Exemple #1
0
int hashbufout_add_cookie(ssh_session session) {
  session->out_hashbuf = ssh_buffer_new();
  if (session->out_hashbuf == NULL) {
    return -1;
  }

  if (buffer_add_u8(session->out_hashbuf, 20) < 0) {
    buffer_reinit(session->out_hashbuf);
    return -1;
  }

  if (session->server) {
    if (buffer_add_data(session->out_hashbuf,
          session->server_kex.cookie, 16) < 0) {
      buffer_reinit(session->out_hashbuf);
      return -1;
    }
  } else {
    if (buffer_add_data(session->out_hashbuf,
          session->client_kex.cookie, 16) < 0) {
      buffer_reinit(session->out_hashbuf);
      return -1;
    }
  }

  return 0;
}
Exemple #2
0
int channel_write1(ssh_channel channel, const void *data, int len) {
  ssh_session session = channel->session;
  int origlen = len;
  int effectivelen;
  const unsigned char *ptr=data;
  while (len > 0) {
    if (buffer_add_u8(session->out_buffer, SSH_CMSG_STDIN_DATA) < 0) {
      return -1;
    }

    effectivelen = len > 32000 ? 32000 : len;

    if (buffer_add_u32(session->out_buffer, htonl(effectivelen)) < 0 ||
        buffer_add_data(session->out_buffer, ptr, effectivelen) < 0) {
      return -1;
    }

    ptr += effectivelen;
    len -= effectivelen;

    if (packet_send(session) != SSH_OK) {
      return -1;
    }
  }

  return origlen;
}
int channel_write1(ssh_channel channel, const void *data, int len) {
  ssh_session session;
  int origlen = len;
  int effectivelen;
  const unsigned char *ptr=data;

  if (channel == NULL) {
    return -1;
  }
  session = channel->session;

  while (len > 0) {
    if (buffer_add_u8(session->out_buffer, SSH_CMSG_STDIN_DATA) < 0) {
      return -1;
    }

    effectivelen = len > 32000 ? 32000 : len;

    if (buffer_add_u32(session->out_buffer, htonl(effectivelen)) < 0 ||
        buffer_add_data(session->out_buffer, ptr, effectivelen) < 0) {
      return -1;
    }

    ptr += effectivelen;
    len -= effectivelen;

    if (packet_send(session) == SSH_ERROR) {
      return -1;
    }
    ssh_handle_packets(session, SSH_TIMEOUT_NONBLOCKING);
  }
  if (ssh_blocking_flush(session,SSH_TIMEOUT_USER) == SSH_ERROR)
      return -1;
  return origlen;
}
Exemple #4
0
PUBLIC_KEY *publickey_from_string(SSH_SESSION *session, STRING *pubkey_s){
    BUFFER *tmpbuf=buffer_new();
    STRING *type_s;
    char *type;

    buffer_add_data(tmpbuf,pubkey_s->string,string_len(pubkey_s));
    type_s=buffer_get_ssh_string(tmpbuf);
    if(!type_s){
        buffer_free(tmpbuf);
        ssh_set_error(session,SSH_FATAL,"Invalid public key format");
        return NULL;
    }
    type=string_to_char(type_s);
    free(type_s);
    if(!strcmp(type,"ssh-dss")){
        free(type);
        return publickey_make_dss(session, tmpbuf);
    }
    if(!strcmp(type,"ssh-rsa")){
        free(type);
        return publickey_make_rsa(session, tmpbuf,"ssh-rsa");
    }
    if(!strcmp(type,"ssh-rsa1")){
        free(type);
        return publickey_make_rsa(session, tmpbuf,"ssh-rsa1");
    }
    ssh_set_error(session,SSH_FATAL,"unknown public key protocol %s",type);
    buffer_free(tmpbuf);
    free(type);
    return NULL;
}
Exemple #5
0
static int agent_talk(struct ssh_session_struct *session,
    struct ssh_buffer_struct *request, struct ssh_buffer_struct *reply) {
  uint32_t len = 0;
  uint8_t payload[1024] = {0};

  len = buffer_get_len(request);
  ssh_log(session, SSH_LOG_PACKET, "agent_talk - len of request: %u", len);
  agent_put_u32(payload, len);

  /* send length and then the request packet */
  if (atomicio(session->agent->sock, payload, 4, 0) == 4) {
    if (atomicio(session->agent->sock, buffer_get_rest(request), len, 0)
        != len) {
      ssh_log(session, SSH_LOG_PACKET, "atomicio sending request failed: %s",
          strerror(errno));
      return -1;
    }
  } else {
    ssh_log(session, SSH_LOG_PACKET,
        "atomicio sending request length failed: %s",
        strerror(errno));
    return -1;
  }

  /* wait for response, read the length of the response packet */
  if (atomicio(session->agent->sock, payload, 4, 1) != 4) {
    ssh_log(session, SSH_LOG_PACKET, "atomicio read response length failed: %s",
        strerror(errno));
    return -1;
  }

  len = agent_get_u32(payload);
  if (len > 256 * 1024) {
    ssh_set_error(session, SSH_FATAL,
        "Authentication response too long: %u", len);
    return -1;
  }
  ssh_log(session, SSH_LOG_PACKET, "agent_talk - response length: %u", len);

  while (len > 0) {
    size_t n = len;
    if (n > sizeof(payload)) {
      n = sizeof(payload);
    }
    if (atomicio(session->agent->sock, payload, n, 1) != n) {
      ssh_log(session, SSH_LOG_RARE,
          "Error reading response from authentication socket.");
      return -1;
    }
    if (buffer_add_data(reply, payload, n) < 0) {
      ssh_log(session, SSH_LOG_FUNCTIONS,
          "Not enough space");
      return -1;
    }
    len -= n;
  }

  return 0;
}
Exemple #6
0
/* this function only sends the predefined set of kex methods */
int ssh_send_kex(ssh_session session, int server_kex) {
  struct ssh_kex_struct *kex = (server_kex ? &session->next_crypto->server_kex :
      &session->next_crypto->client_kex);
  ssh_string str = NULL;
  int i;

  enter_function();

  if (buffer_add_u8(session->out_buffer, SSH2_MSG_KEXINIT) < 0) {
    goto error;
  }
  if (buffer_add_data(session->out_buffer, kex->cookie, 16) < 0) {
    goto error;
  }

  if (hashbufout_add_cookie(session) < 0) {
    goto error;
  }

  ssh_list_kex(session, kex);

  for (i = 0; i < KEX_METHODS_SIZE; i++) {
    str = ssh_string_from_char(kex->methods[i]);
    if (str == NULL) {
      goto error;
    }

    if (buffer_add_ssh_string(session->out_hashbuf, str) < 0) {
      goto error;
    }
    if (buffer_add_ssh_string(session->out_buffer, str) < 0) {
      goto error;
    }
    ssh_string_free(str);
  }

