Daniel Stenberg's libssh2 presentation at FSCONS 2099.

1. FSCONS Göteborg, November 14 th 2009

3. Consultant at Haxx

4. Open Source since 15 years

5. Contributed to 20+ projects

6. 15K public commits

7. cURL, Rockbox etc

8. Questions Please do interrupt and ask if you have questions!

10. Background

11. Why a lib is needed

12. The project

14. App examples

15. Competitors

16. Future

17. Contributors

19. On top of TCP/IP

20. Invented by Tatu Ylönen in 1995

21. OpenSSH 1999

22. Internet Standard 2002, RFC4251 and friends

23. SSH is not SSL but similarities exist

25. A little story Once upon a time...

26. 1997 Wouldn't it be nice with a tool that grabs HTTP?

27. 1998 Wouldn't it be nice if it did FTP too?

28. 1999 And Gopher!

29. 1999 Wouldn't it be nice if it did HTTPS too?

30. 2000 You get the picture. Time moved on. It was now also a lib

31. 2006 Supporting HTTP, HTTPS, FTP, FTPS, TELNET, LDAP, LDAPS, DICT, TFTP and FILE. Using several underlying libraries. Wouldn't it be nice if it did SCP and SFTP too?

33. Putty – no lib

34. Libssh (license, blocking, thread-safety...)

35. Libssh2 – there you go

37. Embeddable, command line tools aren't enough

38. Portability – not limited to POSIX (C89)

39. Use SSH for SSL-like stuff

40. License – as free as possible

41. Only 20K LOC

43. Client and server

44. SSH2 only (no v1)

45. For PHP

46. Sara set the API, made it run

47. Daniel entered Nov 2006

48. For libcurl (non-blocking!)

49. Client-side only (for simplicity)

51. Plain ANSI C89 C

52. Low key

53. Mailing list driven

54. Meritocracy

55. Start-up feeling

57. Not many users (apps)

58. git

59. Individual copyrights

60. No umbrella org

62. Channels

63. SCP

64. X11

65. SFTP

66. Publickey

68. pass in socket

69. external poll()

70. Crypto-layer abstracted

71. Knownhost

72. Blocking API SCP client /* create a socket */ sockfd = socket(); /* connect to server */ connect(sockfd, address); /* get a libssh2 session handle (blocking behavior is default) */ session = libssh2_session_init(); /* pass in the socket to the SSH2 session */ libssh2_session_startup(session, sockfd); /* password authentication (known host handling skipped) */ libssh2_userauth_password(session, username, password)); /* request a file with SCP */ channel = libssh2_scp_recv(session, “/home/daniel/textfile”, &fileinfo); while (!done) libssh2_channel_read(channel, mem, amount); /* free the SCP channel */ libssh2_channel_free(channel); /* disconnect session */ libssh2_session_disconnect(session, "shutdown”); /* free the session */ libssh2_session_free(session); /* close the socket */ close(socket);

73. /* create a socket */ sockfd = socket(); /* connect to server */ connect(sockfd, address); /* get a libssh2 session handle (blocking behavior is default) */ session = libssh2_session_init(); /* pass in the socket to the SSH2 session */ libssh2_session_startup(session, sockfd); /* password authentication (known host handling skipped) */ libssh2_userauth_password(session, username, password)); /* request a file with SCP */ channel = libssh2_scp_recv(session, “/home/daniel/textfile”, &fileinfo); while (!done) libssh2_channel_read(channel, mem, amount); /* free the SCP channel */ libssh2_channel_free(channel); /* disconnect session */ libssh2_session_disconnect(session, "shutdown”); /* free the session */ libssh2_session_free(session); /* close the socket */ close(socket); Blocking API SFTP client /* create the SFTP session */ sftp_session = libssh2_sftp_init(session); sftp_handle = libssh2_sftp_open(sftp_session, “/home/daniel/file”, LIBSSH2_FXF_READ, 0); while (!done) libssh2_sftp_read(sftp_handle, mem, amount); /* close the SFTP handle */ libssh2_sftp_close(sftp_handle); /* close the SFTP session */ libssh2_sftp_shutdown(sftp_session);

74. Or use libcurl! Libcurl supports SCP and SFTP URLs http://curl.haxx.se/

76. Feature wise?

77. Bug and stability wise?

79. Free for virtually every use

80. Sara G picked it

81. Suitable for re-use by other libs/platforms

83. License

84. non-blocking

85. Name-space polluting

87. Commercial?

89. Me

90. Simon J

91. A few other happy campers

92. No particular company backing

93. Company-funded features

95. Make more stable

96. Improve speed (esp SFTP)

97. Use less mallocs

98. Use less memory (adjust windows etc)

99. Missing features?

100. Scratch itches

102. Written in C

103. The best one available

104. Small team

105. www.libssh2.org

106. Join in! libssh2 needs you!