampoline()
+
+//go:linkname x509_CFDataGetLength x509_CFDataGetLength
+//go:cgo_import_dynamic x509_CFDataGetLength CFDataGetLength "/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation"
+
+func CFDataGetLength(data CFRef) int {
+	ret := syscall(funcPC(x509_CFDataGetLength_trampoline), uintptr(data), 0, 0, 0, 0, 0)
+	return int(ret)
+}
+func x509_CFDataGetLength_trampoline()
+
+//go:linkname x509_CFDataGetBytePtr x509_CFDataGetBytePtr
+//go:cgo_import_dynamic x509_CFDataGetBytePtr CFDataGetBytePtr "/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation"
+
+func CFDataGetBytePtr(data CFRef) uintptr {
+	ret := syscall(funcPC(x509_CFDataGetBytePtr_trampoline), uintptr(data), 0, 0, 0, 0, 0)
+	return ret
+}
+func x509_CFDataGetBytePtr_trampoline()
+
+//go:linkname x509_CFArrayGetCount x509_CFArrayGetCount
+//go:cgo_import_dynamic x509_CFArrayGetCount CFArrayGetCount "/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation"
+
+func CFArrayGetCount(array CFRef) int {
+	ret := syscall(funcPC(x509_CFArrayGetCount_trampoline), uintptr(array), 0, 0, 0, 0, 0)
+	return int(ret)
+}
+func x509_CFArrayGetCount_trampoline()
+
+//go:linkname x509_CFArrayGetValueAtIndex x509_CFArrayGetValueAtIndex
+//go:cgo_import_dynamic x509_CFArrayGetValueAtIndex CFArrayGetValueAtIndex "/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation"
+
+func CFArrayGetValueAtIndex(array CFRef, index int) CFRef {
+	ret := syscall(funcPC(x509_CFArrayGetValueAtIndex_trampoline), uintptr(array), uintptr(index), 0, 0, 0, 0)
+	return CFRef(ret)
+}
+func x509_CFArrayGetValueAtIndex_trampoline()
+
+//go:linkname x509_CFEqual x509_CFEqual
+//go:cgo_import_dynamic x509_CFEqual CFEqual "/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation"
+
+func CFEqual(a, b CFRef) bool {
+	ret := syscall(funcPC(x509_CFEqual_trampoline), uintptr(a), uintptr(b), 0, 0, 0, 0)
+	return ret == 1
+}
+func x509_CFEqual_trampoline()
+
+//go:linkname x509_CFRelease x509_CFRelease
+//go:cgo_import_dynamic x509_CFRelease CFRelease "/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation"
+
+func CFRelease(ref CFRef) {
+	syscall(funcPC(x509_CFRelease_trampoline), uintptr(ref), 0, 0, 0, 0, 0)
+}
+func x509_CFRelease_trampoline()
+
+// syscall is implemented in the runtime package (runtime/sys_darwin.go)
+func syscall(fn, a1, a2, a3, a4, a5, a6 uintptr) uintptr
+
+// funcPC returns the entry point for f. See comments in runtime/proc.go
+// for the function of the same name.
+//go:nosplit
+func funcPC(f func()) uintptr {
+	return **(**uintptr)(unsafe.Pointer(&f))
+}
diff --git a/src/crypto/x509/internal/macOS/corefoundation.s b/src/crypto/x509/internal/macOS/corefoundation.s
new file mode 100644
index 0000000000000..8f6be47e4b57e
--- /dev/null
+++ b/src/crypto/x509/internal/macOS/corefoundation.s
@@ -0,0 +1,26 @@
+// Copyright 2020 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 darwin,amd64
+
+#include "textflag.h"
+
+TEXT ·x509_CFArrayGetCount_trampoline(SB),NOSPLIT,$0-0
+	JMP	x509_CFArrayGetCount(SB)
+TEXT ·x509_CFArrayGetValueAtIndex_trampoline(SB),NOSPLIT,$0-0
+	JMP	x509_CFArrayGetValueAtIndex(SB)
+TEXT ·x509_CFDataGetBytePtr_trampoline(SB),NOSPLIT,$0-0
+	JMP	x509_CFDataGetBytePtr(SB)
+TEXT ·x509_CFDataGetLength_trampoline(SB),NOSPLIT,$0-0
+	JMP	x509_CFDataGetLength(SB)
+TEXT ·x509_CFStringCreateWithBytes_trampoline(SB),NOSPLIT,$0-0
+	JMP	x509_CFStringCreateWithBytes(SB)
+TEXT ·x509_CFRelease_trampoline(SB),NOSPLIT,$0-0
+	JMP	x509_CFRelease(SB)
+TEXT ·x509_CFDictionaryGetValueIfPresent_trampoline(SB),NOSPLIT,$0-0
+	JMP	x509_CFDictionaryGetValueIfPresent(SB)
+TEXT ·x509_CFNumberGetValue_trampoline(SB),NOSPLIT,$0-0
+	JMP	x509_CFNumberGetValue(SB)
+TEXT ·x509_CFEqual_trampoline(SB),NOSPLIT,$0-0
+	JMP	x509_CFEqual(SB)
diff --git a/src/crypto/x509/internal/macOS/security.go b/src/crypto/x509/internal/macOS/security.go
new file mode 100644
index 0000000000000..64fe20639019d
--- /dev/null
+++ b/src/crypto/x509/internal/macOS/security.go
@@ -0,0 +1,116 @@
+// Copyright 2020 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 darwin,amd64
+
+package macOS
+
+import (
+	"errors"
+	"strconv"
+	"unsafe"
+)
+
+// Based on https://opensource.apple.com/source/Security/Security-59306.41.2/base/Security.h
+
+type SecTrustSettingsResult int32
+
+const (
+	SecTrustSettingsResultInvalid SecTrustSettingsResult = iota
+	SecTrustSettingsResultTrustRoot
+	SecTrustSettingsResultTrustAsRoot
+	SecTrustSettingsResultDeny
+	SecTrustSettingsResultUnspecified
+)
+
+type SecTrustSettingsDomain int32
+
+const (
+	SecTrustSettingsDomainUser SecTrustSettingsDomain = iota
+	SecTrustSettingsDomainAdmin
+	SecTrustSettingsDomainSystem
+)
+
+type OSStatus struct {
+	call   string
+	status int32
+}
+
+func (s OSStatus) Error() string {
+	return s.call + " error: " + strconv.Itoa(int(s.status))
+}
+
