OpenSSL S_SERVER(1openssl)
NNNNAAAAMMMMEEEEs_server - SSL/TLS server program
SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSSooooppppeeeennnnssssssssllll ssss_sssseeeerrrrvvvveeeerrrr [---aaacccccccceeeepppptttt ppppoooorrrrtttt] [---cccoooonnnntttteeeexxxxtttt iiiidddd] [---vvveeeerrrriiiiffffyyyy
ddddeeeepppptttthhhh] [---VVVeeeerrrriiiiffffyyyy ddddeeeepppptttthhhh] [---cccrrrrllll_cccchhhheeeecccckkkk] [---cccrrrrllll_cccchhhheeeecccckkkk_aaaallllllll] [---ccceeeerrrrtttt
ffffiiiilllleeeennnnaaaammmmeeee] [---ccceeeerrrrttttffffoooorrrrmmmm DDDDEEEERRRR||||PPPPEEEEMMMM] [---kkkeeeeyyyy kkkkeeeeyyyyffffiiiilllleeee] [---kkkeeeeyyyyffffoooorrrrmmmm
DDDDEEEERRRR||||PPPPEEEEMMMM] [---pppaaaassssssss aaaarrrrgggg] [---dddcccceeeerrrrtttt ffffiiiilllleeeennnnaaaammmmeeee] [---dddcccceeeerrrrttttffffoooorrrrmmmm DDDDEEEERRRR||||PPPPEEEEMMMM]
[---dddkkkkeeeeyyyy kkkkeeeeyyyyffffiiiilllleeee] [---dddkkkkeeeeyyyyffffoooorrrrmmmm DDDDEEEERRRR||||PPPPEEEEMMMM] [---dddppppaaaassssssss aaaarrrrgggg] [---dddhhhhppppaaaarrrraaaammmm
ffffiiiilllleeeennnnaaaammmmeeee] [---nnnbbbbiiiioooo] [---nnnbbbbiiiioooo_tttteeeesssstttt] [---cccrrrrllllffff] [---dddeeeebbbbuuuugggg] [---mmmssssgggg]
[---sssttttaaaatttteeee] [---CCCAAAAppppaaaatttthhhh ddddiiiirrrreeeeccccttttoooorrrryyyy] [---CCCAAAAffffiiiilllleeee ffffiiiilllleeeennnnaaaammmmeeee] [---nnnoooocccceeeerrrrtttt]
[---ccciiiipppphhhheeeerrrr cccciiiipppphhhheeeerrrrlllliiiisssstttt] [---qqquuuuiiiieeeetttt] [---nnnoooo_ttttmmmmpppp_rrrrssssaaaa] [---sssssssllll2222] [---sssssssllll3333]
[---tttllllssss1111] [---nnnoooo_ssssssssllll2222] [---nnnoooo_ssssssssllll3333] [---nnnoooo_ttttllllssss1111] [---nnnoooo_ddddhhhheeee] [---bbbuuuuggggssss]
[---hhhaaaacccckkkk] [---wwwwwww] [---WWWWWWWWWWW] [---HHHTTTTTTTTPPPP] [---eeennnnggggiiiinnnneeee iiiidddd] [---tttllllsssseeeexxxxttttddddeeeebbbbuuuugggg]
[---nnnoooo_ttttiiiicccckkkkeeeetttt] [---iiidddd_pppprrrreeeeffffiiiixxxx aaaarrrrgggg] [---rrraaaannnndddd ffffiiiilllleeee((((ssss))))]
DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNNThe ssss_sssseeeerrrrvvvveeeerrrr command implements a generic SSL/TLS server
which listens for connections on a given port using SSL/TLS. OOOOPPPPTTTTIIIIOOOONNNNSSSS
-aaaacccccccceeeepppptttt ppppoooorrrrtttt
the TCP port to listen on for connections. If not specified 4433 is used.-ccccoooonnnntttteeeexxxxtttt iiiidddd
sets the SSL context id. It can be given any string value. If this option is not present a default value will be used.-cccceeeerrrrtttt cccceeeerrrrttttnnnnaaaammmmeeee
The certificate to use, most servers cipher suites require the use of a certificate and some require a certificate with a certain public key type: for example the DSS cipher suites require a certificate containing a DSS (DSA) key. If not specified then the filename "server.pem" will be used.-cccceeeerrrrttttffffoooorrrrmmmm ffffoooorrrrmmmmaaaatttt
The certificate format to use: DER or PEM. PEM is the default.-kkkkeeeeyyyy kkkkeeeeyyyyffffiiiilllleeee
The private key to use. If not specified then the certificate file will be used.-kkkkeeeeyyyyffffoooorrrrmmmm ffffoooorrrrmmmmaaaatttt
The private format to use: DER or PEM. PEM is the default.-ppppaaaassssssss aaaarrrrgggg
the private key password source. For more information19/May/2008 Last change: 0.9.8o 1
OpenSSL S_SERVER(1openssl)
about the format of aaaarrrrgggg see the PPPPAAAASSSSSSSS PPPPHHHHRRRRAAAASSSSEEEE AAAARRRRGGGGUUUUMMMMEEEENNNNTTTTSSSS section in openssl(1).-ddddcccceeeerrrrtttt ffffiiiilllleeeennnnaaaammmmeeee, -ddddkkkkeeeeyyyy kkkkeeeeyyyynnnnaaaammmmeeee
specify an additional certificate and private key, thesebehave in the same manner as the ---ccceeeerrrrtttt and ---kkkeeeeyyyy options
except there is no default if they are not specified (no additional certificate and key is used). As noted above some cipher suites require a certificate containing a key of a certain type. Some cipher suites need a certificate carrying an RSA key and some a DSS (DSA) key. By using RSA and DSS certificates and keys a server can support clients which only support RSA or DSS cipher suites by using an appropriate certificate.-ddddcccceeeerrrrttttffffoooorrrrmmmm ffffoooorrrrmmmmaaaatttt, -ddddkkkkeeeeyyyyffffoooorrrrmmmm ffffoooorrrrmmmmaaaatttt, -ddddppppaaaassssssss aaaarrrrgggg
