ref: aa8713e13b9f8de595b6c34015a9d068425fc9c4
parent: ac9970d30b5153298b96d551379f99923b4d1a57
author: Ori Bernstein <ori@eigenstate.org>
date: Mon Jul 5 19:22:15 EDT 2021
renamed, update manpages
--- a/aclient.c
+++ /dev/null
@@ -1,794 +1,0 @@
-#include <u.h>
-#include <libc.h>
-#include <json.h>
-#include <libsec.h>
-#include <auth.h>
-#include <authsrv.h>
-
-typedef struct Hdr Hdr;
-
-#pragma varargck type "E" char*
-
-struct Hdr {
- char *name;
- char *val;
- int nval;
-};
-
-#define Keyspec "proto=rsa service=acme role=sign hash=sha256 acct=%s"
-#define Useragent "useragent aclient-plan9"
-#define Contenttype "contenttype application/jose+json"
-#define between(x,min,max) (((min-1-x) & (x-max-1))>>8)
-int debug;
-int (*challengefn)(JSON*, char*, int*);
-char *keyspec;
-char *provider = "https://acme-v02.api.letsencrypt.org/directory"; /* test endpoint */
-char *challengedir = "/usr/web/.well-known/acme-challenge";
-char *outdir;
-char *keyid;
-char *epnewnonce;
-char *epnewacct;
-char *epneworder;
-char *eprevokecert;
-char *epkeychange;
-char *csrkey;
-char *jwsthumb;
-JSON *jwskey;
-
-#define dprint(...) if(debug)fprint(2, __VA_ARGS__);
-
-char*
-evsmprint(char *fmt, va_list ap)
-{
- char *r;
-
- if((r = vsmprint(fmt, ap)) == nil)
- abort();
- return r;
-}
-
-char*
-esmprint(char *fmt, ...)
-{
- va_list ap;
- char *r;
-
- va_start(ap, fmt);
- r = evsmprint(fmt, ap);
- va_end(ap);
- return r;
-}
-
-int
-encurl64chr(int o)
-{
- int c;
-
- c = between(o, 0, 25) & ('A'+o);
- c |= between(o, 26, 51) & ('a'+(o-26));
- c |= between(o, 52, 61) & ('0'+(o-52));
- c |= between(o, 62, 62) & ('-');
- c |= between(o, 63, 63) & ('_');
- return c;
-}
-char*
-encurl64(void *in, int n)
-{
- int lim;
- char *out, *p;
-
- lim = 4*n/3 + 5;
- if((out = malloc(lim)) == nil)
- abort();
- enc64x(out, lim, in, n, encurl64chr);
- if((p = strchr(out, '=')) != nil)
- *p = 0;
- return out;
-}
-
-char*
-signRS256(char *hdr, char *prot)
-{
- uchar hash[SHA2_256dlen];
- DigestState *s;
- AuthRpc *rpc;
- int afd;
- char *r;
-
- if((afd = open("/mnt/factotum/rpc", ORDWR)) < 0)
- return nil;
- if((rpc = auth_allocrpc(afd)) == nil){
- close(afd);
- return nil;
- }
- if(auth_rpc(rpc, "start", keyspec, strlen(keyspec)) != ARok){
- auth_freerpc(rpc);
- close(afd);
- return nil;
- }
-
- s = sha2_256((uchar*)hdr, strlen(hdr), nil, nil);
- s = sha2_256((uchar*)".", strlen("."), nil, s);
- sha2_256((uchar*)prot, strlen(prot), hash, s);
-
- if(auth_rpc(rpc, "write", hash, sizeof(hash)) != ARok)
- sysfatal("sign: write hash: %r");
- if(auth_rpc(rpc, "read", nil, 0) != ARok)
- sysfatal("sign: read sig: %r");
- r = encurl64(rpc->arg, rpc->narg);
- auth_freerpc(rpc);
- close(afd);
- return r;
-}
-
-/*
- * Reads all available data from an fd.
- * guarantees returned value is terminated.
- */
-static char*
-slurp(int fd, int *n)
-{
- char *b;
- int r, sz;
-
- *n = 0;
- sz = 32;
- if((b = malloc(sz)) == nil)
- abort();
- while(1){
- if(*n + 1 == sz){
- sz *= 2;
- if((b = realloc(b, sz)) == nil)
- abort();
- }
- r = read(fd, b + *n, sz - *n - 1);
- if(r == 0)
- break;
- if(r == -1){
- free(b);
- return nil;
- }
- *n += r;
- }
- b[*n] = 0;
- return b;
-}
-
-static int
-webopen(char *url, char *dir, int ndir)
-{
- char buf[16];
- int n, cfd, conn;
-
- if((cfd = open("/mnt/web/clone", ORDWR)) == -1)
- return -1;
- if((n = read(cfd, buf, sizeof(buf)-1)) == -1)
- return -1;
- buf[n] = 0;
- conn = atoi(buf);
-
- if(fprint(cfd, "url %s", url) == -1)
- goto Error;
- snprint(dir, ndir, "/mnt/web/%d", conn);
- return cfd;
-Error:
- close(cfd);
- return -1;
-}
-
-static char*
-get(char *url, int *n)
-{
- char *r, dir[64], path[80];
- int cfd, dfd;
-
- r = nil;
- dfd = -1;
- if((cfd = webopen(url, dir, sizeof(dir))) == -1)
- goto Error;
- snprint(path, sizeof(path), "%s/%s", dir, "body");
- if((dfd = open(path, OREAD)) == -1)
- goto Error;
- r = slurp(dfd, n);
-Error:
- if(dfd != -1) close(dfd);
- if(cfd != -1) close(cfd);
- return r;
-}
-
-static char*
-post(char *url, char *buf, int nbuf, int *nret, Hdr *h)
-{
- char *r, dir[64], path[80];
- int cfd, dfd, hfd, ok;
-
- r = nil;
- ok = 0;
- dfd = -1;
- if((cfd = webopen(url, dir, sizeof(dir))) == -1)
- goto Error;
- if(write(cfd, Contenttype, strlen(Contenttype)) == -1)
- goto Error;
- snprint(path, sizeof(path), "%s/%s", dir, "postbody");
- if((dfd = open(path, OWRITE)) == -1)
- goto Error;
- if(write(dfd, buf, nbuf) != nbuf)
- goto Error;
- close(dfd);
- snprint(path, sizeof(path), "%s/%s", dir, "body");
- if((dfd = open(path, OREAD)) == -1)
- goto Error;
- if((r = slurp(dfd, nret)) == nil)
- goto Error;
- if(h != nil){
- snprint(path, sizeof(path), "%s/%s", dir, h->name);
- if((hfd = open(path, OREAD)) == -1)
- goto Error;
- if((h->val = slurp(hfd, &h->nval)) == nil)
