diff --git a/acme/api/order.go b/acme/api/order.go
index 166db0e6..e2666154 100644
--- a/acme/api/order.go
+++ b/acme/api/order.go
@@ -33,7 +33,7 @@ func (n *NewOrderRequest) Validate() error {
 		return acme.NewError(acme.ErrorMalformedType, "identifiers list cannot be empty")
 	}
 	for _, id := range n.Identifiers {
-		if !(id.Type == acme.DNS || id.Type == acme.IP || id.Type == acme.PermanentIdentifier) {
+		if !(id.Type == acme.DNS || id.Type == acme.IP || id.Type == acme.PermanentIdentifier || id.Type == acme.CA) {
 			return acme.NewError(acme.ErrorMalformedType, "identifier type unsupported: %s", id.Type)
 		}
 		if id.Type == acme.IP && net.ParseIP(id.Value) == nil {
@@ -375,6 +375,8 @@ func challengeTypes(az *acme.Authorization) []acme.ChallengeType {
 		}
 	case acme.PermanentIdentifier:
 		chTypes = []acme.ChallengeType{acme.DEVICEATTEST01}
+	case acme.CA:
+		chTypes = []acme.ChallengeType{acme.APPLEATTEST01}
 	default:
 		chTypes = []acme.ChallengeType{}
 	}
diff --git a/acme/challenge.go b/acme/challenge.go
index 5153dc26..56b4ebaf 100644
--- a/acme/challenge.go
+++ b/acme/challenge.go
@@ -13,11 +13,13 @@ import (
 	"encoding/base64"
 	"encoding/hex"
 	"encoding/json"
+	"encoding/pem"
 	"errors"
 	"fmt"
 	"io"
 	"net"
 	"net/url"
+	"os"
 	"reflect"
 	"strings"
 	"time"
@@ -41,6 +43,7 @@ const (
 	TLSALPN01 ChallengeType = "tls-alpn-01"
 	// DEVICEATTEST01 is the device-attest-01 ACME challenge type
 	DEVICEATTEST01 ChallengeType = "device-attest-01"
+	APPLEATTEST01  ChallengeType = "client-01"
 )
 
 // Challenge represents an ACME response Challenge type.
@@ -84,6 +87,8 @@ func (ch *Challenge) Validate(ctx context.Context, db DB, jwk *jose.JSONWebKey,
 		return tlsalpn01Validate(ctx, ch, db, jwk)
 	case DEVICEATTEST01:
 		return deviceAttest01Validate(ctx, ch, db, jwk, payload)
+	case APPLEATTEST01:
+		return appleAttest01Validate(ctx, ch, db, jwk, payload)
 	default:
 		return NewErrorISE("unexpected challenge type '%s'", ch.Type)
 	}
@@ -416,6 +421,68 @@ func deviceAttest01Validate(ctx context.Context, ch *Challenge, db DB, jwk *jose
 	return nil
 }
 
