1 files changed, 578 insertions, 0 deletions

diff --git a/other/ssharp/authfd.c b/other/ssharp/authfd.c
new file mode 100644
index 0000000..3e1ef81
--- /dev/null
+++ b/other/ssharp/authfd.c
@@ -0,0 +1,578 @@
+/*
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ *                    All rights reserved
+ * Functions for connecting the local authentication agent.
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose.  Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ *
+ * SSH2 implementation,
+ * Copyright (c) 2000 Markus Friedl.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+RCSID("$OpenBSD: authfd.c,v 1.39 2001/04/05 10:42:48 markus Exp $");
+
+#include <openssl/evp.h>
+
+#include "ssh.h"
+#include "rsa.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "xmalloc.h"
+#include "getput.h"
+#include "key.h"
+#include "authfd.h"
+#include "cipher.h"
+#include "kex.h"
+#include "compat.h"
+#include "log.h"
+#include "atomicio.h"
+
+/* helper */
+int     decode_reply(int type);
+
+/* macro to check for "agent failure" message */
+#define agent_failed(x) \
+    ((x == SSH_AGENT_FAILURE) || (x == SSH_COM_AGENT2_FAILURE))
+
+/* Returns the number of the authentication fd, or -1 if there is none. */
+
+int
+ssh_get_authentication_socket(void)
+{
+        const char *authsocket;
+        int sock, len;
+        struct sockaddr_un sunaddr;
+
+        authsocket = getenv(SSH_AUTHSOCKET_ENV_NAME);
+        if (!authsocket)
+                return -1;
+
+        sunaddr.sun_family = AF_UNIX;
+        strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path));
+        len = SUN_LEN(&sunaddr)+1;
+#ifdef HAVE_SUN_LEN_IN_SOCKADDR_UN
+        sunaddr.sun_len = len;
+#endif /* HAVE_SUN_LEN_IN_SOCKADDR_UN */
+
+        sock = socket(AF_UNIX, SOCK_STREAM, 0);
+        if (sock < 0)
+                return -1;
+
+        /* close on exec */
+        if (fcntl(sock, F_SETFD, 1) == -1) {
+                close(sock);
+                return -1;
+        }
+        if (connect(sock, (struct sockaddr *) & sunaddr, len) < 0) {
+                close(sock);
+                return -1;
+        }
+        return sock;
+}
+
+int
+ssh_request_reply(AuthenticationConnection *auth, Buffer *request, Buffer *reply)
+{
+        int l, len;
+        char buf[1024];
+
+        /* Get the length of the message, and format it in the buffer. */
+        len = buffer_len(request);
+        PUT_32BIT(buf, len);
+
+        /* Send the length and then the packet to the agent. */
+        if (atomicio(write, auth->fd, buf, 4) != 4 ||
+            atomicio(write, auth->fd, buffer_ptr(request),
+            buffer_len(request)) != buffer_len(request)) {
+                error("Error writing to authentication socket.");
+                return 0;
+        }
+        /*
+         * Wait for response from the agent.  First read the length of the
+         * response packet.
+         */
+        len = 4;
+        while (len > 0) {
+                l = read(auth->fd, buf + 4 - len, len);
+                if (l == -1 && (errno == EAGAIN || errno == EINTR))
+                        continue;
+                if (l <= 0) {
+                        error("Error reading response length from authentication socket.");
+                        return 0;
+                }
+                len -= l;
+        }
+
+        /* Extract the length, and check it for sanity. */
+        len = GET_32BIT(buf);
+        if (len > 256 * 1024)
+                fatal("Authentication response too long: %d", len);
+
+        /* Read the rest of the response in to the buffer. */
+        buffer_clear(reply);
+        while (len > 0) {
+                l = len;
+                if (l > sizeof(buf))
+                        l = sizeof(buf);
+                l = read(auth->fd, buf, l);
+                if (l == -1 && (errno == EAGAIN || errno == EINTR))
+                        continue;
+                if (l <= 0) {
+                        error("Error reading response from authentication socket.");
+                        return 0;
+                }
+                buffer_append(reply, (char *) buf, l);
+                len -= l;
+        }
+        return 1;
+}
+
+/*
+ * Closes the agent socket if it should be closed (depends on how it was
+ * obtained).  The argument must have been returned by
+ * ssh_get_authentication_socket().
+ */
+
+void
+ssh_close_authentication_socket(int sock)
+{
+        if (getenv(SSH_AUTHSOCKET_ENV_NAME))
+                close(sock);
+}
+
+/*
+ * Opens and connects a private socket for communication with the
+ * authentication agent.  Returns the file descriptor (which must be
+ * shut down and closed by the caller when no longer needed).
