Patent Publication Number: US-8539239-B2

Title: Information processing apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from Japanese Patent Application No. 2010-164825 filed on Jul. 22, 2010, the entire subject matter of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The invention relates to an information processing apparatus that prepares a certificate signing request. 
     BACKGROUND 
     There has been disclosed a technology relating to an electronic certificate of an x509 format that is used in communication such as SSL (Secure Socket Layer), TLS (Transport Layer Security) and the like. In particular, Patent Document 1 discloses a client apparatus that makes out a certificate signing request (CSR) including an extended area (hereinafter referred to as “extensions”) in accordance with version 3 of the x509 format. A certificate authority makes out the electronic certificate including the extensions based on the certificate signing request prepared by the client apparatus. 
     SUMMARY OF THE INVENTION 
     Illustrative aspects of exemplary embodiments of the present invention provide a technology which enables a user to easily acquire one of a certificate signing request including extensions and a certificate signing request not including extensions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an example of an information processing system according to a first exemplary embodiment of the invention; 
         FIG. 2  shows an example of a CSR preparing process; 
         FIG. 3  shows an example of a CSR preparation screen; 
         FIG. 4  shows an example of a CSR selection screen; 
         FIG. 5  shows an example of memory contents of a VRAM and an NVRAM; 
         FIG. 6  shows a flow chart of a CSR preparing process according to a second exemplary embodiment; 
         FIG. 7  shows an example of memory contents of a VRAM and an NVRAM; 
         FIG. 8  shows a flow chart of a CSR preparing process and a CSR acquiring process of a third exemplary embodiment; 
         FIG. 9  shows a flow chart of a CSR deleting process; and 
         FIG. 10  shows an example of memory contents of a VRAM and an NVRAM. 
     
    
    
     DETAILED DESCRIPTION 
     &lt;General Overview&gt; 
     However, there is a certificate authority that cannot make out an electronic certificate based on a certificate singing request including extensions. Accordingly, when a user wants the corresponding certificate authority to make out an electronic certificate, the user is required to enable a client apparatus to prepare a certificate signing request not including extensions. 
     Therefore, illustrative aspects of exemplary embodiments of the present invention provide a technology which enables a user to easily acquire one of a certificate signing request including extensions and a certificate signing request not including extensions. 
     According to one illustrative aspect of the invention, there is provided an information processing apparatus comprising: an acquiring unit that is configured to acquire specific information; a preparation unit that is configured to make out a certificate signing request based on the specific information, wherein the preparation unit is configured to make out a first type certificate signing request including extensions and to make out a second type certificate signing request not including extensions; a display control unit that is configured to display a selection screen on a display unit; and an output unit that is configured to output one of the first type certificate signing request and the second type certificate request to an outside accoding to selecting by a user in the selection screen. 
     According thereto, the information processing apparatus outputs one of the first and second type certificate signing requests according to a user&#39;s selection on the selection screen. Therefore, the user can select one of the first and second type certificate signing requests according to the selection screen, thereby easily acquiring one of the first and second type certificate signing requests. 
     According to another illustrative aspect of the invention, in the information processing apparatus, the selection screen is a screen that allows the user to select one of a first type certificate authority and a second type certificate authority that is different from the first type certificate authority, wherein when the user selects the first type certificate authority in the selection screen, the output unit outputs the first type certificate signing request, and wherein when the user selects the second type certificate authority in the selection screen, the output unit outputs the second type certificate signing request. 
     According thereto, by selecting one of the first and second type certificate authorities, the user can select the first or second type certificate signing request. In other words, the user can select one of the first and second type certificate signing requests based on the certificate authority that should make out a certificate. Thus, the user can easily image the options. Even if the user does not have sufficient knowledge about a difference between the first and second type certificate signing requests, the user can appropriately select one of the first and second type certificate signing requests. 
     According to still another illustrative aspect of the invention, in the information processing apparatus, the preparation unit makes out both the first type certificate signing request and the second type certificate signing request based on the specific information, and wherein the display control unit displays the selection screen on the display unit after the preparation unit makes out both the first type certificate signing request and the second type certificate signing request. 
     According thereto, after making out the first and second type certificate signing requests, the information processing apparatus can output the first or second type certificate signing request that is selected by the user. Therefore, compared to a configuration in which a user selects one of the first and second type certificate signing requests and then the one certificate signing request is made out and output, it is possible to shorten a time period from the user selection to the output of the certificate signing request. 
     According to still another illustrative aspect of the invention, in the information processing apparatus, the preparation unit makes out both the first type certificate signing request and the second type certificate signing request in a memory, and wherein the preparation unit is configured to: delete the second type certificate signing request from the memory when the user selects for the first type certificate singing request in the selection screen; and delete the first type certificate signing request from the memory when the user selects for the second type certificate singing request in the selection screen. 
     According thereto, the information processing apparatus can quickly delete the non-selected first or second certificate signing request of the prepared first and second certificate signing requests from the memory. 