+// Dictionary keys are defined as build-time strings with CFSTR, but the Go
+// linker's internal linking mode can't handle CFSTR relocations. Create our
+// own dynamic strings instead and just never release them.
+//
+// Note that this might be the only thing that can break over time if
+// these values change, as the ABI arguably requires using the strings
+// pointed to by the symbols, not values that happen to be equal to them.
+
+var SecTrustSettingsResultKey = StringToCFString("kSecTrustSettingsResult")
+var SecTrustSettingsPolicy = StringToCFString("kSecTrustSettingsPolicy")
+var SecTrustSettingsPolicyString = StringToCFString("kSecTrustSettingsPolicyString")
+var SecPolicyOid = StringToCFString("SecPolicyOid")
+var SecPolicyAppleSSL = StringToCFString("1.2.840.113635.100.1.3") // defined by POLICYMACRO
+
+var ErrNoTrustSettings = errors.New("no trust settings found")
+
+const errSecNoTrustSettings = -25263
+
+//go:linkname x509_SecTrustSettingsCopyCertificates x509_SecTrustSettingsCopyCertificates
+//go:cgo_import_dynamic x509_SecTrustSettingsCopyCertificates SecTrustSettingsCopyCertificates "/System/Library/Frameworks/Security.framework/Versions/A/Security"
+
+func SecTrustSettingsCopyCertificates(domain SecTrustSettingsDomain) (certArray CFRef, err error) {
+	ret := syscall(funcPC(x509_SecTrustSettingsCopyCertificates_trampoline), uintptr(domain),
+		uintptr(unsafe.Pointer(&certArray)), 0, 0, 0, 0)
+	if int32(ret) == errSecNoTrustSettings {
+		return 0, ErrNoTrustSettings
+	} else if ret != 0 {
+		return 0, OSStatus{"SecTrustSettingsCopyCertificates", int32(ret)}
+	}
+	return certArray, nil
+}
+func x509_SecTrustSettingsCopyCertificates_trampoline()
+
+const kSecFormatX509Cert int32 = 9
+
+//go:linkname x509_SecItemExport x509_SecItemExport
+//go:cgo_import_dynamic x509_SecItemExport SecItemExport "/System/Library/Frameworks/Security.framework/Versions/A/Security"
+
+func SecItemExport(cert CFRef) (data CFRef, err error) {
+	ret := syscall(funcPC(x509_SecItemExport_trampoline), uintptr(cert), uintptr(kSecFormatX509Cert),
+		0 /* flags */, 0 /* keyParams */, uintptr(unsafe.Pointer(&data)), 0)
+	if ret != 0 {
+		return 0, OSStatus{"SecItemExport", int32(ret)}
+	}
+	return data, nil
+}
+func x509_SecItemExport_trampoline()
+
+const errSecItemNotFound = -25300
+
+//go:linkname x509_SecTrustSettingsCopyTrustSettings x509_SecTrustSettingsCopyTrustSettings
+//go:cgo_import_dynamic x509_SecTrustSettingsCopyTrustSettings SecTrustSettingsCopyTrustSettings "/System/Library/Frameworks/Security.framework/Versions/A/Security"
+
+func SecTrustSettingsCopyTrustSettings(cert CFRef, domain SecTrustSettingsDomain) (trustSettings CFRef, err error) {
+	ret := syscall(funcPC(x509_SecTrustSettingsCopyTrustSettings_trampoline), uintptr(cert), uintptr(domain),
+		uintptr(unsafe.Pointer(&trustSettings)), 0, 0, 0)
+	if int32(ret) == errSecItemNotFound {
+		return 0, ErrNoTrustSettings
+	} else if ret != 0 {
+		return 0, OSStatus{"SecTrustSettingsCopyTrustSettings", int32(ret)}
+	}
+	return trustSettings, nil
+}
+func x509_SecTrustSettingsCopyTrustSettings_trampoline()
+
+//go:linkname x509_SecPolicyCopyProperties x509_SecPolicyCopyProperties
+//go:cgo_import_dynamic x509_SecPolicyCopyProperties SecPolicyCopyProperties "/System/Library/Frameworks/Security.framework/Versions/A/Security"
+
+func SecPolicyCopyProperties(policy CFRef) CFRef {
+	ret := syscall(funcPC(x509_SecPolicyCopyProperties_trampoline), uintptr(policy), 0, 0, 0, 0, 0)
+	return CFRef(ret)
+}
+func x509_SecPolicyCopyProperties_trampoline()
diff --git a/src/crypto/x509/internal/macOS/security.s b/src/crypto/x509/internal/macOS/security.s
new file mode 100644
index 0000000000000..1630c55bab256
--- /dev/null
+++ b/src/crypto/x509/internal/macOS/security.s
@@ -0,0 +1,16 @@
+// Copyright 2020 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 darwin,amd64
+
+#include "textflag.h"
+
+TEXT ·x509_SecTrustSettingsCopyCertificates_trampoline(SB),NOSPLIT,$0-0
+	JMP	x509_SecTrustSettingsCopyCertificates(SB)
+TEXT ·x509_SecItemExport_trampoline(SB),NOSPLIT,$0-0
+	JMP	x509_SecItemExport(SB)
+TEXT ·x509_SecTrustSettingsCopyTrustSettings_trampoline(SB),NOSPLIT,$0-0
+	JMP	x509_SecTrustSettingsCopyTrustSettings(SB)
+TEXT ·x509_SecPolicyCopyProperties_trampoline(SB),NOSPLIT,$0-0
+	JMP	x509_SecPolicyCopyProperties(SB)
diff --git a/src/crypto/x509/root_cgo_darwin.go b/src/crypto/x509/root_cgo_darwin_amd64.go
similarity index 97%
rename from src/crypto/x509/root_cgo_darwin.go
rename to src/crypto/x509/root_cgo_darwin_amd64.go
index 784470bb3b2e7..bec57eb8367dc 100644
--- a/src/crypto/x509/root_cgo_darwin.go
+++ b/src/crypto/x509/root_cgo_darwin_amd64.go
@@ -2,10 +2,12 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build cgo,!arm64,!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
@@ -283,7 +285,11 @@ import (
 	"unsafe"
 )
 
