Initial revision
diff --git a/authfd.c b/authfd.c
new file mode 100644
index 0000000..07893ca
--- /dev/null
+++ b/authfd.c
@@ -0,0 +1,565 @@
+/*
+
+authfd.c
+
+Author: Tatu Ylonen <ylo@cs.hut.fi>
+
+Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ All rights reserved
+
+Created: Wed Mar 29 01:30:28 1995 ylo
+
+Functions for connecting the local authentication agent.
+
+*/
+
+#include "includes.h"
+RCSID("$Id: authfd.c,v 1.1 1999/10/27 03:42:43 damien Exp $");
+
+#include "ssh.h"
+#include "rsa.h"
+#include "authfd.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "xmalloc.h"
+#include "getput.h"
+
+#include <openssl/rsa.h>
+
+/* Returns the number of the authentication fd, or -1 if there is none. */
+
+int
+ssh_get_authentication_socket()
+{
+ const char *authsocket;
+ int sock;
+ 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));
+
+ sock = socket(AF_UNIX, SOCK_STREAM, 0);
+ if (sock < 0)
+ return -1;
+
+ if (connect(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0)
+ {
+ close(sock);
+ return -1;
+ }
+
+ return sock;
+}
+
+/* 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()
+{
+ 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;
+
+ /* Applocate the connection structure and initialize it. */
+ auth = xmalloc(sizeof(*auth));
+ auth->fd = sock;
+ buffer_init(&auth->packet);
+ 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 *ac)
+{
+ buffer_free(&ac->packet);
+ buffer_free(&ac->identities);
+ close(ac->fd);
+ /* Free the connection data structure. */
+ xfree(ac);
+}
+
+/* Returns the first authentication identity held by the agent.
+ Returns true if an identity is available, 0 otherwise.
+ The caller must initialize the integers before the call, and free the
+ comment after a successful call (before calling ssh_get_next_identity). */
+
+int
+ssh_get_first_identity(AuthenticationConnection *auth,
+ int *bitsp, BIGNUM *e, BIGNUM *n, char **comment)
+{
+ unsigned char msg[8192];
+ int len, l;
+
+ /* Send a message to the agent requesting for a list of the identities
+ it can represent. */
+ msg[0] = 0;
+ msg[1] = 0;
+ msg[2] = 0;
+ msg[3] = 1;
+ msg[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
+ if (write(auth->fd, msg, 5) != 5)
+ {
+ error("write auth->fd: %.100s", strerror(errno));
+ return 0;
+ }
+
+ /* Read the length of the response. XXX implement timeouts here. */
+ len = 4;
+ while (len > 0)
+ {
+ l = read(auth->fd, msg + 4 - len, len);
+ if (l <= 0)
+ {
+ error("read auth->fd: %.100s", strerror(errno));
+ return 0;
+ }
+ len -= l;
+ }
+
+ /* Extract the length, and check it for sanity. (We cannot trust
+ authentication agents). */
+ len = GET_32BIT(msg);
+ if (len < 1 || len > 256*1024)
+ fatal("Authentication reply message too long: %d\n", len);
+
+ /* Read the packet itself. */
+ buffer_clear(&auth->identities);
+ while (len > 0)
+ {
+ l = len;
+ if (l > sizeof(msg))
+ l = sizeof(msg);
+ l = read(auth->fd, msg, l);
+ if (l <= 0)
+ fatal("Incomplete authentication reply.");
+ buffer_append(&auth->identities, (char *)msg, l);
+ len -= l;
+ }
+
+ /* Get message type, and verify that we got a proper answer. */
+ buffer_get(&auth->identities, (char *)msg, 1);
+ if (msg[0] != SSH_AGENT_RSA_IDENTITIES_ANSWER)
+ fatal("Bad authentication reply message type: %d", msg[0]);
+
+ /* 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\n", auth->howmany);
+
+ /* Return the first entry (if any). */
+ return ssh_get_next_identity(auth, bitsp, e, n, comment);
+}
+
+/* Returns the next authentication identity for the agent. Other functions
+ can be called between this and ssh_get_first_identity or two calls of this
+ function. This returns 0 if there are no more identities. The caller
+ must free comment after a successful return. */
+
+int
+ssh_get_next_identity(AuthenticationConnection *auth,
+ int *bitsp, BIGNUM *e, BIGNUM *n, char **comment)
+{
+ /* Return failure if no more entries. */
+ if (auth->howmany <= 0)
+ return 0;
+
+ /* Get the next entry from the packet. These will abort with a fatal
+ error if the packet is too short or contains corrupt data. */