addtional certificate and private key format and passphrase respectively.-nnnnoooocccceeeerrrrtttt
if this option is set then no certificate is used. This restricts the cipher suites available to the anonymous ones (currently just anonymous DH).-ddddhhhhppppaaaarrrraaaammmm ffffiiiilllleeeennnnaaaammmmeeee
the DH parameter file to use. The ephemeral DH cipher suites generate keys using a set of DH parameters. If not specified then an attempt is made to load the parameters from the server certificate file. If this fails then a static set of parameters hard coded intothe s_server program will be used.
-nnnnoooo_ddddhhhheeee
if this option is set then no DH parameters will be loaded effectively disabling the ephemeral DH cipher suites.-nnnnoooo_ttttmmmmpppp_rrrrssssaaaa
certain export cipher suites sometimes use a temporary RSA key, this option disables temporary RSA key generation.-vvvveeeerrrriiiiffffyyyy ddddeeeepppptttthhhh, -VVVVeeeerrrriiiiffffyyyy ddddeeeepppptttthhhh
The verify depth to use. This specifies the maximum length of the client certificate chain and makes the server request a certificate from the client. With the---vvveeeerrrriiiiffffyyyy option a certificate is requested but the client
does not have to send one, with the ---VVVeeeerrrriiiiffffyyyy option the
client must supply a certificate or an error occurs.-ccccrrrrllll_cccchhhheeeecccckkkk, -ccccrrrrllll_cccchhhheeeecccckkkk_aaaallllllll
Check the peer certificate has not been revoked by its19/May/2008 Last change: 0.9.8o 2
OpenSSL S_SERVER(1openssl)
CA. The CRL(s) are appended to the certificate file.With the ---cccrrrrllll_cccchhhheeeecccckkkk_aaaallllllll option all CRLs of all CAs in
the chain are checked.-CCCCAAAAppppaaaatttthhhh ddddiiiirrrreeeeccccttttoooorrrryyyy
The directory to use for client certificate verification. This directory must be in "hash format", see vvvveeeerrrriiiiffffyyyy for more information. These are also used when building the server certificate chain.-CCCCAAAAffffiiiilllleeee ffffiiiilllleeee
A file containing trusted certificates to use during client authentication and to use when attempting to build the server certificate chain. The list is also used in the list of acceptable client CAs passed to the client when a certificate is requested.-ssssttttaaaatttteeee
prints out the SSL session states.-ddddeeeebbbbuuuugggg
print extensive debugging information including a hex dump of all traffic.-mmmmssssgggg
show all protocol messages with hex dump.-nnnnbbbbiiiioooo_tttteeeesssstttt
tests non blocking I/O
-nnnnbbbbiiiioooo
turns on non blocking I/O
-ccccrrrrllllffff
this option translated a line feed from the terminal into CR+LF.-qqqquuuuiiiieeeetttt
inhibit printing of session and certificate information.-ssssssssllll2222, -ssssssssllll3333, -ttttllllssss1111, -nnnnoooo_ssssssssllll2222, -nnnnoooo_ssssssssllll3333, -nnnnoooo_ttttllllssss1111
these options disable the use of certain SSL or TLS protocols. By default the initial handshake uses a method which should be compatible with all servers and permit them to use SSL v3, SSL v2 or TLS as appropriate.-bbbbuuuuggggssss
there are several known bug in SSL and TLS implementations. Adding this option enables various workarounds.19/May/2008 Last change: 0.9.8o 3
OpenSSL S_SERVER(1openssl)
-hhhhaaaacccckkkk
this option enables a further workaround for some some early Netscape SSL code (?).-cccciiiipppphhhheeeerrrr cccciiiipppphhhheeeerrrrlllliiiisssstttt
this allows the cipher list used by the server to be modified. When the client sends a list of supported ciphers the first client cipher also included in the server list is used. Because the client specifies the preference order, the order of the server cipherlist irrelevant. See the cccciiiipppphhhheeeerrrrssss command for more information.-ttttllllsssseeeexxxxttttddddeeeebbbbuuuugggg
print out a hex dump of any TLS extensions received from the server.-nnnnoooo_ttttiiiicccckkkkeeeetttt
disable RFC4507bis session ticket support.-wwwwwwww