     According to still another illustrative aspect of the invention, in the information processing apparatus, the preparation unit makes out both the first type certificate signing request and the second type certificate signing request in a memory, and wherein the preparation unit is configured to delete the first type and second type certificate signing requests from the memory when a first certificate, which is made out based on the first type certificate signing request, or a second certificate, which is made out based on the second type certificate signing request, is installed into the information processing apparatus. 
     According thereto, the information processing apparatus does not delete the first and second type certificate signing requests until the first or second certificate is installed in the information processing apparatus. Therefore, when a certificate authority does not make out a certificate based on the one certificate signing request that is selected according to the selection screen and the user wants the certificate authority to make out a certificate based on the other certificate signing request, for example, the user can acquire the other certificate signing request from the information processing apparatus without enabling the information processing apparatus to re-prepare the other certificate signing request. 
     According to Still another illustrative aspect of the invention, in the information processing apparatus, the preparation unit is configured to: make out the first type certificate signing request without making out the second type certificate signing request when the user selects for the first type certificate signing request in the selection screen; and make out the second type certificate signing request without making out the first type certificate signing request when the user selects for the second type certificate signing request in the selection screen. 
     According thereto, the information processing apparatus makes out only one certificate signing request that is selected by the user. The information processing apparatus does not have to prepare a certificate signing request that is not selected by the user. Thus, it is possible to reduce the resource burden of the information processing apparatus (for example, burden of the preparing process and burden of the memory). 
     According to still another illustrative aspect of the invention, in the information processing apparatus, the preparation unit is further configured to: when the user selects for the first type certificate signing request, make out a first secret key and a first public key and make out the first type certificate signing request including the first public key; and when the user selects for the second type certificate singing request, make out a second secret key and a second public key and make out the second type certificate signing request including the second public key. 
     According to still another illustrative aspect of the invention, the information processing apparatus further comprises a memory control unit that is configured to: associate and store a first certificate and the first secret key in the memory when the first certificate, which is made out based on the first type certificate signing request, is installed in the information processing apparatus; and associate and store a second certificate and the second secret key in the memory when the second certificate, which is made out based on the second type certificate signing request, is installed in the information processing apparatus. 
     According thereto, the information processing apparatus can use the installed certificate to communicate with another device. 
     According to still another illustrative aspect of the invention, the preparation unit is configured to: delete the second secret key from the memory, when the first certificate is installed in the information processing apparatus; and delete the first secret key from the memory, when the first certificate is installed in the information processing apparatus. 
     Incidentally, a control method for the above-described information processing apparatus, a method of preparing a certificate signing request, a computer program for the above-described information processing apparatus and a non-transitory computer-readable medium which stores the computer program are also novel and useful. 
     &lt;Exemplary Embodiments&gt; 
     Exemplary embodiments of the invention will now be described with reference to the drawings. 
     [First Exemplary Embodiment] 
     (System Configuration) 
     A first exemplary embodiment will be described with reference to the drawings. As shown in  FIG. 1 , an information processing system  1  includes a LAN  4 , an Internet  6 , a multi-function device  10  (a peripheral apparatus of a terminal apparatus  60 ), a terminal apparatus  60  and certificate authorities  70 ,  80 . The multi-function device  10 , the terminal apparatus  60  and the certificate authority  70  are connected to the LAN  4 . The multi-function device  10 , the terminal apparatus  60  and the certificate authority  70  can communicate with each other via the LAN  4 . The LAN  4  and the certificate authority  80  are connected to the Internet  6 . The terminal apparatus  60  and the certificate authority  80  can communicate with each other via the LAN  4  and the Internet  6 . 
     (Configuration of Multi-function Device  10 ) 
     A configuration of the multi-function device  10  will be described. The multi-function device  10  includes a printing function, a scanner function, a copier function, an IPFAX function, electronic mail transmitting and receiving functions and the like. The multi-function device  10  includes a display unit  12 , an operation unit  14 , a network interface  16 , a scan execution unit  18 , a printing execution unit  20  and a control unit  22 . The respective units  12  to  22  are connected to a bus line  24 . The display unit  12  is a display for displaying a variety of information. The operation unit  14  has a plurality of keys. A user can operate the operation unit  14  to input various instructions to the multi-function device  10 . The network interface  16  is connected to the LAN  4 . The scan execution unit  18  has a scan mechanism such as CIS, CCD and the like and scans a scan target to generate image data. The printing execution unit  20  has a printing mechanism of an inkjet head manner, a laser manner and the like and performs a printing operation in response to an instruction from the control unit  22 . The control unit  22  includes a CPU  30  and a memory  32 . The memory  32  includes a ROM  34 , a VRAM (volatile memory)  36  and an NVRAM (non-volatile memory)  38 . The ROM  34  stores therein a program  35 . The CPU  30  executes a process in accordance with the program  35  in the ROM  34 . The CPU  30  executes a process in accordance with the program  35  so as to implement the functions of respective units  40 ,  42 ,  44 ,  46  and  48 . 
