acmeapi: Expose more fields on Challenge

If manually using acmeapi and you get an invalid challenge, it's nice to be able
to see the specific error on the challenge.  Added the other fields that I see
on actual challenges today as well. Field names inspired by those used in
boulder.

acmeapi/types.go

@@ -3,9 +3,11 @@ package acmeapi
 import (
 	"encoding/json"
 	"fmt"
-	denet "github.com/hlandau/goutils/net"
-	"gopkg.in/square/go-jose.v1"
+	"net"
 	"time"
+
+	denet "github.com/hlandau/goutils/net"
+	jose "gopkg.in/square/go-jose.v1"
 )
 
 // Represents an account registration.
@@ -28,6 +30,25 @@ type Registration struct {
 	LatestAgreementURI string `json:"-"`
 }
 
+// Represents an error that may have happened.
+// https://tools.ietf.org/html/draft-ietf-appsawg-http-problem-00
+type ProblemDetails struct {
+	Type       string `json:"type,omitempty"`
+	Detail     string `json:"detail,omitempty"`
+	HTTPStatus int    `json:"status,omitempty"`
+}
+
+// Represents a single validation attempt.
+type ValidationRecord struct {
+	Authorities       []string `json:",omitempty"`
+	URL               string   `json:"url,omitempty"`
+	Hostname          string   `json:"hostname"`
+	Port              string   `json:"port"`
+	AddressesResolved []net.IP `json:"addressesResolved"`
+	AddressUsed       net.IP   `json:"addressUsed"`
+	AddressesTried    []net.IP `json:"addressesTried"`
+}
+
 // Represents a Challenge which is part of an Authorization.
 type Challenge struct {
 	URI      string `json:"uri"`      // The URI of the challenge.
@@ -41,6 +62,10 @@ type Challenge struct {
 	// proofOfPossession
 	Certs []denet.Base64up `json:"certs,omitempty"`
 
+	Error                    *ProblemDetails    `json:"error,omitempty"`
+	ProvidedKeyAuthorization string             `json:"keyAuthorization,omitempty"`
+	ValidationRecord         []ValidationRecord `json:"validationRecord,omitempty"`
+
 	retryAt time.Time
 }
 

acmeapi/types_test.go

@@ -1,7 +1,9 @@
 package acmeapi
 
 import (
+	"bytes"
 	"encoding/json"
+	"net"
 	"testing"
 )
 
@@ -19,3 +21,43 @@ func TestStatus(t *testing.T) {
 		t.Fatal()
 	}
 }
+
+func TestChallenge(t *testing.T) {
+	const cJSON = `{
+  "type": "http-01",
+  "status": "invalid",
+  "error": {
+    "type": "urn:acme:error:caa",
+    "detail": "CAA record for mymonash2021.conference.monash.edu prevents issuance",
+    "status": 403
+  },
+  "uri": "https://acme-v01.api.letsencrypt.org/acme/challenge/wL4hNlUUJtGoMp6QeavoaAZjbqmBgJk2FMpOSC1aoIU/2676511905",
+  "token": "GMgoj5xYX7qSIfN9GdmyqhdAHYrCco_Md9kKrT8v0jE",
+  "keyAuthorization": "GMgoj5xYX7qSIfN9GdmyqhdAHYrCco_Md9kKrT8v0jE.QRRvz3cNxWGJObT4gl6G9ZNx-4cXE2eK81kX5lpYzmo",
+  "validationRecord": [
+    {
+      "url": "http://mysite.foo.com/.well-known/acme-challenge/GMgoj5xYX7qSIfN9GdmyqHdAHYrCco_Md9kKrT8v0jE",
+      "hostname": "mysite.foo.com",
+      "port": "80",
+      "addressesResolved": [
+        "54.85.70.226",
+        "52.21.26.68",
+        "54.210.179.160",
+        "52.1.9.49"
+      ],
+      "addressUsed": "54.85.70.226",
+      "addressesTried": []
+    }
+  ]
+}`
+	var c Challenge
+	if err := json.Unmarshal([]byte(cJSON), &c); err != nil {
+		t.Fatalf("%v", err)
+	}
+	if g, e := c.Error.Type, "urn:acme:error:caa"; g != e {
+		t.Fatalf("%v != %v", g, e)
+	}
+	if g, e := c.ValidationRecord[0].AddressesResolved[1], net.IPv4(52, 21, 26, 68); !bytes.Equal(g, e) {
+		t.Fatalf("%v != %v", g, e)
+	}
+}