checking in all the old panacean stuff

puttysrc/UNIX/UXAGENTC.C

@@ -0,0 +1,162 @@
+/*
+ * SSH agent client code.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <fcntl.h>
+
+#include "putty.h"
+#include "misc.h"
+#include "tree234.h"
+#include "puttymem.h"
+
+int agent_exists(void)
+{
+    if (getenv("SSH_AUTH_SOCK") != NULL)
+	return TRUE;
+    return FALSE;
+}
+
+static tree234 *agent_connections;
+struct agent_connection {
+    int fd;
+    char *retbuf;
+    char sizebuf[4];
+    int retsize, retlen;
+    void (*callback)(void *, void *, int);
+    void *callback_ctx;
+};
+static int agent_conncmp(void *av, void *bv)
+{
+    struct agent_connection *a = (struct agent_connection *) av;
+    struct agent_connection *b = (struct agent_connection *) bv;
+    if (a->fd < b->fd)
+	return -1;
+    if (a->fd > b->fd)
+	return +1;
+    return 0;
+}
+static int agent_connfind(void *av, void *bv)
+{
+    int afd = *(int *) av;
+    struct agent_connection *b = (struct agent_connection *) bv;
+    if (afd < b->fd)
+	return -1;
+    if (afd > b->fd)
+	return +1;
+    return 0;
+}
+
+static int agent_select_result(int fd, int event)
+{
+    int ret;
+    struct agent_connection *conn;
+
+    assert(event == 1);		       /* not selecting for anything but R */
+
+    conn = find234(agent_connections, &fd, agent_connfind);
+    if (!conn) {
+	uxsel_del(fd);
+	return 1;
+    }
+
+    ret = read(fd, conn->retbuf+conn->retlen, conn->retsize-conn->retlen);
+    if (ret <= 0) {
+	if (conn->retbuf != conn->sizebuf) sfree(conn->retbuf);
+	conn->retbuf = NULL;
+	conn->retlen = 0;
+	goto done;
+    }
+    conn->retlen += ret;
+    if (conn->retsize == 4 && conn->retlen == 4) {
+	conn->retsize = GET_32BIT(conn->retbuf);
+	if (conn->retsize <= 0) {
+	    conn->retbuf = NULL;
+	    conn->retlen = 0;
+	    goto done;
+	}
+	conn->retsize += 4;
+	assert(conn->retbuf == conn->sizebuf);
+	conn->retbuf = snewn(conn->retsize, char);
+	memcpy(conn->retbuf, conn->sizebuf, 4);
+    }
+
+    if (conn->retlen < conn->retsize)
+	return 0;		       /* more data to come */
+
+    done:
+    /*
+     * We have now completed the agent query. Do the callback, and
+     * clean up. (Of course we don't free retbuf, since ownership
+     * of that passes to the callback.)
+     */
+    conn->callback(conn->callback_ctx, conn->retbuf, conn->retlen);
+    uxsel_del(fd);
+    close(fd);
+    del234(agent_connections, conn);
+    sfree(conn);
+    return 0;
+}
+
+int agent_query(void *in, int inlen, void **out, int *outlen,
+		void (*callback)(void *, void *, int), void *callback_ctx)
+{
+    char *name;
+    int sock;
+    struct sockaddr_un addr;
+    int done;
+    struct agent_connection *conn;
+
+    name = getenv("SSH_AUTH_SOCK");
+    if (!name)
+	goto failure;
+
+    sock = socket(PF_UNIX, SOCK_STREAM, 0);
+    if (sock < 0) {
+	perror("socket(PF_UNIX)");
+	exit(1);
+    }
+
+    cloexec(sock);
+
+    addr.sun_family = AF_UNIX;
+    strncpy(addr.sun_path, name, sizeof(addr.sun_path));
+    if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
+	close(sock);
+	goto failure;
+    }
+
+    for (done = 0; done < inlen ;) {
+	int ret = write(sock, (char *)in + done, inlen - done);
+	if (ret <= 0) {
+	    close(sock);
+	    goto failure;
+	}
+	done += ret;
+    }
+
+    if (!agent_connections)
+	agent_connections = newtree234(agent_conncmp);
+
+    conn = snew(struct agent_connection);
+    conn->fd = sock;
+    conn->retbuf = conn->sizebuf;
+    conn->retsize = 4;
+    conn->retlen = 0;
+    conn->callback = callback;
+    conn->callback_ctx = callback_ctx;
+    add234(agent_connections, conn);
+
+    uxsel_set(sock, 1, agent_select_result);
+    return 0;
+
+    failure:
+    *out = NULL;
+    *outlen = 0;
+    return 1;
+}