+ * Returns NULL if an error occurred and the connection could not be
+ * opened.
+ */
+
+AuthenticationConnection *
+ssh_get_authentication_connection(void)
+{
+        AuthenticationConnection *auth;
+        int sock;
+
+        sock = ssh_get_authentication_socket();
+
+        /*
+         * Fail if we couldn't obtain a connection.  This happens if we
+         * exited due to a timeout.
+         */
+        if (sock < 0)
+                return NULL;
+
+        auth = xmalloc(sizeof(*auth));
+        auth->fd = sock;
+        buffer_init(&auth->identities);
+        auth->howmany = 0;
+
+        return auth;
+}
+
+/*
+ * Closes the connection to the authentication agent and frees any associated
+ * memory.
+ */
+
+void
+ssh_close_authentication_connection(AuthenticationConnection *auth)
+{
+        buffer_free(&auth->identities);
+        close(auth->fd);
+        xfree(auth);
+}
+
+/*
+ * Returns the first authentication identity held by the agent.
+ */
+
+int
+ssh_get_num_identities(AuthenticationConnection *auth, int version)
+{
+        int type, code1 = 0, code2 = 0;
+        Buffer request;
+
+        switch(version){
+        case 1:
+                code1 = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
+                code2 = SSH_AGENT_RSA_IDENTITIES_ANSWER;
+                break;
+        case 2:
+                code1 = SSH2_AGENTC_REQUEST_IDENTITIES;
+                code2 = SSH2_AGENT_IDENTITIES_ANSWER;
+                break;
+        default:
+                return 0;
+        }
+
+        /*
+         * Send a message to the agent requesting for a list of the
+         * identities it can represent.
+         */
+        buffer_init(&request);
+        buffer_put_char(&request, code1);
+
+        buffer_clear(&auth->identities);
+        if (ssh_request_reply(auth, &request, &auth->identities) == 0) {
+                buffer_free(&request);
+                return 0;
+        }
+        buffer_free(&request);
+
+        /* Get message type, and verify that we got a proper answer. */
+        type = buffer_get_char(&auth->identities);
+        if (agent_failed(type)) {
+                return 0;
+        } else if (type != code2) {
+                fatal("Bad authentication reply message type: %d", type);
+        }
+
+        /* Get the number of entries in the response and check it for sanity. */
+        auth->howmany = buffer_get_int(&auth->identities);
+        if (auth->howmany > 1024)
+                fatal("Too many identities in authentication reply: %d",
+                    auth->howmany);
+
+        return auth->howmany;
+}
+
+Key *
+ssh_get_first_identity(AuthenticationConnection *auth, char **comment, int version)
+{
+        /* get number of identities and return the first entry (if any). */
+        if (ssh_get_num_identities(auth, version) > 0)
+                return ssh_get_next_identity(auth, comment, version);
+        return NULL;
+}
+
+Key *
+ssh_get_next_identity(AuthenticationConnection *auth, char **comment, int version)
+{
+        u_int bits;
+        u_char *blob;
+        u_int blen;
+        Key *key = NULL;
+
+        /* Return failure if no more entries. */
+        if (auth->howmany <= 0)
+                return NULL;
+
+        /*
+         * Get the next entry from the packet.  These will abort with a fatal
+         * error if the packet is too short or contains corrupt data.
+         */
+        switch(version){
+        case 1:
+                key = key_new(KEY_RSA1);
+                bits = buffer_get_int(&auth->identities);
+                buffer_get_bignum(&auth->identities, key->rsa->e);
+                buffer_get_bignum(&auth->identities, key->rsa->n);
+                *comment = buffer_get_string(&auth->identities, NULL);
+                if (bits != BN_num_bits(key->rsa->n))
+                        log("Warning: identity keysize mismatch: actual %d, announced %u",
+                            BN_num_bits(key->rsa->n), bits);
+                break;
+        case 2:
+                blob = buffer_get_string(&auth->identities, &blen);
+                *comment = buffer_get_string(&auth->identities, NULL);
+                key = key_from_blob(blob, blen);
+                xfree(blob);
+                break;
+        default:
+                return NULL;
+                break;
+        }
+        /* Decrement the number of remaining entries. */
+        auth->howmany--;
+        return key;
+}
+
+/*
+ * Generates a random challenge, sends it to the agent, and waits for
+ * response from the agent.  Returns true (non-zero) if the agent gave the
+ * correct answer, zero otherwise.  Response type selects the style of
+ * response desired, with 0 corresponding to protocol version 1.0 (no longer
+ * supported) and 1 corresponding to protocol version 1.1.
