MINOR: acme: handle the nonce

ACME requests are supposed to be sent with a Nonce, the first Nonce
should be retrieved using the newNonce URI provided by the directory.

This nonce is stored and must be replaced by the new one received in the
each response.

include/haproxy/acme-t.h

@@ -31,6 +31,7 @@ struct acme_cfg {
 
 enum acme_st {
 	ACME_RESSOURCES = 0,
+	ACME_NEWNONCE,
 	ACME_END
 };
 
@@ -52,5 +53,6 @@ struct acme_ctx {
 		struct ist newAccount;
 		struct ist newOrder;
 	} ressources;
+	struct ist nonce;
 };
 #endif

src/acme.c

@@ -529,6 +529,43 @@ error:
 
 }
 
+int acme_nonce(struct task *task, struct acme_ctx *ctx, char **errmsg)
+{
+	struct httpclient *hc;
+	struct http_hdr *hdrs, *hdr;
+
+	hc = ctx->hc;
+	if (!hc)
+		goto error;
+
+	if (hc->res.status < 200 || hc->res.status >= 300) {
+		memprintf(errmsg, "invalid HTTP status code %d when getting Nonce URL", hc->res.status);
+		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);
+//			fprintf(stderr, "Replay-Nonce: %.*s\n", (int)hdr->v.len, hdr->v.ptr);
+
+		}
+	}
+
+	httpclient_destroy(hc);
+	ctx->hc = NULL;
+
+	return 0;
+
+error:
+	httpclient_destroy(hc);
+	ctx->hc = NULL;
+
+	return 1;
+}
+
 int acme_directory(struct task *task, struct acme_ctx *ctx, char **errmsg)
 {
 	struct httpclient *hc;
@@ -617,10 +654,25 @@ struct task *acme_process(struct task *task, void *context, unsigned int state)
 					http_st = ACME_HTTP_REQ;
 					goto retry;
 				}
-				st = ACME_END;
+				st = ACME_NEWNONCE;
+				http_st = ACME_HTTP_REQ;
+				task_wakeup(task, TASK_WOKEN_MSG);
 			}
 		break;
+		case ACME_NEWNONCE:
+			if (http_st == ACME_HTTP_REQ) {
+				if (acme_http_req(task, ctx, ctx->ressources.newNonce, HTTP_METH_HEAD) != 0)
+					goto retry;
+			}
+			if (http_st == ACME_HTTP_RES) {
+				if (acme_nonce(task, ctx, &errmsg) != 0) {
+					http_st = ACME_HTTP_REQ;
+					goto retry;
+				}
+				st = ACME_END;
+			}
 
+		break;
 		case ACME_END:
 			goto end;
 		break;