sends a status message back to the client when it connects. This includes lots of information about the ciphers used and various session parameters. The output is in HTML format so this option will normally be used with a web browser.-WWWWWWWWWWWW
emulates a simple web server. Pages will be resolved relative to the current directory, for example if the URL https://myhost/page.html is requested the file ./page.html will be loaded.-HHHHTTTTTTTTPPPP
emulates a simple web server. Pages will be resolved relative to the current directory, for example if the URL https://myhost/page.html is requested the file ./page.html will be loaded. The files loaded are assumed to contain a complete and correct HTTP response (lines that are part of the HTTP response line and headers must end with CRLF).-eeeennnnggggiiiinnnneeee iiiidddd
specifying an engine (by it's unique iiiidddd string) willcause ssss_sssseeeerrrrvvvveeeerrrr to attempt to obtain a functional
reference to the specified engine, thus initialising it if needed. The engine will then be set as the default for all available algorithms.-iiiidddd_pppprrrreeeeffffiiiixxxx aaaarrrrgggg
generate SSL/TLS session IDs prefixed by aaaarrrrgggg. This is
mostly useful for testing any SSL/TLS code (eg. proxies)
19/May/2008 Last change: 0.9.8o 4
OpenSSL S_SERVER(1openssl)
that wish to deal with multiple servers, when each of which might be generating a unique range of session IDs (eg. with a certain prefix).-rrrraaaannnndddd ffffiiiilllleeee((((ssss))))
a file or files containing random data used to seed the random number generator, or an EGD socket (seeRAND_egd(3)). Multiple files can be specified separated
by a OS-dependent character. The separator is ;;;; for
MS-Windows, ,,,, for OpenVMS, and :::: for all others.
CCCCOOOONNNNNNNNEEEECCCCTTTTEEEEDDDD CCCCOOOOMMMMMMMMAAAANNNNDDDDSSSS If a connection request is established with an SSL clientand neither the ---wwwwwww nor the ---WWWWWWWWWWW option has been used then
normally any data received from the client is displayed and any key presses will be sent to the client. Certain single letter commands are also recognized which perform special operations: these are listed below. qqqq end the current SSL connection but still accept new connections. QQQQ end the current SSL connection and exit. rrrr renegotiate the SSL session. RRRR renegotiate the SSL session and request a client certificate. PPPP send some plain text down the underlying TCP connection: this should cause the client to disconnect due to a protocol violation. SSSS print out some session cache status information. NNNNOOOOTTTTEEEESSSSssss_sssseeeerrrrvvvveeeerrrr can be used to debug SSL clients. To accept
connections from a web browser the command:openssl s_server -accept 443 -www
can be used for example. Most web browsers (in particular Netscape and MSIE) only support RSA cipher suites, so they cannot connect to servers which don't use a certificate carrying an RSA key or a version of OpenSSL with RSA disabled. Although specifying an empty list of CAs when requesting a client certificate is strictly speaking a protocol violation, some SSL clients interpret this to mean any CA is19/May/2008 Last change: 0.9.8o 5
OpenSSL S_SERVER(1openssl)
acceptable. This is useful for debugging purposes.The session parameters can printed out using the sssseeeessssssss_iiiidddd
program. TLS extensions are only supported in OpenSSL 0.9.8 if they are explictly enabled at compile time using for example theeeeennnnaaaabbbblllleeee---tttllllsssseeeexxxxtttt switch.
BBBBUUUUGGGGSSSS Because this program has a lot of options and also because some of the techniques used are rather old, the C source ofs_server is rather hard to read and not a model of how
things should be done. A typical SSL server program would be much simpler. The output of common ciphers is wrong: it just gives the list of ciphers that OpenSSL recognizes and the client supports.There should be a way for the ssss_sssseeeerrrrvvvveeeerrrr program to print out
details of any unknown cipher suites a client says it supports. SSSSEEEEEEEE AAAALLLLSSSSOOOOsess_id(1), s_client(1), ciphers(1)
19/May/2008 Last change: 0.9.8o 6
OpenSSL S_SERVER(1openssl)
19/May/2008 Last change: 0.9.8o 7