     (Configuration of Terminal Apparatus  60 ) 
     The terminal apparatus  60  is a personal computer and the like, for example. The terminal apparatus  60  is connected to the LAN  4 . The terminal apparatus  60  includes a display unit  62 , an operation unit  64 , a network interface  65  and a control unit  66 . The respective units are connected to a bus line  61 . The display unit  62  is a display for displaying a variety of information. The operation unit  64  includes a keyboard, a mouse, and the like. The network interface  65  is connected to the LAN  4 . The control unit  66  includes a CPU  67  and a memory  68 . 
     (Configuration of Certificate Authorities  70 ,  80 ) 
     The certificate authorities  70 ,  80  are authorities that make out a certificate in response to a certificate signing request (hereinafter, referred to as ‘CSR’) made by the multi-function device  10 . The CSR is classified into: a first type CSR including a basic area and extensions; and a second type CSR that includes a basic area but does not include extensions. In the basic area, various information of a certificate user such as common name, organization, department, city, province, country and the like (hereinafter, referred to as ‘basic area information’) are described. In the extensions, a variety of information such as ‘extended key usage (ExtendedKeyUsage)=email protection (emailProtection)’, ‘subject alternative name (SubjectAltName)=IPv4 address (IPv4addresss)’ and the like are described. The ‘extended key usage’, the ‘subject alternative name’ and the like are item names of the information that is described in the extensions. In addition, the ‘email protection’, the ‘IPv4 address’ and the like are item contents. The first CSR is a CSR for making out a certificate of version 3 of an x509 format (hereinafter, referred to as ‘CSR of x509v3’), for example. The second type CSR is a CSR for making out a certificate of version 1 of the x509 format (hereinafter, referred to as ‘CSR of x509v1’), for example. The certificate authority  70  makes out a certificate including extensions based on the first type CSR including extensions. In addition, the certificate authority  70  can make out a certificate not including extensions based on the second type CSR that does not include extensions. On the other hand, the certificate authority  80  can make out a certificate not including extensions based on the second type CSR, but the certificate authority  80  cannot make out a certificate based on the first type CSR including the extensions. In the followings, the certificate authority  70  and the certificate authority  80  having the above characteristics are sometimes referred to as ‘Private certificate authority  70 ’ and ‘Public certificate authority  80 ’, respectively. Here, the Private certificate authority means an authority that can make out a certificate, only based on a CSR that the multi-function device  10  prepares in accordance with an application of the multi-function device  10 . The Public certificate authority  80  means an enterprise, a public institution and the like that makes out a certificate. In this exemplary embodiment, the IPv4 address is adopted as an IP address. However, the IP address is not limited to the IPv4 address. For example, an IPv6 address may be adopted. 
     (Process executed by Multi-function Device  10 ) 
     In the followings, a process that is executed by the control unit  22  of the multi-function device  10  will be described with reference to  FIGS. 2 to 5 . 
     A user can use the operation unit  64  of the terminal apparatus  60  to access the web server installed on the multi-function device  10 . When the user performs an operation for displaying a certificate setting screen (not shown), a display control unit  44  (refer to  FIG. 1 ) transmits data, which indicates the certificate setting screen, to the terminal apparatus  60 . As a result, the terminal apparatus  60  displays the certificate setting screen on the display unit  62 . The certificate setting screen is a screen for making a variety of settings relating to a certificate. The certificate setting screen has a first hyperlink for displaying a CSR preparation screen (refer to  FIG. 3 ) and a second hyperlink screen for displaying an install screen (not shown). The user can use the operation unit  64  to operate the first hyperlink, thereby performing an operation for displaying the CSR preparation screen (refer to  FIG. 3 ). In addition, the user can use the operation unit  64  to operate the second hyperlink, thereby performing an operation for displaying the install screen. The install screen is a screen that enables the user to perform an install operation for installing a certificate acquired from the certificate authority in the multi-function device  10 , which will be described later. 
     (CSR Preparing Process) 
     Referring to  FIG. 2 , a CSR preparing process will be described. When a user performs an operation for displaying the CSR preparation screen, the display control unit  44  (refer to  FIG. 1 ) transmits data, which indicates a CSR preparation screen  100  (refer to  FIG. 3 ), to the terminal apparatus  60 . As a result, the CSR preparation screen  100  is displayed on the display unit  62  of the terminal apparatus  60  (S 2  in  FIG. 2 ). 
