1 files changed, 365 insertions, 0 deletions
diff --git a/credential.c b/credential.c
new file mode 100644
index 0000000000..a17eafea58
--- /dev/null
+++ b/credential.c
@@ -0,0 +1,365 @@
+#include "cache.h"
+#include "credential.h"
+#include "string-list.h"
+#include "run-command.h"
+#include "url.h"
+
+void credential_init(struct credential *c)
+{
+	memset(c, 0, sizeof(*c));
+	c->helpers.strdup_strings = 1;
+}
+
+void credential_clear(struct credential *c)
+{
+	free(c->protocol);
+	free(c->host);
+	free(c->path);
+	free(c->username);
+	free(c->password);
+	string_list_clear(&c->helpers, 0);
+
+	credential_init(c);
+}
+
+int credential_match(const struct credential *want,
+		     const struct credential *have)
+{
+#define CHECK(x) (!want->x || (have->x && !strcmp(want->x, have->x)))
+	return CHECK(protocol) &&
+	       CHECK(host) &&
+	       CHECK(path) &&
+	       CHECK(username);
+#undef CHECK
+}
+
+static int credential_config_callback(const char *var, const char *value,
+				      void *data)
+{
+	struct credential *c = data;
+	const char *key, *dot;
+
+	key = skip_prefix(var, "credential.");
+	if (!key)
+		return 0;
+
+	if (!value)
+		return config_error_nonbool(var);
+
+	dot = strrchr(key, '.');
+	if (dot) {
+		struct credential want = CREDENTIAL_INIT;
+		char *url = xmemdupz(key, dot - key);
+		int matched;
+
+		credential_from_url(&want, url);
+		matched = credential_match(&want, c);
+
+		credential_clear(&want);
+		free(url);
+
+		if (!matched)
+			return 0;
+		key = dot + 1;
+	}
+
+	if (!strcmp(key, "helper"))
+		string_list_append(&c->helpers, value);
+	else if (!strcmp(key, "username")) {
+		if (!c->username)
+			c->username = xstrdup(value);
+	}
+	else if (!strcmp(key, "usehttppath"))
+		c->use_http_path = git_config_bool(var, value);
+
+	return 0;
+}
+
+static int proto_is_http(const char *s)
+{
+	if (!s)
+		return 0;
+	return !strcmp(s, "https") || !strcmp(s, "http");
+}
+
+static void credential_apply_config(struct credential *c)
+{
+	if (c->configured)
+		return;
+	git_config(credential_config_callback, c);
+	c->configured = 1;
+
+	if (!c->use_http_path && proto_is_http(c->protocol)) {
+		free(c->path);
+		c->path = NULL;
+	}
+}
+
+static void credential_describe(struct credential *c, struct strbuf *out)
+{
+	if (!c->protocol)
+		return;
+	strbuf_addf(out, "%s://", c->protocol);
+	if (c->username && *c->username)
+		strbuf_addf(out, "%s@", c->username);
+	if (c->host)
+		strbuf_addstr(out, c->host);
+	if (c->path)
+		strbuf_addf(out, "/%s", c->path);
+}
+
+static char *credential_ask_one(const char *what, struct credential *c)
+{
+	struct strbuf desc = STRBUF_INIT;
+	struct strbuf prompt = STRBUF_INIT;
+	char *r;
+
+	credential_describe(c, &desc);
+	if (desc.len)
+		strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
+	else
+		strbuf_addf(&prompt, "%s: ", what);
+
+	/* FIXME: for usernames, we should do something less magical that
+	 * actually echoes the characters. However, we need to read from
+	 * /dev/tty and not stdio, which is not portable (but getpass will do
+	 * it for us). http.c uses the same workaround. */
+	r = git_getpass(prompt.buf);
+
+	strbuf_release(&desc);
+	strbuf_release(&prompt);
+	return xstrdup(r);
+}
+
+static void credential_getpass(struct credential *c)
+{
+	if (!c->username)
+		c->username = credential_ask_one("Username", c);
+	if (!c->password)
+		c->password = credential_ask_one("Password", c);
+}
+
+int credential_read(struct credential *c, FILE *fp)
+{
+	struct strbuf line = STRBUF_INIT;
+
+	while (strbuf_getline(&line, fp, '\n') != EOF) {
+		char *key = line.buf;
+		char *value = strchr(key, '=');
+
+		if (!line.len)
+			break;
+
+		if (!value) {
+			warning("invalid credential line: %s", key);
+			strbuf_release(&line);
+			return -1;
+		}
+		*value++ = '\0';
+
+		if (!strcmp(key, "username")) {
+			free(c->username);
+			c->username = xstrdup(value);
+		} else if (!strcmp(key, "password")) {
+			free(c->password);
+			c->password = xstrdup(value);
+		} else if (!strcmp(key, "protocol")) {
+			free(c->protocol);
+			c->protocol = xstrdup(value);
+		} else if (!strcmp(key, "host")) {
+			free(c->host);
+			c->host = xstrdup(value);
+		} else if (!strcmp(key, "path")) {
+			free(c->path);
+			c->path = xstrdup(value);
+		}
+		/*
+		 * Ignore other lines; we don't know what they mean, but
+		 * this future-proofs us when later versions of git do
+		 * learn new lines, and the helpers are updated to match.