  if (buffer_add_u8(session->out_buffer, 0) < 0) {
    goto error;
  }
  if (buffer_add_u32(session->out_buffer, 0) < 0) {
    goto error;
  }

  if (packet_send(session) == SSH_ERROR) {
    leave_function();
    return -1;
  }

  leave_function();
  return 0;
error:
  buffer_reinit(session->out_buffer);
  buffer_reinit(session->out_hashbuf);
  ssh_string_free(str);

  leave_function();
  return -1;
}
Exemple #7
0
/* this function only sends the predefined set of kex methods */
int ssh_send_kex(SSH_SESSION *session, int server_kex) {
  KEX *kex = (server_kex ? &session->server_kex : &session->client_kex);
  STRING *str = NULL;
  int i;

  enter_function();

  if (buffer_add_u8(session->out_buffer, SSH2_MSG_KEXINIT) < 0) {
    goto error;
  }
  if (buffer_add_data(session->out_buffer, kex->cookie, 16) < 0) {
    goto error;
  }

  if (hashbufout_add_cookie(session) < 0) {
    goto error;
  }

  ssh_list_kex(session, kex);

  for (i = 0; i < 10; i++) {
    str = string_from_char(kex->methods[i]);
    if (str == NULL) {
      goto error;
    }

    if (buffer_add_ssh_string(session->out_hashbuf, str) < 0) {
      goto error;
    }
    if (buffer_add_ssh_string(session->out_buffer, str) < 0) {
      goto error;
    }
    string_free(str);
  }

  if (buffer_add_u8(session->out_buffer, 0) < 0) {
    goto error;
  }
  if (buffer_add_u32(session->out_buffer, 0) < 0) {
    goto error;
  }

  if (packet_send(session) != SSH_OK) {
    leave_function();
    return -1;
  }

  leave_function();
  return 0;
error:
  buffer_free(session->out_buffer);
  buffer_free(session->out_hashbuf);
  string_free(str);

  leave_function();
  return -1;
}
Exemple #8
0
/*
 * Test if the continuously growing buffer size never exceeds 2 time its
 * real capacity, when we remove 1 byte after each call (sliding window)
 */
static void torture_growing_buffer_shifting(void **state) {
    ssh_buffer buffer = *state;
    int i;
    unsigned char c;
    for(i=0; i<1024; ++i) {
        buffer_add_data(buffer,"S",1);
    }
    for(i=0; i<LIMIT; ++i) {
        buffer_get_u8(buffer,&c);
        buffer_add_data(buffer,"A",1);
        if(buffer->used >= 128) {
            if(buffer_get_rest_len(buffer) * 4 < buffer->allocated) {
                assert_true(buffer_get_rest_len(buffer) * 4 >= buffer->allocated);
                return;
            }
        }
    }
}
int sftp_reply_data(SFTP_CLIENT_MESSAGE *msg, void *data, int len) {
    BUFFER *out=buffer_new();
    int r;
    buffer_add_u32(out,msg->id);
    buffer_add_u32(out,ntohl(len));
    buffer_add_data(out,data,len);
    r=sftp_packet_write(msg->sftp,SSH_FXP_DATA,out);
    buffer_free(out);
    return r<0;
}
Exemple #10
0
/** \internal
 * \brief buffered write of data
 * \returns SSH_OK, or SSH_ERROR
 * \warning has no effect on socket before a flush
 */
int ssh_socket_write(ssh_socket s, const void *buffer, int len) {
  if(len > 0) {
    if (buffer_add_data(s->out_buffer, buffer, len) < 0) {
      ssh_set_error_oom(s->session);
      return SSH_ERROR;
    }
    ssh_socket_nonblocking_flush(s);
  }

  return SSH_OK;
}
Exemple #11
0
/*
 * Test if the continuously growing buffer size never exceeds 2 time its
 * real capacity
 */
static void torture_growing_buffer(void **state) {
    ssh_buffer buffer = *state;
    int i;

    for(i=0; i<LIMIT; ++i) {
        buffer_add_data(buffer,"A",1);
        if(buffer->used >= 128) {
            if(buffer_get_rest_len(buffer) * 2 < buffer->allocated) {
                assert_true(buffer_get_rest_len(buffer) * 2 >= buffer->allocated);
            }
        }
    }
}
int sftp_reply_names(SFTP_CLIENT_MESSAGE *msg) {
    BUFFER *out=buffer_new();
    int r;
    buffer_add_u32(out,msg->id);
    buffer_add_u32(out,htonl(msg->attr_num));
    buffer_add_data(out,buffer_get(msg->attrbuf),
                    buffer_get_len(msg->attrbuf));
    r=sftp_packet_write(msg->sftp,SSH_FXP_NAME,out);
    buffer_free(out);
    buffer_free(msg->attrbuf);
    msg->attr_num=0;
    msg->attrbuf=NULL;
    return r<0;
}
Exemple #13
0
static ssh_buffer gzip_decompress(ssh_session session, ssh_buffer source, size_t maxlen) {
    z_stream *zin = session->current_crypto->compress_in_ctx;
    void *in_ptr = buffer_get_rest(source);
    unsigned long in_size = buffer_get_rest_len(source);
    unsigned char out_buf[BLOCKSIZE] = {0};
    ssh_buffer dest = NULL;
    unsigned long len;
    int status;

    if (zin == NULL) {
        zin = session->current_crypto->compress_in_ctx = initdecompress(session);
        if (zin == NULL) {
            return NULL;
        }
    }

    dest = ssh_buffer_new();
    if (dest == NULL) {
        return NULL;
    }

    zin->next_out = out_buf;
    zin->next_in = in_ptr;
    zin->avail_in = in_size;

    do {
        zin->avail_out = BLOCKSIZE;
        status = inflate(zin, Z_PARTIAL_FLUSH);
        if (status != Z_OK && status != Z_BUF_ERROR) {
            ssh_set_error(session, SSH_FATAL,
                          "status %d inflating zlib packet", status);
            ssh_buffer_free(dest);
            return NULL;
        }

        len = BLOCKSIZE - zin->avail_out;
        if (buffer_add_data(dest,out_buf,len) < 0) {
            ssh_buffer_free(dest);
            return NULL;
        }
        if (buffer_get_rest_len(dest) > maxlen) {
            /* Size of packet exceeded, avoid a denial of service attack */
            ssh_buffer_free(dest);
            return NULL;
        }
        zin->next_out = out_buf;
    } while (zin->avail_out == 0);

    return dest;
}
/*
 * When data has been received from the ssh server, it can be applied to the
 * known user function, with help of the callback, or inserted here
 *
 * FIXME is the window changed?
 */
int channel_default_bufferize(CHANNEL *channel, void *data, int len,
    int is_stderr) {
  struct ssh_session *session = channel->session;

  ssh_log(session, SSH_LOG_RARE,
      "placing %d bytes into channel buffer (stderr=%d)", len, is_stderr);
  if (is_stderr == 0) {
    /* stdout */
    if (channel->stdout_buffer == NULL) {
      channel->stdout_buffer = buffer_new();
      if (channel->stdout_buffer == NULL) {
        return -1;
      }
    }

    if (buffer_add_data(channel->stdout_buffer, data, len) < 0) {
      buffer_free(channel->stdout_buffer);
      return -1;
    }
  } else {
    /* stderr */
    if (channel->stderr_buffer == NULL) {
      channel->stderr_buffer = buffer_new();
      if (channel->stderr_buffer == NULL) {
        return -1;
      }
    }

    if (buffer_add_data(channel->stderr_buffer, data, len) < 0) {
      buffer_free(channel->stderr_buffer);
      return -1;
    }
  }

  return 0;
}
Exemple #15
0
static int ssh_gssapi_send_mic(ssh_session session){
    OM_uint32 maj_stat, min_stat;
    gss_buffer_desc mic_buf = GSS_C_EMPTY_BUFFER;
    gss_buffer_desc mic_token_buf = GSS_C_EMPTY_BUFFER;
    ssh_buffer mic_buffer;
    int rc;

