allow "ssh-add - < key"; feedback and ok markus@

3 files changed, 92 insertions, 45 deletions

diff --git a/usr.bin/ssh/authfile.c b/usr.bin/ssh/authfile.c
index edf6a5982db..dae41798aba 100644
--- a/usr.bin/ssh/authfile.c
+++ b/usr.bin/ssh/authfile.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: authfile.c,v 1.87 2010/11/29 18:57:04 markus Exp $ */
+/* $OpenBSD: authfile.c,v 1.88 2011/05/04 21:15:29 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -64,6 +64,8 @@
 #include "misc.h"
 #include "atomicio.h"
 
+#define MAX_KEY_FILE_SIZE	(1024 * 1024)
+
 /* Version identification string for SSH v1 identity files. */
 static const char authfile_id_string[] =
     "SSH PRIVATE KEY FILE FORMAT 1.1\n";
@@ -301,12 +303,12 @@ key_parse_public_rsa1(Buffer *blob, char **commentp)
 	return pub;
 }
 
-/* Load the contents of a key file into a buffer */
-static int
+/* Load a key from a fd into a buffer */
+int
 key_load_file(int fd, const char *filename, Buffer *blob)
 {
+	u_char buf[1024];
 	size_t len;
-	u_char *cp;
 	struct stat st;
 
 	if (fstat(fd, &st) < 0) {
@@ -314,30 +316,45 @@ key_load_file(int fd, const char *filename, Buffer *blob)
 		    filename == NULL ? "" : filename,
 		    filename == NULL ? "" : " ",
 		    strerror(errno));
-		close(fd);
 		return 0;
 	}
-	if (st.st_size > 1*1024*1024) {
+	if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
+	    st.st_size > MAX_KEY_FILE_SIZE) {
+ toobig:
 		error("%s: key file %.200s%stoo large", __func__,
 		    filename == NULL ? "" : filename,
 		    filename == NULL ? "" : " ");
-		close(fd);
 		return 0;
 	}
-	len = (size_t)st.st_size;		/* truncated */
-
 	buffer_init(blob);
-	cp = buffer_append_space(blob, len);
-
-	if (atomicio(read, fd, cp, len) != len) {
-		debug("%s: read from key file %.200s%sfailed: %.100s", __func__,
-		    filename == NULL ? "" : filename,
-		    filename == NULL ? "" : " ",
-		    strerror(errno));
+	for (;;) {
+		if ((len = atomicio(read, fd, buf, sizeof(buf))) == 0) {
+			if (errno == EPIPE)
+				break;
+			debug("%s: read from key file %.200s%sfailed: %.100s",
+			    __func__, filename == NULL ? "" : filename,
+			    filename == NULL ? "" : " ", strerror(errno));
+			buffer_clear(blob);
+			bzero(buf, sizeof(buf));
+			return 0;
+		}
+		buffer_append(blob, buf, len);
+		if (buffer_len(blob) > MAX_KEY_FILE_SIZE) {
+			buffer_clear(blob);
+			bzero(buf, sizeof(buf));
+			goto toobig;
+		}
+	}
+	bzero(buf, sizeof(buf));
+	if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
+	    st.st_size != buffer_len(blob)) {
+		debug("%s: key file %.200s%schanged size while reading",
+		    __func__, filename == NULL ? "" : filename,
+		    filename == NULL ? "" : " ");
 		buffer_clear(blob);
-		close(fd);
 		return 0;
 	}
+
 	return 1;
 }
 
@@ -654,11 +671,38 @@ key_load_private_type(int type, const char *filename, const char *passphrase,
 }
 
 Key *
+key_parse_private(Buffer *buffer, const char *filename,
+    const char *passphrase, char **commentp)
+{
+	Key *pub, *prv;
+	Buffer pubcopy;
+
+	buffer_init(&pubcopy);
+	buffer_append(&pubcopy, buffer_ptr(buffer), buffer_len(buffer));
+	/* it's a SSH v1 key if the public key part is readable */
+	pub = key_parse_public_rsa1(&pubcopy, commentp);
+	buffer_free(&pubcopy);
+	if (pub == NULL) {
+		prv = key_parse_private_type(buffer, KEY_UNSPEC,
+		    passphrase, NULL);
+		/* use the filename as a comment for PEM */
+		if (commentp && prv)
+			*commentp = xstrdup(filename);
+	} else {
+		key_free(pub);
+		/* key_parse_public_rsa1() has already loaded the comment */
+		prv = key_parse_private_type(buffer, KEY_RSA1, passphrase,
+		    NULL);
+	}
+	return prv;
+}
+
+Key *
 key_load_private(const char *filename, const char *passphrase,
     char **commentp)
 {
-	Key *pub, *prv;
-	Buffer buffer, pubcopy;
+	Key *prv;
+	Buffer buffer;
 	int fd;
 
 	fd = open(filename, O_RDONLY);
@@ -681,23 +725,7 @@ key_load_private(const char *filename, const char *passphrase,
 	}
 	close(fd);
 
