--- 1/draft-ietf-dhc-sedhcpv6-17.txt 2016-12-05 00:13:09.545758197 -0800 +++ 2/draft-ietf-dhc-sedhcpv6-18.txt 2016-12-05 00:13:09.605759556 -0800 @@ -1,25 +1,25 @@ DHC Working Group S. Jiang Internet-Draft Huawei Technologies Co., Ltd Intended status: Standards Track L. Li -Expires: April 23, 2017 Y. Cui +Expires: June 7, 2017 Y. Cui Tsinghua University T. Jinmei Infoblox Inc. T. Lemon Nominum, Inc. D. Zhang - October 20, 2016 + December 4, 2016 Secure DHCPv6 - draft-ietf-dhc-sedhcpv6-17 + draft-ietf-dhc-sedhcpv6-18 Abstract DHCPv6 includes no deployable security mechanism that can protect end-to-end communication between DHCP clients and servers. This document describes a mechanism for using public key cryptography to provide such security. The mechanism provides encryption in all cases, and can be used for authentication based on pre-sharing of authorized certificates. @@ -31,21 +31,21 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on April 23, 2017. + This Internet-Draft will expire on June 7, 2017. Copyright Notice Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -61,40 +61,42 @@ 2. Requirements Language and Terminology . . . . . . . . . . . . 3 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Security Issues of DHCPv6 . . . . . . . . . . . . . . . . . . 4 5. Secure DHCPv6 Overview . . . . . . . . . . . . . . . . . . . 5 5.1. Solution Overview . . . . . . . . . . . . . . . . . . . . 5 5.2. New Components . . . . . . . . . . . . . . . . . . . . . 6 5.3. Support for Algorithm Agility . . . . . . . . . . . . . . 7 5.4. Caused change to RFC3315 . . . . . . . . . . . . . . . . 7 5.5. Applicability . . . . . . . . . . . . . . . . . . . . . . 8 6. DHCPv6 Client Behavior . . . . . . . . . . . . . . . . . . . 8 - 7. DHCPv6 Server Behavior . . . . . . . . . . . . . . . . . . . 12 - 8. Relay Agent Behavior . . . . . . . . . . . . . . . . . . . . 14 + 7. DHCPv6 Server Behavior . . . . . . . . . . . . . . . . . . . 11 + 8. Relay Agent Behavior . . . . . . . . . . . . . . . . . . . . 13 9. Processing Rules . . . . . . . . . . . . . . . . . . . . . . 14 9.1. Increasing Number Check . . . . . . . . . . . . . . . . . 14 - 10. Extensions for Secure DHCPv6 . . . . . . . . . . . . . . . . 15 - 10.1. New DHCPv6 Options . . . . . . . . . . . . . . . . . . . 15 - 10.1.1. Certificate Option . . . . . . . . . . . . . . . . . 15 - 10.1.2. Signature option . . . . . . . . . . . . . . . . . . 17 - 10.1.3. Increasing-number Option . . . . . . . . . . . . . . 19 - 10.1.4. Encrypted-message Option . . . . . . . . . . . . . . 20 + 10. Extensions for Secure DHCPv6 . . . . . . . . . . . . . . . . 14 + 10.1. New DHCPv6 Options . . . . . . . . . . . . . . . . . . . 14 + 10.1.1. Algorithm Option . . . . . . . . . . . . . . . . . . 15 + 10.1.2. Certificate Option . . . . . . . . . . . . . . . . . 17 + 10.1.3. Signature option . . . . . . . . . . . . . . . . . . 18 + 10.1.4. Increasing-number Option . . . . . . . . . . . . . . 19 + 10.1.5. Encryption Key Tag Option . . . . . . . . . . . . . 19 + 10.1.6. Encrypted-message Option . . . . . . . . . . . . . . 20 10.2. New DHCPv6 Messages . . . . . . . . . . . . . . . . . . 21 10.3. Status Codes . . . . . . . . . . . . . . . . . . . . . . 21 11. Security Considerations . . . . . . . . . . . . . . . . . . . 22 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 24 14. Change log [RFC Editor: Please remove] . . . . . . . . . . . 24 - 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 26 - 15.1. Normative References . . . . . . . . . . . . . . . . . . 26 + 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 27 + 15.1. Normative References . . . . . . . . . . . . . . . . . . 27 15.2. Informative References . . . . . . . . . . . . . . . . . 28 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 28 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29 1. Introduction The Dynamic Host Configuration Protocol for IPv6 (DHCPv6, [RFC3315]) allows DHCPv6 servers to flexibly provide addressing and other configuration information relating to local network infrastructure to DHCP clients. The protocol provides no deployable security mechanism, and consequently is vulnerable to various attacks. This document provides a brief summary of the security @@ -110,26 +112,27 @@ monitoring. The extension specified in this document applies only to end-to-end communication between DHCP servers and clients. Options added by relay agents in Relay-Forward messages, and options other than the client message in Relay-Reply messages sent by DHCP servers, are not protected. Such communications are already protected using the mechanism described in section 21.1 in [RFC3315]. This extension introduces two new DHCPv6 messages: the Encrypted- - Query and the Encrypted-Response messages. It defines four new - DHCPv6 options: the Certificate, the Signature, the Increasing- - number, and the Encrypted-message options. The Certificate, - Signature, and Increasing-number options are used for authentication. - The Encryption-Query message, Encryption-Response message and - Encrypted-message option are used for encryption. + Query and the Encrypted-Response messages. It defines six new DHCPv6 + options: the Algorithm, Certificate, Signature, Increasing-number, + Encryption Key Tag option and Encrypted-message options. The + Algorithm, Certificate, Signature, and Increasing-number options are + used for authentication. The Encryption-Query message, Encryption- + Response message, Encrypted-message option and Encryption Key Tag + option are used for encryption. 