    SSH_LOG(SSH_LOG_PACKET,"Sending SSH_MSG_USERAUTH_GSSAPI_MIC");

    mic_buffer = ssh_gssapi_build_mic(session);
    if (mic_buffer == NULL) {
        ssh_set_error_oom(session);
        return SSH_ERROR;
    }
    mic_buf.length = ssh_buffer_get_len(mic_buffer);
    mic_buf.value = ssh_buffer_get_begin(mic_buffer);

    maj_stat = gss_get_mic(&min_stat,session->gssapi->ctx, GSS_C_QOP_DEFAULT, &mic_buf, &mic_token_buf);
    if (GSS_ERROR(maj_stat)){
        ssh_buffer_free(mic_buffer);
        ssh_gssapi_log_error(0, "generating MIC", maj_stat);
        return SSH_ERROR;
    }

    rc = buffer_add_u8(session->out_buffer, SSH2_MSG_USERAUTH_GSSAPI_MIC);
    if (rc < 0) {
        ssh_buffer_free(mic_buffer);
        ssh_set_error_oom(session);
        return SSH_ERROR;
    }

    rc = buffer_add_u32(session->out_buffer, htonl(mic_token_buf.length));
    if (rc < 0) {
        ssh_buffer_free(mic_buffer);
        ssh_set_error_oom(session);
        return SSH_ERROR;
    }

    rc = buffer_add_data(session->out_buffer, mic_token_buf.value, mic_token_buf.length);
    ssh_buffer_free(mic_buffer);
    if (rc < 0) {
        ssh_set_error_oom(session);
        return SSH_ERROR;
    }

    return packet_send(session);
}
Exemple #16
0
int hashbufin_add_cookie(ssh_session session, unsigned char *cookie) {
  session->in_hashbuf = ssh_buffer_new();
  if (session->in_hashbuf == NULL) {
    return -1;
  }

  if (buffer_add_u8(session->in_hashbuf, 20) < 0) {
    buffer_reinit(session->in_hashbuf);
    return -1;
  }
  if (buffer_add_data(session->in_hashbuf,cookie, 16) < 0) {
    buffer_reinit(session->in_hashbuf);
    return -1;
  }

  return 0;
}
Exemple #17
0
PUBLIC_KEY *publickey_from_string(SSH_SESSION *session, STRING *pubkey_s) {
  BUFFER *tmpbuf = NULL;
  STRING *type_s = NULL;
  char *type_c = NULL;
  int type;

  tmpbuf = buffer_new();
  if (tmpbuf == NULL) {
    return NULL;
  }

  if (buffer_add_data(tmpbuf, pubkey_s->string, string_len(pubkey_s)) < 0) {
    goto error;
  }

  type_s = buffer_get_ssh_string(tmpbuf);
  if (type_s == NULL) {
    ssh_set_error(session,SSH_FATAL,"Invalid public key format");
    goto error;
  }

  type_c = string_to_char(type_s);
  string_free(type_s);
  if (type_c == NULL) {
    goto error;
  }

  type = ssh_type_from_name(type_c);
  SAFE_FREE(type_c);

  switch (type) {
    case TYPE_DSS:
      return publickey_make_dss(session, tmpbuf);
    case TYPE_RSA:
    case TYPE_RSA1:
      return publickey_make_rsa(session, tmpbuf, type);
  }

  ssh_set_error(session, SSH_FATAL, "Unknown public key protocol %s",
      ssh_type_to_char(type));

error:
  buffer_free(tmpbuf);
  return NULL;
}
Exemple #18
0
ssh_public_key publickey_from_string(ssh_session session, ssh_string pubkey_s) {
    ssh_buffer tmpbuf = NULL;
    ssh_string type_s = NULL;
    char *type_c = NULL;
    int type;

    tmpbuf = ssh_buffer_new();
    if (tmpbuf == NULL) {
        return NULL;
    }

    if (buffer_add_data(tmpbuf, ssh_string_data(pubkey_s), ssh_string_len(pubkey_s)) < 0) {
        goto error;
    }

    type_s = buffer_get_ssh_string(tmpbuf);
    if (type_s == NULL) {
        ssh_set_error(session,SSH_FATAL,"Invalid public key format");
        goto error;
    }

    type_c = ssh_string_to_char(type_s);
    ssh_string_free(type_s);
    if (type_c == NULL) {
        goto error;
    }

    type = ssh_type_from_name(type_c);
    SAFE_FREE(type_c);

    switch (type) {
    case SSH_KEYTYPE_DSS:
        return publickey_make_dss(session, tmpbuf);
    case SSH_KEYTYPE_RSA:
    case SSH_KEYTYPE_RSA1:
        return publickey_make_rsa(session, tmpbuf, type);
    }

    ssh_set_error(session, SSH_FATAL, "Unknown public key protocol %s",
                  ssh_type_to_char(type));

error:
    ssh_buffer_free(tmpbuf);
    return NULL;
}
Exemple #19
0
static ssh_buffer gzip_compress(ssh_session session,ssh_buffer source,int level) {
    z_stream *zout = session->current_crypto->compress_out_ctx;
    void *in_ptr = buffer_get_rest(source);
    unsigned long in_size = buffer_get_rest_len(source);
    ssh_buffer dest = NULL;
    unsigned char out_buf[BLOCKSIZE] = {0};
    unsigned long len;
    int status;

    if(zout == NULL) {
        zout = session->current_crypto->compress_out_ctx = initcompress(session, level);
        if (zout == NULL) {
            return NULL;
        }
    }

    dest = ssh_buffer_new();
    if (dest == NULL) {
        return NULL;
    }

    zout->next_out = out_buf;
    zout->next_in = in_ptr;
    zout->avail_in = in_size;
    do {
        zout->avail_out = BLOCKSIZE;
        status = deflate(zout, Z_PARTIAL_FLUSH);
        if (status != Z_OK) {
            ssh_buffer_free(dest);
            ssh_set_error(session, SSH_FATAL,
                          "status %d deflating zlib packet", status);
            return NULL;
        }
        len = BLOCKSIZE - zout->avail_out;
        if (buffer_add_data(dest, out_buf, len) < 0) {
            ssh_buffer_free(dest);
            return NULL;
        }
        zout->next_out = out_buf;
    } while (zout->avail_out == 0);

