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-rw-r--r--credential.c548
1 files changed, 548 insertions, 0 deletions
diff --git a/credential.c b/credential.c
new file mode 100644
index 0000000..18098bd
--- /dev/null
+++ b/credential.c
@@ -0,0 +1,548 @@
+#include "git-compat-util.h"
+#include "abspath.h"
+#include "config.h"
+#include "credential.h"
+#include "gettext.h"
+#include "string-list.h"
+#include "run-command.h"
+#include "url.h"
+#include "prompt.h"
+#include "sigchain.h"
+#include "strbuf.h"
+#include "urlmatch.h"
+#include "git-compat-util.h"
+
+void credential_init(struct credential *c)
+{
+ struct credential blank = CREDENTIAL_INIT;
+ memcpy(c, &blank, sizeof(*c));
+}
+
+void credential_clear(struct credential *c)
+{
+ free(c->protocol);
+ free(c->host);
+ free(c->path);
+ free(c->username);
+ free(c->password);
+ free(c->oauth_refresh_token);
+ string_list_clear(&c->helpers, 0);
+ strvec_clear(&c->wwwauth_headers);
+
+ credential_init(c);
+}
+
+int credential_match(const struct credential *want,
+ const struct credential *have, int match_password)
+{
+#define CHECK(x) (!want->x || (have->x && !strcmp(want->x, have->x)))
+ return CHECK(protocol) &&
+ CHECK(host) &&
+ CHECK(path) &&
+ CHECK(username) &&
+ (!match_password || CHECK(password));
+#undef CHECK
+}
+
+
+static int credential_from_potentially_partial_url(struct credential *c,
+ const char *url);
+
+static int credential_config_callback(const char *var, const char *value,
+ const struct config_context *ctx UNUSED,
+ void *data)
+{
+ struct credential *c = data;
+ const char *key;
+
+ if (!skip_prefix(var, "credential.", &key))
+ return 0;
+
+ if (!value)
+ return config_error_nonbool(var);
+
+ if (!strcmp(key, "helper")) {
+ if (*value)
+ string_list_append(&c->helpers, value);
+ else
+ string_list_clear(&c->helpers, 0);
+ } else if (!strcmp(key, "username")) {
+ if (!c->username_from_proto) {
+ free(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_describe(struct credential *c, struct strbuf *out);
+static void credential_format(struct credential *c, struct strbuf *out);
+
+static int select_all(const struct urlmatch_item *a UNUSED,
+ const struct urlmatch_item *b UNUSED)
+{
+ return 0;
+}
+
+static int match_partial_url(const char *url, void *cb)
+{
+ struct credential *c = cb;
+ struct credential want = CREDENTIAL_INIT;
+ int matches = 0;
+
+ if (credential_from_potentially_partial_url(&want, url) < 0)
+ warning(_("skipping credential lookup for key: credential.%s"),
+ url);
+ else
+ matches = credential_match(&want, c, 0);
+ credential_clear(&want);
+
+ return matches;
+}
+
+static void credential_apply_config(struct credential *c)
+{
+ char *normalized_url;
+ struct urlmatch_config config = URLMATCH_CONFIG_INIT;
+ struct strbuf url = STRBUF_INIT;
+
+ if (!c->host)
+ die(_("refusing to work with credential missing host field"));
+ if (!c->protocol)
+ die(_("refusing to work with credential missing protocol field"));
+
+ if (c->configured)
+ return;
+
+ config.section = "credential";
+ config.key = NULL;
+ config.collect_fn = credential_config_callback;
+ config.cascade_fn = NULL;
+ config.select_fn = select_all;
+ config.fallback_match_fn = match_partial_url;
+ config.cb = c;
+
+ credential_format(c, &url);
+ normalized_url = url_normalize(url.buf, &config.url);
+
+ git_config(urlmatch_config_entry, &config);
+ string_list_clear(&config.vars, 1);
+ free(normalized_url);
+ urlmatch_config_release(&config);
+ strbuf_release(&url);
+
+ c->configured = 1;
+
+ if (!c->use_http_path && proto_is_http(c->protocol)) {