-func loadSystemRoots() (*CertPool, error) {
+func init() {
+	loadSystemRootsWithCgo = _loadSystemRootsWithCgo
+}
+
+func _loadSystemRootsWithCgo() (*CertPool, error) {
 	var data, untrustedData C.CFDataRef
 	err := C.CopyPEMRoots(&data, &untrustedData, C.bool(debugDarwinRoots))
 	if err == -1 {
diff --git a/src/crypto/x509/root_darwin.go b/src/crypto/x509/root_darwin.go
deleted file mode 100644
index 2f6a8b8d60762..0000000000000
--- a/src/crypto/x509/root_darwin.go
+++ /dev/null
@@ -1,288 +0,0 @@
-// Copyright 2013 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.
-
-//go:generate go run root_darwin_arm_gen.go -output root_darwin_armx.go
-
-package x509
-
-import (
-	"bufio"
-	"bytes"
-	"crypto/sha1"
-	"encoding/pem"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"os"
-	"os/exec"
-	"path/filepath"
-	"strings"
-	"sync"
-)
-
-var debugDarwinRoots = strings.Contains(os.Getenv("GODEBUG"), "x509roots=1")
-
-func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
-	return nil, nil
-}
-
-// This code is only used when compiling without cgo.
-// It is here, instead of root_nocgo_darwin.go, so that tests can check it
-// even if the tests are run with cgo enabled.
-// The linker will not include these unused functions in binaries built with cgo enabled.
-
-// execSecurityRoots finds the macOS list of trusted root certificates
-// using only command-line tools. This is our fallback path when cgo isn't available.
-//
-// The strategy is as follows:
-//
-// 1. Run "security trust-settings-export" and "security
-//    trust-settings-export -d" to discover the set of certs with some
-//    user-tweaked trust policy. We're too lazy to parse the XML
-//    (Issue 26830) to understand what the trust
-//    policy actually is. We just learn that there is _some_ policy.
-//
-// 2. Run "security find-certificate" to dump the list of system root
-//    CAs in PEM format.
-//
-// 3. For each dumped cert, conditionally verify it with "security
-//    verify-cert" if that cert was in the set discovered in Step 1.
-//    Without the Step 1 optimization, running "security verify-cert"
-//    150-200 times takes 3.5 seconds. With the optimization, the
-//    whole process takes about 180 milliseconds with 1 untrusted root
-//    CA. (Compared to 110ms in the cgo path)
-func execSecurityRoots() (*CertPool, error) {
-	hasPolicy, err := getCertsWithTrustPolicy()
-	if err != nil {
-		return nil, err
-	}
-	if debugDarwinRoots {
-		fmt.Fprintf(os.Stderr, "crypto/x509: %d certs have a trust policy\n", len(hasPolicy))
-	}
-
-	keychains := []string{"/Library/Keychains/System.keychain"}
-
-	// Note that this results in trusting roots from $HOME/... (the environment
-	// variable), which might not be expected.
-	home, err := os.UserHomeDir()
-	if err != nil {
-		if debugDarwinRoots {
-			fmt.Fprintf(os.Stderr, "crypto/x509: can't get user home directory: %v\n", err)
-		}
-	} else {
-		keychains = append(keychains,
-			filepath.Join(home, "/Library/Keychains/login.keychain"),
-
-			// Fresh installs of Sierra use a slightly different path for the login keychain
-			filepath.Join(home, "/Library/Keychains/login.keychain-db"),
-		)
-	}
-
-	type rootCandidate struct {
-		c      *Certificate
-		system bool
-	}
-
-	var (
-		mu          sync.Mutex
-		roots       = NewCertPool()
-		numVerified int // number of execs of 'security verify-cert', for debug stats
-		wg          sync.WaitGroup
-		verifyCh    = make(chan rootCandidate)
-	)
-
-	// Using 4 goroutines to pipe into verify-cert seems to be
-	// about the best we can do. The verify-cert binary seems to
-	// just RPC to another server with coarse locking anyway, so
-	// running 16 at a time for instance doesn't help at all. Due
-	// to the "if hasPolicy" check below, though, we will rarely
-	// (or never) call verify-cert on stock macOS systems, though.
-	// The hope is that we only call verify-cert when the user has
-	// tweaked their trust policy. These 4 goroutines are only
-	// defensive in the pathological case of many trust edits.
-	for i := 0; i < 4; i++ {
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
-			for cert := range verifyCh {
-				sha1CapHex := fmt.Sprintf("%X", sha1.Sum(cert.c.Raw))
-
-				var valid bool
-				verifyChecks := 0
-				if hasPolicy[sha1CapHex] {
-					verifyChecks++
-					valid = verifyCertWithSystem(cert.c)
-				} else {
-					// Certificates not in SystemRootCertificates without user
-					// or admin trust settings are not trusted.
-					valid = cert.system
-				}
-
-				mu.Lock()
-				numVerified += verifyChecks
-				if valid {
-					roots.AddCert(cert.c)
-				}
-				mu.Unlock()
-			}
-		}()
-	}
-	err = forEachCertInKeychains(keychains, func(cert *Certificate) {
-		verifyCh <- rootCandidate{c: cert, system: false}
-	})
-	if err != nil {
-		close(verifyCh)
-		return nil, err
-	}
-	err = forEachCertInKeychains([]string{
-		"/System/Library/Keychains/SystemRootCertificates.keychain",
-	}, func(cert *Certificate) {
-		verifyCh <- rootCandidate{c: cert, system: true}
-	})
-	if err != nil {
-		close(verifyCh)
-		return nil, err
-	}
-	close(verifyCh)
-	wg.Wait()
-
-	if debugDarwinRoots {
-		fmt.Fprintf(os.Stderr, "crypto/x509: ran security verify-cert %d times\n", numVerified)
-	}
-
-	return roots, nil
-}
-
-func forEachCertInKeychains(paths []string, f func(*Certificate)) error {
-	args := append([]string{"find-certificate", "-a", "-p"}, paths...)
-	cmd := exec.Command("/usr/bin/security", args...)
-	data, err := cmd.Output()
-	if err != nil {
-		return err
-	}
-	for len(data) > 0 {
-		var block *pem.Block
-		block, data = pem.Decode(data)