    return dest;
}
Exemple #20
0
/* this function only sends the predefined set of kex methods */    
void ssh_send_kex(SSH_SESSION *session, int server_kex){
    STRING *str;
    int i=0;
    KEX *kex=(server_kex ? &session->server_kex : &session->client_kex);
    packet_clear_out(session);
    buffer_add_u8(session->out_buffer,SSH2_MSG_KEXINIT);
    buffer_add_data(session->out_buffer,kex->cookie,16);
    hashbufout_add_cookie(session);
    ssh_list_kex(kex);
    for(i=0;i<10;i++){
        str=string_from_char(kex->methods[i]);
        buffer_add_ssh_string(session->out_hashbuf,str);
        buffer_add_ssh_string(session->out_buffer,str);
        free(str);
    }
    i=0;
    buffer_add_u8(session->out_buffer,0);
    buffer_add_u32(session->out_buffer,0);
    packet_send(session);
}
Exemple #21
0
int compress_buffer(ssh_session session, ssh_buffer buf) {
    ssh_buffer dest = NULL;

    dest = gzip_compress(session, buf, session->compressionlevel);
    if (dest == NULL) {
        return -1;
    }

    if (buffer_reinit(buf) < 0) {
        ssh_buffer_free(dest);
        return -1;
    }

    if (buffer_add_data(buf, buffer_get_rest(dest), buffer_get_rest_len(dest)) < 0) {
        ssh_buffer_free(dest);
        return -1;
    }

    ssh_buffer_free(dest);
    return 0;
}
Exemple #22
0
int decompress_buffer(ssh_session session,ssh_buffer buf, size_t maxlen) {
    ssh_buffer dest = NULL;

    dest = gzip_decompress(session,buf, maxlen);
    if (dest == NULL) {
        return -1;
    }

    if (buffer_reinit(buf) < 0) {
        ssh_buffer_free(dest);
        return -1;
    }

    if (buffer_add_data(buf, buffer_get_rest(dest), buffer_get_rest_len(dest)) < 0) {
        ssh_buffer_free(dest);
        return -1;
    }

    ssh_buffer_free(dest);
    return 0;
}
Exemple #23
0
/*
 * Test the behavior of buffer_prepend_data
 */
static void torture_buffer_prepend(void **state) {
    ssh_buffer buffer = *state;
    uint32_t v;
    buffer_add_data(buffer,"abcdef",6);
    buffer_prepend_data(buffer,"xyz",3);
    assert_int_equal(buffer_get_rest_len(buffer),9);
    assert_int_equal(memcmp(buffer_get_rest(buffer), "xyzabcdef", 9), 0);
// Now remove 4 bytes and see if we can replace them
    buffer_get_u32(buffer,&v);
    assert_int_equal(buffer_get_rest_len(buffer),5);
    assert_int_equal(memcmp(buffer_get_rest(buffer), "bcdef", 5), 0);
    buffer_prepend_data(buffer,"aris",4);
    assert_int_equal(buffer_get_rest_len(buffer),9);
    assert_int_equal(memcmp(buffer_get_rest(buffer), "arisbcdef", 9), 0);
    /* same thing but we add 5 bytes now */
    buffer_get_u32(buffer,&v);
    assert_int_equal(buffer_get_rest_len(buffer),5);
    assert_int_equal(memcmp(buffer_get_rest(buffer), "bcdef", 5), 0);
    buffer_prepend_data(buffer,"12345",5);
    assert_int_equal(buffer_get_rest_len(buffer),10);
    assert_int_equal(memcmp(buffer_get_rest(buffer), "12345bcdef", 10), 0);

}
Exemple #24
0
int ssh_get_kex1(SSH_SESSION *session) {
  STRING *server_exp = NULL;
  STRING *server_mod = NULL;
  STRING *host_exp = NULL;
  STRING *host_mod = NULL;
  STRING *serverkey = NULL;
  STRING *hostkey = NULL;
  STRING *enc_session = NULL;
  PUBLIC_KEY *srv = NULL;
  PUBLIC_KEY *host = NULL;
  u32 server_bits;
  u32 host_bits;
  u32 protocol_flags;
  u32 supported_ciphers_mask;
  u32 supported_authentications_mask;
  u16 bits;
  int rc = -1;
  int ko;

  enter_function();
  ssh_log(session, SSH_LOG_PROTOCOL, "Waiting for a SSH_SMSG_PUBLIC_KEY");
  if (packet_wait(session, SSH_SMSG_PUBLIC_KEY, 1) != SSH_OK) {
    leave_function();
    return -1;
  }

  ssh_log(session, SSH_LOG_PROTOCOL, "Got a SSH_SMSG_PUBLIC_KEY");
  if (buffer_get_data(session->in_buffer, session->server_kex.cookie, 8) != 8) {
    ssh_set_error(session, SSH_FATAL, "Can't get cookie in buffer");
    leave_function();
    return -1;
  }

  buffer_get_u32(session->in_buffer, &server_bits);
  server_exp = buffer_get_mpint(session->in_buffer);
  if (server_exp == NULL) {
    goto error;
  }
  server_mod = buffer_get_mpint(session->in_buffer);
  if (server_mod == NULL) {
    goto error;
  }
  buffer_get_u32(session->in_buffer, &host_bits);
  host_exp = buffer_get_mpint(session->in_buffer);
  if (host_exp == NULL) {
    goto error;
  }
  host_mod = buffer_get_mpint(session->in_buffer);
  if (host_mod == NULL) {
    goto error;
  }
  buffer_get_u32(session->in_buffer, &protocol_flags);
  buffer_get_u32(session->in_buffer, &supported_ciphers_mask);
  ko = buffer_get_u32(session->in_buffer, &supported_authentications_mask);

  if ((ko != sizeof(u32)) || !host_mod || !host_exp
      || !server_mod || !server_exp) {
    ssh_log(session, SSH_LOG_RARE, "Invalid SSH_SMSG_PUBLIC_KEY packet");
    ssh_set_error(session, SSH_FATAL, "Invalid SSH_SMSG_PUBLIC_KEY packet");
    goto error;
  }

  server_bits = ntohl(server_bits);
  host_bits = ntohl(host_bits);
  protocol_flags = ntohl(protocol_flags);
  supported_ciphers_mask = ntohl(supported_ciphers_mask);
  supported_authentications_mask = ntohl(supported_authentications_mask);
  ssh_log(session, SSH_LOG_PROTOCOL,
      "Server bits: %d; Host bits: %d; Protocol flags: %.8lx; "
      "Cipher mask: %.8lx; Auth mask: %.8lx",
      server_bits,
      host_bits,
      (unsigned long int) protocol_flags,
      (unsigned long int) supported_ciphers_mask,
      (unsigned long int) supported_authentications_mask);

  serverkey = make_rsa1_string(server_exp, server_mod);
  if (serverkey == NULL) {
    goto error;
  }
  hostkey = make_rsa1_string(host_exp,host_mod);
  if (serverkey == NULL) {
    goto error;
  }
  if (build_session_id1(session, server_mod, host_mod) < 0) {
    goto error;
  }

  srv = publickey_from_string(session, serverkey);
  if (srv == NULL) {
    goto error;
  }
  host = publickey_from_string(session, hostkey);
  if (host == NULL) {
    goto error;
  }

  session->next_crypto->server_pubkey = string_copy(hostkey);
  if (session->next_crypto->server_pubkey == NULL) {
    goto error;
  }
  session->next_crypto->server_pubkey_type = "ssh-rsa1";

