static void handle_new_lock_ctx(struct xml_ctx *ctx, int tag_closed)
{
	struct remote_lock *lock = (struct remote_lock *)ctx->userData;
	git_SHA_CTX sha_ctx;
	unsigned char lock_token_sha1[20];

	if (tag_closed && ctx->cdata) {
		if (!strcmp(ctx->name, DAV_ACTIVELOCK_OWNER)) {
			lock->owner = xstrdup(ctx->cdata);
		} else if (!strcmp(ctx->name, DAV_ACTIVELOCK_TIMEOUT)) {
			const char *arg;
			if (skip_prefix(ctx->cdata, "Second-", &arg))
				lock->timeout = strtol(arg, NULL, 10);
		} else if (!strcmp(ctx->name, DAV_ACTIVELOCK_TOKEN)) {
			lock->token = xstrdup(ctx->cdata);

			git_SHA1_Init(&sha_ctx);
			git_SHA1_Update(&sha_ctx, lock->token, strlen(lock->token));
			git_SHA1_Final(lock_token_sha1, &sha_ctx);

			lock->tmpfile_suffix[0] = '_';
			memcpy(lock->tmpfile_suffix + 1, sha1_to_hex(lock_token_sha1), 40);
		}
	}
}

static const char *remote_submodule_branch(const char *path)
{
	const struct submodule *sub;
	gitmodules_config();
	git_config(submodule_config, NULL);

	sub = submodule_from_path(null_sha1, path);
	if (!sub)
		return NULL;

	if (!sub->branch)
		return "master";

	if (!strcmp(sub->branch, ".")) {
		unsigned char sha1[20];
		const char *refname = resolve_ref_unsafe("HEAD", 0, sha1, NULL);

		if (!refname)
			die(_("No such ref: %s"), "HEAD");

		/* detached HEAD */
		if (!strcmp(refname, "HEAD"))
			die(_("Submodule (%s) branch configured to inherit "
			      "branch from superproject, but the superproject "
			      "is not on any branch"), sub->name);

		if (!skip_prefix(refname, "refs/heads/", &refname))
			die(_("Expecting a full ref name, got %s"), refname);
		return refname;
	}

	return sub->branch;
}

static enum ack_type get_ack(struct packet_reader *reader,
			     struct object_id *result_oid)
{
	int len;
	const char *arg;

	if (packet_reader_read(reader) != PACKET_READ_NORMAL)
		die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
	len = reader->pktlen;

	if (!strcmp(reader->line, "NAK"))
		return NAK;
	if (skip_prefix(reader->line, "ACK ", &arg)) {
		if (!get_oid_hex(arg, result_oid)) {
			arg += 40;
			len -= arg - reader->line;
			if (len < 1)
				return ACK;
			if (strstr(arg, "continue"))
				return ACK_continue;
			if (strstr(arg, "common"))
				return ACK_common;
			if (strstr(arg, "ready"))
				return ACK_ready;
			return ACK;
		}
	}
	die(_("git fetch-pack: expected ACK/NAK, got '%s'"), reader->line);
}

static void show_one_commit(struct commit *commit, int no_name)
{
	struct strbuf pretty = STRBUF_INIT;
	const char *pretty_str = "(unavailable)";
	struct commit_name *name = commit->util;

	if (commit->object.parsed) {
		pp_commit_easy(CMIT_FMT_ONELINE, commit, &pretty);
		pretty_str = pretty.buf;
	}
	skip_prefix(pretty_str, "[PATCH] ", &pretty_str);

	if (!no_name) {
		if (name && name->head_name) {
			printf("[%s", name->head_name);
			if (name->generation) {
				if (name->generation == 1)
					printf("^");
				else
					printf("~%d", name->generation);
			}
			printf("] ");
		}
		else
			printf("[%s] ",
			       find_unique_abbrev(commit->object.oid.hash,
						  DEFAULT_ABBREV));
	}
	puts(pretty_str);
	strbuf_release(&pretty);
}

static char *get_default_remote(void)
{
	char *dest = NULL, *ret;
	unsigned char sha1[20];
	struct strbuf sb = STRBUF_INIT;
	const char *refname = resolve_ref_unsafe("HEAD", 0, sha1, NULL);

	if (!refname)
		die(_("No such ref: %s"), "HEAD");