-		if block == nil {
-			break
-		}
-		if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
-			continue
-		}
-		cert, err := ParseCertificate(block.Bytes)
-		if err != nil {
-			continue
-		}
-		f(cert)
-	}
-	return nil
-}
-
-func verifyCertWithSystem(cert *Certificate) bool {
-	data := pem.EncodeToMemory(&pem.Block{
-		Type: "CERTIFICATE", Bytes: cert.Raw,
-	})
-
-	f, err := ioutil.TempFile("", "cert")
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "can't create temporary file for cert: %v", err)
-		return false
-	}
-	defer os.Remove(f.Name())
-	if _, err := f.Write(data); err != nil {
-		fmt.Fprintf(os.Stderr, "can't write temporary file for cert: %v", err)
-		return false
-	}
-	if err := f.Close(); err != nil {
-		fmt.Fprintf(os.Stderr, "can't write temporary file for cert: %v", err)
-		return false
-	}
-	cmd := exec.Command("/usr/bin/security", "verify-cert", "-p", "ssl", "-c", f.Name(), "-l", "-L")
-	var stderr bytes.Buffer
-	if debugDarwinRoots {
-		cmd.Stderr = &stderr
-	}
-	if err := cmd.Run(); err != nil {
-		if debugDarwinRoots {
-			fmt.Fprintf(os.Stderr, "crypto/x509: verify-cert rejected %s: %q\n", cert.Subject, bytes.TrimSpace(stderr.Bytes()))
-		}
-		return false
-	}
-	if debugDarwinRoots {
-		fmt.Fprintf(os.Stderr, "crypto/x509: verify-cert approved %s\n", cert.Subject)
-	}
-	return true
-}
-
-// getCertsWithTrustPolicy returns the set of certs that have a
-// possibly-altered trust policy. The keys of the map are capitalized
-// sha1 hex of the raw cert.
-// They are the certs that should be checked against `security
-// verify-cert` to see whether the user altered the default trust
-// settings. This code is only used for cgo-disabled builds.
-func getCertsWithTrustPolicy() (map[string]bool, error) {
-	set := map[string]bool{}
-	td, err := ioutil.TempDir("", "x509trustpolicy")
-	if err != nil {
-		return nil, err
-	}
-	defer os.RemoveAll(td)
-	run := func(file string, args ...string) error {
-		file = filepath.Join(td, file)
-		args = append(args, file)
-		cmd := exec.Command("/usr/bin/security", args...)
-		var stderr bytes.Buffer
-		cmd.Stderr = &stderr
-		if err := cmd.Run(); err != nil {
-			// If there are no trust settings, the
-			// `security trust-settings-export` command
-			// fails with:
-			//    exit status 1, SecTrustSettingsCreateExternalRepresentation: No Trust Settings were found.
-			// Rather than match on English substrings that are probably
-			// localized on macOS, just interpret any failure to mean that
-			// there are no trust settings.
-			if debugDarwinRoots {
-				fmt.Fprintf(os.Stderr, "crypto/x509: exec %q: %v, %s\n", cmd.Args, err, stderr.Bytes())
-			}
-			return nil
-		}
-
-		f, err := os.Open(file)
-		if err != nil {
-			return err
-		}
-		defer f.Close()
-
-		// Gather all the runs of 40 capitalized hex characters.
-		br := bufio.NewReader(f)
-		var hexBuf bytes.Buffer
-		for {
-			b, err := br.ReadByte()
-			isHex := ('A' <= b && b <= 'F') || ('0' <= b && b <= '9')
-			if isHex {
-				hexBuf.WriteByte(b)
-			} else {
-				if hexBuf.Len() == 40 {
-					set[hexBuf.String()] = true
-				}
-				hexBuf.Reset()
-			}
-			if err == io.EOF {
-				break
-			}
-			if err != nil {
-				return err
-			}
-		}
-
-		return nil
-	}
-	if err := run("user", "trust-settings-export"); err != nil {
-		return nil, fmt.Errorf("dump-trust-settings (user): %v", err)
-	}
-	if err := run("admin", "trust-settings-export", "-d"); err != nil {
-		return nil, fmt.Errorf("dump-trust-settings (admin): %v", err)
-	}
-	return set, nil
-}
diff --git a/src/crypto/x509/root_darwin_amd64.go b/src/crypto/x509/root_darwin_amd64.go
new file mode 100644
index 0000000000000..3ddd3a46f45f9
--- /dev/null
+++ b/src/crypto/x509/root_darwin_amd64.go
@@ -0,0 +1,222 @@
+// Copyright 2020 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.
+
+package x509
+
+import (
+	"bytes"
+	"crypto/x509/internal/macOS"
+	"fmt"
+	"os"
+	"strings"
+)
+
+var debugDarwinRoots = strings.Contains(os.Getenv("GODEBUG"), "x509roots=1")
+
+func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
+	return nil, nil
+}
+
+// loadSystemRootsWithCgo is set in root_cgo_darwin_amd64.go when cgo is
+// available, and is only used for testing.
+var loadSystemRootsWithCgo func() (*CertPool, error)
+
+func loadSystemRoots() (*CertPool, error) {
+	var trustedRoots []*Certificate
+	untrustedRoots := make(map[string]bool)
+
+	// macOS has three trust domains: one for CAs added by users to their
+	// "login" keychain, one for CAs added by Admins to the "System" keychain,
+	// and one for the CAs that ship with the OS.
+	for _, domain := range []macOS.SecTrustSettingsDomain{
+		macOS.SecTrustSettingsDomainUser,
+		macOS.SecTrustSettingsDomainAdmin,
+		macOS.SecTrustSettingsDomainSystem,
+	} {
+		certs, err := macOS.SecTrustSettingsCopyCertificates(domain)
+		if err == macOS.ErrNoTrustSettings {
+			continue
+		} else if err != nil {
+			return nil, err
+		}
+		defer macOS.CFRelease(certs)
+
+		for i := 0; i < macOS.CFArrayGetCount(certs); i++ {
+			c := macOS.CFArrayGetValueAtIndex(certs, i)
+			cert, err := exportCertificate(c)
+			if err != nil {
+				if debugDarwinRoots {
+					fmt.Fprintf(os.Stderr, "crypto/x509: domain %d, certificate #%d: %v\n", domain, i, err)
+				}
+				continue
+			}
+
+			var result macOS.SecTrustSettingsResult
+			if domain == macOS.SecTrustSettingsDomainSystem {
+				// 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 untrustedRoots.
+				result = macOS.SecTrustSettingsResultTrustRoot
+			} else {
+				result, err = sslTrustSettingsResult(c)
+				if err != nil {