  /* now, we must choose an encryption algo */
  /* hardcode 3des */
  if (!(supported_ciphers_mask & (1 << SSH_CIPHER_3DES))) {
    ssh_set_error(session, SSH_FATAL, "Remote server doesn't accept 3DES");
    goto error;
  }

  ssh_log(session, SSH_LOG_PROTOCOL, "Sending SSH_CMSG_SESSION_KEY");

  if (buffer_add_u8(session->out_buffer, SSH_CMSG_SESSION_KEY) < 0) {
    goto error;
  }
  if (buffer_add_u8(session->out_buffer, SSH_CIPHER_3DES) < 0) {
    goto error;
  }
  if (buffer_add_data(session->out_buffer, session->server_kex.cookie, 8) < 0) {
    goto error;
  }

  enc_session = encrypt_session_key(session, srv, host, server_bits, host_bits);
  if (enc_session == NULL) {
    goto error;
  }

  bits = string_len(enc_session) * 8 - 7;
  ssh_log(session, SSH_LOG_PROTOCOL, "%d bits, %zu bytes encrypted session",
      bits, string_len(enc_session));
  bits = htons(bits);
  /* the encrypted mpint */
  if (buffer_add_data(session->out_buffer, &bits, sizeof(u16)) < 0) {
    goto error;
  }
  if (buffer_add_data(session->out_buffer, enc_session->string,
        string_len(enc_session)) < 0) {
    goto error;
  }
  /* the protocol flags */
  if (buffer_add_u32(session->out_buffer, 0) < 0) {
    goto error;
  }

  if (packet_send(session) != SSH_OK) {
    goto error;
  }

  /* we can set encryption */
  if (crypt_set_algorithms(session)) {
    goto error;
  }

  session->current_crypto = session->next_crypto;
  session->next_crypto = NULL;

  ssh_log(session, SSH_LOG_PROTOCOL, "Waiting for a SSH_SMSG_SUCCESS");
  if (packet_wait(session,SSH_SMSG_SUCCESS,1) != SSH_OK) {
    char buffer[1024] = {0};
    snprintf(buffer, sizeof(buffer),
        "Key exchange failed: %s", ssh_get_error(session));
    ssh_set_error(session, SSH_FATAL, "%s",buffer);
    goto error;
  }
  ssh_log(session, SSH_LOG_PROTOCOL, "received SSH_SMSG_SUCCESS\n");

  rc = 0;
error:
  string_free(host_mod);
  string_free(host_exp);
  string_free(server_mod);
  string_free(server_exp);
  string_free(serverkey);
  string_free(hostkey);

  publickey_free(srv);
  publickey_free(host);

  leave_function();
  return rc;
}
static int channel_request(CHANNEL *channel, const char *request,
    BUFFER *buffer, int reply) {
  SSH_SESSION *session = channel->session;
  STRING *req = NULL;
  int rc = SSH_ERROR;

  enter_function();

  req = string_from_char(request);
  if (req == NULL) {
    goto error;
  }

  if (buffer_add_u8(session->out_buffer, SSH2_MSG_CHANNEL_REQUEST) < 0 ||
      buffer_add_u32(session->out_buffer, htonl(channel->remote_channel)) < 0 ||
      buffer_add_ssh_string(session->out_buffer, req) < 0 ||
      buffer_add_u8(session->out_buffer, reply == 0 ? 0 : 1) < 0) {
    goto error;
  }
  string_free(req);

  if (buffer != NULL) {
    if (buffer_add_data(session->out_buffer, buffer_get(buffer),
        buffer_get_len(buffer)) < 0) {
      goto error;
    }
  }

  if (packet_send(session) != SSH_OK) {
    leave_function();
    return rc;
  }

  ssh_log(session, SSH_LOG_RARE,
      "Sent a SSH_MSG_CHANNEL_REQUEST %s", request);
  if (reply == 0) {
    leave_function();
    return SSH_OK;
  }

  rc = packet_wait(session, SSH2_MSG_CHANNEL_SUCCESS, 1);
  if (rc) {
    if (session->in_packet.type == SSH2_MSG_CHANNEL_FAILURE) {
      ssh_log(session, SSH_LOG_PACKET,
          "%s channel request failed", request);
      ssh_set_error(session, SSH_REQUEST_DENIED,
          "Channel request %s failed", request);
    } else {
      ssh_log(session, SSH_LOG_RARE,
          "Received an unexpected %d message", session->in_packet.type);
    }
  } else {
    ssh_log(session, SSH_LOG_RARE, "Received a SUCCESS");
  }

  leave_function();
  return rc;
error:
  buffer_free(session->out_buffer);
  string_free(req);

  leave_function();
  return rc;
}
Exemple #26
0
ssh_string ssh_agent_sign_data(ssh_session session,
                               const ssh_key pubkey,
                               struct ssh_buffer_struct *data)
{
    ssh_buffer request;
    ssh_buffer reply;
    ssh_string key_blob;
    ssh_string sig_blob;
    int type = SSH2_AGENT_FAILURE;
    int flags = 0;
    uint32_t dlen;
    int rc;

    request = ssh_buffer_new();
    if (request == NULL) {
        return NULL;
    }

    /* create request */
    if (buffer_add_u8(request, SSH2_AGENTC_SIGN_REQUEST) < 0) {
        return NULL;
    }

    rc = ssh_pki_export_pubkey_blob(pubkey, &key_blob);
    if (rc < 0) {
        ssh_buffer_free(request);
        return NULL;
    }

    /* adds len + blob */
    rc = buffer_add_ssh_string(request, key_blob);
    ssh_string_free(key_blob);
    if (rc < 0) {
        ssh_buffer_free(request);
        return NULL;
    }