-	buffer_init(&pubcopy);
-	buffer_append(&pubcopy, buffer_ptr(&buffer), buffer_len(&buffer));
-	/* it's a SSH v1 key if the public key part is readable */
-	pub = key_parse_public_rsa1(&pubcopy, commentp);
-	buffer_free(&pubcopy);
-	if (pub == NULL) {
-		prv = key_parse_private_type(&buffer, KEY_UNSPEC,
-		    passphrase, NULL);
-		/* use the filename as a comment for PEM */
-		if (commentp && prv)
-			*commentp = xstrdup(filename);
-	} else {
-		key_free(pub);
-		/* key_parse_public_rsa1() has already loaded the comment */
-		prv = key_parse_private_type(&buffer, KEY_RSA1, passphrase,
-		    NULL);
-	}
+	prv = key_parse_private(&buffer, filename, passphrase, commentp);
 	buffer_free(&buffer);
 	return prv;
 }
diff --git a/usr.bin/ssh/authfile.h b/usr.bin/ssh/authfile.h
index 6745dc062be..78349beb561 100644
--- a/usr.bin/ssh/authfile.h
+++ b/usr.bin/ssh/authfile.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: authfile.h,v 1.15 2010/08/04 05:42:47 djm Exp $ */
+/* $OpenBSD: authfile.h,v 1.16 2011/05/04 21:15:29 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -16,9 +16,11 @@
 #define AUTHFILE_H
 
 int	 key_save_private(Key *, const char *, const char *, const char *);
+int	 key_load_file(int, const char *, Buffer *);
 Key	*key_load_cert(const char *);
 Key	*key_load_public(const char *, char **);
 Key	*key_load_public_type(int, const char *, char **);
+Key	*key_parse_private(Buffer *, const char *, const char *, char **);
 Key	*key_load_private(const char *, const char *, char **);
 Key	*key_load_private_cert(int, const char *, const char *, int *);
 Key	*key_load_private_type(int, const char *, const char *, char **, int *);
diff --git a/usr.bin/ssh/ssh-add.c b/usr.bin/ssh/ssh-add.c
index fe89da13b57..0cec954ff5a 100644
--- a/usr.bin/ssh/ssh-add.c
+++ b/usr.bin/ssh/ssh-add.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-add.c,v 1.100 2010/08/31 12:33:38 djm Exp $ */
+/* $OpenBSD: ssh-add.c,v 1.101 2011/05/04 21:15:29 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -139,8 +139,12 @@ add_file(AuthenticationConnection *ac, const char *filename)
 	char *comment = NULL;
 	char msg[1024], *certpath;
 	int fd, perms_ok, ret = -1;
+	Buffer keyblob;
 
-	if ((fd = open(filename, O_RDONLY)) < 0) {
+	if (strcmp(filename, "-") == 0) {
+		fd = STDIN_FILENO;
+		filename = "(stdin)";
+	} else if ((fd = open(filename, O_RDONLY)) < 0) {
 		perror(filename);
 		return -1;
 	}
@@ -149,18 +153,28 @@ add_file(AuthenticationConnection *ac, const char *filename)
 	 * Since we'll try to load a keyfile multiple times, permission errors
 	 * will occur multiple times, so check perms first and bail if wrong.
 	 */
-	perms_ok = key_perm_ok(fd, filename);
-	close(fd);
-	if (!perms_ok)
+	if (fd != STDIN_FILENO) {
+		perms_ok = key_perm_ok(fd, filename);
+		if (!perms_ok) {
+			close(fd);
+			return -1;
+		}
+	}
+	buffer_init(&keyblob);
+	if (!key_load_file(fd, filename, &keyblob)) {
+		buffer_free(&keyblob);
+		close(fd);
 		return -1;
+	}
+	close(fd);
 
 	/* At first, try empty passphrase */
-	private = key_load_private(filename, "", &comment);
+	private = key_parse_private(&keyblob, filename, "", &comment);
 	if (comment == NULL)
 		comment = xstrdup(filename);
 	/* try last */
 	if (private == NULL && pass != NULL)
-		private = key_load_private(filename, pass, NULL);
+		private = key_parse_private(&keyblob, filename, pass, NULL);
 	if (private == NULL) {
 		/* clear passphrase since it did not work */
 		clear_pass();
@@ -171,9 +185,11 @@ add_file(AuthenticationConnection *ac, const char *filename)
 			if (strcmp(pass, "") == 0) {
 				clear_pass();
 				xfree(comment);
+				buffer_free(&keyblob);
 				return -1;
 			}
-			private = key_load_private(filename, pass, &comment);
+			private = key_parse_private(&keyblob, filename, pass,
+			    &comment);
 			if (private != NULL)
 				break;
 			clear_pass();
@@ -181,6 +197,7 @@ add_file(AuthenticationConnection *ac, const char *filename)
 			    "Bad passphrase, try again for %.200s: ", comment);
 		}
 	}
+	buffer_free(&keyblob);
 
 	if (ssh_add_identity_constrained(ac, private, comment, lifetime,
 	    confirm)) {