+					if debugDarwinRoots {
+						fmt.Fprintf(os.Stderr, "crypto/x509: trust settings for %v: %v\n", cert.Subject, err)
+					}
+					continue
+				}
+				if debugDarwinRoots {
+					fmt.Fprintf(os.Stderr, "crypto/x509: trust settings for %v: %d\n", cert.Subject, result)
+				}
+			}
+
+			switch result {
+			// "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."
+			case macOS.SecTrustSettingsResultTrustRoot:
+				if isRootCertificate(cert) {
+					trustedRoots = append(trustedRoots, cert)
+				}
+			case macOS.SecTrustSettingsResultTrustAsRoot:
+				if !isRootCertificate(cert) {
+					trustedRoots = append(trustedRoots, cert)
+				}
+
+			case macOS.SecTrustSettingsResultDeny:
+				// Add this certificate to untrustedRoots, which are subtracted
+				// from trustedRoots, so that we don't have to evaluate policies
+				// for every root in the system domain, but still apply user and
+				// admin policies that override system roots.
+				untrustedRoots[string(cert.Raw)] = true
+
+			case macOS.SecTrustSettingsResultUnspecified:
+				// Certificates with unspecified trust should be added to a pool
+				// of intermediates for chain building, but we don't support it
+				// at the moment. This is Issue 35631.
+
+			default:
+				if debugDarwinRoots {
+					fmt.Fprintf(os.Stderr, "crypto/x509: unknown trust setting for %v: %d\n", cert.Subject, result)
+				}
+			}
+		}
+	}
+
+	pool := NewCertPool()
+	for _, cert := range trustedRoots {
+		if !untrustedRoots[string(cert.Raw)] {
+			pool.AddCert(cert)
+		}
+	}
+	return pool, nil
+}
+
+// exportCertificate returns a *Certificate for a SecCertificateRef.
+func exportCertificate(cert macOS.CFRef) (*Certificate, error) {
+	data, err := macOS.SecItemExport(cert)
+	if err != nil {
+		return nil, err
+	}
+	defer macOS.CFRelease(data)
+	der := macOS.CFDataToSlice(data)
+
+	return ParseCertificate(der)
+}
+
+// isRootCertificate reports whether Subject and Issuer match.
+func isRootCertificate(cert *Certificate) bool {
+	return bytes.Equal(cert.RawSubject, cert.RawIssuer)
+}
+
+// sslTrustSettingsResult obtains the final kSecTrustSettingsResult value for a
+// certificate in the user or admin domain, combining usage constraints for the
+// SSL SecTrustSettingsPolicy,
+//
+// It ignores SecTrustSettingsKeyUsage and kSecTrustSettingsAllowedError, and
+// doesn't support kSecTrustSettingsDefaultRootCertSetting.
+//
+// https://developer.apple.com/documentation/security/1400261-sectrustsettingscopytrustsetting
+func sslTrustSettingsResult(cert macOS.CFRef) (macOS.SecTrustSettingsResult, error) {
+	trustSettings, err := macOS.SecTrustSettingsCopyTrustSettings(cert, macOS.SecTrustSettingsDomainUser)
+	// 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 there are no
+	// user trust settings.
+	if err == macOS.ErrNoTrustSettings {
+		trustSettings, err = macOS.SecTrustSettingsCopyTrustSettings(cert, macOS.SecTrustSettingsDomainAdmin)
+		// "no trust settings [...] means 'this certificate must be verified to a known trusted certificate'"
+		if err == macOS.ErrNoTrustSettings {
+			return macOS.SecTrustSettingsResultUnspecified, nil
+		}
+	}
+	if err != nil {
+		return 0, err
+	}
+	defer macOS.CFRelease(trustSettings)
+
+	// "An empty trust settings array means 'always trust this certificate' with an
+	// overall trust setting for the certificate of kSecTrustSettingsResultTrustRoot."
+	if macOS.CFArrayGetCount(trustSettings) == 0 {
+		return macOS.SecTrustSettingsResultTrustRoot, nil
+	}
+
+	isSSLPolicy := func(policyRef macOS.CFRef) bool {
+		properties := macOS.SecPolicyCopyProperties(policyRef)
+		defer macOS.CFRelease(properties)
+		if v, ok := macOS.CFDictionaryGetValueIfPresent(properties, macOS.SecPolicyOid); ok {
+			return macOS.CFEqual(v, macOS.CFRef(macOS.SecPolicyAppleSSL))
+		}
+		return false
+	}
+
+	for i := 0; i < macOS.CFArrayGetCount(trustSettings); i++ {
+		tSetting := macOS.CFArrayGetValueAtIndex(trustSettings, i)
+
+		// First, check if this trust setting is constrained to a non-SSL policy.
+		if policyRef, ok := macOS.CFDictionaryGetValueIfPresent(tSetting, macOS.SecTrustSettingsPolicy); ok {
+			if !isSSLPolicy(policyRef) {
+				continue
+			}
+		}
+
+		// Then check if it is restricted to a hostname, so not a root.
+		if _, ok := macOS.CFDictionaryGetValueIfPresent(tSetting, macOS.SecTrustSettingsPolicyString); ok {
+			continue
+		}
+
+		cfNum, ok := macOS.CFDictionaryGetValueIfPresent(tSetting, macOS.SecTrustSettingsResultKey)
+		// "If this key is not present, a default value of kSecTrustSettingsResultTrustRoot is assumed."
+		if !ok {
+			return macOS.SecTrustSettingsResultTrustRoot, nil
+		}
+		result, err := macOS.CFNumberGetValue(cfNum)
+		if err != nil {
+			return 0, err
+		}
+
+		// 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.
+		switch r := macOS.SecTrustSettingsResult(result); r {
+		case macOS.SecTrustSettingsResultTrustRoot,
+			macOS.SecTrustSettingsResultTrustAsRoot,
+			macOS.SecTrustSettingsResultDeny:
+			return r, nil
+		}
+	}
+
+	// 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 maybe
+	// fallback to the admin trust settings? TODO(golang.org/issue/38888).
+
+	return macOS.SecTrustSettingsResultUnspecified, nil
+}
diff --git a/src/crypto/x509/root_darwin_arm64.go b/src/crypto/x509/root_darwin_arm64.go
index 639c6ae7dec1f..2fb079ba6695a 100644
--- a/src/crypto/x509/root_darwin_arm64.go
+++ b/src/crypto/x509/root_darwin_arm64.go
@@ -1,13 +1,18 @@
-// Code generated by root_darwin_arm_gen --output root_darwin_arm64.go; DO NOT EDIT.
+// Code generated by root_darwin_arm64_gen.go; DO NOT EDIT.
 