    /* Add data */
    dlen = buffer_get_rest_len(data);
    if (buffer_add_u32(request, htonl(dlen)) < 0) {
        ssh_buffer_free(request);
        return NULL;
    }
    if (buffer_add_data(request, buffer_get_rest(data), dlen) < 0) {
        ssh_buffer_free(request);
        return NULL;
    }

    if (buffer_add_u32(request, htonl(flags)) < 0) {
        ssh_buffer_free(request);
        return NULL;
    }

    reply = ssh_buffer_new();
    if (reply == NULL) {
        ssh_buffer_free(request);
        return NULL;
    }

    /* send the request */
    if (agent_talk(session, request, reply) < 0) {
        ssh_buffer_free(request);
        return NULL;
    }
    ssh_buffer_free(request);

    /* check if reply is valid */
    if (buffer_get_u8(reply, (uint8_t *) &type) != sizeof(uint8_t)) {
        ssh_buffer_free(reply);
        return NULL;
    }

    if (agent_failed(type)) {
        SSH_LOG(session, SSH_LOG_WARN, "Agent reports failure in signing the key");
        ssh_buffer_free(reply);
        return NULL;
    } else if (type != SSH2_AGENT_SIGN_RESPONSE) {
        ssh_set_error(session, SSH_FATAL, "Bad authentication response: %d", type);
        ssh_buffer_free(reply);
        return NULL;
    }

    sig_blob = buffer_get_ssh_string(reply);
    ssh_buffer_free(reply);

    return sig_blob;
}
Exemple #27
0
static int packet_send2(ssh_session session) {
  unsigned int blocksize = (session->current_crypto ?
      session->current_crypto->out_cipher->blocksize : 8);
  uint32_t currentlen = buffer_get_rest_len(session->out_buffer);
  unsigned char *hmac = NULL;
  char padstring[32] = {0};
  int rc = SSH_ERROR;
  uint32_t finallen,payloadsize,compsize;
  uint8_t padding;

  payloadsize = currentlen;
#ifdef WITH_ZLIB
  if (session->current_crypto
      && session->current_crypto->do_compress_out
      && buffer_get_rest_len(session->out_buffer)) {
    if (compress_buffer(session,session->out_buffer) < 0) {
      goto error;
    }
    currentlen = buffer_get_rest_len(session->out_buffer);
  }
#endif /* WITH_ZLIB */
  compsize = currentlen;
  padding = (blocksize - ((currentlen +5) % blocksize));
  if(padding < 4) {
    padding += blocksize;
  }

  if (session->current_crypto) {
    ssh_get_random(padstring, padding, 0);
  } else {
    memset(padstring,0,padding);
  }

  finallen = htonl(currentlen + padding + 1);

  if (buffer_prepend_data(session->out_buffer, &padding, sizeof(uint8_t)) < 0) {
    goto error;
  }
  if (buffer_prepend_data(session->out_buffer, &finallen, sizeof(uint32_t)) < 0) {
    goto error;
  }
  if (buffer_add_data(session->out_buffer, padstring, padding) < 0) {
    goto error;
  }
#ifdef WITH_PCAP
  if(session->pcap_ctx){
  	ssh_pcap_context_write(session->pcap_ctx,SSH_PCAP_DIR_OUT,
  			buffer_get_rest(session->out_buffer),buffer_get_rest_len(session->out_buffer)
  			,buffer_get_rest_len(session->out_buffer));
  }
#endif
  hmac = packet_encrypt(session, buffer_get_rest(session->out_buffer),
      buffer_get_rest_len(session->out_buffer));
  if (hmac) {
    if (buffer_add_data(session->out_buffer, hmac, 20) < 0) {
      goto error;
    }
  }

  rc = ssh_packet_write(session);
  session->send_seq++;

  SSH_LOG(SSH_LOG_PACKET,
          "packet: wrote [len=%d,padding=%hhd,comp=%d,payload=%d]",
          ntohl(finallen), padding, compsize, payloadsize);
  if (buffer_reinit(session->out_buffer) < 0) {
    rc = SSH_ERROR;
  }
error:

  return rc; /* SSH_OK, AGAIN or ERROR */
}
Exemple #28
0
/** @internal
 * @handles a data received event. It then calls the handlers for the different packet types
 * or and exception handler callback.
 * @param user pointer to current ssh_session
 * @param data pointer to the data received
 * @len length of data received. It might not be enough for a complete packet
 * @returns number of bytes read and processed.
 */
int ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user){
  ssh_session session=(ssh_session) user;
  unsigned int blocksize = (session->current_crypto ?
      session->current_crypto->in_cipher->blocksize : 8);
  int current_macsize = session->current_crypto ? MACSIZE : 0;
  unsigned char mac[30] = {0};
  char buffer[16] = {0};
  const void *packet = NULL;
  int to_be_read;
  int rc;
  uint32_t len, compsize, payloadsize;
  uint8_t padding;
  size_t processed=0; /* number of byte processed from the callback */

  if (data == NULL) {
    goto error;
  }

  if (session->session_state == SSH_SESSION_STATE_ERROR)
	  goto error;
  switch(session->packet_state) {
    case PACKET_STATE_INIT:
    	if(receivedlen < blocksize){
    		/* We didn't receive enough data to read at least one block size, give up */
    		return 0;
    	}
      memset(&session->in_packet, 0, sizeof(PACKET));

      if (session->in_buffer) {
        if (buffer_reinit(session->in_buffer) < 0) {
          goto error;
        }
      } else {
        session->in_buffer = ssh_buffer_new();
        if (session->in_buffer == NULL) {
          goto error;
        }
      }

      memcpy(buffer,data,blocksize);
      processed += blocksize;
      len = packet_decrypt_len(session, buffer);

      if (buffer_add_data(session->in_buffer, buffer, blocksize) < 0) {
        goto error;
      }

      if(len > MAX_PACKET_LEN) {
        ssh_set_error(session, SSH_FATAL,
            "read_packet(): Packet len too high(%u %.4x)", len, len);
        goto error;
      }

      to_be_read = len - blocksize + sizeof(uint32_t);
      if (to_be_read < 0) {
        /* remote sshd sends invalid sizes? */
        ssh_set_error(session, SSH_FATAL,
            "given numbers of bytes left to be read < 0 (%d)!", to_be_read);
        goto error;
      }

      /* saves the status of the current operations */
      session->in_packet.len = len;
      session->packet_state = PACKET_STATE_SIZEREAD;
      /* FALL TROUGH */
    case PACKET_STATE_SIZEREAD:
      len = session->in_packet.len;
      to_be_read = len - blocksize + sizeof(uint32_t) + current_macsize;
      /* if to_be_read is zero, the whole packet was blocksize bytes. */
      if (to_be_read != 0) {
        if(receivedlen - processed < (unsigned int)to_be_read){
        	/* give up, not enough data in buffer */
            SSH_LOG(SSH_LOG_PACKET,"packet: partial packet (read len) [len=%d]",len);
        	return processed;
        }

        packet = ((unsigned char *)data) + processed;
//        ssh_socket_read(session->socket,packet,to_be_read-current_macsize);

        if (buffer_add_data(session->in_buffer, packet,
              to_be_read - current_macsize) < 0) {
          goto error;
        }
        processed += to_be_read - current_macsize;
      }

      if (session->current_crypto) {
        /*
         * decrypt the rest of the packet (blocksize bytes already
         * have been decrypted)
         */
        if (packet_decrypt(session,
              ((uint8_t*)buffer_get_rest(session->in_buffer) + blocksize),
              buffer_get_rest_len(session->in_buffer) - blocksize) < 0) {
          ssh_set_error(session, SSH_FATAL, "Decrypt error");
          goto error;
        }
        /* copy the last part from the incoming buffer */
        memcpy(mac,(unsigned char *)packet + to_be_read - current_macsize, MACSIZE);

        if (packet_hmac_verify(session, session->in_buffer, mac) < 0) {
          ssh_set_error(session, SSH_FATAL, "HMAC error");
          goto error;
        }
        processed += current_macsize;
      }