2. Requirements Language and Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119] when they appear in ALL CAPS. When these words are not in ALL CAPS (such as "should" or "Should"), they have their usual English meanings, and are not to be interpreted as [RFC2119] key words. @@ -194,86 +197,95 @@ authentication without requiring a symmetric key distribution solution for DHCP, this document defines an asymmetric key authentication and encryption mechanism. This protects against both active attacks, such as spoofing, and passive attacks, such as pervasive monitoring. 5. Secure DHCPv6 Overview 5.1. Solution Overview - The following figure illustrated secure DHCPv6 procedure. Briefly, + The following figure illustrates secure DHCPv6 procedure. Briefly, this extension establishes the server's identity with an anonymous Information-Request exchange. Once the server's identity has been established, the client may either choose to communicate with the server or not. Not communicating with an unknown server avoids revealing private information, but if there is no known server on a particular link, the client will be unable to communicate with a DHCP server. - If the client chooses to communicate with a server, it uses the - Encrypted-Query message to encapsulate its communications to the DHCP - server. The server responds with Encrypted-Response messages. - Normal DHCP messages are encapsulated in these two new messages using - the new defined Encrypted-message option. Besides the Encrypted- - message option, the Signature option is defined to verify the - integrity of the DHCPv6 messages and then authentication of client - and server. The Increasing number option is defined to detect replay - attack. + If the client chooses to communicate with the selected server(s), it + uses the Encrypted-Query message to encapsulate its communications to + the DHCP server. The server responds with Encrypted-Response + messages. Normal DHCP messages are encapsulated in these two new + messages using the new defined Encrypted-message option. Besides the + Encrypted-message option, the Signature option is defined to verify + the integrity of the DHCPv6 messages and then authentication of + client and server. The Increasing number option is defined to detect + replay attack. +-------------+ +-------------+ |DHCPv6 Client| |DHCPv6 Server| +-------------+ +-------------+ | Information-request | |----------------------------------------->| + | Algorithm option | | Option Request option | | | | Reply | |<-----------------------------------------| | Certificate option | | Signature option | | Increasing-number option | | Server Identifier option | | | | Encryption-Query | |----------------------------------------->| | Encrypted-message option | | Server Identifier option | + | Encryption Key Tag option | | | | Encryption-Response | |<-----------------------------------------| | Encrypted-message option | | | Figure 1: Secure DHCPv6 Procedure 5.2. New Components The new components of the mechanism specified in this document are as follows: o Servers and clients that use certificates first generate a public/ private key pair and then obtain a certificate that signs the public key. The Certificate option is defined to carry the certificate of the sender. - o A signature is generated using the private key to verify the + o The algorithm option is defined to carry the algorithms lists for + algorithm agility. + + o The signature is generated using the private key to verify the integrity of the DHCPv6 messages. The Signature option is defined to carry the signature. - o A Increasing-number is used to detect replayed packet. The + o The increasing number is used to detect replayed packet. The Timestamp is one of the possible implementation choices. The Increasing-number option is defined to carry a strictly-increasing serial number. - o The Encrypted-message option contains the encrypted DHCPv6 - message. + o The encryption key Tag is calculated from the public key data. + The Encryption Key Tag option is defined to identify the used + public/private key pair. + + o The Encrypted-message option is defined to contain the encrypted + DHCPv6 message. o The Encrypted-Query message is sent from the secure DHCPv6 client to the secure DHCPv6 server. The Encrypted-Query message MUST contain the Encrypted-message option. In addition, the Server Identifier option MUST be contained if it is contained in the original DHCPv6 message. The Encrypted-Query message MUST NOT contain other options except the above options. o The Encrypted-Response message is sent from the secure DHCPv6 server to the secure DHCPv6 client. The Encrypted-Response @@ -285,40 +297,28 @@ In order to provide a means of addressing problems that may emerge with existing hash algorithms, signature algorithm and encryption algorithms in the future, this document provides a mechanism to support algorithm agility. The support for algorithm agility in this