MINOR: acme: finalize by sending the CSR

This patch does the finalize step of the ACME task.
This encodes the CSR into base64 format and send it to the finalize URL.

https://www.rfc-editor.org/rfc/rfc8555#section-7.4

include/haproxy/acme-t.h

@@ -38,6 +38,7 @@ enum acme_st {
 	ACME_AUTH,
 	ACME_CHALLENGE,
 	ACME_CHKCHALLENGE,
+	ACME_FINALIZE,
 	ACME_END
 };
 
@@ -72,5 +73,6 @@ struct acme_ctx {
 	struct acme_auth *auths;
 	struct acme_auth *next_auth;
 	X509_REQ *req;
+	struct ist finalize;
 };
 #endif

src/acme.c

@@ -578,6 +578,109 @@ error:
 	return ret;
 }
 
+/* Send the CSR over the Finalize URL */
+int acme_req_finalize(struct task *task, struct acme_ctx *ctx, char **errmsg)
+{
+	X509_REQ *req = ctx->req;
+	struct buffer *csr = NULL;
+	struct buffer *req_in = NULL;
+	struct buffer *req_out = NULL;
+	const struct http_hdr hdrs[] = {
+		{ IST("Content-Type"), IST("application/jose+json") },
+		{ IST_NULL, IST_NULL }
+	};
+	int ret = 1;
+	size_t len = 0;
+	unsigned char *data = NULL;
+
+        if ((csr = alloc_trash_chunk()) == NULL)
+		goto error;
+        if ((req_in = alloc_trash_chunk()) == NULL)
+		goto error;
+        if ((req_out = alloc_trash_chunk()) == NULL)
+		goto error;
+
+	len = i2d_X509_REQ(req, &data);
+	if (len <= 0)
+		goto error;
+
+	ret = a2base64url((char *)data, len, csr->area, csr->size);
+	if (ret <= 0)
+		goto error;
+	csr->data = ret;
+
+	chunk_printf(req_in, "{ \"csr\": \"%.*s\" }", (int)csr->data, csr->area);
+	free(data);
+
+
+	if (acme_jws_payload(req_in, ctx->nonce, ctx->finalize, ctx->cfg->account.pkey, ctx->kid, req_out, errmsg) != 0)
+		goto error;
+
+	if (acme_http_req(task, ctx, ctx->finalize, HTTP_METH_POST, hdrs, ist2(req_out->area, req_out->data)))
+		goto error;
+
+
+	ret = 0;
+error:
+	memprintf(errmsg, "couldn't request the finalize URL");
+
+	free_trash_chunk(req_in);
+	free_trash_chunk(req_out);
+	free_trash_chunk(csr);
+
+	return ret;
+
+}
+
+int acme_res_finalize(struct task *task, struct acme_ctx *ctx, char **errmsg)
+{
+	struct httpclient *hc;
+	struct http_hdr *hdrs, *hdr;
+	struct buffer *t1 = NULL, *t2 = NULL;
+	int ret = 1;
+
+	hc = ctx->hc;
+	if (!hc)
+		goto error;
+
+        if ((t1 = alloc_trash_chunk()) == NULL)
+		goto error;
+        if ((t2 = alloc_trash_chunk()) == NULL)
+		goto error;
+
+	hdrs = hc->res.hdrs;
+
+	for (hdr = hdrs; isttest(hdr->v); hdr++) {
+		if (isteqi(hdr->n, ist("Replay-Nonce"))) {
+			istfree(&ctx->nonce);
+			ctx->nonce = istdup(hdr->v);
+		}
+	}
+
+	if (hc->res.status < 200 || hc->res.status >= 300) {
+		if ((ret = mjson_get_string(hc->res.buf.area, hc->res.buf.data, "$.detail", t1->area, t1->size)) > -1)
+			t1->data = ret;
+		if ((ret = mjson_get_string(hc->res.buf.area, hc->res.buf.data, "$.type", t2->area, t2->size)) > -1)
+			t2->data = ret;
+
+		if (t2->data && t1->data)
+			memprintf(errmsg, "invalid HTTP status code %d when getting Finalize URL: \"%.*s\" (%.*s)", hc->res.status, (int)t1->data, t1->area, (int)t2->data, t2->area);
+		else
+			memprintf(errmsg, "invalid HTTP status code %d when getting Finalize URL", hc->res.status);
+		goto error;
+	}
+out:
+	ret = 0;
+
+error:
+	free_trash_chunk(t1);
+	free_trash_chunk(t2);
+	httpclient_destroy(hc);
+	ctx->hc = NULL;
+
+	return ret;
+}
+
 /*
  * Send the READY request for the challenge
  */
@@ -932,6 +1035,18 @@ int acme_res_neworder(struct task *task, struct acme_ctx *ctx, char **errmsg)
 		ctx->next_auth = auth;
 	}
 
+	if ((ret = mjson_get_string(hc->res.buf.area, hc->res.buf.data, "$.finalize", trash.area, trash.size)) <= 0) {
+		memprintf(errmsg, "couldn't find the finalize URL");
+		goto error;
+	}
+	trash.data = ret;
+	istfree(&ctx->finalize);
+	ctx->finalize = istdup(ist2(trash.area, trash.data));
+	if (!isttest(ctx->finalize)) {
+		memprintf(errmsg, "out of memory");
+		goto error;
+	}
+
 out:
 	ret = 0;
 
@@ -1299,12 +1414,26 @@ struct task *acme_process(struct task *task, void *context, unsigned int state)
 				}
 				http_st = ACME_HTTP_REQ;
 				if ((ctx->next_auth = ctx->next_auth->next) == NULL)
-					goto end;
+					st = ACME_FINALIZE;
 
-				/* call with next auth or do the challenge step */
+				/* do it with the next auth or finalize */
 				task_wakeup(task, TASK_WOKEN_MSG);
 			}
 		break;
+		case ACME_FINALIZE:
+			if (http_st == ACME_HTTP_REQ) {
+				if (acme_req_finalize(task, ctx, &errmsg) != 0)
+					goto retry;
+			}
+			if (http_st == ACME_HTTP_RES) {
+				if (acme_res_finalize(task, ctx, &errmsg) != 0) {
+					http_st = ACME_HTTP_REQ;
+					goto retry;
+				}
+				http_st = ACME_HTTP_REQ;
+				goto end;
+			}
+		break;
 
 		default:
 		break;