      /* skip the size field which has been processed before */
      buffer_pass_bytes(session->in_buffer, sizeof(uint32_t));

      if (buffer_get_u8(session->in_buffer, &padding) == 0) {
        ssh_set_error(session, SSH_FATAL, "Packet too short to read padding");
        goto error;
      }

      if (padding > buffer_get_rest_len(session->in_buffer)) {
        ssh_set_error(session, SSH_FATAL,
            "Invalid padding: %d (%d left)",
            padding,
            buffer_get_rest_len(session->in_buffer));
        goto error;
      }
      buffer_pass_bytes_end(session->in_buffer, padding);
      compsize = buffer_get_rest_len(session->in_buffer);

#ifdef WITH_ZLIB
      if (session->current_crypto
          && session->current_crypto->do_compress_in
          && buffer_get_rest_len(session->in_buffer)) {
        if (decompress_buffer(session, session->in_buffer,MAX_PACKET_LEN) < 0) {
          goto error;
        }
      }
#endif /* WITH_ZLIB */
      payloadsize=buffer_get_rest_len(session->in_buffer);
      session->recv_seq++;
      /* We don't want to rewrite a new packet while still executing the packet callbacks */
      session->packet_state = PACKET_STATE_PROCESSING;
      ssh_packet_parse_type(session);
      SSH_LOG(SSH_LOG_PACKET,
              "packet: read type %hhd [len=%d,padding=%hhd,comp=%d,payload=%d]",
              session->in_packet.type, len, padding, compsize, payloadsize);
      /* execute callbacks */
      ssh_packet_process(session, session->in_packet.type);
      session->packet_state = PACKET_STATE_INIT;
      if(processed < receivedlen){
      	/* Handle a potential packet left in socket buffer */
      	SSH_LOG(SSH_LOG_PACKET,"Processing %" PRIdS " bytes left in socket buffer",
      			receivedlen-processed);
        rc = ssh_packet_socket_callback(((unsigned char *)data) + processed,
      			receivedlen - processed,user);
      	processed += rc;
      }

      return processed;
    case PACKET_STATE_PROCESSING:
    	SSH_LOG(SSH_LOG_RARE, "Nested packet processing. Delaying.");
    	return 0;
  }

  ssh_set_error(session, SSH_FATAL,
      "Invalid state into packet_read2(): %d",
      session->packet_state);

error:
  session->session_state= SSH_SESSION_STATE_ERROR;

  return processed;
}
Exemple #29
0
/* TODO : split this function in two so it becomes smaller */
SIGNATURE *signature_from_string(ssh_session session, ssh_string signature,
                                 ssh_public_key pubkey, int needed_type) {
    SIGNATURE *sign = NULL;
    ssh_buffer tmpbuf = NULL;
    ssh_string rs = NULL;
    ssh_string type_s = NULL;
    ssh_string e = NULL;
    char *type_c = NULL;
    int type;
    int len;
    int rsalen;
#ifdef HAVE_LIBGCRYPT
    gcry_sexp_t sig;
#elif defined HAVE_LIBCRYPTO
    DSA_SIG *sig = NULL;
    ssh_string r = NULL;
    ssh_string s = NULL;
#endif

    sign = malloc(sizeof(SIGNATURE));
    if (sign == NULL) {
        ssh_set_error(session, SSH_FATAL, "Not enough space");
        return NULL;
    }
    ZERO_STRUCTP(sign);

    tmpbuf = ssh_buffer_new();
    if (tmpbuf == NULL) {
        ssh_set_error(session, SSH_FATAL, "Not enough space");
        signature_free(sign);
        return NULL;
    }

    if (buffer_add_data(tmpbuf, ssh_string_data(signature), ssh_string_len(signature)) < 0) {
        signature_free(sign);
        ssh_buffer_free(tmpbuf);
        return NULL;
    }

    type_s = buffer_get_ssh_string(tmpbuf);
    if (type_s == NULL) {
        ssh_set_error(session, SSH_FATAL, "Invalid signature packet");
        signature_free(sign);
        ssh_buffer_free(tmpbuf);
        return NULL;
    }

    type_c = ssh_string_to_char(type_s);
    ssh_string_free(type_s);
    if (type_c == NULL) {
        signature_free(sign);
        ssh_buffer_free(tmpbuf);
        return NULL;
    }
    type = ssh_type_from_name(type_c);
    SAFE_FREE(type_c);

    if (needed_type != type) {
        ssh_set_error(session, SSH_FATAL, "Invalid signature type: %s",
                      ssh_type_to_char(type));
        signature_free(sign);
        ssh_buffer_free(tmpbuf);
        return NULL;
    }

    switch(needed_type) {
    case SSH_KEYTYPE_DSS:
        rs = buffer_get_ssh_string(tmpbuf);
        ssh_buffer_free(tmpbuf);

        /* 40 is the dual signature blob len. */
        if (rs == NULL || ssh_string_len(rs) != 40) {
            ssh_string_free(rs);
            signature_free(sign);
            return NULL;
        }

        /* we make use of strings (because we have all-made functions to convert
         * them to bignums (ou pas ;) */
#ifdef HAVE_LIBGCRYPT
        if (gcry_sexp_build(&sig, NULL, "(sig-val(dsa(r %b)(s %b)))",
                            20 ,ssh_string_data(rs), 20,(unsigned char *)ssh_string_data(rs) + 20)) {
            ssh_string_free(rs);
            signature_free(sign);
            return NULL;
        }
#elif defined HAVE_LIBCRYPTO
        r = ssh_string_new(20);
        s = ssh_string_new(20);
        if (r == NULL || s == NULL) {
            ssh_string_free(r);
            ssh_string_free(s);
            ssh_string_free(rs);
            signature_free(sign);
            return NULL;
        }

        ssh_string_fill(r, ssh_string_data(rs), 20);
        ssh_string_fill(s, (char *)ssh_string_data(rs) + 20, 20);

        sig = DSA_SIG_new();
        if (sig == NULL) {
            ssh_string_free(r);
            ssh_string_free(s);
            ssh_string_free(rs);
            signature_free(sign);
            return NULL;
        }
        sig->r = make_string_bn(r); /* is that really portable ? Openssh's hack isn't better */
        sig->s = make_string_bn(s);
        ssh_string_free(r);
        ssh_string_free(s);

        if (sig->r == NULL || sig->s == NULL) {
            ssh_string_free(rs);
            DSA_SIG_free(sig);
            signature_free(sign);
            return NULL;
        }
#endif