document is mainly a algorithm notification mechanism between the client and the server. The same client and server SHOULD use the same algorithm in a single communication session. The sender can offer a set of algorithms, and then the receiver selects one algorithm for the future communication. - If the server does not support the algorithm used by the client, the - server SHOULD reply with an AlgorithmNotSupported status code - (defined in Section 10.3) to the client. Upon receiving this status - code, the client MAY resend the message protected with the mandatory - algorithm. - 5.4. Caused change to RFC3315 - This protocol changes DHCPv6 message exchanges quite substantially: - previously, the client first sends a Solicit message, gets possibly - multiple Advertise messages, chooses the server (= sender of one of - the Advertises) that would be best for the client, and then sends a - Request to that chosen server. Now the server selection is done at - the key exchange phase (the initial Information-request and Reply - exchange). In addition, the Solicit and Rebind messages can be sent - only to a single server. If the client doesn't like the Advertise it - could restart the whole process, but it will be more expensive, and - there's no guarantee that other servers can provide a better - Advertise. For the privacy consideration, we have to give up the - previous server selection feature. + For secure DHCPv6, the Solicit and Rebind messages can be sent only + to the selected server(s) which share one common certificate. If the + client doesn't like the received Advertise(s) it could restart the + whole process and selects another certificate, but it will be more + expensive, and there's no guarantee that other servers can provide + better Advertise(s). [RFC3315] provides an additional mechanism for preventing off-network timing attacks using the Reconfigure message: the Reconfigure Key authentication method. Secure DHCPv6 can protect the Reconfigure message using the encryption method. So the Reconfigure Key authentication method SHOULD NOT be used if Secure DHCPv6 is applied. 5.5. Applicability In principle, secure DHCPv6 is applicable in any environment where @@ -349,266 +349,243 @@ server are stolen that does not mean an immediate threat as these are public keys. In addition, if some kind of PKI is used with Secure DHCPv6, even if the initial installation of the certificates is done manually, it will help reduce operational costs of revocation in case a private key (especially that of the server) is compromised. 6. DHCPv6 Client Behavior The secure DHCPv6 client is pre-configured with a certificate and its corresponding private key for client authentication. If the client - is pre-configured with public key but not with a certificate, it can - generate the self-signed certificate. + does not obtain a certificate from CA, it can generate the self- + signed certificate. The secure DHCPv6 client sends Information-request message as per [RFC3315]. The Information-request message is used by the DHCPv6 - client to request the server's identity verification information - without having addresses, prefixes or any non-security options - assigned to it. The Information-request message MUST NOT include any - other DHCPv6 options except the ORO option to minimize client's - privacy information leakage. The Option Request option in the - Information-request message MUST contain the option code of the - Certificate option. + client to request the server's certificate information without having + addresses, prefixes or any non-security options assigned to it. The + contained Option Request option MUST carry the option code of the + Certificate option. In addition, the contained Algorithm option MUST + be constructed as explained in Section 10.1.1. The Information- + request message MUST NOT include any other DHCPv6 options except the + above options to minimize client's privacy information leakage. When receiving the Reply messages from DHCPv6 servers, a secure - DHCPv6 client discards any DHCPv6 messages that meet any of the + DHCPv6 client discards any DHCPv6 message that meets any of the following conditions: o the Signature option is missing, o multiple Signature options are present, o the Certificate option is missing. - And then the client first checks the support of the hash algorithm, - signature algorithm and encryption algorithms that the server - supports. If the checks fails, the Reply message is dropped. If the - hash algorithm field is zero, then it indicates that the hash - algorithm is fixed according to the corresponding signature - algorithm. If all the algorithms are supported, then the client - selects one hash algorithm, signature algorithm and encryption - algorithm from the provided algorithms set. And then the client also - uses the same algorithms in the return messages. + And then the client first checks acknowledged hash, signature and + encryption algorithms that the server supports. If the hash + algorithm field is zero, then it indicates that the hash algorithm is + fixed according to the corresponding signature algorithm. The client + also uses the acknowledged algorithms in the return messages. Then the client checks the authority of the server. The