-// Copyright 2015 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.
+//go:generate go run root_darwin_arm64_gen.go -output root_darwin_arm64.go
 
 // +build !x509omitbundledroots
 
 package x509
 
+func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
+	return nil, nil
+}
+
+// loadSystemRootsWithCgo is not available on iOS.
+var loadSystemRootsWithCgo func() (*CertPool, error)
+
 func loadSystemRoots() (*CertPool, error) {
 	p := NewCertPool()
 	p.AppendCertsFromPEM([]byte(systemRootsPEM))
diff --git a/src/crypto/x509/root_darwin_arm_gen.go b/src/crypto/x509/root_darwin_arm64_gen.go
similarity index 92%
rename from src/crypto/x509/root_darwin_arm_gen.go
rename to src/crypto/x509/root_darwin_arm64_gen.go
index cba950fcc941b..e7e312e8820be 100644
--- a/src/crypto/x509/root_darwin_arm_gen.go
+++ b/src/crypto/x509/root_darwin_arm64_gen.go
@@ -42,8 +42,6 @@ func main() {
 	}
 
 	buf := new(bytes.Buffer)
-
-	fmt.Fprintf(buf, "// Code generated by root_darwin_arm_gen --output %s; DO NOT EDIT.\n", *output)
 	fmt.Fprintf(buf, "%s", header)
 
 	fmt.Fprintf(buf, "const systemRootsPEM = `\n")
@@ -167,15 +165,21 @@ func fetchCertIDs() ([]certID, error) {
 	return ids, nil
 }
 
-const header = `
-// Copyright 2015 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.
+const header = `// Code generated by root_darwin_arm64_gen.go; DO NOT EDIT.
+
+//go:generate go run root_darwin_arm64_gen.go -output root_darwin_arm64.go
 
 // +build !x509omitbundledroots
 
 package x509
 
+func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
+	return nil, nil
+}
+
+// loadSystemRootsWithCgo is not available on iOS.
+var loadSystemRootsWithCgo func() (*CertPool, error)
+
 func loadSystemRoots() (*CertPool, error) {
 	p := NewCertPool()
 	p.AppendCertsFromPEM([]byte(systemRootsPEM))
diff --git a/src/crypto/x509/root_darwin_test.go b/src/crypto/x509/root_darwin_test.go
index bd14d34b90abe..2c773b91203bd 100644
--- a/src/crypto/x509/root_darwin_test.go
+++ b/src/crypto/x509/root_darwin_test.go
@@ -5,120 +5,60 @@
 package x509
 
 import (
-	"crypto/rsa"
 	"os"
 	"os/exec"
-	"path/filepath"
-	"runtime"
 	"testing"
 	"time"
 )
 
 func TestSystemRoots(t *testing.T) {
-	switch runtime.GOARCH {
-	case "arm64":
-		t.Skipf("skipping on %s/%s, no system root", runtime.GOOS, runtime.GOARCH)
-	}
-
 	t0 := time.Now()
-	sysRoots := systemRootsPool() // actual system roots
+	sysRoots, err := loadSystemRoots() // actual system roots
 	sysRootsDuration := time.Since(t0)
 