     As shown in  FIG. 3 , the CSR preparation screen  100  includes an input unit  102 , a selection unit  104  and an OK button  106 . The input unit  102  has input columns  102   a  to  102   f  of each information of common name, organization, department, city, province and country. The information that should be input in the input columns  102   a  to  102   f  is the basic area information. The selection unit  104  has radio buttons  104   a ,  104   b  and an input column  104   c . The radio button  104   a  (automatic) is a button for selecting that the IPv4 address of the multi-function device  10  will be used as a subject alternative name (SubjectAltName) that can be included in extensions. The radio button  104   b  (manual) is a button for selecting that a character string input in the input column  104   c  will be used as an alias name of a certificate. The user can check any one of the radio buttons  104   a ,  104   b . The user can operate the operation unit  64  to input specific information in the input columns  102   a  to  102   f , to check any one of the radio button  104   a ,  104   b  and to operate the OK button  106 . When the OK button  106  is operated at a state in which the specific information is input in the input columns  102   a  to  102   f  and any one of the radio buttons  104   a ,  104   b  is checked, the control unit  66  of the terminal apparatus  60  transmits the basic area information, which is input in the input columns  102   a  to  102   f , the check information, which indicates that any one of the radio buttons  104   a ,  104   b  is checked, and the character string, which is input in the input column  104   c , to the multi-function device  10 . 
     An acquiring unit  40  (refer to  FIG. 1 ) monitors whether the information transmitted from the terminal apparatus  60  is received (S 4 ). The acquiring unit  40  (refer to  FIG. 1 ) receives and acquires the information from the terminal apparatus  60 , wherein the information includes the basic area information, the check information and the character string input in the input column  104   c . When the acquiring unit  40  acquires the information (YES in S 4 ), a preparation unit  42  (refer to  FIG. 1 ) makes out a key pair for a first type CSR (S 6 ). Specifically, in S 6 , the preparation unit  42  makes out a first public key that should be included in a first type CSR and a first secret key that corresponds to the first public key. Then, the preparation unit  42  makes out a first type CSR by using the basic area information, the check information, the character string input in the input column  104   c  and the first public key (S 8 ). Specifically, in S 8 , the preparation unit  42  prepares a basic area including the basic area information and the first public key. In addition, the preparation unit  42  acquires information that should be included in extensions from the program  35 . Specifically, when the check information indicates that the radio button  104   a  is checked, the preparation unit  42  acquires, as the ‘subject alternative name (SubjectAltName)=IPv4 address (IPv4address) of multi-function device  10 ’ that should be included in extensions, the name of the subject alternative name (SubjectAltName) and the IPv4 address that is set in the multi-function device  10  from the program  35 . On the other hand, when the check information indicates that the radio button  104   b  is checked, the preparation unit  42  further acquires, as the item name of the information that should be included in extensions, the ‘subject alternative name (SubjectAltName)’ from the program  35  and acquires as the item content, the character string input in the input column  114   c . The preparation unit  42  makes out extensions including the acquired information. Although specifically not described in this exemplary embodiment, the information that should be included in the extensions is not limited to the subject alternative name (SubjectAltName). For example, the information that should be included in the extensions may include the extended key usage (ExtendedKeyUsage) and the like. Further, the information that should be included in the extensions may include the other information, instead of including the subject alternative name (SubjectAltName). The selection unit  104  of the extensions setting of the CSR preparation screen  100  may be provided with the other check column or input column in addition to the respective columns  104   a  to  104   c  or instead of the respective columns  104   a  to  104   c . The information that should be included in the extensions may any one of a preset value that is acquired from the program  35  and a value that is set by a user. In other words, the information that should be included in the extensions is generated by the information that is input from the CSR preparation screen  100  by the CSR preparing process and the information that is acquired from the program  35 . The preparation unit  42  makes out a first type CSR by combining the prepared basic area information and extensions. When the preparation unit  42  makes out the first type CSR, the preparation unit  42  saves the first type CSR and the first secret key in the VRAM  36  (S 10 ). 
     Then, the preparation unit  42  makes out a key pair for a second type CSR (S 12 ). Specifically, the preparation unit  42  makes out a second public key and a second secret key. Then, the preparation unit  42  makes out a second type CSR by using the basic area information and the second public key (S 14 ). Specifically, in S 14 , the preparation unit  42  makes out a basic area including the basic area information and the second public key, thereby preparing a second type CSR. As described above, the second type CSR does not include extensions. When the preparation unit  42  makes out the second type CSR, the preparation unit  42  stores the second type CSR and the second secret key in the VRAM  36  (S 16 ). Accordingly, at this time, as shown in  FIG. 5(   a ), the VRAM  36  stores information, in which the first type CSR and the first secret key are associated with each other, and information, in which the second type CSR and the second secret key are associated with each other. Then, the display control unit  44  transmits data, which indicates a CSR selection screen  110  (refer to  FIG. 4) , to the terminal apparatus  60 . As a result, the CSR selection screen  110  is displayed on the display unit  62  of the terminal apparatus  60  (S 18  in  FIG. 2 ). 