+ FREE_AND_NULL(c->path);
+ }
+}
+
+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 void credential_format(struct credential *c, struct strbuf *out)
+{
+ if (!c->protocol)
+ return;
+ strbuf_addf(out, "%s://", c->protocol);
+ if (c->username && *c->username) {
+ strbuf_add_percentencode(out, c->username, STRBUF_ENCODE_SLASH);
+ strbuf_addch(out, '@');
+ }
+ if (c->host)
+ strbuf_addstr(out, c->host);
+ if (c->path) {
+ strbuf_addch(out, '/');
+ strbuf_add_percentencode(out, c->path, 0);
+ }
+}
+
+static char *credential_ask_one(const char *what, struct credential *c,
+ int flags)
+{
+ 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);
+
+ r = git_prompt(prompt.buf, flags);
+
+ 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,
+ PROMPT_ASKPASS|PROMPT_ECHO);
+ if (!c->password)
+ c->password = credential_ask_one("Password", c,
+ PROMPT_ASKPASS);
+}
+
+int credential_read(struct credential *c, FILE *fp)
+{
+ struct strbuf line = STRBUF_INIT;
+
+ while (strbuf_getline(&line, fp) != 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);
+ c->username_from_proto = 1;
+ } 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);
+ } else if (!strcmp(key, "wwwauth[]")) {
+ strvec_push(&c->wwwauth_headers, value);
+ } else if (!strcmp(key, "password_expiry_utc")) {
+ errno = 0;
+ c->password_expiry_utc = parse_timestamp(value, NULL, 10);
+ if (c->password_expiry_utc == 0 || errno == ERANGE)
+ c->password_expiry_utc = TIME_MAX;
+ } else if (!strcmp(key, "oauth_refresh_token")) {
+ free(c->oauth_refresh_token);
+ c->oauth_refresh_token = xstrdup(value);
+ } else if (!strcmp(key, "url")) {
+ credential_from_url(c, value);
+ } else if (!strcmp(key, "quit")) {
+ c->quit = !!git_config_bool("quit", 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,
+ int required)
+{
+ if (!value && required)
+ BUG("credential value for %s is missing", key);
+ if (!value)
+ return;
+ if (strchr(value, '\n'))
+ die("credential value for %s contains newline", key);
+ fprintf(fp, "%s=%s\n", key, value);
+}
+
+void credential_write(const struct credential *c, FILE *fp)
+{
+ credential_write_item(fp, "protocol", c->protocol, 1);
+ credential_write_item(fp, "host", c->host, 1);
+ credential_write_item(fp, "path", c->path, 0);
+ credential_write_item(fp, "username", c->username, 0);
+ credential_write_item(fp, "password", c->password, 0);
+ credential_write_item(fp, "oauth_refresh_token", c->oauth_refresh_token, 0);
+ if (c->password_expiry_utc != TIME_MAX) {
+ char *s = xstrfmt("%"PRItime, c->password_expiry_utc);
+ credential_write_item(fp, "password_expiry_utc", s, 0);
+ free(s);
+ }
+ for (size_t i = 0; i < c->wwwauth_headers.nr; i++)
+ credential_write_item(fp, "wwwauth[]", c->wwwauth_headers.v[i], 0);
+}
+
+static int run_credential_helper(struct credential *c,
+ const char *cmd,
+ int want_output)
+{
+ struct child_process helper = CHILD_PROCESS_INIT;
+ FILE *fp;
+
+ strvec_push(&helper.args, cmd);
+ 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");
+ sigchain_push(SIGPIPE, SIG_IGN);
+ credential_write(c, fp);
+ fclose(fp);
+ sigchain_pop(SIGPIPE);
+
+ 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->password_expiry_utc < time(NULL)) {
+ /* Discard expired password */
+ FREE_AND_NULL(c->password);
+ /* Reset expiry to maintain consistency */
+ c->password_expiry_utc = TIME_MAX;
+ }
+ if (c->username && c->password)
+ return;
+ if (c->quit)
+ die("credential helper '%s' told us to quit",
+ c->helpers.items[i].string);
+ }
+
+ 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 || c->password_expiry_utc < time(NULL))