-	t1 := time.Now()
-	execRoots, err := execSecurityRoots() // non-cgo roots
-	execSysRootsDuration := time.Since(t1)
-
 	if err != nil {
 		t.Fatalf("failed to read system roots: %v", err)
 	}
 
-	t.Logf("    cgo sys roots: %v", sysRootsDuration)
-	t.Logf("non-cgo sys roots: %v", execSysRootsDuration)
+	t.Logf("loadSystemRoots: %v", sysRootsDuration)
 
-	// On Mavericks, there are 212 bundled certs, at least there was at
-	// one point in time on one machine. (Maybe it was a corp laptop
-	// with extra certs?) Other OS X users report 135, 142, 145...
-	// Let's try requiring at least 100, since this is just a sanity
-	// check.
+	// There are 174 system roots on Catalina, and 163 on iOS right now, require
+	// at least 100 to make sure this is not completely broken.
 	if want, have := 100, len(sysRoots.certs); have < want {
 		t.Errorf("want at least %d system roots, have %d", want, have)
 	}
 
-	// Fetch any intermediate certificate that verify-cert might be aware of.
-	out, err := exec.Command("/usr/bin/security", "find-certificate", "-a", "-p",
-		"/Library/Keychains/System.keychain",
-		filepath.Join(os.Getenv("HOME"), "/Library/Keychains/login.keychain"),
-		filepath.Join(os.Getenv("HOME"), "/Library/Keychains/login.keychain-db")).Output()
+	if loadSystemRootsWithCgo == nil {
+		t.Skip("cgo not available, can't compare pool")
+	}
+
+	t1 := time.Now()
+	cgoRoots, err := loadSystemRootsWithCgo() // cgo roots
+	cgoSysRootsDuration := time.Since(t1)
+
 	if err != nil {
-		t.Fatal(err)
+		t.Fatalf("failed to read cgo roots: %v", err)
 	}
-	allCerts := NewCertPool()
-	allCerts.AppendCertsFromPEM(out)
+
+	t.Logf("loadSystemRootsWithCgo: %v", cgoSysRootsDuration)
 
 	// Check that the two cert pools are the same.
 	sysPool := make(map[string]*Certificate, len(sysRoots.certs))
 	for _, c := range sysRoots.certs {
 		sysPool[string(c.Raw)] = c
 	}
-	for _, c := range execRoots.certs {
+	for _, c := range cgoRoots.certs {
 		if _, ok := sysPool[string(c.Raw)]; ok {
 			delete(sysPool, string(c.Raw))
 		} else {
-			// verify-cert lets in certificates that are not trusted roots, but
-			// are signed by trusted roots. This is not great, but unavoidable
-			// until we parse real policies without cgo, so confirm that's the
-			// case and skip them.
-			if _, err := c.Verify(VerifyOptions{
-				Roots:         sysRoots,
-				Intermediates: allCerts,
-				KeyUsages:     []ExtKeyUsage{ExtKeyUsageAny},
-				CurrentTime:   c.NotBefore, // verify-cert does not check expiration
-			}); err != nil {
-				t.Errorf("certificate only present in non-cgo pool: %v (verify error: %v)", c.Subject, err)
-			} else {
-				t.Logf("signed certificate only present in non-cgo pool (acceptable): %v", c.Subject)
-			}
+			t.Errorf("certificate only present in cgo pool: %v", c.Subject)
 		}
 	}
 	for _, c := range sysPool {
-		// The nocgo codepath uses verify-cert with the ssl policy, which also
-		// happens to check EKUs, so some certificates will appear only in the
-		// cgo pool. We can't easily make them consistent because the EKU check
-		// is only applied to the certificates passed to verify-cert.
-		var ekuOk bool
-		for _, eku := range c.ExtKeyUsage {
-			if eku == ExtKeyUsageServerAuth || eku == ExtKeyUsageNetscapeServerGatedCrypto ||
-				eku == ExtKeyUsageMicrosoftServerGatedCrypto || eku == ExtKeyUsageAny {
-				ekuOk = true
-			}
-		}
-		if len(c.ExtKeyUsage) == 0 && len(c.UnknownExtKeyUsage) == 0 {
-			ekuOk = true
-		}
-		if !ekuOk {
-			t.Logf("off-EKU certificate only present in cgo pool (acceptable): %v", c.Subject)
-			continue
-		}
-
-		// Same for expired certificates. We don't chain to them anyway.
-		now := time.Now()
-		if now.Before(c.NotBefore) || now.After(c.NotAfter) {
-			t.Logf("expired certificate only present in cgo pool (acceptable): %v", c.Subject)
-			continue
-		}
-
-		// On 10.11 there are five unexplained roots that only show up from the
-		// C API. They have in common the fact that they are old, 1024-bit
-		// certificates. It's arguably better to ignore them anyway.
-		if key, ok := c.PublicKey.(*rsa.PublicKey); ok && key.N.BitLen() == 1024 {
-			t.Logf("1024-bit certificate only present in cgo pool (acceptable): %v", c.Subject)
-			continue
-		}
-
-		t.Errorf("certificate only present in cgo pool: %v", c.Subject)
+		t.Errorf("certificate only present in real pool: %v", c.Subject)
 	}
 