     As shown in  FIG. 4 , the CSR selection screen  110  includes: a message to prompt the user to select a certificate authority; a radio button  112  for selecting the Public certificate authority  80  (refer to  FIG. 1 ); a radio button  114  for selecting the Private certificate authority  70  (refer to  FIG. 1 ); and an OK button  116 . The user can use the operation unit  64  to check one of the radio buttons  112 ,  114  and to operate the OK button  116 . When the user checks the radio button  112 , it means that the user selects, as a certificate authority for preparing a certificate by using a CSR, the Public certificate authority  80 . In other words, it means that the user selects the preparation of the second type CSR. On the other hand, when the user checks the radio button  114 , it means that the user selects, as a certificate authority for preparing a certificate by using a CSR, the Private certificate authority  70 . As described above, the Private certificate authority  70  can make out a certificate based on both the first type CSR and the second type CSR. However, in this exemplary embodiment, when the user checks the radio button  114 , it means that the user selects the first type CSR. In this exemplary embodiment, the user can select any one of the Public certificate authority  80  and the Private certificate authority  70  in accordance with the CSR selection screen  110 , thereby selecting any one of the first type CSR and the second type CSR. When the user operates the OK button  116 , the control unit  66  of the terminal apparatus  60  transmits the selection result of the user to the multi-function device  10 . 
     As described above, in this exemplary embodiment, the user can select any one of the first type CSR and the second type CSR based on the certificate authority that should prepare a certificate. Thus, the user can easily image the options. Even when the user does not have sufficient knowledge about a difference between the first and second type CSRs, the user can appropriately select one of the first and second type CSRs. 
     The preparation unit  42  determines whether the user selects the first type CSR (S 20 ). Specifically, when the selection result from the terminal apparatus  60  indicates the Private certificate authority  70 , the preparation unit  42  determines YES in S 20 . On the other hand, when the selection result from the terminal apparatus  60  indicates the Public certificate authority  80 , the preparation unit  42  determines NO in S 20 . When a result of the determination in S 20  is YES, the preparation unit  42  stores the first secret key, which is stored in the VRAM  36 , in the NVRAM  38 . Further, the preparation unit  42  deletes the first secret key from the VRAM  36  (S 21 ). Then, the preparation unit  42  deletes the second type CSR and the second secret key from the VRAM  36  (S 22 ). According to this configuration, the multi-function device  10  can rapidly delete the second type CSR and the second secret key from the VRAM  34 . At the completion time of S 22 , as shown in  FIG. 5(   b ), the VRAM  36  stores the first type CSR. In addition, the NVRAM  38  stores the first secret key. Then, an output unit  46  (refer to  FIG. 1)  transmits the first type CSR in the VRAM  36  to the terminal apparatus  60 . As a result, the first type CSR is displayed on the display unit  62  (S 24 ). The user can confirm the content of the first type CSR. When the user uses the operation unit  64  to perform a predetermined operation, the control unit  66  saves the first type CSR, which is displayed on the display unit  62 , in the memory  68  of the terminal apparatus  60 . 
     When a result of the determination in S 20  is NO, the preparation unit  42  stores the second secret key, which is stored in the VRAM  36 , in the NVRAM  38 . Further, the preparation unit  42  deletes the second secret key from the VRAM  36  (S 25 ). Then, the preparation unit  42  deletes the first type CSR and the first secret key from the VRAM  36  (S 26 ). According to this configuration, the multi-function device  10  can rapidly delete the first type CSR and the first secret key from the VRAM  36 . Then, the output unit  46  transmits the second type CSR in the VRAM  36  to the terminal apparatus  60 . As a result, the second type CSR is displayed on the display unit  62  (S 28 ). The user can confirm the content of the second type CSR. When the user uses the operation unit  64  to perform a predetermined operation, the control unit  66  saves the second type CSR, which is displayed on the display unit  62 , in the memory  68  of the terminal apparatus  60 . 
     In this exemplary embodiment, before the user selects one of the first type CSR and the second type CSR, the first type CSR and the second type CSR have been already prepared. Accordingly, when the user performs the selection, the multi-function device  10  can immediately transmit the first or second type CSR. Thus, compared to a configuration in which after a user selects one of the first type CSR and the second type CSR, the corresponding one CSR is prepared and output, it is possible to shorten a time period from the user selection to the transmission of the CSR. 
     (Process After CSR Preparing Process is Completed) 
     The process of the multi-function device  10  after the CSR preparing process is completed will be described. When the CSR preparing process (refer to  FIG. 2 ) is completed, as shown in  FIG. 5(   c ), a memory control unit  48  (refer to  FIG. 1)  deletes the first or second CSR, which has been transmitted to the terminal apparatus  60  in S 24  or S 28 , from the VRAM  36 . 
     The user can use the operation unit  64  of the terminal apparatus  60  to perform an operation for designating a certificate authority. In this case, the terminal apparatus  60  transmits the CSR acquired from the multi-function device  10  (CSR that is saved in the memory  68 ) to a certificate authority that is designated by the user. 
     For example, when the Private certificate authority  70  receives the first type CSR from the terminal apparatus  60 , the Private certificate authority  70  makes out a first certificate including extensions based on the first type CSR and transmits the first certificate to the terminal apparatus  60 . In addition, for example, when the Public certificate authority  80  receives the second type CSR from the terminal apparatus  60 , the Public certificate authority  80  makes out a second certificate not including extensions based on the second type CSR and transmits the second certificate to the terminal apparatus  60 . Incidentally, if the user selects the Public certificate authority  80  even though the first type CSR is acquired, the Public certificate authority  80  cannot make out a certificate based on the first type CSR. In this case, the terminal apparatus  60  cannot obtain a certificate. 
