diff options
| -rw-r--r-- | .gitignore | 2 | ||||
| -rw-r--r-- | Documentation/git-credential-cache--daemon.txt | 26 | ||||
| -rw-r--r-- | Documentation/git-credential-cache.txt | 77 | ||||
| -rw-r--r-- | Documentation/gitcredentials.txt | 17 | ||||
| -rw-r--r-- | Makefile | 3 | ||||
| -rw-r--r-- | credential-cache--daemon.c | 269 | ||||
| -rw-r--r-- | credential-cache.c | 120 | ||||
| -rw-r--r-- | git-compat-util.h | 1 | ||||
| -rwxr-xr-x | t/lib-credential.sh | 221 | ||||
| -rwxr-xr-x | t/t0301-credential-cache.sh | 18 | ||||
| -rw-r--r-- | unix-socket.c | 56 | ||||
| -rw-r--r-- | unix-socket.h | 7 |
12 files changed, 812 insertions, 5 deletions
diff --git a/.gitignore b/.gitignore index 7d2fefce9..a6b0bd403 100644 --- a/.gitignore +++ b/.gitignore @@ -30,6 +30,8 @@ /git-commit-tree /git-config /git-count-objects +/git-credential-cache +/git-credential-cache--daemon /git-cvsexportcommit /git-cvsimport /git-cvsserver diff --git a/Documentation/git-credential-cache--daemon.txt b/Documentation/git-credential-cache--daemon.txt new file mode 100644 index 000000000..11edc5a17 --- /dev/null +++ b/Documentation/git-credential-cache--daemon.txt @@ -0,0 +1,26 @@ +git-credential-cache--daemon(1) +=============================== + +NAME +---- +git-credential-cache--daemon - temporarily store user credentials in memory + +SYNOPSIS +-------- +[verse] +git credential-cache--daemon <socket> + +DESCRIPTION +----------- + +NOTE: You probably don't want to invoke this command yourself; it is +started automatically when you use linkgit:git-credential-cache[1]. + +This command listens on the Unix domain socket specified by `<socket>` +for `git-credential-cache` clients. Clients may store and retrieve +credentials. Each credential is held for a timeout specified by the +client; once no credentials are held, the daemon exits. + +GIT +--- +Part of the linkgit:git[1] suite diff --git a/Documentation/git-credential-cache.txt b/Documentation/git-credential-cache.txt new file mode 100644 index 000000000..f3d09c5d5 --- /dev/null +++ b/Documentation/git-credential-cache.txt @@ -0,0 +1,77 @@ +git-credential-cache(1) +======================= + +NAME +---- +git-credential-cache - helper to temporarily store passwords in memory + +SYNOPSIS +-------- +----------------------------- +git config credential.helper 'cache [options]' +----------------------------- + +DESCRIPTION +----------- + +This command caches credentials in memory for use by future git +programs. The stored credentials never touch the disk, and are forgotten +after a configurable timeout. The cache is accessible over a Unix +domain socket, restricted to the current user by filesystem permissions. + +You probably don't want to invoke this command directly; it is meant to +be used as a credential helper by other parts of git. See +linkgit:gitcredentials[7] or `EXAMPLES` below. + +OPTIONS +------- + +--timeout <seconds>:: + + Number of seconds to cache credentials (default: 900). + +--socket <path>:: + + Use `<path>` to contact a running cache daemon (or start a new + cache daemon if one is not started). Defaults to + `~/.git-credential-cache/socket`. If your home directory is on a + network-mounted filesystem, you may need to change this to a + local filesystem. + +CONTROLLING THE DAEMON +---------------------- + +If you would like the daemon to exit early, forgetting all cached +credentials before their timeout, you can issue an `exit` action: + +-------------------------------------- +git credential-cache exit +-------------------------------------- + +EXAMPLES +-------- + +The point of this helper is to reduce the number of times you must type +your username or password. For example: + +------------------------------------ +$ git config credential.helper cache +$ git push http://example.com/repo.git +Username: <type your username> +Password: <type your password> + +[work for 5 more minutes] +$ git push http://example.com/repo.git +[your credentials are used automatically] +------------------------------------ + +You can provide options via the credential.helper configuration +variable (this example drops the cache time to 5 minutes): + +------------------------------------------------------- +$ git config credential.helper 'cache --timeout=300' +------------------------------------------------------- + +GIT +--- +Part of the linkgit:git[1] suite diff --git a/Documentation/gitcredentials.txt b/Documentation/gitcredentials.txt index 07f659697..4e3f860ea 100644 --- a/Documentation/gitcredentials.txt +++ b/Documentation/gitcredentials.txt @@ -63,11 +63,18 @@ Credential helpers, on the other hand, are external programs from which git can request both usernames and passwords; they typically interface with secure storage provided by the OS or other programs. -To use a helper, you must first select one to use. Git does not yet -include any credential helpers, but you may have third-party helpers -installed; search for `credential-*` in the output of `git help -a`, and -consult the documentation of individual helpers. Once you have selected -a helper, you can tell git to use it by putting its name into the +To use a helper, you must first select one to use. Git currently +includes the following helpers: + +cache:: + + Cache credentials in memory for a short period of time. See + linkgit:git-credential-cache[1] for details. + +You may also have third-party helpers installed; search for +`credential-*` in the output of `git help -a`, and consult the +documentation of individual helpers. Once you have selected a helper, +you can tell git to use it by putting its name into the credential.helper variable. 1. Find a helper. @@ -427,6 +427,8 @@ PROGRAM_OBJS += show-index.o PROGRAM_OBJS += upload-pack.o PROGRAM_OBJS += http-backend.o PROGRAM_OBJS += sh-i18n--envsubst.o +PROGRAM_OBJS += credential-cache.o +PROGRAM_OBJS += credential-cache--daemon.o PROGRAMS += $(patsubst %.o,git-%$X,$(PROGRAM_OBJS)) @@ -699,6 +701,7 @@ LIB_OBJS += transport-helper.o LIB_OBJS += tree-diff.o LIB_OBJS += tree.o LIB_OBJS += tree-walk.o +LIB_OBJS += unix-socket.o LIB_OBJS += unpack-trees.o LIB_OBJS += url.o LIB_OBJS += usage.o diff --git a/credential-cache--daemon.c b/credential-cache--daemon.c new file mode 100644 index 000000000..390f19425 --- /dev/null +++ b/credential-cache--daemon.c @@ -0,0 +1,269 @@ +#include "cache.h" +#include "credential.h" +#include "unix-socket.h" +#include "sigchain.h" + +static const char *socket_path; + +static void cleanup_socket(void) +{ + if (socket_path) + unlink(socket_path); +} + +static void cleanup_socket_on_signal(int sig) +{ + cleanup_socket(); + sigchain_pop(sig); + raise(sig); +} + +struct credential_cache_entry { + struct credential item; + unsigned long expiration; +}; +static struct credential_cache_entry *entries; +static int entries_nr; +static int entries_alloc; + +static void cache_credential(struct credential *c, int timeout) +{ + struct credential_cache_entry *e; + + ALLOC_GROW(entries, entries_nr + 1, entries_alloc); + e = &entries[entries_nr++]; + + /* take ownership of pointers */ + memcpy(&e->item, c, sizeof(*c)); + memset(c, 0, sizeof(*c)); + e->expiration = time(NULL) + timeout; +} + +static struct credential_cache_entry *lookup_credential(const struct credential *c) +{ + int i; + for (i = 0; i < entries_nr; i++) { + struct credential *e = &entries[i].item; + if (credential_match(c, e)) + return &entries[i]; + } + return NULL; +} + +static void remove_credential(const struct credential *c) +{ + struct credential_cache_entry *e; + + e = lookup_credential(c); + if (e) + e->expiration = 0; +} + +static int check_expirations(void) +{ + static unsigned long wait_for_entry_until; + int i = 