client validates the certificates through the pre-configured local trusted certificates list or other methods. A certificate that finds a match - in the local trust certificates list is treated as verified. The - message transaction-id is used as the identifier of the authenticated - server's public key for further message encryption. At this point, - the client has either recognized the certificate of the server, or - decided to drop the message. + in the local trust certificates list is treated as verified. At this + point, the client has either recognized the certificate of the + server, or decided to drop the message. The client MUST now authenticate the server by verifying the signature and checking increasing number, if there is a Increasing- number option. The order of two procedures is left as an implementation decision. It is RECOMMENDED to check increasing number first, because signature verification is much more - computationally expensive. If the decrypted message contains the - Increasing-number option, the client checks it according to the rule - defined in Section 9.1. For the message without an Increasing-number - option, according to the client's local policy, it MAY be acceptable - or rejected. If the server rejects such a message, the increasing - number check fails. - - The Signature field verification MUST show that the signature has - been calculated as specified in Section 10.1.2. Only the messages - that get through both the signature verification and increasing - number check (if there is a Increasing-number option) are accepted. - Reply message that does not pass the above tests MUST be discarded. + computationally expensive. The client checks the Increasing-number + option according to the rule defined in Section 9.1 if it is + contained. For the message without an Increasing-number option, + according to the client's local policy, it MAY be acceptable or + rejected. The Signature field verification MUST show that the + signature has been calculated as specified in Section 10.1.3. Only + the messages that get through both the signature verification and + increasing number check (if there is a Increasing-number option) are + accepted. Reply message that does not pass the above tests MUST be + discarded. If there are multiple authenticated DHCPv6 certs, the client selects - one DHCPv6 cert. The client can also choose other implementation - method depending on the client's local policy if the defined protocol - can also run normally. For example, the client can try multiple - transactions (each encrypted with different public key) at the "same" - time. It should be noted that the selected certificate may - correspond to multiple DHCPv6 servers. - - If there are no authenticated DHCPv6 certs or existing servers fail + one DHCPv6 cert for the following communication. The selected + certificate may correspond to multiple DHCPv6 servers. If there are + no authenticated DHCPv6 certs or existing servers fail authentication, the client should retry a number of times. The client conducts the server discovery process as per section 18.1.5 of + [RFC3315] to avoid the packet storm. In this way, it is difficult for the rogue server to beat out a busy "real" server. And then the client takes some alternative action depending on its local policy, such as attempting to use an unsecured DHCPv6 server. Once the server has been authenticated, the DHCPv6 client sends the Encrypted-Query message to the DHCPv6 server. The Encrypted-Query message contains the Encrypted-message option, which MUST be - constructed as explained in Section 10.1.4. In addition, the Server - Identifier option MUST be included if it is in the original message - (i.e. Request, Renew, Decline, Release) to avoid the need for other - servers receiving the message to attempt to decrypt it. The - Encrypted-message option contains the DHCPv6 message that is - encrypted using the public key contained in the selected cert. The - Encrypted-Query message MUST NOT contain any other DHCPv6 option - except the Server Identifier option and Encrypted-Message option. + constructed as explained in Section 10.1.6. The Encrypted-message + option contains the encrypted DHCPv6 message using the public key + contained in the selected cert. In addition, the Server Identifier + option MUST be included if it is in the original message (i.e. + Request, Renew, Decline, Release) to avoid the need for other servers + receiving the message to attempt to decrypt it. The Encrypted-Query + message MUST include the Encryption Key Tag option to identify the + used public/private key pair, which is constructed as explained in + Section 10.1.5. The Encrypted-Query message MUST NOT contain any + other DHCPv6 option except the Server Identifier option, Encryption + Key Tag option, Encrypted-Message option. The first DHCPv6 message sent from the client to the server, such as Solicit message, MUST contain the Certificate option, Signature option and Increasing-number option for client authentication. The encryption text SHOULD be formatted as explain in [RFC5652]. The Certificate option MUST be constructed as explained in - Section 10.1.1. It should be noted that a client's certificate for - the mandatory algorithm MUST