+ */
+
+int
+ssh_decrypt_challenge(AuthenticationConnection *auth,
+    Key* key, BIGNUM *challenge,
+    u_char session_id[16],
+    u_int response_type,
+    u_char response[16])
+{
+        Buffer buffer;
+        int success = 0;
+        int i;
+        int type;
+
+        if (key->type != KEY_RSA1)
+                return 0;
+        if (response_type == 0) {
+                log("Compatibility with ssh protocol version 1.0 no longer supported.");
+                return 0;
+        }
+        buffer_init(&buffer);
+        buffer_put_char(&buffer, SSH_AGENTC_RSA_CHALLENGE);
+        buffer_put_int(&buffer, BN_num_bits(key->rsa->n));
+        buffer_put_bignum(&buffer, key->rsa->e);
+        buffer_put_bignum(&buffer, key->rsa->n);
+        buffer_put_bignum(&buffer, challenge);
+        buffer_append(&buffer, (char *) session_id, 16);
+        buffer_put_int(&buffer, response_type);
+
+        if (ssh_request_reply(auth, &buffer, &buffer) == 0) {
+                buffer_free(&buffer);
+                return 0;
+        }
+        type = buffer_get_char(&buffer);
+
+        if (agent_failed(type)) {
+                log("Agent admitted failure to authenticate using the key.");
+        } else if (type != SSH_AGENT_RSA_RESPONSE) {
+                fatal("Bad authentication response: %d", type);
+        } else {
+                success = 1;
+                /*
+                 * Get the response from the packet.  This will abort with a
+                 * fatal error if the packet is corrupt.
+                 */
+                for (i = 0; i < 16; i++)
+                        response[i] = buffer_get_char(&buffer);
+        }
+        buffer_free(&buffer);
+        return success;
+}
+
+/* ask agent to sign data, returns -1 on error, 0 on success */
+int
+ssh_agent_sign(AuthenticationConnection *auth,
+    Key *key,
+    u_char **sigp, int *lenp,
+    u_char *data, int datalen)
+{
+        extern int datafellows;
+        Buffer msg;
+        u_char *blob;
+        u_int blen;
+        int type, flags = 0;
+        int ret = -1;
+
+        if (key_to_blob(key, &blob, &blen) == 0)
+                return -1;
+
+        if (datafellows & SSH_BUG_SIGBLOB)
+                flags = SSH_AGENT_OLD_SIGNATURE;
+
+        buffer_init(&msg);
+        buffer_put_char(&msg, SSH2_AGENTC_SIGN_REQUEST);
+        buffer_put_string(&msg, blob, blen);
+        buffer_put_string(&msg, data, datalen);
+        buffer_put_int(&msg, flags);
+        xfree(blob);
+
+        if (ssh_request_reply(auth, &msg, &msg) == 0) {
+                buffer_free(&msg);
+                return -1;
+        }
+        type = buffer_get_char(&msg);
+        if (agent_failed(type)) {
+                log("Agent admitted failure to sign using the key.");
+        } else if (type != SSH2_AGENT_SIGN_RESPONSE) {
+                fatal("Bad authentication response: %d", type);
+        } else {
+                ret = 0;
+                *sigp = buffer_get_string(&msg, lenp);
+        }
+        buffer_free(&msg);
+        return ret;
+}
+
+/* Encode key for a message to the agent. */
+
+void
+ssh_encode_identity_rsa1(Buffer *b, RSA *key, const char *comment)
+{
+        buffer_clear(b);
+        buffer_put_char(b, SSH_AGENTC_ADD_RSA_IDENTITY);
+        buffer_put_int(b, BN_num_bits(key->n));
+        buffer_put_bignum(b, key->n);
+        buffer_put_bignum(b, key->e);
+        buffer_put_bignum(b, key->d);
+        /* To keep within the protocol: p < q for ssh. in SSL p > q */
+        buffer_put_bignum(b, key->iqmp);        /* ssh key->u */
+        buffer_put_bignum(b, key->q);   /* ssh key->p, SSL key->q */
+        buffer_put_bignum(b, key->p);   /* ssh key->q, SSL key->p */
+        buffer_put_string(b, comment, strlen(comment));
+}
+
+void
+ssh_encode_identity_ssh2(Buffer *b, Key *key, const char *comment)
+{
+        buffer_clear(b);
+        buffer_put_char(b, SSH2_AGENTC_ADD_IDENTITY);
+        buffer_put_cstring(b, key_ssh_name(key));
+        switch(key->type){
+        case KEY_RSA:
+                buffer_put_bignum2(b, key->rsa->n);
+                buffer_put_bignum2(b, key->rsa->e);
+                buffer_put_bignum2(b, key->rsa->d);
+                buffer_put_bignum2(b, key->rsa->iqmp);
+                buffer_put_bignum2(b, key->rsa->p);
+                buffer_put_bignum2(b, key->rsa->q);
+                break;
+        case KEY_DSA:
+                buffer_put_bignum2(b, key->dsa->p);
+                buffer_put_bignum2(b, key->dsa->q);
+                buffer_put_bignum2(b, key->dsa->g);
+                buffer_put_bignum2(b, key->dsa->pub_key);
+                buffer_put_bignum2(b, key->dsa->priv_key);
+                break;
+        }
+        buffer_put_cstring(b, comment);
+}
+
+/*
+ * Adds an identity to the authentication server.  This call is not meant to
+ * be used by normal applications.