0; + unsigned long now = time(NULL); + unsigned long next = (unsigned long)-1; + + /* + * Initially give the client 30 seconds to actually contact us + * and store a credential before we decide there's no point in + * keeping the daemon around. + */ + if (!wait_for_entry_until) + wait_for_entry_until = now + 30; + + while (i < entries_nr) { + if (entries[i].expiration <= now) { + entries_nr--; + credential_clear(&entries[i].item); + if (i != entries_nr) + memcpy(&entries[i], &entries[entries_nr], sizeof(*entries)); + /* + * Stick around 30 seconds in case a new credential + * shows up (e.g., because we just removed a failed + * one, and we will soon get the correct one). + */ + wait_for_entry_until = now + 30; + } + else { + if (entries[i].expiration < next) + next = entries[i].expiration; + i++; + } + } + + if (!entries_nr) { + if (wait_for_entry_until <= now) + return 0; + next = wait_for_entry_until; + } + + return next - now; +} + +static int read_request(FILE *fh, struct credential *c, + struct strbuf *action, int *timeout) { + static struct strbuf item = STRBUF_INIT; + const char *p; + + strbuf_getline(&item, fh, '\n'); + p = skip_prefix(item.buf, "action="); + if (!p) + return error("client sent bogus action line: %s", item.buf); + strbuf_addstr(action, p); + + strbuf_getline(&item, fh, '\n'); + p = skip_prefix(item.buf, "timeout="); + if (!p) + return error("client sent bogus timeout line: %s", item.buf); + *timeout = atoi(p); + + if (credential_read(c, fh) < 0) + return -1; + return 0; +} + +static void serve_one_client(FILE *in, FILE *out) +{ + struct credential c = CREDENTIAL_INIT; + struct strbuf action = STRBUF_INIT; + int timeout = -1; + + if (read_request(in, &c, &action, &timeout) < 0) + /* ignore error */ ; + else if (!strcmp(action.buf, "get")) { + struct credential_cache_entry *e = lookup_credential(&c); + if (e) { + fprintf(out, "username=%s\n", e->item.username); + fprintf(out, "password=%s\n", e->item.password); + } + } + else if (!strcmp(action.buf, "exit")) + exit(0); + else if (!strcmp(action.buf, "erase")) + remove_credential(&c); + else if (!strcmp(action.buf, "store")) { + if (timeout < 0) + warning("cache client didn't specify a timeout"); + else if (!c.username || !c.password) + warning("cache client gave us a partial credential"); + else { + remove_credential(&c); + cache_credential(&c, timeout); + } + } + else + warning("cache client sent unknown action: %s", action.buf); + + credential_clear(&c); + strbuf_release(&action); +} + +static int serve_cache_loop(int fd) +{ + struct pollfd pfd; + unsigned long wakeup; + + wakeup = check_expirations(); + if (!wakeup) + return 0; + + pfd.fd = fd; + pfd.events = POLLIN; + if (poll(&pfd, 1, 1000 * wakeup) < 0) { + if (errno != EINTR) + die_errno("poll failed"); + return 1; + } + + if (pfd.revents & POLLIN) { + int client, client2; + FILE *in, *out; + + client = accept(fd, NULL, NULL); + if (client < 0) { + warning("accept failed: %s", strerror(errno)); + return 1; + } + client2 = dup(client); + if (client2 < 0) { + warning("dup failed: %s", strerror(errno)); + close(client); + return 1; + } + + in = xfdopen(client, "r"); + out = xfdopen(client2, "w"); + serve_one_client(in, out); + fclose(in); + fclose(out); + } + return 1; +} + +static void serve_cache(const char *socket_path) +{ + int fd; + + fd = unix_stream_listen(socket_path); + if (fd < 0) + die_errno("unable to bind to '%s'", socket_path); + + printf("ok\n"); + fclose(stdout); + + while (serve_cache_loop(fd)) + ; /* nothing */ + + close(fd); + unlink(socket_path); +} + +static const char permissions_advice[] = +"The permissions on your socket directory are too loose; other\n" +"users may be able to read your cached credentials. Consider running:\n" +"\n" +" chmod 0700 %s"; +static void check_socket_directory(const char *path) +{ + struct stat