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| 1 | +@node Howto Create a Server Cert |
| 2 | +@section Creating a TLS server certificate |
| 3 | + |
| 4 | + |
| 5 | +Here is a brief run up on how to create a server certificate. It has |
| 6 | +actually been done this way to get a certificate from CAcert to be used |
| 7 | +on a real server. It has only been tested with this CA, but there |
| 8 | +shouldn't be any problem to run this against any other CA. |
| 9 | + |
| 10 | +Before you start, make sure that gpg-agent is running. As there is no |
| 11 | +need for a configuration file, you may simply enter: |
| 12 | + |
| 13 | +@cartouche |
| 14 | +@example |
| 15 | + $ gpgsm-gencert.sh >a.p10 |
| 16 | + Key type |
| 17 | + [1] RSA |
| 18 | + [2] Existing key |
| 19 | + [3] Direct from card |
| 20 | + Your selection: 1 |
| 21 | + You selected: RSA |
| 22 | +@end example |
| 23 | +@end cartouche |
| 24 | + |
| 25 | +I opted for creating a new RSA key. The other option is to use an |
| 26 | +already existing key, by selecting @kbd{2} and entering the so-called |
| 27 | +keygrip. Running the command @samp{gpgsm --dump-secret-key USERID} |
| 28 | +shows you this keygrip. Using @kbd{3} offers another menu to create a |
| 29 | +certificate directly from a smart card based key. |
| 30 | + |
| 31 | +Let's continue: |
| 32 | + |
| 33 | +@cartouche |
| 34 | +@example |
| 35 | + Key length |
| 36 | + [1] 1024 |
| 37 | + [2] 2048 |
| 38 | + Your selection: 1 |
| 39 | + You selected: 1024 |
| 40 | +@end example |
| 41 | +@end cartouche |
| 42 | + |
| 43 | +The script offers two common key sizes. With the current setup of |
| 44 | +CAcert, it does not make much sense to use a 2k key; their policies need |
| 45 | +to be revised anyway (a CA root key valid for 30 years is not really |
| 46 | +serious). |
| 47 | + |
| 48 | +@cartouche |
| 49 | +@example |
| 50 | + Key usage |
| 51 | + [1] sign, encrypt |
| 52 | + [2] sign |
| 53 | + [3] encrypt |
| 54 | + Your selection: 1 |
| 55 | + You selected: sign, encrypt |
| 56 | +@end example |
| 57 | +@end cartouche |
| 58 | + |
| 59 | +We want to sign and encrypt using this key. This is just a suggestion |
| 60 | +and the CA may actually assign other key capabilities. |
| 61 | + |
| 62 | +Now for some real data: |
| 63 | + |
| 64 | +@cartouche |
| 65 | +@example |
| 66 | + Name (DN) |
| 67 | + > CN=kerckhoffs.g10code.com |
| 68 | +@end example |
| 69 | +@end cartouche |
| 70 | + |
| 71 | +This is the most important value for a server certificate. Enter here |
| 72 | +the canonical name of your server machine. You may add other virtual |
| 73 | +server names later. |
| 74 | + |
| 75 | +@cartouche |
| 76 | +@example |
| 77 | + E-Mail addresses (end with an empty line) |
| 78 | + > |
| 79 | +@end example |
| 80 | +@end cartouche |
| 81 | + |
| 82 | +We don't need email addresses in a server certificate and CAcert would |
| 83 | +anyway ignore such a request. Thus just hit enter. |
| 84 | + |
| 85 | +If you want to create a client certificate for email encryption, this |