- goto Error;
- close(hfd);
- }
- ok = 1;
-Error:
- if(dfd != -1) close(dfd);
- if(cfd != -1) close(cfd);
- if(!ok && h != nil)
- free(h->val);
- return r;
-}
-
-static int
-endpoints(void)
-{
- JSON *j;
- JSONEl *e;
- char *s;
- int n;
-
- if((s = get(provider, &n)) == nil)
- sysfatal("get %s: %r", provider);
- if((j = jsonparse(s)) == nil)
- sysfatal("parse endpoints: %r");
- if(j->t != JSONObject)
- sysfatal("expected object");
- for(e = j->first; e != nil; e = e->next){
- if(e->val->t != JSONString)
- continue;
- if(strcmp(e->name, "keyChange") == 0)
- epkeychange = strdup(e->val->s);
- else if(strcmp(e->name, "newAccount") == 0)
- epnewacct = strdup(e->val->s);
- else if(strcmp(e->name, "newNonce") == 0)
- epnewnonce = strdup(e->val->s);
- else if(strcmp(e->name, "newOrder") == 0)
- epneworder = strdup(e->val->s);
- else if(strcmp(e->name, "revokeCert") == 0)
- eprevokecert = strdup(e->val->s);
- }
- jsonfree(j);
- free(s);
- if(epnewnonce==nil|| epnewacct==nil || epneworder==nil
- || eprevokecert==nil || epkeychange==nil){
- sysfatal("missing directory entries");
- return -1;
- }
- return 0;
-}
-
-static char*
-getnonce(void)
-{
- char *r, dir[64], path[80];
- int n, cfd, dfd, hfd;
-
- r = nil;
- dfd = -1;
- hfd = -1;
- if((cfd = webopen(epnewnonce, dir, sizeof(dir))) == -1)
- goto Error;
- fprint(cfd, "request HEAD");
-
- snprint(path, sizeof(path), "%s/%s", dir, "body");
- if((dfd = open(path, OREAD)) == -1)
- goto Error;
- snprint(path, sizeof(path), "%s/%s", dir, "replaynonce");
- if((hfd = open(path, OREAD)) == -1)
- goto Error;
- r = slurp(hfd, &n);
-Error:
- if(hfd != -1)
- close(hfd);
- if(dfd != -1)
- close(dfd);
- close(cfd);
- return r;
-}
-
-char*
-jwsenc(char *hdr, char *msg, int *nbuf)
-{
- char *h, *m, *s, *r;
-
- h = encurl64(hdr, strlen(hdr));
- m = encurl64(msg, strlen(msg));
- s = signRS256(h, m);
- if(s == nil)
- return nil;
-
- r = esmprint(
- "{\n"
- "\"protected\": \"%s\",\n"
- "\"payload\": \"%s\",\n"
- "\"signature\": \"%s\"\n"
- "}\n",
- h, m, s);
- *nbuf = strlen(r);
- free(h);
- free(m);
- free(s);
-
- return r;
-}
-
-char*
-jwsheader(char *url)
-{
- char *nonce;
-
- if((nonce = getnonce()) == nil)
- sysfatal("get nonce: %r");
- return esmprint(
- "{"
- "\"alg\": \"RS256\","
- "\"nonce\": \"%E\","
- "\"kid\": \"%E\","
- "\"url\": \"%E\""
- "}",
- nonce, keyid, url);
-}
-
-char*
-jwsrequest(char *url, int *nresp, Hdr *h, char *fmt, ...)
-{
- char *hdr, *msg, *req, *resp;
- int nreq;
- va_list ap;
-
- va_start(ap, fmt);
- hdr = jwsheader(url);
- msg = evsmprint(fmt, ap);
- req = jwsenc(hdr, msg, &nreq);
- dprint("req=\"%s\"\n", req);
- resp = post(url, req, nreq, nresp, h);
- free(hdr);
- free(req);
- free(msg);
- va_end(ap);
- dprint("resp=%s\n", resp);
- return resp;
-}
-
-static void
-mkaccount(char *addr)
-{
- char *nonce, *hdr, *msg, *req, *resp;
- int nreq, nresp;
- Hdr loc;
-
- if((nonce = getnonce()) == nil)
- sysfatal("get nonce: %r");
- hdr = esmprint(
- "{"
- "\"alg\": \"RS256\","
- "\"jwk\": %J,"
- "\"nonce\": \"%E\","
- "\"url\": \"%E\""
- "}",
- jwskey, nonce, epnewacct);
- msg = esmprint(
- "{"
- "\"termsOfServiceAgreed\": true,"
- "\"contact\": [\"mailto:%E\"]"
- "}",
- addr);
- free(nonce);
- if((req = jwsenc(hdr, msg, &nreq)) == nil)
- sysfatal("failed to sign: %r");
- dprint("req=\"%s\"\n", req);
-
- loc.name = "location";
- if((resp = post(epnewacct, req, nreq, &nresp, &loc)) == nil)
- sysfatal("failed req: %r");
- dprint("resp=%s, loc=%s\n", resp, loc.val);
- keyid = loc.val;
-}
-
-static JSON*
-submitorder(char *dom, Hdr *hdr)
-{
- char *resp;
- int nresp;
- JSON *r;
-
- resp = jwsrequest(epneworder, &nresp, hdr,
- "{"
- " \"identifiers\": [{"
- " \"type\": \"dns\","
- " \"value\": \"%E\""
- " }],"
- " \"wildcard\": false"
- "}",
- dom);
- if(resp == nil)
- sysfatal("submit order: %r");
- if((r = jsonparse(resp)) == nil)
- sysfatal("parse order: %r");
- free(resp);
- return r;
-}
-
-static int
-httpchallenge(JSON *j, char *authurl, int *matched)
-{
- JSON *ty, *url, *tok, *poll, *state;
- char *resp, path[1024];
- int i, fd, nresp;
-
- if((ty = jsonbyname(j, "type")) == nil)
- return -1;
- if((url = jsonbyname(j, "url")) == nil)
- return -1;
- if((tok = jsonbyname(j, "token")) == nil)
- return -1;
- if(ty->t != JSONString || url->t != JSONString || tok->t != JSONString)
- return -1;
- if(strcmp(ty->s, "http-01") != 0)
- return -1;
- *matched = 1;
-
- snprint(path, sizeof(path), "%s/%s", challengedir, tok->s);
- if((fd = create(path, OWRITE, 0666)) == -1)
- sysfatal("create: %r"); //return -1;
- if(fprint(fd, "%s.%s\n", tok->s, jwsthumb) == -1)
- return -1;
- close(fd);
-
- if((resp = jwsrequest(url->s, &nresp, nil, "{}")) == nil)
- sysfatal("challenge: post %s: %r", url->s);
- free(resp);
-