-	if t.Failed() && debugDarwinRoots {
+	if t.Failed() {
 		cmd := exec.Command("security", "dump-trust-settings")
 		cmd.Stdout, cmd.Stderr = os.Stderr, os.Stderr
 		cmd.Run()
diff --git a/src/crypto/x509/root_nocgo_darwin.go b/src/crypto/x509/root_nocgo_darwin.go
deleted file mode 100644
index 2ac4666aff65b..0000000000000
--- a/src/crypto/x509/root_nocgo_darwin.go
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright 2013 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 !cgo
-
-package x509
-
-func loadSystemRoots() (*CertPool, error) {
-	return execSecurityRoots()
-}
diff --git a/src/crypto/x509/root_omit.go b/src/crypto/x509/root_omit.go
index f466e24dce8c1..b757ea81c20d5 100644
--- a/src/crypto/x509/root_omit.go
+++ b/src/crypto/x509/root_omit.go
@@ -19,3 +19,10 @@ import "errors"
 func loadSystemRoots() (*CertPool, error) {
 	return nil, errors.New("x509: system root bundling disabled")
 }
+
+func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
+	return nil, nil
+}
+
+// loadSystemRootsWithCgo is not available on iOS.
+var loadSystemRootsWithCgo func() (*CertPool, error)
diff --git a/src/go/build/deps_test.go b/src/go/build/deps_test.go
index d980781416b35..d3bbf087c3565 100644
--- a/src/go/build/deps_test.go
+++ b/src/go/build/deps_test.go
@@ -412,11 +412,12 @@ var pkgDeps = map[string][]string{
 		"container/list", "context", "crypto/x509", "encoding/pem", "net", "syscall", "crypto/ed25519",
 	},
 	"crypto/x509": {
-		"L4", "CRYPTO-MATH", "OS", "CGO", "crypto/ed25519",
+		"L4", "CRYPTO-MATH", "OS", "CGO", "crypto/ed25519", "crypto/x509/internal/macOS",
 		"crypto/x509/pkix", "encoding/pem", "encoding/hex", "net", "os/user", "syscall", "net/url",
 		"golang.org/x/crypto/cryptobyte", "golang.org/x/crypto/cryptobyte/asn1",
 	},
-	"crypto/x509/pkix": {"L4", "CRYPTO-MATH", "encoding/hex"},
+	"crypto/x509/pkix":           {"L4", "CRYPTO-MATH", "encoding/hex"},
+	"crypto/x509/internal/macOS": {"L4"},
 
 	// Simple net+crypto-aware packages.
 	"mime/multipart": {"L4", "OS", "mime", "crypto/rand", "net/textproto", "mime/quotedprintable"},
diff --git a/src/runtime/sys_darwin.go b/src/runtime/sys_darwin.go
index 1b136f88a8e4e..28c500a71005a 100644
--- a/src/runtime/sys_darwin.go
+++ b/src/runtime/sys_darwin.go
@@ -127,6 +127,19 @@ func syscall_rawSyscall6(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintpt
 	return
 }
 
+// syscallNoErr is used in crypto/x509 to call into Security.framework and CF.
+
+//go:linkname crypto_x509_syscall crypto/x509/internal/macOS.syscall
+//go:nosplit
+//go:cgo_unsafe_args
+func crypto_x509_syscall(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1 uintptr) {
+	entersyscall()
+	libcCall(unsafe.Pointer(funcPC(syscallNoErr)), unsafe.Pointer(&fn))
+	exitsyscall()
+	return
+}
+func syscallNoErr()
+
 // The *_trampoline functions convert from the Go calling convention to the C calling convention
 // and then call the underlying libc function.  They are defined in sys_darwin_$ARCH.s.
 
@@ -477,6 +490,8 @@ func setNonblock(fd int32) {
 //go:cgo_import_dynamic libc_pthread_cond_timedwait_relative_np pthread_cond_timedwait_relative_np "/usr/lib/libSystem.B.dylib"
 //go:cgo_import_dynamic libc_pthread_cond_signal pthread_cond_signal "/usr/lib/libSystem.B.dylib"
 
-// Magic incantation to get libSystem actually dynamically linked.
+// Magic incantation to get libSystem and friends actually dynamically linked.
 // TODO: Why does the code require this?  See cmd/link/internal/ld/go.go
 //go:cgo_import_dynamic _ _ "/usr/lib/libSystem.B.dylib"
+//go:cgo_import_dynamic _ _ "/System/Library/Frameworks/Security.framework/Versions/A/Security"
+//go:cgo_import_dynamic _ _ "/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation"
diff --git a/src/runtime/sys_darwin_amd64.s b/src/runtime/sys_darwin_amd64.s
index a45ea42e5d91c..825852d673975 100644
--- a/src/runtime/sys_darwin_amd64.s
+++ b/src/runtime/sys_darwin_amd64.s
@@ -825,3 +825,29 @@ ok:
 	MOVQ	BP, SP
 	POPQ	BP
 	RET
+
+// syscallNoErr is like syscall6 but does not check for errors, and
+// only returns one value, for use with standard C ABI library functions.
+TEXT runtime·syscallNoErr(SB),NOSPLIT,$0
+	PUSHQ	BP
+	MOVQ	SP, BP
+	SUBQ	$16, SP
+	MOVQ	(0*8)(DI), R11// fn
+	MOVQ	(2*8)(DI), SI // a2
+	MOVQ	(3*8)(DI), DX // a3
+	MOVQ	(4*8)(DI), CX // a4
+	MOVQ	(5*8)(DI), R8 // a5
+	MOVQ	(6*8)(DI), R9 // a6
+	MOVQ	DI, (SP)
+	MOVQ	(1*8)(DI), DI // a1
+	XORL	AX, AX	      // vararg: say "no float args"
+
+	CALL	R11
+
+	MOVQ	(SP), DI
+	MOVQ	AX, (7*8)(DI) // r1
+
+	XORL	AX, AX        // no error (it's ignored anyway)
+	MOVQ	BP, SP
+	POPQ	BP
+	RET