| 86 | +would be the place to enter your mail address |
| 87 | +(e.g. @email{joe@@example.org}). You may enter as many addresses as you like, |
| 88 | +however the CA may not accept them all or reject the entire request. |
| 89 | + |
| 90 | +@cartouche |
| 91 | +@example |
| 92 | + DNS Names (optional; end with an empty line) |
| 93 | + > www.g10code.com |
| 94 | + DNS Names (optional; end with an empty line) |
| 95 | + > ftp.g10code.com |
| 96 | + DNS Names (optional; end with an empty line) |
| 97 | + > |
| 98 | +@end example |
| 99 | +@end cartouche |
| 100 | + |
| 101 | +Here I entered the names of the servers which actually run on the |
| 102 | +machine given in the DN above. The browser will accept a certificate for |
| 103 | +any of these names. As usual the CA must approve all of these names. |
| 104 | + |
| 105 | +@cartouche |
| 106 | +@example |
| 107 | + URIs (optional; end with an empty line) |
| 108 | + > |
| 109 | +@end example |
| 110 | +@end cartouche |
| 111 | + |
| 112 | +It is possible to insert arbitrary URIs into a certificate; for a server |
| 113 | +certificate this does not make sense. |
| 114 | + |
| 115 | +We have now entered all required information and @command{gpgsm} will |
| 116 | +display what it has gathered and ask whether to create the certificate |
| 117 | +request: |
| 118 | + |
| 119 | +@cartouche |
| 120 | +@example |
| 121 | + Parameters for certificate request to create: |
| 122 | + 1 Key-Type: RSA |
| 123 | + 2 Key-Length: 1024 |
| 124 | + 3 Key-Usage: sign, encrypt |
| 125 | + 4 Name-DN: CN=kerckhoffs.g10code.com |
| 126 | + 5 Name-DNS: www.g10code.com |
| 127 | + 6 Name-DNS: ftp.g10code.com |
| 128 | + |
| 129 | + Really create such a CSR? |
| 130 | + [1] yes |
| 131 | + [2] no |
| 132 | + Your selection: 1 |
| 133 | + You selected: yes |
| 134 | +@end example |
| 135 | +@end cartouche |
| 136 | + |
| 137 | +@command{gpgsm} will now start working on creating the request. As this |
| 138 | +includes the creation of an RSA key it may take a while. During this |
| 139 | +time you will be asked 3 times for a passphrase to protect the created |
| 140 | +private key on your system. A pop up window will appear to ask for |
| 141 | +it. The first two prompts are for the new passphrase and for re-entering it; |
| 142 | +the third one is required to actually create the certificate signing request. |
| 143 | + |
| 144 | +When it is ready, you should see the final notice: |
| 145 | + |
| 146 | +@cartouche |
| 147 | +@example |
| 148 | + gpgsm: certificate request created |
| 149 | +@end example |
| 150 | +@end cartouche |
| 151 | + |
| 152 | +Now, you may look at the created request: |
| 153 | + |
| 154 | +@cartouche |
| 155 | +@example |
| 156 | + $ cat a.p10 |
| 157 | + -----BEGIN CERTIFICATE REQUEST----- |
| 158 | + MIIBnzCCAQgCAQAwITEfMB0GA1UEAxMWa2VyY2tob2Zmcy5nMTBjb2RlLmNvbTCB |
| 159 | + nzANBgkqhkiG9w0BAQEFAAOBjQAwgYkCgYEA5h+uKRenpvbe+BnMY6siPO50LVyg |
| 160 | + HtB7kr+YISlPJ5JAFO12yQFz9Y0sBLHbjR+V+TOawwP1dZhGjlgnEBkMdWKuEBlS |
| 161 | + wFTALLX78GAyvAYAmPqSPDEYXkMECyUXVX/bbGI1bY8Y2OGy4w4D+v7e+xD2NBkm |