- for(i = 0; i < 60; i++){
- sleep(1000);
- if((resp = jwsrequest(authurl, &nresp, nil, "")) == nil)
- sysfatal("challenge: post %s: %r", url->s);
- if((poll = jsonparse(resp)) == nil){
- free(resp);
- return -1;
- }
- if((state = jsonbyname(poll, "status")) != nil && state->t == JSONString){
- if(strcmp(state->s, "valid") == 0){
- jsonfree(poll);
- return 0;
- }
- else if(strcmp(state->s, "pending") != 0){
- fprint(2, "error: %J", poll);
- werrstr("status '%s'", state->s);
- jsonfree(poll);
- return -1;
- }
- }
- jsonfree(poll);
- }
- werrstr("timeout");
- return -1;
-}
-
-static int
-dnschallenge(JSON*, char*, int*)
-{
- return -1;
-}
-
-static int
-dochallenges(JSON *order)
-{
- JSON *chals, *j, *cl;
- JSONEl *ae, *ce;
- int nresp, matched;
- char *resp;
-
- if((j = jsonbyname(order, "authorizations")) == nil)
- sysfatal("parse response: missing authorizations");
- if(j->t != JSONArray)
- sysfatal("parse response: authorizations must be array");
- for(ae = j->first; ae != nil; ae = ae->next){
- if(ae->val->t != JSONString)
- sysfatal("challenge: auth must be url");
- if((resp = jwsrequest(ae->val->s, &nresp, nil, "")) == nil)
- sysfatal("challenge: request %s: %r", ae->val->s);
- if((chals = jsonparse(resp)) == nil)
- goto Error;
- if((cl = jsonbyname(chals, "challenges")) == nil){
- jsonfree(chals);
- goto Error;
- }
- matched = 0;
- for(ce = cl->first; ce != nil; ce = ce->next){
- if(challengefn(ce->val, ae->val->s, &matched) == 0)
- break;
- if(matched)
- sysfatal("could not complete challenge: %r");
- }
- if(!matched)
- sysfatal("no matching auth type");
- jsonfree(chals);
- free(resp);
- }
- return 0;
-Error:
- jsonfree(j);
- return -1;
-}
-
-static char*
-gencsr(char *dom)
-{
- char cn[512];
- char *der, *b64;
- int nder, pid, pfd[2];
- Waitmsg *w;
-
- snprint(cn, sizeof(cn), "CN=%s,%s", dom,dom);
-
- if(pipe(pfd) == -1)
- return nil;
- if((pid = fork()) == -1)
- return nil;
- if(pid == 0){
- close(pfd[1]);
- dup(pfd[0], 0);
- dup(pfd[0], 1);
- execl("/bin/auth/rsa2csr", "rsa2csr", cn, csrkey, nil);
- sysfatal("exec: %r");
- }
- close(pfd[0]);
- if((der = slurp(pfd[1], &nder)) == nil)
- return nil;
- if((w = wait()) == nil){
- free(der);
- return nil;
- }
- if(w->msg == nil && strlen(w->msg) != 0){
- werrstr(w->msg);
- free(der);
- free(w);
- return nil;
- }
- free(w);
- b64 = encurl64(der, nder);
- free(der);
- return b64;
-}
-
-static int
-submitcsr(JSON *order, char *dom)
-{
- char *csr, *resp;
- int nresp;
- JSON *j;
-
- if((j = jsonbyname(order, "finalize")) == nil)
- sysfatal("parse response: missing authorizations");
- if(j->t != JSONString)
- sysfatal("parse response: finalizer must be string");
- if((csr = gencsr(dom)) == nil)
- sysfatal("gencsr: %r");
- if((resp = jwsrequest(j->s, &nresp, nil, "{\"csr\":\"%E\"}", csr)) == nil)
- sysfatal("submit csr: %r");
- free(csr);
- free(resp);
- return 0;
-}
-
-static int
-fetchcert(char *url, char *dom)
-{
- JSON *cert, *poll, *state;
- char *resp, path[1024];
- int fd, nresp, i;
-
- poll = nil;
- for(i = 0; i < 60; i++){
- sleep(1000);
- if((resp = jwsrequest(url, &nresp, nil, "")) == nil)
- return -1;
- if((poll = jsonparse(resp)) == nil){
- free(resp);
- return -1;
- }
- free(resp);
- if((state = jsonbyname(poll, "status")) != nil && state->t == JSONString){
- if(strcmp(state->s, "valid") == 0)
- break;
- else if(strcmp(state->s, "pending") != 0 && strcmp(state->s, "processing") != 0){
- fprint(2, "error: %J", poll);
- werrstr("invalid request: %s", state->s);
- jsonfree(poll);
- return -1;
-
- }
- }
- jsonfree(poll);
- }
- if(poll == nil){
- werrstr("timed out");
- return -1;
- }
- if((cert = jsonbyname(poll, "certificate")) == nil || cert->t != JSONString){
- werrstr("missing cert url in response");
- jsonfree(poll);
- return -1;
- }
- if((resp = jwsrequest(cert->s, &nresp, nil, "")) == nil){
- jsonfree(poll);
- return -1;
- }
- jsonfree(poll);
- snprint(path, sizeof(path), "%s/%s.crt", outdir, dom);
- if((fd = create(path, OWRITE, 0600)) == -1){
- free(resp);
- return -1;
- }
- if(write(fd, resp, nresp) != nresp){
- free(resp);
- close(fd);
- return -1;
- }
- close(fd);
- return 0;
-}
-
-static void
-getcert(char *addr, char *dom)
-{
- Hdr loc;
- JSON *o;
-
- USED(addr);
- loc.name = "location";
- if((o = submitorder(dom, &loc)) == nil)
- sysfatal("order: %r");
- if(dochallenges(o) == -1)
- sysfatal("challenge: %r");
- if(submitcsr(o, dom) == -1)
- sysfatal("signing cert: %r");
- if(fetchcert(loc.val, dom) == -1)
- sysfatal("saving cert: %r");
-}
-
-static int
-Econv(Fmt *f)
-{
- char *s;
- Rune r;
- int w;
-
- w = 0;
- s = va_arg(f->args, char*);
- while(*s){
- s += chartorune(&r, s);
- if(r == '\\' || r == '\"')
- w += fmtrune(f, '\\');
- w += fmtrune(f, r);
- }
- return w;
-}
-
-static int