st; + char *path_copy = xstrdup(path); + char *dir = dirname(path_copy); + + if (!stat(dir, &st)) { + if (st.st_mode & 077) + die(permissions_advice, dir); + free(path_copy); + return; + } + + /* + * We must be sure to create the directory with the correct mode, + * not just chmod it after the fact; otherwise, there is a race + * condition in which somebody can chdir to it, sleep, then try to open + * our protected socket. + */ + if (safe_create_leading_directories_const(dir) < 0) + die_errno("unable to create directories for '%s'", dir); + if (mkdir(dir, 0700) < 0) + die_errno("unable to mkdir '%s'", dir); + free(path_copy); +} + +int main(int argc, const char **argv) +{ + socket_path = argv[1]; + + if (!socket_path) + die("usage: git-credential-cache--daemon <socket_path>"); + check_socket_directory(socket_path); + + atexit(cleanup_socket); + sigchain_push_common(cleanup_socket_on_signal); + + serve_cache(socket_path); + + return 0; +} diff --git a/credential-cache.c b/credential-cache.c new file mode 100644 index 000000000..dc98372e5 --- /dev/null +++ b/credential-cache.c @@ -0,0 +1,120 @@ +#include "cache.h" +#include "credential.h" +#include "string-list.h" +#include "parse-options.h" +#include "unix-socket.h" +#include "run-command.h" + +#define FLAG_SPAWN 0x1 +#define FLAG_RELAY 0x2 + +static int send_request(const char *socket, const struct strbuf *out) +{ + int got_data = 0; + int fd = unix_stream_connect(socket); + + if (fd < 0) + return -1; + + if (write_in_full(fd, out->buf, out->len) < 0) + die_errno("unable to write to cache daemon"); + shutdown(fd, SHUT_WR); + + while (1) { + char in[1024]; + int r; + + r = read_in_full(fd, in, sizeof(in)); + if (r == 0) + break; + if (r < 0) + die_errno("read error from cache daemon"); + write_or_die(1, in, r); + got_data = 1; + } + return got_data; +} + +static void spawn_daemon(const char *socket) +{ + struct child_process daemon; + const char *argv[] = { NULL, NULL, NULL }; + char buf[128]; + int r; + + memset(&daemon, 0, sizeof(daemon)); + argv[0] = "git-credential-cache--daemon"; + argv[1] = socket; + daemon.argv = argv; + daemon.no_stdin = 1; + daemon.out = -1; + + if (start_command(&daemon)) + die_errno("unable to start cache daemon"); + r = read_in_full(daemon.out, buf, sizeof(buf)); + if (r < 0) + die_errno("unable to read result code from cache daemon"); + if (r != 3 || memcmp(buf, "ok\n", 3)) + die("cache daemon did not start: %.*s", r, buf); + close(daemon.out); +} + +static void do_cache(const char *socket, const char *action, int timeout, + int flags) +{ + struct strbuf buf = STRBUF_INIT; + + strbuf_addf(&buf, "action=%s\n", action); + strbuf_addf(&buf, "timeout=%d\n", timeout); + if (flags & FLAG_RELAY) { + if (strbuf_read(&buf, 0, 0) < 0) + die_errno("unable to relay credential"); + } + + if (!send_request(socket, &buf)) + return; + if (flags & FLAG_SPAWN) { + spawn_daemon(socket); + send_request(socket, &buf); + } + strbuf_release(&buf); +} + +int main(int argc, const char **argv) +{ + char *socket_path = NULL; + int timeout = 900; + const char *op; + const char * const usage[] = { + "git credential-cache [options] <action>", + NULL + }; + struct option options[] = { + OPT_INTEGER(0, "timeout", &timeout, + "number of seconds to cache credentials"), + OPT_STRING(0, "socket", &socket_path, "path", + "path of cache-daemon socket"), + OPT_END() + }; + + argc = parse_options(argc, argv, NULL, options, usage, 0); + if (!argc) + usage_with_options(usage, options); + op = argv[0]; + + if (!socket_path) + socket_path = expand_user_path("~/.git-credential-cache/socket"); + if (!socket_path) + die("unable to find a suitable socket path; use --socket"); + + if (!strcmp(op, "exit")) + do_cache(socket_path, op, timeout, 0); + else if (!strcmp(op, "get") || !strcmp(op, "erase")) + do_cache(socket_path, op, timeout, FLAG_RELAY); + else