| 162 | + Bj5cNy+YMbGVldECAwEAAaA+MDwGCSqGSIb3DQEJDjEvMC0wKwYDVR0RBCQwIoIP |
| 163 | + d3d3LmcxMGNvZGUuY29tgg9mdHAuZzEwY29kZS5jb20wDQYJKoZIhvcNAQEFBQAD |
| 164 | + gYEAzBRIi8KTfKyebOlMtDN6oDYBOv+r9A4w3u/Z1ikjffaiN1Bmd2o9Ez9KXKHA |
| 165 | + IezLeSEA/rGUPN5Ur5qIJnRNQ8xrS+iLftr8msWQSZppVnA/vnqMrtqBUpitqAr0 |
| 166 | + eYBmt1Uem2Y3UFABrKPglv2xzgGkrKX6AqmFoOnJWQ0QcTw= |
| 167 | + -----END CERTIFICATE REQUEST----- |
| 168 | + $ |
| 169 | +@end example |
| 170 | +@end cartouche |
| 171 | + |
| 172 | +You may now proceed by logging into your account at the CAcert website, |
| 173 | +choose @code{Server Certificates - New}, check @code{sign by class 3 root |
| 174 | +certificate}, paste the above request block into the text field and |
| 175 | +click on @code{Submit}. |
| 176 | + |
| 177 | +If everything works out fine, a certificate will be shown. Now run |
| 178 | + |
| 179 | +@cartouche |
| 180 | +@example |
| 181 | +$ gpgsm --import |
| 182 | +@end example |
| 183 | +@end cartouche |
| 184 | + |
| 185 | +and paste the certificate from the CAcert page into your terminal |
| 186 | +followed by a Ctrl-D |
| 187 | + |
| 188 | +@cartouche |
| 189 | +@example |
| 190 | + -----BEGIN CERTIFICATE----- |
| 191 | + MIIEIjCCAgqgAwIBAgIBTDANBgkqhkiG9w0BAQQFADBUMRQwEgYDVQQKEwtDQWNl |
| 192 | + cnQgSW5jLjEeMBwGA1UECxMVaHR0cDovL3d3dy5DQWNlcnQub3JnMRwwGgYDVQQD |
| 193 | + ExNDQWNlcnQgQ2xhc3MgMyBSb290MB4XDTA1MTAyODE2MjA1MVoXDTA3MTAyODE2 |
| 194 | + MjA1MVowITEfMB0GA1UEAxMWa2VyY2tob2Zmcy5nMTBjb2RlLmNvbTCBnzANBgkq |
| 195 | + hkiG9w0BAQEFAAOBjQAwgYkCgYEA5h+uKRenpvbe+BnMY6siPO50LVygHtB7kr+Y |
| 196 | + ISlPJ5JAFO12yQFz9Y0sBLHbjR+V+TOawwP1dZhGjlgnEBkMdWKuEBlSwFTALLX7 |
| 197 | + 8GAyvAYAmPqSPDEYXkMECyUXVX/bbGI1bY8Y2OGy4w4D+v7e+xD2NBkmBj5cNy+Y |
| 198 | + MbGVldECAwEAAaOBtTCBsjAMBgNVHRMBAf8EAjAAMDQGA1UdJQQtMCsGCCsGAQUF |
| 199 | + BwMCBggrBgEFBQcDAQYJYIZIAYb4QgQBBgorBgEEAYI3CgMDMAsGA1UdDwQEAwIF |
| 200 | + oDAyBggrBgEFBQcBAQQmMCQwIgYIKwYBBQUHMAGGFmh0dHA6Ly9vY3NwLmNhY2Vy |
| 201 | + dC5vcmcwKwYDVR0RBCQwIoIPd3d3LmcxMGNvZGUuY29tgg9mdHAuZzEwY29kZS5j |
| 202 | + b20wDQYJKoZIhvcNAQEEBQADggIBAAj5XAHCtzQR8PV6PkQBgZqUCbcfxGO/ZIp9 |
| 203 | + aIT6J2z0Jo1OZI6KmConbqnZG9WyDlV5P7msQXW/Z9nBfoj4KSmNR8G/wtb8ClJn |
| 204 | + W8s75+K3ZLq1UgEyxBDrS7GjtbVaj7gsfZsuiQzxmk9lbl1gbkpJ3VEMjwVCTMlM |
| 205 | + fpjp8etyPhUZqOZaoKVaq//KTOsjhPMwz7TcfOkHvXketPrWTcefJQU7NKLH16D3 |
| 206 | + mZAwnBxp3P51H6E6VG8AoJO8xCBuVwsbXKEf/FW+tmKG9pog6CaZQ9WibROTtnKj |
| 207 | + NJjSBsrUk5C+JowO/EyZRGm6R1tlok8iFXj+2aimyeBqDcxozNmFgh9F3S5u0wK0 |
| 208 | + 6cfYgkPVMHxgwV3f3Qh+tJkgLExN7KfO9hvpZqAh+CLQtxVmvpxEVEXKR6nwBI5U |
| 209 | + BaseulvVy3wUfg2daPkG17kDDBzQlsWC0BRF8anH+FWSrvseC3nS0a9g3sXF1Ic3 |
| 210 | + gIqeAMhkant1Ac3RR6YCWtJKr2rcQNdDAxXK35/gUSQNCi9dclEzoOgjziuA1Mha |
| 211 | + 94jYcvGKcwThn0iITVS5hOsCfaySBLxTzfIruLbPxXlpWuCW/6I/7YyivppKgEZU |
| 212 | + rUTFlNElRXCwIl0YcJkIaYYqWf7+A/aqYJCi8+51usZwMy3Jsq3hJ6MA3h1BgwZs |
| 213 | + Rtct3tIX |
| 214 | + -----END CERTIFICATE----- |
| 215 | + gpgsm: issuer certificate (#/CN=CAcert Class 3 Ro[...]) not found |
| 216 | + gpgsm: certificate imported |