-loadkey(char *path)
-{
- uchar h[SHA2_256dlen];
- char key[8192];
- JSON *j, *e, *kty, *n;
- DigestState *ds;
- int fd, nr;
-
- if((fd = open(path, OREAD)) == -1)
- return -1;
- if((nr = readn(fd, key, sizeof(key))) == -1)
- return -1;
- key[nr] = 0;
-
- if((j = jsonparse(key)) == nil)
- return -1;
- if((e = jsonbyname(j, "e")) == nil || e->t != JSONString)
- return -1;
- if((kty = jsonbyname(j, "kty")) == nil || kty->t != JSONString)
- return -1;
- if((n = jsonbyname(j, "n")) == nil || n->t != JSONString)
- return -1;
-
- ds = sha2_256((uchar*)"{\"e\":\"", 6, nil, nil);
- ds = sha2_256((uchar*)e->s, strlen(e->s), nil, ds);
- ds = sha2_256((uchar*)"\",\"kty\":\"", 9, nil, ds);
- ds = sha2_256((uchar*)kty->s, strlen(kty->s), nil, ds);
- ds = sha2_256((uchar*)"\",\"n\":\"", 7, nil, ds);
- ds = sha2_256((uchar*)n->s, strlen(n->s), nil, ds);
- sha2_256((uchar*)"\"}", 2, h, ds);
- jwskey = j;
- jwsthumb = encurl64(h, sizeof(h));
- return 0;
-}
-
-static void
-usage(void)
-{
- fprint(2, "usage: %s [-a acctkey] [-c csrkey] [-p chalpath] [-o crtdir] acct cert\n", argv0);
- exits("usage");
-}
-
-void
-main(int argc, char **argv)
-{
- char *acctkey, *t;
-
- JSONfmtinstall();
- fmtinstall('E', Econv);
-
- acctkey = nil;
- outdir = nil;
- challengefn = httpchallenge;
- ARGBEGIN{
- case 'd':
- debug++;
- break;
- case 'o':
- outdir = EARGF(usage());
- break;
- case 'p':
- provider = EARGF(usage());
- break;
- case 'a':
- acctkey = EARGF(usage());
- break;
- case 'c':
- csrkey = EARGF(usage());
- break;
- case 'w':
- challengedir = EARGF(usage());
- break;
- case 't':
- t = EARGF(usage());
- if(strcmp(t, "http") == 0)
- challengefn = httpchallenge;
- else if(strcmp(t, "dns") != 0)
- challengefn = dnschallenge;
- else
- sysfatal("unknown challenge type '%s' (need http or dns)", t);
- break;
- default:
- usage();
- break;
- }ARGEND;
-
- if(argc != 2)
- usage();
-
- if(acctkey == nil)
- acctkey = esmprint("/sys/lib/tls/acme/%s.pub", argv[0]);
- if(outdir == nil)
- outdir = "/sys/lib/tls/acme";
- if(csrkey == nil)
- csrkey = esmprint("/sys/lib/tls/acme/%s.key", argv[1]);
-
- if((keyspec = smprint(Keyspec, argv[0])) == nil)
- sysfatal("smprint: %r");
- if(loadkey(acctkey) == -1)
- sysfatal("load key: %r");
-
- if(endpoints() == -1)
- sysfatal("endpoints: %r");
- mkaccount(argv[0]);
- getcert(argv[0], argv[1]);
- exits(nil);
-}
--- a/aclient.man
+++ /dev/null
@@ -1,118 +1,0 @@
-.TH ACLIENT 1
-.SH NAME
-aclient \- acme certificate client
-.SH SYNOPSIS
-.B aclient
-[
-.B -o
-.I outdir
-]
-[
-.B -p
-.I provider
-]
-[
-.B -a
-.I acctkey
-]
-[
-.B c
-.I csrkey
-]
-[
-.B w
-.I chaldir
-]
-.I acctname
-.I domain
-.SH DESCRIPTION
-Aclient fetches and renews TLS certificates
-using the
-.I acme
-protocol.
-It requires a pregenerated account key
-and certificate signing key.
-.PP
-There are a number of options.
-.TP
-.B -o
-.I outdir
-Specifies that the signed certificate is placed in
-.I outdir
-in place of the default
-.IR /sys/lib/tls/acme/ .
-.TP
-.B -p
-.I provider
-Specifies that
-.I provider
-is used as the provider URL, in place of the default
-.IR https://acme-v02.api.letsencrypt.org/directory .
-This must be the directory URL for the desired
-.I RFC8555
-compliant provider
-.TP
-.B -a
-.I acctkey
-Specifies that
-.I acctkey
-is used to sign requests to the
-.I provider
-in place of the default
-.IR /sys/lib/tls/acme/$acctname.pub .
-The key must be a
-.I jwk
-formatted RSA key.
-.TP
-.B c
-.I csrkey
-Specifies that
-.I csrkey
-is used to produce the CSR sent to
-.I provider
-in place of the default
-.IR /sys/lib/tls/acme/$domain.key .
-The key must be a plan 9 formatted
-RSA key suitable for
-.IR aux/rsa2csr .
-.TP
-.B w
-.I chaldir
-Specifies that the challenge is written out to
-.IR chaldir .
-For HTTP challenges, this defaults to
-.IR /usr/web/.well-known/acme-challenge/ .
-.SH EXAMPLES
-Before
-.B aclient
-is run, the keys must be generated.
-.IP
-.EX
-auth/rsagen -t 'service=acme role=sign hash=sha256 acct=me@example.org' |
- tee /sys/lib/acme/me@example.org.priv |
- auth/rsa2jwk > /sys/lib/acme/me@example.org.pub
-auth/rsagen -t 'service=tls owner=*'
- >/sys/lib/acme/mydomain.com.key
-.EE
-.PP
-This need only be run once.
-Once the keys are generated, they should be loaded into factotum:
-.IP
-.EX
-cat /sys/lib/acme/mydomain.com.key >/mnt/factotum/ctl
-cat /sys/lib/acme/me@example.org.priv >/mnt/factotum/ctl
-.EE
-.PP
-The certificate for the domain can now be fetched:
-.IP
-.EX
-aclient me@example.org mydomain.com
-.EE
-.SH SOURCE
-.B /sys/src/cmd/$somewhere/aclient.c
-.SH BUGS
-.I Aclient only supports HTTP challenges that are
-placed in static directories.
-It should add support for DNS challenges, and provide
-a way for a script to be invoked while handling them.