     When the terminal apparatus  60  receives the first certificate from the Private certificate authority  70 , the terminal apparatus  60  stores the first certificate in the memory  68 . Then, as described above, the user can use the operation unit  64  of the terminal apparatus  60  to execute an operation for displaying the install screen (not shown). When an operation for displaying the install screen is executed, the display control unit  44  transmits data, which indicates the install screen, to the terminal apparatus  60 . As a result the install screen is displayed on the display unit  62  of the terminal apparatus  60 . The user can use the operation unit  64  of the terminal apparatus  60  to execute an install operation for installing the first certificate stored in the memory  68  into the NVRAM  38  of the multi-function device  10 , in the install screen. In this case, the control unit  66  of the terminal apparatus  60  transmits the first certificate to the multi-function device  10 . As a result, as shown in  FIG. 5(   d ), the memory control unit  48  of the multi-function device  10  associates and stores (installs) the first certificate and the first secret key in the NVRAM  38 . Like the first certificate, when the terminal apparatus  60  receives the second certificate from the Public certificate authority  80 , the terminal apparatus  60  transmits the second certificate to the multi-function device  10 . As a result, the memory control unit  48  of the multi-function device  10  associates and stores (installs) the second certificate and the second secret key in the NVRAM  38 . 
     When the certificate and the secret key are installed in the NVRAM  36 , the multi-function device  10  can use the installed certificate to communicate with another device (not shown). 
     The information processing system  2  of this exemplary embodiment has been described. In this exemplary embodiment, the CSR selection screen  110  shown in  FIG. 4  enables the user to select one of the first and second type CSRs. When the user selects the first type CSR (YES in S 20  of  FIG. 2 ), the output unit  46  transmits the first type CSR to the terminal apparatus  60  (S 30 ). On the other hand, when the user selects the second type CSR (NO in S 20 ), the output unit  46  transmits the second type CSR to the terminal apparatus  60  (S 30 ). Accordingly, the user executes the operation of selecting one of the first type CSR and the second type CSR in accordance with the CSR selection screen  110 , thereby easily acquiring the CSR. 
     The correspondence between the configuration of this exemplary embodiment and the configuration of the invention will be described. The multi-function device  10  is one example of the ‘information processing apparatus.’ The CSR selection screen  110  of  FIG. 4  is one example of the ‘selection screen.’ The display unit  62  of the terminal apparatus  60  is one example of the ‘display unit.’ The result YES in S 20  of  FIG. 2  and the result NO in S 20  are examples of the ‘first case’ and the ‘second case’, respectively. The Private certificate authority  70  and the Public certificate authority  80  are examples of the ‘first type certificate authority’ and the ‘second type certificate authority’, respectively. The basic area information that is acquired in S 4  of  FIG. 2 , the information that should be included in the extensions and is acquired from the program  35  in S 8  of  FIG. 2  and the character string that is input in the input column  104   c  (refer to  FIG. 3 ) and is acquired in S 4  of  FIG. 2  are examples of the ‘specific information.’ 
     [Second Exemplary Embodiment] 
     A second exemplary embodiment of the present invention will be described. Incidentally, a detailed description common to the first exemplary embodiment will be omitted. 
     (CSR Preparing Process) 
     The differences between the second exemplary embodiment and the first exemplary embodiment are described with reference to  FIGS. 6 and 7 . S 40  and S 42  of  FIG. 6  are the same as S 2  and S 4  of  FIGS. 2 . S 44  and S 46  of  FIG. 6  are the same as S 18  and S 20  of  FIG. 2 . When the first type CSR is selected (YES in S 46 ), the preparation unit  42  makes out a key pair for the first type CSR (S 48 ). Then, the preparation unit  42  makes out the first type CSR (S 50 ). The first type CSR and the first secret key are prepared in the VRAM  36 . Then, the preparation unit  42  stores the first secret key, which is stored in the, VRAM  36 , in the NVRAM  38  (S 52 ). In S 52 , the preparation unit  42  further deletes the first secret key from the VRAM  36 . At the completion time of S 52 , as shown in  FIG. 7(   a ), the VRAM  36  stores the first type CSR. In addition, the NVRAM  38  stores the first secret key. Then, the output unit  46  transmits the first type CSR to the terminal apparatus  60 . As a result, the first type CSR is displayed on the display unit  62  (S 54 ). 
     Like the case where the first type CSR is selected, when the second type CSR is selected (NO in S 46 ), the preparation unit  42  makes out a key pair for the second type CSR (S 56 ) and makes out the second type CSR (S 58 ). Then, the preparation unit  42  stores the second secret key in the NVRAM  38  (S 60 ). Then, the output unit  46  transmits the second type CSR to the terminal apparatus  60 . As a result, the second type CSR is displayed on the display unit  62  (S 62 ). 