+ *bitsp = buffer_get_int(&auth->identities);
+ buffer_get_bignum(&auth->identities, e);
+ buffer_get_bignum(&auth->identities, n);
+ *comment = buffer_get_string(&auth->identities, NULL);
+
+ /* Decrement the number of remaining entries. */
+ auth->howmany--;
+
+ return 1;
+}
+
+/* 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,
+ int bits, BIGNUM *e, BIGNUM *n, BIGNUM *challenge,
+ unsigned char session_id[16],
+ unsigned int response_type,
+ unsigned char response[16])
+{
+ Buffer buffer;
+ unsigned char buf[8192];
+ int len, l, i;
+
+ /* Response type 0 is no longer supported. */
+ if (response_type == 0)
+ fatal("Compatibility with ssh protocol version 1.0 no longer supported.");
+
+ /* Format a message to the agent. */
+ buf[0] = SSH_AGENTC_RSA_CHALLENGE;
+ buffer_init(&buffer);
+ buffer_append(&buffer, (char *)buf, 1);
+ buffer_put_int(&buffer, bits);
+ buffer_put_bignum(&buffer, e);
+ buffer_put_bignum(&buffer, n);
+ buffer_put_bignum(&buffer, challenge);
+ buffer_append(&buffer, (char *)session_id, 16);
+ buffer_put_int(&buffer, response_type);
+
+ /* Get the length of the message, and format it in the buffer. */
+ len = buffer_len(&buffer);
+ PUT_32BIT(buf, len);
+
+ /* Send the length and then the packet to the agent. */
+ if (write(auth->fd, buf, 4) != 4 ||
+ write(auth->fd, buffer_ptr(&buffer), buffer_len(&buffer)) !=
+ buffer_len(&buffer))
+ {
+ error("Error writing to authentication socket.");
+ error_cleanup:
+ buffer_free(&buffer);
+ 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 <= 0)
+ {
+ error("Error reading response length from authentication socket.");
+ goto error_cleanup;
+ }
+ 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 tothe buffer. */
+ buffer_clear(&buffer);
+ while (len > 0)
+ {
+ l = len;
+ if (l > sizeof(buf))
+ l = sizeof(buf);
+ l = read(auth->fd, buf, l);
+ if (l <= 0)
+ {
+ error("Error reading response from authentication socket.");
+ goto error_cleanup;
+ }
+ buffer_append(&buffer, (char *)buf, l);
+ len -= l;
+ }
+
+ /* Get the type of the packet. */
+ buffer_get(&buffer, (char *)buf, 1);
+
+ /* Check for agent failure message. */
+ if (buf[0] == SSH_AGENT_FAILURE)
+ {
+ log("Agent admitted failure to authenticate using the key.");
+ goto error_cleanup;
+ }
+
+ /* Now it must be an authentication response packet. */
+ if (buf[0] != SSH_AGENT_RSA_RESPONSE)
+ fatal("Bad authentication response: %d", buf[0]);
+
+ /* 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);
+
+ /* The buffer containing the packet is no longer needed. */
+ buffer_free(&buffer);
+
+ /* Correct answer. */
+ return 1;
+}
+
+/* Adds an identity to the authentication server. This call is not meant to
+ be used by normal applications. */
+
+int ssh_add_identity(AuthenticationConnection *auth,
+ RSA *key, const char *comment)
+{
+ Buffer buffer;
+ unsigned char buf[8192];
+ int len, l, type;
+
+ /* Format a message to the agent. */
+ buffer_init(&buffer);
+ buffer_put_char(&buffer, SSH_AGENTC_ADD_RSA_IDENTITY);
+ buffer_put_int(&buffer, BN_num_bits(key->n));
+ buffer_put_bignum(&buffer, key->n);
+ buffer_put_bignum(&buffer, key->e);
+ buffer_put_bignum(&buffer, key->d);
+ /* To keep within the protocol: p < q for ssh. in SSL p > q */
+ buffer_put_bignum(&buffer, key->iqmp); /* ssh key->u */
+ buffer_put_bignum(&buffer, key->q); /* ssh key->p, SSL key->q */
+ buffer_put_bignum(&buffer, key->p); /* ssh key->q, SSL key->p */
+ buffer_put_string(&buffer, comment, strlen(comment));
+
+ /* Get the length of the message, and format it in the buffer. */
+ len = buffer_len(&buffer);
+ PUT_32BIT(buf, len);
+
+ /* Send the length and then the packet to the agent. */
+ if (write(auth->fd, buf, 4) != 4 ||
+ write(auth->fd, buffer_ptr(&buffer), buffer_len(&buffer)) !=
+ buffer_len(&buffer))
+ {
+ error("Error writing to authentication socket.");
+ error_cleanup:
+ buffer_free(&buffer);
+ 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 <= 0)
+ {
+ error("Error reading response length from authentication socket.");
+ goto error_cleanup;
+ }
+ len -= l;
+ }
+
+ /* Extract the length, and check it for sanity. */