if (!strcmp(op, "store")) + do_cache(socket_path, op, timeout, FLAG_RELAY|FLAG_SPAWN); + else + ; /* ignore unknown operation */ + + return 0; +} diff --git a/git-compat-util.h b/git-compat-util.h index 8b4dd5c02..5c238bd6d 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -130,6 +130,7 @@ #include <arpa/inet.h> #include <netdb.h> #include <pwd.h> +#include <sys/un.h> #ifndef NO_INTTYPES_H #include <inttypes.h> #else diff --git a/t/lib-credential.sh b/t/lib-credential.sh index 54ae1f484..4a37cd79e 100755 --- a/t/lib-credential.sh +++ b/t/lib-credential.sh @@ -21,6 +21,227 @@ read_chunk() { done } +# Clear any residual data from previous tests. We only +# need this when testing third-party helpers which read and +# write outside of our trash-directory sandbox. +# +# Don't bother checking for success here, as it is +# outside the scope of tests and represents a best effort to +# clean up after ourselves. +helper_test_clean() { + reject $1 https example.com store-user + reject $1 https example.com user1 + reject $1 https example.com user2 + reject $1 http path.tld user + reject $1 https timeout.tld user +} + +reject() { + ( + echo protocol=$2 + echo host=$3 + echo username=$4 + ) | test-credential reject $1 +} + +helper_test() { + HELPER=$1 + + test_expect_success "helper ($HELPER) has no existing data" ' + check fill $HELPER <<-\EOF + protocol=https + host=example.com + -- + username=askpass-username + password=askpass-password + -- + askpass: Username for '\''https://example.com'\'': + askpass: Password for '\''https://askpass-username@example.com'\'': + EOF + ' + + test_expect_success "helper ($HELPER) stores password" ' + check approve $HELPER <<-\EOF + protocol=https + host=example.com + username=store-user + password=store-pass + EOF + ' + + test_expect_success "helper ($HELPER) can retrieve password" ' + check fill $HELPER <<-\EOF + protocol=https + host=example.com + -- + username=store-user + password=store-pass + -- + EOF + ' + + test_expect_success "helper ($HELPER) requires matching protocol" ' + check fill $HELPER <<-\EOF + protocol=http + host=example.com + -- + username=askpass-username + password=askpass-password + -- + askpass: Username for '\''http://example.com'\'': + askpass: Password for '\''http://askpass-username@example.com'\'': + EOF + ' + + test_expect_success "helper ($HELPER) requires matching host" ' + check fill $HELPER <<-\EOF + protocol=https + host=other.tld + -- + username=askpass-username + password=askpass-password + -- + askpass: Username for '\''https://other.tld'\'': + askpass: Password for '\''https://askpass-username@other.tld'\'': + EOF + ' + + test_expect_success "helper ($HELPER) requires matching username" ' + check fill $HELPER <<-\EOF + protocol=https + host=example.com + username=other + -- + username=other + password=askpass-password + -- + askpass: Password for '\''https://other@example.com'\'': + EOF + ' + + test_expect_success "helper ($HELPER) requires matching path" ' + test_config credential.usehttppath true && + check approve $HELPER <<-\EOF && + protocol=http + host=path.tld + path=foo.git + username=user + password=pass + EOF + check fill $HELPER <<-\EOF + protocol=http + host=path.tld + path=bar.git + -- + username=askpass-username + password=askpass-password + -- + askpass: Username for '\''http://path.tld/bar.git'\'': + askpass: Password for '\''http://askpass-username@path.tld/bar.git'\'': + EOF + ' + + test_expect_success "helper ($HELPER) can forget host" ' + check reject $HELPER <<-\EOF && + protocol=https + host=example.com + EOF + check fill $HELPER <<-\EOF + protocol=https + host=example.com + -- + username=askpass-username + password=askpass-password + -- + askpass: Username for '\''https://example.com'\'': + askpass: Password for '\''https://askpass-username@example.com'\'': + EOF + ' + + test_expect_success "helper ($HELPER) can store multiple users" ' + check approve $HELPER <<-\EOF && + protocol=https + host=example.com + username=user1 + password=pass1 + EOF + check approve $HELPER <<-\EOF && + protocol=https + host=example.com + username=user2 + password=pass2 + EOF + check fill $HELPER <<-\EOF && + protocol=https + host=example.com + username=user1 + -- + username=user1 + password=pass1 + EOF + check fill $HELPER <<-\EOF + protocol=https + host=example.com + username=user2 + -- + username=user2 + password=pass2 + EOF + ' + + test_expect_success "helper ($HELPER) can forget user" ' + check reject $HELPER <<-\EOF && + protocol=https + host=example.com + username=user1 + EOF + check fill $HELPER <<-\EOF + protocol=https + host=example.com + username=user1 + -- + username=user1 + password=askpass-password + -- + askpass: Password for '\''https://user1@example.com'\'': + EOF + ' + + test_expect_success "helper ($HELPER) remembers other user" ' + check fill $HELPER <<-\EOF + protocol=https + host=example.com + username=user2 + -- + username=user2 + password=pass2 + EOF + ' +} + +helper_test_timeout() { + HELPER="$*" + + test_expect_success "helper ($HELPER) times out" ' + check approve "$HELPER" <<-\EOF && + protocol=https + host=timeout.tld + username=user + password=pass + EOF + sleep 2 && + check fill "$HELPER" <<-\EOF + protocol=https + host=timeout.tld + -- + username=askpass-username + password=askpass-password + -- + askpass: Username for '\''https://timeout.tld'\'': + askpass: Password for '\''https://askpass-username@timeout.tld'\'': + EOF + ' +} cat >askpass <<\EOF #!/bin/sh diff --git a/t/t0301-credential-cache.sh b/t/t0301-credential-cache.sh new file mode 100755 index 000000000..3a65f9953 --- /dev/null +++ b/t/t0301-credential-cache.sh @@ -0,0 +1,18 @@ +#!/bin/sh + +test_description='credential-cache tests' +. ./test-lib.sh +. "$TEST_DIRECTORY"/lib-credential.sh + +# don't leave a stale daemon running +trap 'code=$?; git credential-cache exit; (exit $code); die' EXIT + +helper_test cache +helper_test_timeout cache --timeout=1 + +# we can't rely on our "trap" above working after test_done, +# as test_done will delete the trash directory containing +# our socket, leaving us with no way to access the daemon. +git credential-cache exit + +test_done diff --git a/unix-socket.c b/unix-socket.c new file mode 100644 index 000000000..84b15099f --- /dev/null +++ b/unix-socket.c @@ -0,0 +1,56 @@ +#include "cache.h" +#include "unix-socket.h" + +static int unix_stream_socket(void) +{ + int fd = socket(AF_UNIX, SOCK_STREAM, 0); + if (fd < 0) + die_errno("unable to create socket"); + return fd; +} + +static void unix_sockaddr_init(struct sockaddr_un *sa, const char *path) +{ + int size = strlen(path) + 1; + if (size > sizeof(sa->sun_path)) + die("socket path is too long to fit in sockaddr"); + memset(sa, 0, sizeof(*sa)); + sa->sun_family = AF_UNIX; + memcpy(sa->sun_path, path, size); +} + +int unix_stream_connect(const char *path) +{ + int fd; + struct sockaddr_un sa; + + unix_sockaddr_init(&sa, path); + fd = unix_stream_socket(); + if (connect(fd, (struct sockaddr *)&sa, sizeof(sa)) < 0) { + close(fd); + return -1; + } + return fd; +} + +int unix_stream_listen(const char *path) +{ + int fd; + struct sockaddr_un sa; + + unix_sockaddr_init(&sa, path); + fd = unix_stream_socket(); + + unlink(path); + if (bind(fd, (struct sockaddr *)&sa, sizeof(sa)) < 0) { + close(fd); + return -1; + } + + if (listen(fd, 5) < 0) { + close(fd); + return -1; + } + + return fd; +} diff --git a/unix-socket.h b/unix-socket.h new file mode 100644 index 000000000..e271aeec5 --- /dev/null +++ b/unix-socket.h @@ -0,0 +1,7 @@ +#ifndef UNIX_SOCKET_H +#define UNIX_SOCKET_H + +int unix_stream_connect(const char *path); +int unix_stream_listen(const char *path); + +#endif /* UNIX_SOCKET_H */ |