     (Process After CSR Preparing Process is Completed) 
     The process of the multi-function device  10  after the CSR preparing process is completed is the substantially same as the first exemplary embodiment. Accordingly, when the first type CSR is transmitted in S 54  of  FIG. 6 , the memory control unit  48  deletes the first type CSR from the VRAM  36  as shown in  FIG. 7(   b ). Like the first exemplary embodiment, the user can make a request for certificate preparation to acquire the first certificate, which is prepared on the basis of the first type CSR, or the second certificate, which is prepared on the basis of the second type CSR, so as to install the first certificate or the second certificate in the multi-function device  10 . As shown in  FIG. 7(   c ), for example, when the install operation of the first certificate is executed, the memory control unit  48  of the multi-function device  10  associates and stores the first certificate and the first secret key in the NVRAM  38 . 
     In the second exemplary embodiment, the multi-function device  10  makes out only one type CSR that is selected by the user. The multi-function device  10  does not have to prepare a CSR that is not selected by the user. Thus, it is possible to reduce the resource processing burden of the multi-function device  10  (for example, burden of the preparation processing and the burden of the memory). In the second exemplary embodiment, the result YES in S 46  of  FIG. 6  and the result NO in S 46  are examples of the ‘first case’ and the ‘second case’, respectively. 
     [Third Exemplary Embodiment] 
     A third exemplary embodiment of the present invention will be described. 
     Incidentally, a detailed description common to the first exemplary embodiment will be omitted. 
     (CSR Preparing Process) 
     The differences between a third exemplary embodiment and the first exemplary embodiment are described with reference to  FIGS. 8 to 10 . In the third exemplary embodiment, when an operation of starting the CSR preparing process is executed, the control unit  22  executes processes of S 70  to S 84  of  FIG. 8 . The processes of S 70  to S 84  are the substantially same as S 2  to S 16  of  FIG. 2 . However, in S 78  of the third exemplary embodiment, the preparation unit  42  saves the first type CSR and the first secret key in the NVRAM  38 , differently from S 10  of  FIG. 2 . Likewise, in S 84  of the third exemplary embodiment, the preparation unit  42  saves the second type CSR and the second secret key in the NVRAM  38 , differently from S 16  of  FIG. 2 . Accordingly, at the completion time of S 84 , as shown in  FIG. 10(   a ), the NVRAM  38  stores the information in which the first type CSR and the first secret key are associated with each other and the information in which the second type CSR and the second secret key are associated with each other. 
     The processes of S 86  and S 88  are the same as S 18  and S 20  of  FIG. 2 . In addition, the processes of S 90  and S 92  are the same as S 24  and S 26  of  FIG. 2 . In the third exemplary embodiment, even when the CSR preparing process is ended, both the CSR, which is selected by the user, and the CSR, which is not selected by the user, are continuously saved in the NVRAM  38  (refer to  FIG. 10(   a )). 
     (CSR Deleting Process) 
     A process after the CSR preparing process will be described. Like the first exemplary embodiment, the user makes a request for certificate preparation to acquire the first certificate, which is prepared on the basis of the first type CSR, or the second certificate, which is prepared on the basis of the second type CSR, so as to install the first certificate or the second certificate in the multi-function device  10 . For example, when the first certificate is installed in the multi-function device  10 , as shown in  FIG. 10(   b ), the NVRAM  38  stores the first certificate, the first type CSR, the first secret key, the second type CSR and the second secret key. 
     When the certificate is installed in the NVRAM  38 , a CSR deleting process of  FIG. 9  starts. The memory control unit  48  (refer to  FIG. 1 ) specifies a public key that is included in the installed certificate (S 100 ). Then, the memory control unit  48  determines whether the secret key corresponding to the public key specified in S 100  (hereinafter, referred to as ‘specific secret key’) is in the NVRAM  38  (S 102 ). When the specific secret key is in the NVRAM  38  (YES in S 102 ), the memory control unit  48  determines whether the specific secret key is associated with the first type CSR (S 104 ). For example, when the specific secret key is the first secret key, the memory control unit determines YES in S 104 . When the specific secret key is the second secret key, the memory control unit determines NO in S 104 . 
     When the specific secret key is the first secret key (YES in S 104 ), the preparation unit  42  deletes the second type CSR and the second secret key from the NVRAM  38  (S 106 ). Then, the preparation wait  42  deletes the first type CSR from the NVRAM  38  (S 108 ). When the step of S 108  is completed, the memory control unit  48  associates and stores the installed certificate (i.e., first certificate) and the first secret key in the NVRAM  38 . Accordingly, at the completion time of S 108 , the NVRAM  38  stores therein the first certificate and the first secret key with being associated with each other as shown in  FIG. 10(   c ). 