	/* detached HEAD */
	if (!strcmp(refname, "HEAD"))
		return xstrdup("origin");

	if (!skip_prefix(refname, "refs/heads/", &refname))
		die(_("Expecting a full ref name, got %s"), refname);

	strbuf_addf(&sb, "branch.%s.remote", refname);
	if (git_config_get_string(sb.buf, &dest))
		ret = xstrdup("origin");
	else
		ret = dest;

	strbuf_release(&sb);
	return ret;
}

static void update_head(const struct ref *our, const struct ref *remote,
			const char *msg)
{
	if (our && !prefixcmp(our->name, "refs/heads/")) {
		/* Local default branch link */
		create_symref("HEAD", our->name, NULL);
		if (!option_bare) {
			const char *head = skip_prefix(our->name, "refs/heads/");
			update_ref(msg, "HEAD", our->old_sha1, NULL, 0, DIE_ON_ERR);
			install_branch_config(0, head, option_origin, our->name);
		}
	} else if (our) {
		struct commit *c = lookup_commit_reference(our->old_sha1);
		/* --branch specifies a non-branch (i.e. tags), detach HEAD */
		update_ref(msg, "HEAD", c->object.sha1,
			   NULL, REF_NODEREF, DIE_ON_ERR);
	} else if (remote) {
		/*
		 * We know remote HEAD points to a non-branch, or
		 * HEAD points to a branch but we don't know which one.
		 * Detach HEAD in all these cases.
		 */
		update_ref(msg, "HEAD", remote->old_sha1,
			   NULL, REF_NODEREF, DIE_ON_ERR);
	}
}

void parse_gpg_output(struct signature_check *sigc)
{
	const char *buf = sigc->gpg_status;
	int i;

	/* Iterate over all search strings */
	for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
		const char *found, *next;

		if (!skip_prefix(buf, sigcheck_gpg_status[i].check + 1, &found)) {
			found = strstr(buf, sigcheck_gpg_status[i].check);
			if (!found)
				continue;
			found += strlen(sigcheck_gpg_status[i].check);
		}
		sigc->result = sigcheck_gpg_status[i].result;
		/* The trust messages are not followed by key/signer information */
		if (sigc->result != 'U') {
			sigc->key = xmemdupz(found, 16);
			/* The ERRSIG message is not followed by signer information */
			if (sigc-> result != 'E') {
				found += 17;
				next = strchrnul(found, '\n');
				sigc->signer = xmemdupz(found, next - found);
			}
		}
	}
}

static const char *anonymize_refname(const char *refname)
{
	/*
	 * If any of these prefixes is found, we will leave it intact
	 * so that tags remain tags and so forth.
	 */
	static const char *prefixes[] = {
		"refs/heads/",
		"refs/tags/",
		"refs/remotes/",
		"refs/"
	};
	static struct hashmap refs;
	static struct strbuf anon = STRBUF_INIT;
	int i;

	/*
	 * We also leave "master" as a special case, since it does not reveal
	 * anything interesting.
	 */
	if (!strcmp(refname, "refs/heads/master"))
		return refname;

	strbuf_reset(&anon);
	for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
		if (skip_prefix(refname, prefixes[i], &refname)) {
			strbuf_addstr(&anon, prefixes[i]);
			break;
		}
	}

	anonymize_path(&anon, refname, &refs, anonymize_ref_component);
	return anon.buf;
}

struct taginfo *cgit_parse_tag(struct tag *tag)
{
	void *data;
	enum object_type type;
	unsigned long size;
	const char *p;
	struct taginfo *ret = NULL;