-
--- /dev/null
+++ b/acmed.c
@@ -1,0 +1,772 @@
+#include <u.h>
+#include <libc.h>
+#include <json.h>
+#include <mp.h>
+#include <libsec.h>
+#include <auth.h>
+#include <authsrv.h>
+
+typedef struct Hdr Hdr;
+
+#pragma varargck type "E" char*
+
+struct Hdr {
+ char *name;
+ char *val;
+ int nval;
+};
+
+#define Keyspec "proto=rsa service=acme role=sign hash=sha256 acct=%s"
+#define Useragent "useragent aclient-plan9"
+#define Contenttype "contenttype application/jose+json"
+#define between(x,min,max) (((min-1-x) & (x-max-1))>>8)
+int debug;
+int (*challengefn)(JSON*, char*, int*);
+char *keyspec;
+char *provider = "https://acme-v02.api.letsencrypt.org/directory"; /* test endpoint */
+char *challengedir = "/usr/web/.well-known/acme-challenge";
+char *challengecmd;
+char *keyid;
+char *epnewnonce;
+char *epnewacct;
+char *epneworder;
+char *eprevokecert;
+char *epkeychange;
+char *jwsthumb;
+JSON *jwskey;
+
+#define dprint(...) if(debug)fprint(2, __VA_ARGS__);
+
+char*
+evsmprint(char *fmt, va_list ap)
+{
+ char *r;
+
+ if((r = vsmprint(fmt, ap)) == nil)
+ abort();
+ return r;
+}
+
+char*
+esmprint(char *fmt, ...)
+{
+ va_list ap;
+ char *r;
+
+ va_start(ap, fmt);
+ r = evsmprint(fmt, ap);
+ va_end(ap);
+ return r;
+}
+
+int
+encurl64chr(int o)
+{
+ int c;
+
+ c = between(o, 0, 25) & ('A'+o);
+ c |= between(o, 26, 51) & ('a'+(o-26));
+ c |= between(o, 52, 61) & ('0'+(o-52));
+ c |= between(o, 62, 62) & ('-');
+ c |= between(o, 63, 63) & ('_');
+ return c;
+}
+char*
+encurl64(void *in, int n)
+{
+ int lim;
+ char *out, *p;
+
+ lim = 4*n/3 + 5;
+ if((out = malloc(lim)) == nil)
+ abort();
+ enc64x(out, lim, in, n, encurl64chr);
+ if((p = strchr(out, '=')) != nil)
+ *p = 0;
+ return out;
+}
+
+char*
+signRS256(char *hdr, char *prot)
+{
+ uchar hash[SHA2_256dlen];
+ DigestState *s;
+ AuthRpc *rpc;
+ int afd;
+ char *r;
+
+ if((afd = open("/mnt/factotum/rpc", ORDWR)) < 0)
+ return nil;
+ if((rpc = auth_allocrpc(afd)) == nil){
+ close(afd);
+ return nil;
+ }
+ if(auth_rpc(rpc, "start", keyspec, strlen(keyspec)) != ARok){
+ auth_freerpc(rpc);
+ close(afd);
+ return nil;
+ }
+
+ s = sha2_256((uchar*)hdr, strlen(hdr), nil, nil);
+ s = sha2_256((uchar*)".", strlen("."), nil, s);
+ sha2_256((uchar*)prot, strlen(prot), hash, s);
+
+ if(auth_rpc(rpc, "write", hash, sizeof(hash)) != ARok)
+ sysfatal("sign: write hash: %r");
+ if(auth_rpc(rpc, "read", nil, 0) != ARok)
+ sysfatal("sign: read sig: %r");
+ r = encurl64(rpc->arg, rpc->narg);
+ auth_freerpc(rpc);
+ close(afd);
+ return r;
+}
+
+/*
+ * Reads all available data from an fd.
+ * guarantees returned value is terminated.
+ */
+static void*
+slurp(int fd, int *n)
+{
+ char *b;
+ int r, sz;
+
+ *n = 0;
+ sz = 32;
+ if((b = malloc(sz)) == nil)
+ abort();
+ while(1){
+ if(*n + 1 == sz){
+ sz *= 2;
+ if((b = realloc(b, sz)) == nil)
+ abort();
+ }
+ r = read(fd, b + *n, sz - *n - 1);
+ if(r == 0)
+ break;
+ if(r == -1){
+ free(b);
+ return nil;
+ }
+ *n += r;
+ }
+ b[*n] = 0;
+ return b;
+}
+
+static int
+webopen(char *url, char *dir, int ndir)
+{
+ char buf[16];
+ int n, cfd, conn;
+
+ if((cfd = open("/mnt/web/clone", ORDWR)) == -1)
+ return -1;
+ if((n = read(cfd, buf, sizeof(buf)-1)) == -1)
+ return -1;
+ buf[n] = 0;
+ conn = atoi(buf);
+
+ if(fprint(cfd, "url %s", url) == -1)
+ goto Error;
+ snprint(dir, ndir, "/mnt/web/%d", conn);
+ return cfd;
+Error:
+ close(cfd);
+ return -1;
+}
+
+static char*
+get(char *url, int *n)
+{
+ char *r, dir[64], path[80];
+ int cfd, dfd;
+
+ r = nil;
+ dfd = -1;
+ if((cfd = webopen(url, dir, sizeof(dir))) == -1)
+ goto Error;
+ snprint(path, sizeof(path), "%s/%s", dir, "body");
+ if((dfd = open(path, OREAD)) == -1)
+ goto Error;
+ r = slurp(dfd, n);
+Error:
+ if(dfd != -1) close(dfd);
+ if(cfd != -1) close(cfd);
+ return r;
+}
+
+static char*
+post(char *url, char *buf, int nbuf, int *nret, Hdr *h)
+{
+ char *r, dir[64], path[80];
+ int cfd, dfd, hfd, ok;
+
+ r = nil;
+ ok = 0;
+ dfd = -1;
+ if((cfd = webopen(url, dir, sizeof(dir))) == -1)
+ goto Error;
+ if(write(cfd, Contenttype, strlen(Contenttype)) == -1)
+ goto Error;
+ snprint(path, sizeof(path), "%s/%s", dir, "postbody");
+ if((dfd = open(path, OWRITE)) == -1)
+ goto Error;
+ if(write(dfd, buf, nbuf) != nbuf)
+ goto Error;
+ close(dfd);
+ snprint(path, sizeof(path), "%s/%s", dir, "body");
+ if((dfd = open(path, OREAD)) == -1)
+ goto Error;
+ if((r = slurp(dfd, nret)) == nil)
+ goto Error;
+ if(h != nil){
+ snprint(path, sizeof(path), "%s/%s", dir, h->name);
+ if((hfd = open(path, OREAD)) == -1)
+ goto Error;
+ if((h->val = slurp(hfd, &h->nval)) == nil)
+ goto Error;
+ close(hfd);
+ }
+ ok = 1;
+Error:
+ if(dfd != -1) close(dfd);
+ if(cfd != -1) close(cfd);