+ len = GET_32BIT(buf);
+ if (len > 256*1024)
+ fatal("Add identity response too long: %d", len);
+
+ /* Read the rest of the response in tothe buffer. */
+ buffer_clear(&buffer);
+ while (len > 0)
+ {
+ l = len;
+ if (l > sizeof(buf))
+ l = sizeof(buf);
+ l = read(auth->fd, buf, l);
+ if (l <= 0)
+ {
+ error("Error reading response from authentication socket.");
+ goto error_cleanup;
+ }
+ buffer_append(&buffer, (char *)buf, l);
+ len -= l;
+ }
+
+ /* Get the type of the packet. */
+ type = buffer_get_char(&buffer);
+ switch (type)
+ {
+ case SSH_AGENT_FAILURE:
+ buffer_free(&buffer);
+ return 0;
+ case SSH_AGENT_SUCCESS:
+ buffer_free(&buffer);
+ return 1;
+ default:
+ fatal("Bad response to add identity from authentication agent: %d",
+ type);
+ }
+ /*NOTREACHED*/
+ return 0;
+}
+
+/* Removes an identity from the authentication server. This call is not meant
+ to be used by normal applications. */
+
+int ssh_remove_identity(AuthenticationConnection *auth, RSA *key)
+{
+ Buffer buffer;
+ unsigned char buf[8192];
+ int len, l, type;
+
+ /* Format a message to the agent. */
+ buffer_init(&buffer);
+ buffer_put_char(&buffer, SSH_AGENTC_REMOVE_RSA_IDENTITY);
+ buffer_put_int(&buffer, BN_num_bits(key->n));
+ buffer_put_bignum(&buffer, key->e);
+ buffer_put_bignum(&buffer, key->n);
+
+ /* Get the length of the message, and format it in the buffer. */
+ len = buffer_len(&buffer);
+ PUT_32BIT(buf, len);
+
+ /* Send the length and then the packet to the agent. */
+ if (write(auth->fd, buf, 4) != 4 ||
+ write(auth->fd, buffer_ptr(&buffer), buffer_len(&buffer)) !=
+ buffer_len(&buffer))
+ {
+ error("Error writing to authentication socket.");
+ error_cleanup:
+ buffer_free(&buffer);
+ 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 <= 0)
+ {
+ error("Error reading response length from authentication socket.");
+ goto error_cleanup;
+ }
+ len -= l;
+ }
+
+ /* Extract the length, and check it for sanity. */
+ len = GET_32BIT(buf);
+ if (len > 256*1024)
+ fatal("Remove identity response too long: %d", len);
+
+ /* Read the rest of the response in tothe buffer. */
+ buffer_clear(&buffer);
+ while (len > 0)
+ {
+ l = len;
+ if (l > sizeof(buf))
+ l = sizeof(buf);
+ l = read(auth->fd, buf, l);
+ if (l <= 0)
+ {
+ error("Error reading response from authentication socket.");
+ goto error_cleanup;
+ }
+ buffer_append(&buffer, (char *)buf, l);
+ len -= l;
+ }
+
+ /* Get the type of the packet. */
+ type = buffer_get_char(&buffer);
+ switch (type)
+ {
+ case SSH_AGENT_FAILURE:
+ buffer_free(&buffer);
+ return 0;
+ case SSH_AGENT_SUCCESS:
+ buffer_free(&buffer);
+ return 1;
+ default:
+ fatal("Bad response to remove identity from authentication agent: %d",
+ type);
+ }
+ /*NOTREACHED*/
+ return 0;
+}
+
+/* Removes all identities from the agent. This call is not meant
+ to be used by normal applications. */
+
+int ssh_remove_all_identities(AuthenticationConnection *auth)
+{
+ Buffer buffer;
+ unsigned char buf[8192];
+ int len, l, type;
+
+ /* Get the length of the message, and format it in the buffer. */
+ PUT_32BIT(buf, 1);
+ buf[4] = SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES;
+
+ /* Send the length and then the packet to the agent. */
+ if (write(auth->fd, buf, 5) != 5)
+ {
+ 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 <= 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("Remove identity response too long: %d", len);
+
+ /* Read the rest of the response into the buffer. */
+ buffer_init(&buffer);
+ while (len > 0)
+ {
+ l = len;
+ if (l > sizeof(buf))
+ l = sizeof(buf);
+ l = read(auth->fd, buf, l);
+ if (l <= 0)
+ {
+ error("Error reading response from authentication socket.");
+ buffer_free(&buffer);
+ return 0;
+ }
+ buffer_append(&buffer, (char *)buf, l);
+ len -= l;
+ }
+
+ /* Get the type of the packet. */
+ type = buffer_get_char(&buffer);
+ switch (type)
+ {
+ case SSH_AGENT_FAILURE:
+ buffer_free(&buffer);
+ return 0;
+ case SSH_AGENT_SUCCESS:
+ buffer_free(&buffer);
+ return 1;
+ default:
+ fatal("Bad response to remove identity from authentication agent: %d",
+ type);
+ }
+ /*NOTREACHED*/
+ return 0;
+}