#ifdef DEBUG_CRYPTO
        ssh_print_hexa("r", ssh_string_data(rs), 20);
        ssh_print_hexa("s", (const unsigned char *)ssh_string_data(rs) + 20, 20);
#endif
        ssh_string_free(rs);

        sign->type = SSH_KEYTYPE_DSS;
        sign->dsa_sign = sig;

        return sign;
    case SSH_KEYTYPE_RSA:
        e = buffer_get_ssh_string(tmpbuf);
        ssh_buffer_free(tmpbuf);
        if (e == NULL) {
            signature_free(sign);
            return NULL;
        }
        len = ssh_string_len(e);
#ifdef HAVE_LIBGCRYPT
        rsalen = (gcry_pk_get_nbits(pubkey->rsa_pub) + 7) / 8;
#elif defined HAVE_LIBCRYPTO
        rsalen = RSA_size(pubkey->rsa_pub);
#endif
        if (len > rsalen) {
            ssh_string_free(e);
            signature_free(sign);
            ssh_set_error(session, SSH_FATAL, "Signature too big! %d instead of %d",
                          len, rsalen);
            return NULL;
        }

        if (len < rsalen) {
            ssh_log(session, SSH_LOG_RARE, "RSA signature len %d < %d",
                    len, rsalen);
        }
        sign->type = SSH_KEYTYPE_RSA;
#ifdef HAVE_LIBGCRYPT
        if (gcry_sexp_build(&sig, NULL, "(sig-val(rsa(s %b)))",
                            ssh_string_len(e), ssh_string_data(e))) {
            signature_free(sign);
            ssh_string_free(e);
            return NULL;
        }

        sign->rsa_sign = sig;
#elif defined HAVE_LIBCRYPTO
        sign->rsa_sign = e;
#endif

#ifdef DEBUG_CRYPTO
        ssh_log(session, SSH_LOG_FUNCTIONS, "len e: %d", len);
        ssh_print_hexa("RSA signature", ssh_string_data(e), len);
#endif

#ifdef HAVE_LIBGCRYPT
        ssh_string_free(e);
#endif

        return sign;
    default:
        return NULL;
    }

    return NULL;
}
Exemple #30
0
/* TODO : split this function in two so it becomes smaller */
SIGNATURE *signature_from_string(SSH_SESSION *session, STRING *signature,PUBLIC_KEY *pubkey,int needed_type){
#ifdef HAVE_LIBGCRYPT
    gcry_sexp_t sig;
#elif defined HAVE_LIBCRYPTO
    DSA_SIG *sig;
    STRING *r,*s;
#endif
    SIGNATURE *sign=malloc(sizeof(SIGNATURE));
    BUFFER *tmpbuf=buffer_new();
    STRING *rs;
    STRING *type_s,*e;
    int len,rsalen;
    char *type;
    buffer_add_data(tmpbuf,signature->string,string_len(signature));
    type_s=buffer_get_ssh_string(tmpbuf);
    if(!type_s){
        ssh_set_error(session,SSH_FATAL,"Invalid signature packet");
        buffer_free(tmpbuf);
        return NULL;
    }
    type=string_to_char(type_s);
    free(type_s);
    switch(needed_type){
        case TYPE_DSS:
            if(strcmp(type,"ssh-dss")){
                ssh_set_error(session,SSH_FATAL,"Invalid signature type : %s",type);
                buffer_free(tmpbuf);
                free(type);
                return NULL;
            }
            break;
        case TYPE_RSA:
            if(strcmp(type,"ssh-rsa")){
                ssh_set_error(session,SSH_FATAL,"Invalid signature type : %s",type);
                buffer_free(tmpbuf);
                free(type);
                return NULL;
            }
            break;
        default:
            ssh_set_error(session,SSH_FATAL,"Invalid signature type : %s",type);
            free(type);
            buffer_free(tmpbuf);
            return NULL;
    }
    free(type);
    switch(needed_type){
        case TYPE_DSS:
            rs=buffer_get_ssh_string(tmpbuf);
            buffer_free(tmpbuf);
            if(!rs || string_len(rs)!=40){ /* 40 is the dual signature blob len. */
                if(rs)
                    free(rs);
                return NULL;
            }
            /* we make use of strings (because we have all-made functions to convert them to bignums (ou pas ;)*/
#ifdef HAVE_LIBGCRYPT
            gcry_sexp_build(&sig,NULL,"(sig-val(dsa(r %b)(s %b)))",20,rs->string,20,rs->string+20);
#elif defined HAVE_LIBCRYPTO
            r=string_new(20);
            s=string_new(20);
            string_fill(r,rs->string,20);
            string_fill(s,rs->string+20,20);
            sig=DSA_SIG_new();
            sig->r=make_string_bn(r); /* is that really portable ? Openssh's hack isn't better */
            sig->s=make_string_bn(s);
            free(r);
            free(s);
#endif
#ifdef DEBUG_CRYPTO
            ssh_print_hexa("r",rs->string,20);
            ssh_print_hexa("s",rs->string+20,20);
#endif
            free(rs);
            sign->type=TYPE_DSS;
            sign->dsa_sign=sig;
            return sign;
        case TYPE_RSA:
            e=buffer_get_ssh_string(tmpbuf);
            buffer_free(tmpbuf);
            if(!e){
                return NULL;
            }
            len=string_len(e);
#ifdef HAVE_LIBGCRYPT
            rsalen=(gcry_pk_get_nbits(pubkey->rsa_pub)+7)/8;
#elif defined HAVE_LIBCRYPTO
            rsalen=RSA_size(pubkey->rsa_pub);
#endif
            if(len>rsalen){
                free(e);
                free(sign);
                ssh_set_error(session,SSH_FATAL,"signature too big ! %d instead of %d",len,rsalen);
                return NULL;
            }
            if(len<rsalen)
                ssh_log(session,SSH_LOG_RARE,"RSA signature len %d < %d",len,rsalen);
            sign->type=TYPE_RSA;
#ifdef HAVE_LIBGCRYPT
            gcry_sexp_build(&sig,NULL,"(sig-val(rsa(s %b)))",string_len(e),e->string);
            sign->rsa_sign=sig;
#elif defined HAVE_LIBCRYPTO
            sign->rsa_sign=e;
#endif
#ifdef DEBUG_CRYPTO
            ssh_say(0,"Len : %d\n",len);
            ssh_print_hexa("rsa signature",e->string,len);
#endif
#ifdef HAVE_LIBGCRYPT
            free(e);
#endif
            return sign;
        default:
            return NULL;
    }
}