+type ApplePayload struct {
+	AttObj string `json:"attObj"`
+	Error  string `json:"error"`
+}
+
+func appleAttest01Validate(ctx context.Context, ch *Challenge, db DB, jwk *jose.JSONWebKey, payload []byte) error {
+	var p ApplePayload
+	if err := json.Unmarshal(payload, &p); err != nil {
+		return WrapErrorISE(err, "error unmarshalling JSON")
+	}
+
+	fmt.Fprintf(os.Stderr, "p.AttObj: %v\n", p.AttObj)
+
+	attObj, err := base64.RawURLEncoding.DecodeString(p.AttObj)
+	if err != nil {
+		return WrapErrorISE(err, "error base64 decoding attObj")
+	}
+
+	att := AttestationObject{}
+	if err := cbor.Unmarshal(attObj, &att); err != nil {
+		return WrapErrorISE(err, "error unmarshalling CBOR")
+	}
+
+	if att.Format != "apple" {
+		return storeError(ctx, db, ch, true, NewError(ErrorBadAttestationStatement,
+			"unexpected attestation object format"))
+	}
+
+	x5c, x509present := att.AttStatement["x5c"].([]interface{})
+	if !x509present {
+		return storeError(ctx, db, ch, true, NewError(ErrorBadAttestationStatement,
+			"x5c not present"))
+	}
+
+	attCertBytes, valid := x5c[0].([]byte)
+	if !valid {
+		return storeError(ctx, db, ch, true, NewError(ErrorRejectedIdentifierType,
+			"error getting certificate from x5c cert chain"))
+	}
+
+	attCert, err := x509.ParseCertificate(attCertBytes)
+	if err != nil {
+		return WrapErrorISE(err, "error parsing AK certificate")
+	}
+
+	b := &pem.Block{
+		Type:  "CERTIFICATE",
+		Bytes: attCert.Raw,
+	}
+	pem.Encode(os.Stderr, b)
+
+	// Update and store the challenge.
+	ch.Status = StatusValid
+	ch.Error = nil
+	ch.ValidatedAt = clock.Now().Format(time.RFC3339)
+
+	if err := db.UpdateChallenge(ctx, ch); err != nil {
+		return WrapErrorISE(err, "error updating challenge")
+	}
+	return nil
+}
+
 // serverName determines the SNI HostName to set based on an acme.Challenge
 // for TLS-ALPN-01 challenges RFC8738 states that, if HostName is an IP, it
 // should be the ARPA address https://datatracker.ietf.org/doc/html/rfc8738#section-6.
diff --git a/acme/errors.go b/acme/errors.go
index e9122aa1..6bee949c 100644
--- a/acme/errors.go
+++ b/acme/errors.go
@@ -19,6 +19,8 @@ const (
 	ErrorAccountDoesNotExistType ProblemType = iota
 	// ErrorAlreadyRevokedType request specified a certificate to be revoked that has already been revoked
 	ErrorAlreadyRevokedType
+	// ErrorBadAttestation WebAuthn attestation statement could not be verified
+	ErrorBadAttestationStatement
 	// ErrorBadCSRType CSR is unacceptable (e.g., due to a short key)
 	ErrorBadCSRType
 	// ErrorBadNonceType client sent an unacceptable anti-replay nonce
diff --git a/acme/order.go b/acme/order.go
index 4150e2ce..b880523e 100644
--- a/acme/order.go
+++ b/acme/order.go
@@ -5,7 +5,9 @@ import (
 	"context"
 	"crypto/x509"
 	"encoding/json"
+	"encoding/pem"
 	"net"
+	"os"
 	"sort"
 	"strings"
 	"time"
@@ -25,6 +27,7 @@ const (
 	DNS IdentifierType = "dns"
 	// DNS is the ACME dns identifier type
 	PermanentIdentifier IdentifierType = "permanent-identifier"
+	CA                  IdentifierType = "ca"
 )
 
 // Identifier encodes the type that an order pertains to.
@@ -146,6 +149,12 @@ func (o *Order) Finalize(ctx context.Context, db DB, csr *x509.CertificateReques
 		return NewErrorISE("unexpected status %s for order %s", o.Status, o.ID)
 	}
 
+	b := &pem.Block{
+		Type:  "CERTIFICATE REQUEST",
+		Bytes: csr.Raw,
+	}
+	pem.Encode(os.Stderr, b)
+
 	// canonicalize the CSR to allow for comparison
 	csr = canonicalize(csr)
 
@@ -229,6 +238,7 @@ func (o *Order) sans(csr *x509.CertificateRequest) ([]x509util.SubjectAlternativ
 		case PermanentIdentifier:
 			orderPIDs[indexPID] = n.Value
 			indexPID++
+		case CA:
 		default:
 			return sans, NewErrorISE("unsupported identifier type in order: %s", n.Type)
 		}