+ 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_AND_NULL(c->username);
+ FREE_AND_NULL(c->password);
+ FREE_AND_NULL(c->oauth_refresh_token);
+ c->password_expiry_utc = TIME_MAX;
+ c->approved = 0;
+}
+
+static int check_url_component(const char *url, int quiet,
+ const char *name, const char *value)
+{
+ if (!value)
+ return 0;
+ if (!strchr(value, '\n'))
+ return 0;
+
+ if (!quiet)
+ warning(_("url contains a newline in its %s component: %s"),
+ name, url);
+ return -1;
+}
+
+/*
+ * Potentially-partial URLs can, but do not have to, contain
+ *
+ * - a protocol (or scheme) of the form "<protocol>://"
+ *
+ * - a host name (the part after the protocol and before the first slash after
+ * that, if any)
+ *
+ * - a user name and potentially a password (as "<user>[:<password>]@" part of
+ * the host name)
+ *
+ * - a path (the part after the host name, if any, starting with the slash)
+ *
+ * Missing parts will be left unset in `struct credential`. Thus, `https://`
+ * will have only the `protocol` set, `example.com` only the host name, and
+ * `/git` only the path.
+ *
+ * Note that an empty host name in an otherwise fully-qualified URL (e.g.
+ * `cert:///path/to/cert.pem`) will be treated as unset if we expect the URL to
+ * be potentially partial, and only then (otherwise, the empty string is used).
+ *
+ * The credential_from_url() function does not allow partial URLs.
+ */
+static int credential_from_url_1(struct credential *c, const char *url,
+ int allow_partial_url, int quiet)
+{
+ 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 (!allow_partial_url && (!proto_end || proto_end == url)) {
+ if (!quiet)
+ warning(_("url has no scheme: %s"), url);
+ return -1;
+ }
+ cp = proto_end ? proto_end + 3 : url;
+ at = strchr(cp, '@');
+ colon = strchr(cp, ':');
+
+ /*
+ * A query or fragment marker before the slash ends the host portion.
+ * We'll just continue to call this "slash" for simplicity. Notably our
+ * "trim leading slashes" part won't skip over this part of the path,
+ * but that's what we'd want.
+ */
+ slash = cp + strcspn(cp, "/?#");
+
+ if (!at || slash <= at) {
+ /* Case (1) */
+ host = cp;
+ }
+ else if (!colon || at <= colon) {
+ /* Case (2) */
+ c->username = url_decode_mem(cp, at - cp);
+ if (c->username && *c->username)
+ c->username_from_proto = 1;
+ host = at + 1;
+ } else {
+ /* Case (3) */
+ c->username = url_decode_mem(cp, colon - cp);
+ if (c->username && *c->username)
+ c->username_from_proto = 1;
+ c->password = url_decode_mem(colon + 1, at - (colon + 1));
+ host = at + 1;
+ }
+
+ if (proto_end && proto_end - url > 0)
+ c->protocol = xmemdupz(url, proto_end - url);
+ if (!allow_partial_url || 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';
+ }
+
+ if (check_url_component(url, quiet, "username", c->username) < 0 ||
+ check_url_component(url, quiet, "password", c->password) < 0 ||
+ check_url_component(url, quiet, "protocol", c->protocol) < 0 ||
+ check_url_component(url, quiet, "host", c->host) < 0 ||
+ check_url_component(url, quiet, "path", c->path) < 0)
+ return -1;
+
+ return 0;
+}
+
+static int credential_from_potentially_partial_url(struct credential *c,
+ const char *url)
+{
+ return credential_from_url_1(c, url, 1, 0);
+}
+
+int credential_from_url_gently(struct credential *c, const char *url, int quiet)
+{
+ return credential_from_url_1(c, url, 0, quiet);
+}
+
+void credential_from_url(struct credential *c, const char *url)
+{
+ if (credential_from_url_gently(c, url, 0) < 0)
+ die(_("credential url cannot be parsed: %s"), url);
+}