+ if(!ok && h != nil)
+ free(h->val);
+ return r;
+}
+
+static int
+endpoints(void)
+{
+ JSON *j;
+ JSONEl *e;
+ char *s;
+ int n;
+
+ if((s = get(provider, &n)) == nil)
+ sysfatal("get %s: %r", provider);
+ if((j = jsonparse(s)) == nil)
+ sysfatal("parse endpoints: %r");
+ if(j->t != JSONObject)
+ sysfatal("expected object");
+ for(e = j->first; e != nil; e = e->next){
+ if(e->val->t != JSONString)
+ continue;
+ if(strcmp(e->name, "keyChange") == 0)
+ epkeychange = strdup(e->val->s);
+ else if(strcmp(e->name, "newAccount") == 0)
+ epnewacct = strdup(e->val->s);
+ else if(strcmp(e->name, "newNonce") == 0)
+ epnewnonce = strdup(e->val->s);
+ else if(strcmp(e->name, "newOrder") == 0)
+ epneworder = strdup(e->val->s);
+ else if(strcmp(e->name, "revokeCert") == 0)
+ eprevokecert = strdup(e->val->s);
+ }
+ jsonfree(j);
+ free(s);
+ if(epnewnonce==nil|| epnewacct==nil || epneworder==nil
+ || eprevokecert==nil || epkeychange==nil){
+ sysfatal("missing directory entries");
+ return -1;
+ }
+ return 0;
+}
+
+static char*
+getnonce(void)
+{
+ char *r, dir[64], path[80];
+ int n, cfd, dfd, hfd;
+
+ r = nil;
+ dfd = -1;
+ hfd = -1;
+ if((cfd = webopen(epnewnonce, dir, sizeof(dir))) == -1)
+ goto Error;
+ fprint(cfd, "request HEAD");
+
+ snprint(path, sizeof(path), "%s/%s", dir, "body");
+ if((dfd = open(path, OREAD)) == -1)
+ goto Error;
+ snprint(path, sizeof(path), "%s/%s", dir, "replaynonce");
+ if((hfd = open(path, OREAD)) == -1)
+ goto Error;
+ r = slurp(hfd, &n);
+Error:
+ if(hfd != -1)
+ close(hfd);
+ if(dfd != -1)
+ close(dfd);
+ close(cfd);
+ return r;
+}
+
+char*
+jwsenc(char *hdr, char *msg, int *nbuf)
+{
+ char *h, *m, *s, *r;
+
+ h = encurl64(hdr, strlen(hdr));
+ m = encurl64(msg, strlen(msg));
+ s = signRS256(h, m);
+ if(s == nil)
+ return nil;
+
+ r = esmprint(
+ "{\n"
+ "\"protected\": \"%s\",\n"
+ "\"payload\": \"%s\",\n"
+ "\"signature\": \"%s\"\n"
+ "}\n",
+ h, m, s);
+ *nbuf = strlen(r);
+ free(h);
+ free(m);
+ free(s);
+
+ return r;
+}
+
+char*
+jwsheader(char *url)
+{
+ char *nonce;
+
+ if((nonce = getnonce()) == nil)
+ sysfatal("get nonce: %r");
+ return esmprint(
+ "{"
+ "\"alg\": \"RS256\","
+ "\"nonce\": \"%E\","
+ "\"kid\": \"%E\","
+ "\"url\": \"%E\""
+ "}",
+ nonce, keyid, url);
+}
+
+char*
+jwsrequest(char *url, int *nresp, Hdr *h, char *fmt, ...)
+{
+ char *hdr, *msg, *req, *resp;
+ int nreq;
+ va_list ap;
+
+ va_start(ap, fmt);
+ hdr = jwsheader(url);
+ msg = evsmprint(fmt, ap);
+ req = jwsenc(hdr, msg, &nreq);
+ dprint("req=\"%s\"\n", req);
+ resp = post(url, req, nreq, nresp, h);
+ free(hdr);
+ free(req);
+ free(msg);
+ va_end(ap);
+ dprint("resp=%s\n", resp);
+ return resp;
+}
+
+static void
+mkaccount(char *addr)
+{
+ char *nonce, *hdr, *msg, *req, *resp;
+ int nreq, nresp;
+ Hdr loc;
+
+ if((nonce = getnonce()) == nil)
+ sysfatal("get nonce: %r");
+ hdr = esmprint(
+ "{"
+ "\"alg\": \"RS256\","
+ "\"jwk\": %J,"
+ "\"nonce\": \"%E\","
+ "\"url\": \"%E\""
+ "}",
+ jwskey, nonce, epnewacct);
+ msg = esmprint(
+ "{"
+ "\"termsOfServiceAgreed\": true,"
+ "\"contact\": [\"mailto:%E\"]"
+ "}",
+ addr);
+ free(nonce);
+ if((req = jwsenc(hdr, msg, &nreq)) == nil)
+ sysfatal("failed to sign: %r");
+ dprint("req=\"%s\"\n", req);
+
+ loc.name = "location";
+ if((resp = post(epnewacct, req, nreq, &nresp, &loc)) == nil)
+ sysfatal("failed req: %r");
+ dprint("resp=%s, loc=%s\n", resp, loc.val);
+ keyid = loc.val;
+}
+
+static JSON*
+submitorder(char **dom, int ndom, Hdr *hdr)
+{
+ char *req, *resp, *sep, rbuf[8192];
+ int nresp, i;
+ JSON *r;
+
+ sep = "";
+ req = seprint(rbuf, rbuf+sizeof(rbuf),
+ "{"
+ " \"identifiers\": [");
+ for(i = 0; i < ndom; i++){
+ req = seprint(req, rbuf+sizeof(rbuf),
+ "%s{"
+ " \"type\": \"dns\","
+ " \"value\": \"%E\""
+ "}",
+ sep, dom[i]);
+ sep = ",";
+ }
+ req = seprint(req, rbuf+sizeof(rbuf),
+ " ],"
+ " \"wildcard\": false"
+ "}");
+ if(req - rbuf < 2)
+ sysfatal("truncated order");
+ resp = jwsrequest(epneworder, &nresp, hdr, "%s", rbuf);
+ if(resp == nil)
+ sysfatal("submit order: %r");
+ if((r = jsonparse(resp)) == nil)
+ sysfatal("parse order: %r");
+ free(resp);
+ return r;
+}
+
+static int
+httpchallenge(JSON *j, char *authurl, int *matched)
+{
+ JSON *ty, *url, *tok, *poll, *state;
+ char *resp, path[1024];
+ int i, fd, nresp;
+
+ if((ty = jsonbyname(j, "type")) == nil)
+ return -1;
+ if((url = jsonbyname(j, "url")) == nil)
+ return -1;
+ if((tok = jsonbyname(j, "token")) == nil)
+ return -1;
+ if(ty->t != JSONString || url->t != JSONString || tok->t != JSONString)
+ return -1;
+ if(strcmp(ty->s, "http-01") != 0)
+ return -1;
+ *matched = 1;
+
+ snprint(path, sizeof(path), "%s/%s", challengedir, tok->s);
+ if((fd = create(path, OWRITE, 0666)) == -1)