+ */
+
+int
+ssh_add_identity(AuthenticationConnection *auth, Key *key, const char *comment)
+{
+        Buffer msg;
+        int type;
+
+        buffer_init(&msg);
+
+        switch (key->type) {
+        case KEY_RSA1:
+                ssh_encode_identity_rsa1(&msg, key->rsa, comment);
+                break;
+        case KEY_RSA:
+        case KEY_DSA:
+                ssh_encode_identity_ssh2(&msg, key, comment);
+                break;
+        default:
+                buffer_free(&msg);
+                return 0;
+                break;
+        }
+        if (ssh_request_reply(auth, &msg, &msg) == 0) {
+                buffer_free(&msg);
+                return 0;
+        }
+        type = buffer_get_char(&msg);
+        buffer_free(&msg);
+        return decode_reply(type);
+}
+
+/*
+ * Removes an identity from the authentication server.  This call is not
+ * meant to be used by normal applications.
+ */
+
+int
+ssh_remove_identity(AuthenticationConnection *auth, Key *key)
+{
+        Buffer msg;
+        int type;
+        u_char *blob;
+        u_int blen;
+
+        buffer_init(&msg);
+
+        if (key->type == KEY_RSA1) {
+                buffer_put_char(&msg, SSH_AGENTC_REMOVE_RSA_IDENTITY);
+                buffer_put_int(&msg, BN_num_bits(key->rsa->n));
+                buffer_put_bignum(&msg, key->rsa->e);
+                buffer_put_bignum(&msg, key->rsa->n);
+        } else if (key->type == KEY_DSA || key->type == KEY_RSA) {
+                key_to_blob(key, &blob, &blen);
+                buffer_put_char(&msg, SSH2_AGENTC_REMOVE_IDENTITY);
+                buffer_put_string(&msg, blob, blen);
+                xfree(blob);
+        } else {
+                buffer_free(&msg);
+                return 0;
+        }
+        if (ssh_request_reply(auth, &msg, &msg) == 0) {
+                buffer_free(&msg);
+                return 0;
+        }
+        type = buffer_get_char(&msg);
+        buffer_free(&msg);
+        return decode_reply(type);
+}
+
+/*
+ * Removes all identities from the agent.  This call is not meant to be used
+ * by normal applications.
+ */
+
+int
+ssh_remove_all_identities(AuthenticationConnection *auth, int version)
+{
+        Buffer msg;
+        int type;
+        int code = (version==1) ?
+                SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES :
+                SSH2_AGENTC_REMOVE_ALL_IDENTITIES;
+
+        buffer_init(&msg);
+        buffer_put_char(&msg, code);
+
+        if (ssh_request_reply(auth, &msg, &msg) == 0) {
+                buffer_free(&msg);
+                return 0;
+        }
+        type = buffer_get_char(&msg);
+        buffer_free(&msg);
+        return decode_reply(type);
+}
+
+int
+decode_reply(int type)
+{
+        switch (type) {
+        case SSH_AGENT_FAILURE:
+        case SSH_COM_AGENT2_FAILURE:
+                log("SSH_AGENT_FAILURE");
+                return 0;
+        case SSH_AGENT_SUCCESS:
+                return 1;
+        default:
+                fatal("Bad response from authentication agent: %d", type);
+        }
+        /* NOTREACHED */
+        return 0;
+}