     On the other hand, when the specific secret key is the second secret key (NO in S 104 ), the preparation unit  42  deletes the first type CSR and the first secret key from the NVRAM  38  (S 110 ). Then, the preparation unit  42  deletes the second type CSR from the NVRAM  38  (S 112 ). When the step of S 112  is completed, the memory control unit  48  associates and stores the installed certificate (i.e., second certificate) and the second secret key in the NVRAM  38 . 
     When the step of S 108  or S 112  is completed, the display control unit  44  transmits data, which indicates a screen showing that the install of the certificate has been completed, to the terminal apparatus  60  (S 114 ). Thereby, the user can know that the install of the certificate has been completed. When the step of S 114  is completed, the CSR deleting process is ended. On the other hand, when the specific secret key is not in the NVRAM  38  (NO in S 102 ), the display control unit  44  transmits data, which indicates a screen showing an error, to the terminal apparatus  60  (S 116 ). When the step of S 116  is completed, the CSR deleting process is ended. 
     As described above, in the third exemplary embodiment, as shown in S 78  and S 84  of  FIG. 8 , in the CSR preparing process, the preparation unit  42  stores the information in which the first type CSR and the first secret key are associated with each other and the information in which the second type CSR and the second secret key are associated with each other in the NVRAM  38 . The multi-function device  10  does not delete the first and second type CSRs until the first or second certificate is installed in the multi-function device  10 . For example, there is a possibility that the user will acquire the first type CSR from the multi-function device  10  and erroneously transmit the first type CSR to the Public certificate authority  80 . As described above, the Public certificate authority  80  cannot make out a certificate based on the first type CSR. The user who knows that a certificate is not prepared based on the first type CSR may consider transmitting the second type CSR to the Public certificate authority  80 . In the third exemplary embodiment, the certificate setting screen further includes a third hyperlink for displaying the CSR selection screen (refer to  FIG. 4 ). Accordingly, in the above situation, the user can use the operation unit  64  of the terminal apparatus  60  to operate the third hyperlink in the certificate setting screen, thereby executing the operation for displaying the CSR selection screen (refer to  FIG. 4 ). When the operation for displaying the CSR selection screen is executed, the control unit  66  of the terminal apparatus  60  transmits a predetermined command to the multi-function device  10 . In this case, the control unit  22  of the multi-function device  10  performs the same processes as S 86  to S 92  of  FIG. 8 . In other words, the display control unit  44  transmits the data, which indicates the CSR selection screen  110  (refer to  FIG. 4 ), to the terminal apparatus  60 . As a result, the CSR selection screen  110  (refer to  FIG. 4 ) is displayed on the display unit  62  of the terminal apparatus  60  (S 86  in  FIG. 8 ). The user can select the second type CSR (i.e., ‘Public’) in accordance with the CSR selection screen  110  (refer to  FIG. 4 ), so that the user can acquire the second type CSR. In other words, the user can acquire the second type CSR from the multi-function device  10  without requiring the multi-function device  10  to prepare the second type CSR again. Incidentally, in the third exemplary embodiment, the result YES in S 88  of  FIG. 8  and the result NO in S 88  are examples of the ‘ first case’ and the ‘second case’, respectively. 
     &lt;Modifications to Exemplary Embodiments&gt; 
     Modifications to the above-described exemplary embodiments will be described. 
     (1) A CSR of x509v3 including extensions may be the first type CSR, and a CSR of x509v3 including no information in extensions may be the second type CSR. 
     (2) The output of the first type or second type CSR may be performed by an arbitrary method without being limited to the download to the memory of the terminal apparatus  60 . For example, the displayed CSR information may be designated by the user, and a content thereof may be copied and pasted to a text file so as to be saved. 
     (3) The certificate authority  70  may be configured such that the certificate authority  70  is unable to prepare a certificate based on the second type CSR. In other words, generally, the ‘first type certificate authority’ may be a certificate authority that can make out a certificate at least based on the first type CSR. In addition, the ‘second type certificate authority’ may be a certificate authority that cannot make out a certificate based on the first type CSR and can prepare a certificate based on the second type CSR. 
     (4) The respective information may be displayed on the display unit  12  of the multi-function device  10 . In this modified embodiment, the display unit  12  of the multi-function device  10  is an example of the ‘display unit.’ 
     (5) In the above-described exemplary embodiments, the multi-function device  10  has been exemplified. Alternative to the multi-function device  10 , a PC, a server a printer, a scanner, a mobile terminal (PDA, mobile phone and the like) may be used. Each of the devices is included in the configuration of the ‘information processing system.’ 
     The specific exemplary embodiments of the invention have been described. However, the embodiments are exemplary and not to limit the scope of the invention. The technologies defined in the claims include the modified and changed examples to the exemplary embodiments. 
     In addition, the technical elements described and shown in the specification and the drawings provide the technical usefulness independently or in combination and are not limited to a combination of the claims at the time of filing this application. Further, the technologies exemplified in the specification or drawings achieve the purposes at the same time and have a technical usefulness inasmuch as one purpose is realized.