+ sysfatal("create: %r"); //return -1;
+ if(fprint(fd, "%s.%s\n", tok->s, jwsthumb) == -1)
+ return -1;
+ close(fd);
+
+ if((resp = jwsrequest(url->s, &nresp, nil, "{}")) == nil)
+ sysfatal("challenge: post %s: %r", url->s);
+ free(resp);
+
+ for(i = 0; i < 60; i++){
+ sleep(1000);
+ if((resp = jwsrequest(authurl, &nresp, nil, "")) == nil)
+ sysfatal("challenge: post %s: %r", url->s);
+ if((poll = jsonparse(resp)) == nil){
+ free(resp);
+ return -1;
+ }
+ if((state = jsonbyname(poll, "status")) != nil && state->t == JSONString){
+ if(strcmp(state->s, "valid") == 0){
+ jsonfree(poll);
+ return 0;
+ }
+ else if(strcmp(state->s, "pending") != 0){
+ fprint(2, "error: %J", poll);
+ werrstr("status '%s'", state->s);
+ jsonfree(poll);
+ return -1;
+ }
+ }
+ jsonfree(poll);
+ }
+ werrstr("timeout");
+ return -1;
+}
+
+static int
+dnschallenge(JSON*, char*, int*)
+{
+ return -1;
+}
+
+static int
+cmdchallenge(JSON*, char*, int*)
+{
+ return -1;
+}
+
+static int
+dochallenges(JSON *order)
+{
+ JSON *chals, *j, *cl;
+ JSONEl *ae, *ce;
+ int nresp, matched;
+ char *resp;
+
+ if((j = jsonbyname(order, "authorizations")) == nil)
+ sysfatal("parse response: missing authorizations");
+ if(j->t != JSONArray)
+ sysfatal("parse response: authorizations must be array");
+ for(ae = j->first; ae != nil; ae = ae->next){
+ if(ae->val->t != JSONString)
+ sysfatal("challenge: auth must be url");
+ if((resp = jwsrequest(ae->val->s, &nresp, nil, "")) == nil)
+ sysfatal("challenge: request %s: %r", ae->val->s);
+ if((chals = jsonparse(resp)) == nil)
+ goto Error;
+ if((cl = jsonbyname(chals, "challenges")) == nil){
+ jsonfree(chals);
+ goto Error;
+ }
+ matched = 0;
+ for(ce = cl->first; ce != nil; ce = ce->next){
+ if(challengefn(ce->val, ae->val->s, &matched) == 0)
+ break;
+ if(matched)
+ sysfatal("could not complete challenge: %r");
+ }
+ if(!matched)
+ sysfatal("no matching auth type");
+ jsonfree(chals);
+ free(resp);
+ }
+ return 0;
+Error:
+ jsonfree(j);
+ return -1;
+}
+
+static int
+submitcsr(JSON *order, char *b64csr)
+{
+ char *resp;
+ int nresp;
+ JSON *j;
+
+ if((j = jsonbyname(order, "finalize")) == nil)
+ sysfatal("parse response: missing authorizations");
+ if(j->t != JSONString)
+ werrstr("parse response: finalizer must be string");
+ if((resp = jwsrequest(j->s, &nresp, nil, "{\"csr\":\"%E\"}", b64csr)) == nil)
+ sysfatal("submit csr: %r");
+ free(resp);
+ return 0;
+}
+
+static int
+fetchcert(char *url)
+{
+ JSON *cert, *poll, *state;
+ int i, r, nresp;
+ char *resp;
+
+ poll = nil;
+ for(i = 0; i < 60; i++){
+ sleep(1000);
+ if((resp = jwsrequest(url, &nresp, nil, "")) == nil)
+ return -1;
+ if((poll = jsonparse(resp)) == nil){
+ free(resp);
+ return -1;
+ }
+ free(resp);
+ if((state = jsonbyname(poll, "status")) != nil && state->t == JSONString){
+ if(strcmp(state->s, "valid") == 0)
+ break;
+ else if(strcmp(state->s, "pending") != 0 && strcmp(state->s, "processing") != 0){
+ fprint(2, "error: %J", poll);
+ werrstr("invalid request: %s", state->s);
+ jsonfree(poll);
+ return -1;
+
+ }
+ }
+ jsonfree(poll);
+ }
+ if(poll == nil){
+ werrstr("timed out");
+ return -1;
+ }
+ if((cert = jsonbyname(poll, "certificate")) == nil || cert->t != JSONString){
+ werrstr("missing cert url in response");
+ jsonfree(poll);
+ return -1;
+ }
+ if((resp = jwsrequest(cert->s, &nresp, nil, "")) == nil){
+ jsonfree(poll);
+ return -1;
+ }
+ jsonfree(poll);
+ r = write(1, resp, nresp);
+ free(resp);
+ if(r != nresp)
+ return -1;
+ return 0;
+}
+
+static void
+getcert(char *csrpath)
+{
+ char *csr, *dom[64], name[2048];
+ uchar *der;
+ int nder, ndom, fd;
+ RSApub *rsa;
+ Hdr loc;
+ JSON *o;
+
+ if((fd = open(csrpath, OREAD)) == -1)
+ sysfatal("open %s: %r", csrpath);
+ if((der = slurp(fd, &nder)) == nil)
+ sysfatal("read %s: %r", csrpath);
+ if((rsa = X509reqtoRSApub(der, nder, name, sizeof(name))) == nil)
+ sysfatal("decode csr: %r");
+ if((csr = encurl64(der, nder)) == nil)
+ sysfatal("encode %s: %r", csrpath);
+ if((ndom = getfields(name, dom, nelem(dom), 1, ",")) == nelem(dom))
+ sysfatal("too man domains");
+ rsapubfree(rsa);
+ close(fd);
+ free(der);
+
+ loc.name = "location";
+ if((o = submitorder(dom, ndom, &loc)) == nil)
+ sysfatal("order: %r");
+ if(dochallenges(o) == -1)
+ sysfatal("challenge: %r");
+ if(submitcsr(o, csr) == -1)
+ sysfatal("signing cert: %r");
+ if(fetchcert(loc.val) == -1)
+ sysfatal("saving cert: %r");
+ free(csr);
+}
+
+static int
+Econv(Fmt *f)
+{
+ char *s;
+ Rune r;
+ int w;
+
+ w = 0;
+ s = va_arg(f->args, char*);
+ while(*s){
+ s += chartorune(&r, s);
+ if(r == '\\' || r == '\"')
+ w += fmtrune(f, '\\');
+ w += fmtrune(f, r);
+ }
+ return w;
+}
+
+static int
+loadkey(char *path)