+		 */
+	}
+
+	strbuf_release(&line);
+	return 0;
+}
+
+static void credential_write_item(FILE *fp, const char *key, const char *value)
+{
+	if (!value)
+		return;
+	fprintf(fp, "%s=%s\n", key, value);
+}
+
+static void credential_write(const struct credential *c, FILE *fp)
+{
+	credential_write_item(fp, "protocol", c->protocol);
+	credential_write_item(fp, "host", c->host);
+	credential_write_item(fp, "path", c->path);
+	credential_write_item(fp, "username", c->username);
+	credential_write_item(fp, "password", c->password);
+}
+
+static int run_credential_helper(struct credential *c,
+				 const char *cmd,
+				 int want_output)
+{
+	struct child_process helper;
+	const char *argv[] = { NULL, NULL };
+	FILE *fp;
+
+	memset(&helper, 0, sizeof(helper));
+	argv[0] = cmd;
+	helper.argv = argv;
+	helper.use_shell = 1;
+	helper.in = -1;
+	if (want_output)
+		helper.out = -1;
+	else
+		helper.no_stdout = 1;
+
+	if (start_command(&helper) < 0)
+		return -1;
+
+	fp = xfdopen(helper.in, "w");
+	credential_write(c, fp);
+	fclose(fp);
+
+	if (want_output) {
+		int r;
+		fp = xfdopen(helper.out, "r");
+		r = credential_read(c, fp);
+		fclose(fp);
+		if (r < 0) {
+			finish_command(&helper);
+			return -1;
+		}
+	}
+
+	if (finish_command(&helper))
+		return -1;
+	return 0;
+}
+
+static int credential_do(struct credential *c, const char *helper,
+			 const char *operation)
+{
+	struct strbuf cmd = STRBUF_INIT;
+	int r;
+
+	if (helper[0] == '!')
+		strbuf_addstr(&cmd, helper + 1);
+	else if (is_absolute_path(helper))
+		strbuf_addstr(&cmd, helper);
+	else
+		strbuf_addf(&cmd, "git credential-%s", helper);
+
+	strbuf_addf(&cmd, " %s", operation);
+	r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
+
+	strbuf_release(&cmd);
+	return r;
+}
+
+void credential_fill(struct credential *c)
+{
+	int i;
+
+	if (c->username && c->password)
+		return;
+
+	credential_apply_config(c);
+
+	for (i = 0; i < c->helpers.nr; i++) {
+		credential_do(c, c->helpers.items[i].string, "get");
+		if (c->username && c->password)
+			return;
+	}
+
+	credential_getpass(c);
+	if (!c->username && !c->password)
+		die("unable to get password from user");
+}
+
+void credential_approve(struct credential *c)
+{
+	int i;
+
+	if (c->approved)
+		return;
+	if (!c->username || !c->password)
+		return;
+
+	credential_apply_config(c);
+
+	for (i = 0; i < c->helpers.nr; i++)
+		credential_do(c, c->helpers.items[i].string, "store");
+	c->approved = 1;
+}
+
+void credential_reject(struct credential *c)
+{
+	int i;
+
+	credential_apply_config(c);
+
+	for (i = 0; i < c->helpers.nr; i++)
+		credential_do(c, c->helpers.items[i].string, "erase");
+
+	free(c->username);
+	c->username = NULL;
+	free(c->password);
+	c->password = NULL;
+	c->approved = 0;
+}
+
+void credential_from_url(struct credential *c, const char *url)
+{
+	const char *at, *colon, *cp, *slash, *host, *proto_end;
+
+	credential_clear(c);
+
+	/*
+	 * Match one of:
+	 *   (1) proto://<host>/...
+	 *   (2) proto://<user>@<host>/...
+	 *   (3) proto://<user>:<pass>@<host>/...
+	 */
+	proto_end = strstr(url, "://");
+	if (!proto_end)
+		return;
+	cp = proto_end + 3;
+	at = strchr(cp, '@');
+	colon = strchr(cp, ':');
+	slash = strchrnul(cp, '/');
+
+	if (!at || slash <= at) {
+		/* Case (1) */
+		host = cp;
+	}
+	else if (!colon || at <= colon) {
+		/* Case (2) */
+		c->username = url_decode_mem(cp, at - cp);
+		host = at + 1;
+	} else {
+		/* Case (3) */
+		c->username = url_decode_mem(cp, colon - cp);
+		c->password = url_decode_mem(colon + 1, at - (colon + 1));
+		host = at + 1;
+	}
+
+	if (proto_end - url > 0)
+		c->protocol = xmemdupz(url, proto_end - url);
+	if (slash - host > 0)
+		c->host = url_decode_mem(host, slash - host);
+	/* Trim leading and trailing slashes from path */
+	while (*slash == '/')
+		slash++;
+	if (*slash) {
+		char *p;
+		c->path = url_decode(slash);
+		p = c->path + strlen(c->path) - 1;
+		while (p > c->path && *p == '/')
+			*p-- = '\0';
+	}
+}