	data = read_sha1_file(tag->object.oid.hash, &type, &size);
	if (!data || type != OBJ_TAG)
		goto cleanup;

	ret = xcalloc(1, sizeof(struct taginfo));

	for (p = data; !end_of_header(p); p = next_header_line(p)) {
		if (skip_prefix(p, "tagger ", &p)) {
			parse_user(p, &ret->tagger, &ret->tagger_email,
				&ret->tagger_date, &ret->tagger_tz);
		}
	}

	while (p && *p == '\n')
		p++;

	if (p && *p)
		ret->msg = xstrdup(p);

cleanup:
	free(data);
	return ret;
}

static void fetch_symref(const char *path, char **symref, struct object_id *oid)
{
	char *url = xstrfmt("%s%s", repo->url, path);
	struct strbuf buffer = STRBUF_INIT;
	const char *name;

	if (http_get_strbuf(url, &buffer, NULL) != HTTP_OK)
		die("Couldn't get %s for remote symref\n%s", url,
		    curl_errorstr);
	free(url);

	FREE_AND_NULL(*symref);
	oidclr(oid);

	if (buffer.len == 0)
		return;

	/* Cut off trailing newline. */
	strbuf_rtrim(&buffer);

	/* If it's a symref, set the refname; otherwise try for a sha1 */
	if (skip_prefix(buffer.buf, "ref: ", &name)) {
		*symref = xmemdupz(name, buffer.len - (name - buffer.buf));
	} else {
		get_oid_hex(buffer.buf, oid);
	}

	strbuf_release(&buffer);
}

static char *find_branch_name(struct rev_info *rev)
{
	int i, positive = -1;
	struct object_id branch_oid;
	const struct object_id *tip_oid;
	const char *ref, *v;
	char *full_ref, *branch = NULL;

	for (i = 0; i < rev->cmdline.nr; i++) {
		if (rev->cmdline.rev[i].flags & UNINTERESTING)
			continue;
		if (positive < 0)
			positive = i;
		else
			return NULL;
	}
	if (positive < 0)
		return NULL;
	ref = rev->cmdline.rev[positive].name;
	tip_oid = &rev->cmdline.rev[positive].item->oid;
	if (dwim_ref(ref, strlen(ref), branch_oid.hash, &full_ref) &&
	    skip_prefix(full_ref, "refs/heads/", &v) &&
	    !oidcmp(tip_oid, &branch_oid))
		branch = xstrdup(v);
	free(full_ref);
	return branch;
}

static struct rpc_service *select_service(struct strbuf *hdr, const char *name)
{
	const char *svc_name;
	struct rpc_service *svc = NULL;
	int i;

	if (!skip_prefix(name, "git-", &svc_name))
		forbidden(hdr, "Unsupported service: '%s'", name);

	for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
		struct rpc_service *s = &rpc_service[i];
		if (!strcmp(s->name, svc_name)) {
			svc = s;
			break;
		}
	}

	if (!svc)
		forbidden(hdr, "Unsupported service: '%s'", name);

	if (svc->enabled < 0) {
		const char *user = getenv("REMOTE_USER");
		svc->enabled = (user && *user) ? 1 : 0;
	}
	if (!svc->enabled)
		forbidden(hdr, "Service not enabled: '%s'", svc->name);
	return svc;
}

static NORETURN int die_push_simple(struct branch *branch, struct remote *remote) {
	/*
	 * There's no point in using shorten_unambiguous_ref here,
	 * as the ambiguity would be on the remote side, not what
	 * we have locally. Plus, this is supposed to be the simple
	 * mode. If the user is doing something crazy like setting
	 * upstream to a non-branch, we should probably be showing
	 * them the big ugly fully qualified ref.
	 */
	const char *advice_maybe = "";
	const char *short_upstream = branch->merge[0]->src;

	skip_prefix(short_upstream, "refs/heads/", &short_upstream);