+{
+ uchar h[SHA2_256dlen];
+ char key[8192];
+ JSON *j, *e, *kty, *n;
+ DigestState *ds;
+ int fd, nr;
+
+ if((fd = open(path, OREAD)) == -1)
+ return -1;
+ if((nr = readn(fd, key, sizeof(key))) == -1)
+ return -1;
+ key[nr] = 0;
+
+ if((j = jsonparse(key)) == nil)
+ return -1;
+ if((e = jsonbyname(j, "e")) == nil || e->t != JSONString)
+ return -1;
+ if((kty = jsonbyname(j, "kty")) == nil || kty->t != JSONString)
+ return -1;
+ if((n = jsonbyname(j, "n")) == nil || n->t != JSONString)
+ return -1;
+
+ ds = sha2_256((uchar*)"{\"e\":\"", 6, nil, nil);
+ ds = sha2_256((uchar*)e->s, strlen(e->s), nil, ds);
+ ds = sha2_256((uchar*)"\",\"kty\":\"", 9, nil, ds);
+ ds = sha2_256((uchar*)kty->s, strlen(kty->s), nil, ds);
+ ds = sha2_256((uchar*)"\",\"n\":\"", 7, nil, ds);
+ ds = sha2_256((uchar*)n->s, strlen(n->s), nil, ds);
+ sha2_256((uchar*)"\"}", 2, h, ds);
+ jwskey = j;
+ jwsthumb = encurl64(h, sizeof(h));
+ return 0;
+}
+
+static void
+usage(void)
+{
+ fprint(2, "usage: %s [-a acctkey] [-c cmd] [-p provider] [-t chal] [-w chaldir] acct csr\n", argv0);
+ exits("usage");
+}
+
+void
+main(int argc, char **argv)
+{
+ char *acctkey, *t;
+
+ JSONfmtinstall();
+ fmtinstall('E', Econv);
+
+ acctkey = nil;
+ challengefn = httpchallenge;
+ ARGBEGIN{
+ case 'd':
+ debug++;
+ break;
+ case 'p':
+ provider = EARGF(usage());
+ break;
+ case 'a':
+ acctkey = EARGF(usage());
+ break;
+ case 'c':
+ challengecmd = EARGF(usage());
+ break;
+ case 'w':
+ challengedir = EARGF(usage());
+ break;
+ case 't':
+ t = EARGF(usage());
+ if(strcmp(t, "http") == 0)
+ challengefn = httpchallenge;
+ else if(strcmp(t, "dns") != 0)
+ challengefn = dnschallenge;
+ else if(strcmp(t, "cmd"))
+ challengefn = cmdchallenge;
+ else
+ sysfatal("unknown challenge type '%s' (need http or dns)", t);
+ break;
+ default:
+ usage();
+ break;
+ }ARGEND;
+
+ if(argc != 2)
+ usage();
+
+ if(acctkey == nil)
+ acctkey = esmprint("/sys/lib/tls/acmed/%s.pub", argv[0]);
+ if((keyspec = smprint(Keyspec, argv[0])) == nil)
+ sysfatal("smprint: %r");
+ if(loadkey(acctkey) == -1)
+ sysfatal("load key: %r");
+
+ if(endpoints() == -1)
+ sysfatal("endpoints: %r");
+ mkaccount(argv[0]);
+ getcert(argv[1]);
+ exits(nil);
+}
--- /dev/null
+++ b/acmed.man
@@ -1,0 +1,118 @@
+.TH ACLIENT 8
+.SH NAME
+acmed \- acme certificate client
+.SH SYNOPSIS
+.B acmed
+[
+.B -o
+.I outdir
+]
+[
+.B -p
+.I provider
+]
+[
+.B -a
+.I acctkey
+]
+[
+[
+.B e
+.I chalcmd
+]
+[
+.B w
+.I chaldir
+]
+.I acctname
+.I csr
+.SH DESCRIPTION
+Acmed fetches and renews TLS certificates
+using the
+.I acme
+protocol.
+It requires a pregenerated account key
+and certificate signing key.
+.PP
+There are a number of options.
+.TP
+.B -o
+.I outdir
+Specifies that the signed certificate is placed in
+.I outdir
+in place of the default
+.IR /sys/lib/tls/acme/ .
+.TP
+.B -p
+.I provider
+Specifies that
+.I provider
+is used as the provider URL, in place of the default
+.IR https://acme-v02.api.letsencrypt.org/directory .
+This must be the directory URL for the desired
+.I RFC8555
+compliant provider
+.TP
+.B -a
+.I acctkey
+Specifies that
+.I acctkey
+is used to sign requests to the
+.I provider
+in place of the default
+.IR /sys/lib/tls/acme/$acctname.pub .
+The key must be a
+.I jwk
+formatted RSA key.
+.TP
+.B c
+.I csrkey
+Specifies that
+.I csrkey
+is used to produce the CSR sent to
+.I provider
+in place of the default
+.IR /sys/lib/tls/acme/$domain.key .
+The key must be a plan 9 formatted
+RSA key suitable for
+.IR aux/rsa2csr .
+.TP
+.B w
+.I chaldir
+Specifies that the challenge is written out to
+.IR chaldir .
+For HTTP challenges, this defaults to
+.IR /usr/web/.well-known/acme-challenge/ .
+.SH EXAMPLES
+Before
+.B acmed
+is run, the keys must be generated.
+.IP
+.EX
+auth/rsagen -t 'service=acme role=sign hash=sha256 acct=me@example.org' \\
+ | tee >{auth/rsa2jwk \\
+ >/sys/lib/tls/acmed/me@example.org.pub}
+ | ipso -r -l factotum
+auth/rsagen -t 'service=tls owner=*' \\
+ | tee >{auth/rsa2csr 'CN=mydomain.com' \\
+ >/sys/lib/tls/acmed/mydomain.com.csr} \\
+ | ipso -r -l factotum
+.EE
+.PP
+This need only be run once.
+.EE
+.PP
+The certificate for the domain can now be fetched:
+.IP
+.EX
+acmed me@example.org mydomain.com \\
+ >/sys/lib/tls/acmed/mydomain.com.crt
+.EE
+.SH SOURCE
+.B /sys/src/cmd/$somewhere/acmed.c
+.SH BUGS
+.I Acmed only supports HTTP challenges that are
+placed in static directories.
+It should add support for DNS challenges, and provide
+a way for a script to be invoked while handling them.
+
--- a/mkfile
+++ b/mkfile
@@ -2,7 +2,7 @@
BIN=/$objtype/bin
MAN=/sys/man/8
-TARG=aclient
-OFILES=aclient.$O
+TARG=acmed
+OFILES=acmed.$O
</sys/src/cmd/mkone