| 217 | + |
| 218 | + gpgsm: total number processed: 1 |
| 219 | + gpgsm: imported: 1 |
| 220 | +@end example |
| 221 | +@end cartouche |
| 222 | + |
| 223 | +gpgsm tells you that it has imported the certificate. It is now |
| 224 | +associated with the key you used when creating the request. The root |
| 225 | +certificate has not been found, so you may want to import it from the |
| 226 | +CACert website. |
| 227 | + |
| 228 | +To see the content of your certificate, you may now enter: |
| 229 | + |
| 230 | +@cartouche |
| 231 | +@example |
| 232 | + $ gpgsm -K kerckhoffs.g10code.com |
| 233 | + /home/foo/.gnupg/pubring.kbx |
| 234 | + --------------------------- |
| 235 | + Serial number: 4C |
| 236 | + Issuer: /CN=CAcert Class 3 Root/OU=http:\x2f\x2fwww.[...] |
| 237 | + Subject: /CN=kerckhoffs.g10code.com |
| 238 | + aka: (dns-name www.g10code.com) |
| 239 | + aka: (dns-name ftp.g10code.com) |
| 240 | + validity: 2005-10-28 16:20:51 through 2007-10-28 16:20:51 |
| 241 | + key type: 1024 bit RSA |
| 242 | + key usage: digitalSignature keyEncipherment |
| 243 | + ext key usage: clientAuth (suggested), serverAuth (suggested), [...] |
| 244 | + fingerprint: 0F:9C:27:B2:DA:05:5F:CB:33:19:D8:E9:65:B9:BD:4F:B1:98:CC:57 |
| 245 | +@end example |
| 246 | +@end cartouche |
| 247 | + |
| 248 | +I used @option{-K} above because this will only list certificates for |
| 249 | +which a private key is available. To see more details, you may use |
| 250 | +@option{--dump-secret-keys} instead of @option{-K}. |
| 251 | + |
| 252 | + |
| 253 | +To make actual use of the certificate you need to install it on your |
| 254 | +server. Server software usally expects a PKCS\#12 file with key and |
| 255 | +certificate. To create such a file, run: |
| 256 | + |
| 257 | +@cartouche |
| 258 | +@example |
| 259 | + $ gpgsm --export-secret-key-p12 -a >kerckhoffs-cert.pem |
| 260 | +@end example |
| 261 | +@end cartouche |
| 262 | + |
| 263 | +You will be asked for the passphrase as well as for a new passphrase to |
| 264 | +be used to protect the PKCS\#12 file. The file now contains the |
| 265 | +certificate as well as the private key: |
| 266 | + |
| 267 | +@cartouche |
| 268 | +@example |
| 269 | + $ cat kerckhoffs-cert.pem |
| 270 | + Issuer ...: /CN=CAcert Class 3 Root/OU=http:\x2f\x2fwww.CA[...] |
| 271 | + Serial ...: 4C |
| 272 | + Subject ..: /CN=kerckhoffs.g10code.com |
| 273 | + aka ..: (dns-name www.g10code.com) |
| 274 | + aka ..: (dns-name ftp.g10code.com) |
| 275 | + |
| 276 | + -----BEGIN PKCS12----- |
| 277 | + MIIHlwIBAzCCB5AGCSqGSIb37QdHAaCCB4EEggd9MIIHeTk1BJ8GCSqGSIb3DQEu |
| 278 | + [...many more lines...] |
| 279 | + -----END PKCS12----- |
| 280 | + $ |
| 281 | +@end example |
| 282 | +@end cartouche |
| 283 | + |
| 284 | +Copy this file in a secure way to the server, install it there and |
| 285 | +delete the file then. You may export the file again at any time as long |
| 286 | +as it is available in GnuPG's private key database. |
| 287 | + |
| 288 | + |
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