	/*
	 * Don't show advice for people who explicitly set
	 * push.default.
	 */
	if (push_default == PUSH_DEFAULT_UNSPECIFIED)
		advice_maybe = _("\n"
				 "To choose either option permanently, "
				 "see push.default in 'git help config'.");
	die(_("The upstream branch of your current branch does not match\n"
	      "the name of your current branch.  To push to the upstream branch\n"
	      "on the remote, use\n"
	      "\n"
	      "    git push %s HEAD:%s\n"
	      "\n"
	      "To push to the branch of the same name on the remote, use\n"
	      "\n"
	      "    git push %s %s\n"
	      "%s"),
	    remote->name, short_upstream,
	    remote->name, branch->name, advice_maybe);
}

int cmd_get_tar_commit_id(int argc, const char **argv, const char *prefix)
{
	char buffer[HEADERSIZE];
	struct ustar_header *header = (struct ustar_header *)buffer;
	char *content = buffer + RECORDSIZE;
	const char *comment;
	ssize_t n;

	if (argc != 1)
		usage(builtin_get_tar_commit_id_usage);

	git_config(git_default_config, NULL);
	n = read_in_full(0, buffer, HEADERSIZE);
	if (n < 0)
		die_errno("git get-tar-commit-id: read error");
	if (n != HEADERSIZE)
		die_errno("git get-tar-commit-id: EOF before reading tar header");
	if (header->typeflag[0] != 'g')
		return 1;
	if (!skip_prefix(content, "52 comment=", &comment))
		return 1;

	if (write_in_full(1, comment, 41) < 0)
		die_errno("git get-tar-commit-id: write error");

	return 0;
}

static enum ack_type get_ack(int fd, unsigned char *result_sha1)
{
	int len;
	char *line = packet_read_line(fd, &len);
	const char *arg;

	if (!len)
		die(_("git fetch-pack: expected ACK/NAK, got EOF"));
	if (!strcmp(line, "NAK"))
		return NAK;
	if (skip_prefix(line, "ACK ", &arg)) {
		if (!get_sha1_hex(arg, result_sha1)) {
			arg += 40;
			len -= arg - line;
			if (len < 1)
				return ACK;
			if (strstr(arg, "continue"))
				return ACK_continue;
			if (strstr(arg, "common"))
				return ACK_common;
			if (strstr(arg, "ready"))
				return ACK_ready;
			return ACK;
		}
	}
	die(_("git fetch_pack: expected ACK/NAK, got '%s'"), line);
}

static int parse_want(const char *line)
{
	const char *arg;
	if (skip_prefix(line, "want ", &arg)) {
		struct object_id oid;
		struct object *o;

		if (get_oid_hex(arg, &oid))
			die("git upload-pack: protocol error, "
			    "expected to get oid, not '%s'", line);

		o = parse_object(&oid);
		if (!o) {
			packet_write_fmt(1,
					 "ERR upload-pack: not our ref %s",
					 oid_to_hex(&oid));
			die("git upload-pack: not our ref %s",
			    oid_to_hex(&oid));
		}

		if (!(o->flags & WANTED)) {
			o->flags |= WANTED;
			add_object_array(o, NULL, &want_obj);
		}

		return 1;
	}

	return 0;
}

/*
 * Server calls this
 */
void
obfuscate_receive_seed(int sock_in)
{
	struct seed_msg seed;

	u_char padding_drain[OBFUSCATE_MAX_PADDING];
	u_int len;
	u_int32_t padding_length;
	u_int32_t test_magic;
	u_int offset, remaining;

	len = atomicio(read, sock_in, &seed, sizeof(struct seed_msg));

	debug2("obfuscate_receive_seed: read %d byte seed message from client", len);
	if(len != sizeof(struct seed_msg))
		fatal("obfuscate_receive_seed: read failed");

	// PSIPHON: HTTP-PREFIX
	offset = skip_prefix(sock_in, (u_char*)&seed, sizeof(struct seed_msg));
	if (offset > 0)
	{
		remaining = len - offset;
		memmove(&seed, ((unsigned char*)&seed) + offset, remaining);
		len = remaining + atomicio(read, sock_in, ((unsigned char*)&seed) + remaining, sizeof(struct seed_msg) - remaining);

		debug2("obfuscate_receive_seed: read %d byte seed message from client", len);
		if(len != sizeof(struct seed_msg))
			fatal("obfuscate_receive_seed: reread failed");
	}

	initialize(seed.seed_buffer, 1, 1); // try fixed key pair first

	// create a copy of seed.magic because obfuscate_input(..) destroys it
	test_magic = seed.magic;
	obfuscate_input((u_char *)&test_magic, 4);
	if(OBFUSCATE_MAGIC_VALUE != ntohl(test_magic)) {
		debug2("trying ossh backwards compatibility mode");
		initialize(seed.seed_buffer, 1, 0); // try backwards compatible key pair
		obfuscate_input((u_char *)&seed.magic, 4);
		if(OBFUSCATE_MAGIC_VALUE != ntohl(seed.magic)) {
			logit("Magic value check failed (%u) on obfuscated handshake.", ntohl(seed.magic));
			read_forever(sock_in);
		}
	} else {
		seed.magic = test_magic;
	}

	obfuscate_input((u_char *)&seed.padding_length, 4);
	padding_length = ntohl(seed.padding_length);
	if(padding_length > OBFUSCATE_MAX_PADDING) {
		logit("Illegal padding length %d for obfuscated handshake", ntohl(seed.padding_length));
		read_forever(sock_in);
	}
	len = atomicio(read, sock_in, padding_drain, padding_length);
	if(len != padding_length)
		fatal("obfuscate_receive_seed: read failed");
	debug2("obfuscate_receive_seed: read %d bytes of padding from client.", len);
	obfuscate_input(padding_drain, padding_length);
}

static int handshake_version(struct child_process *process,
			     const char *welcome_prefix, int *versions,
			     int *chosen_version)
{
	int version_scratch;
	int i;
	char *line;
	const char *p;

	if (!chosen_version)
		chosen_version = &version_scratch;

	if (packet_write_fmt_gently(process->in, "%s-client\n",
				    welcome_prefix))
		return error("Could not write client identification");
	for (i = 0; versions[i]; i++) {
		if (packet_write_fmt_gently(process->in, "version=%d\n",
					    versions[i]))
			return error("Could not write requested version");
	}
	if (packet_flush_gently(process->in))
		return error("Could not write flush packet");

	if (!(line = packet_read_line(process->out, NULL)) ||
	    !skip_prefix(line, welcome_prefix, &p) ||
	    strcmp(p, "-server"))
		return error("Unexpected line '%s', expected %s-server",
			     line ? line : "<flush packet>", welcome_prefix);
	if (!(line = packet_read_line(process->out, NULL)) ||
	    !skip_prefix(line, "version=", &p) ||
	    strtol_i(p, 10, chosen_version))
		return error("Unexpected line '%s', expected version",
			     line ? line : "<flush packet>");
	if ((line = packet_read_line(process->out, NULL)))
		return error("Unexpected line '%s', expected flush", line);

	/* Check to make sure that the version received is supported */
	for (i = 0; versions[i]; i++) {
		if (versions[i] == *chosen_version)
			break;
	}
	if (!versions[i])
		return error("Version %d not supported", *chosen_version);

	return 0;
}

char *
skip_csi(char *input)
{
  if ((unsigned char) *input == CSI) {
    return input + 1;
  }
  return skip_prefix(csi_input(), input);
}

char *
skip_ss3(char *input)
{
  if ((unsigned char) *input == SS3) {
    return input + 1;
  }
  return skip_prefix(ss3_input(), input);
}