be contained to ensure that the Reply - message with the error code can be encrypted using the mandatory - algorithm. In addition, one and only one Signature option MUST be - contained, which MUST be constructed as explained in Section 10.1.2. - One and only one Increasing-number option SHOULD be contained, which - MUST be constructed as explained in Section 10.1.3. - - If the client has multiple certificates with different public/private - key pairs, the message transaction-id is also used as the identifier - of the client's private key for decryption. In addition, the - subsequent encrypted DHCPv6 message can contain the Increasing-number - option to defend against replay attack. + Section 10.1.2. In addition, one and only one Signature option MUST + be contained, which MUST be constructed as explained in + Section 10.1.3. One and only one Increasing-number option SHOULD be + contained, which MUST be constructed as explained in Section 10.1.4. + In addition, the subsequent encrypted DHCPv6 message can also contain + the Increasing-number option to defend against replay attack. For the received Encrypted-Response message, the client MUST drop the Encrypted-Response message if other DHCPv6 option except Encrypted- message option is contained. Then, the client extracts the Encrypted-message option and decrypts it using its private key to - obtain the original DHCPv6 message. Then it handles the message as - per [RFC3315]. If the decrypted DHCPv6 message contains the - Increasing-number option, the DHCPv6 client checks it according to - the rule defined in Section 9.1. If the client fails to get the - proper parameters from the chosen server, it sends the Encrypted- - Query message to another authenticated server for parameters - configuration until the client obtains the proper parameters. + obtain the original DHCPv6 message. In this document, it is assumed + that the client uses only one certificate for the encrypted DHCPv6 + configuration. So, the corresponding private key is used for + decryption. After the decryption, it handles the message as per + [RFC3315]. If the decrypted DHCPv6 message contains the Increasing- + number option, the DHCPv6 client checks it according to the rule + defined in Section 9.1. + + If the client fails to get the proper parameters from the chosen + server(s), it can select another authenticated certificate and send + the Encrypted-Query message to another authenticated server(s) for + parameters configuration until the client obtains the proper + parameters. When the decrypted message is Reply message with an error status code, the error status code indicates the failure reason on the server side. According to the received status code, the client MAY take follow-up action: - o Upon receiving an AlgorithmNotSupported error status code, the - client SHOULD resend the message protected with one of the - mandatory algorithms. - o Upon receiving an AuthenticationFail error status code, the client is not able to build up the secure communication with the server. However, there may be other DHCPv6 servers available that successfully complete authentication. The client MAY use the - AuthenticationFail as a hint and switch to other certificate if it - has another one; but otherwise treat the message containing the - status code as if it had not been received. But it SHOULD NOT - retry with the same certificate. However, if the client decides - to retransmit using the same certificate after receiving + AuthenticationFail as a hint and switch to other DHCPv6 server if + it has another one. The client SHOULD retry with another + authenticated certificate. However, if the client decides to + retransmit using the same certificate after receiving AuthenticationFail, it MUST NOT retransmit immediately and MUST follow normal retransmission routines defined in [RFC3315]. o Upon receiving a DecryptionFail error status code, the client MAY resend the message following normal retransmission routines defined in [RFC3315]. o Upon receiving a ReplayDetected error status code, the client MAY resend the message with an adjusted Increasing-number option according to the returned number from the DHCPv6 server. o Upon receiving a SignatureFail error status code, the client MAY resend the message following normal retransmission routines defined in [RFC3315]. 7. DHCPv6 Server Behavior The secure DHCPv6 server is pre-configured with a certificate and its corresponding private key for server authentication. If the server - is pre-configured with public key but not with a certificate, it can - generate the self-signed certificate. + does not obtain the certificate from CA, it can generate the self- + signed certificate. When the DHCPv6 server receives the Information-request message and the contained Option Request option identifies the request is for the - server certificate information, it replies with a Reply message to - the client. The Reply message MUST contain the requested Certificate - option, which MUST be constructed as explained in Section 10.1.1, and - Server Identifier option. In addition, the Reply message MUST - contain one and only one Signature option, which MUST be constructed - as explained in Section 10.1.2. Besides, the Reply message SHOULD - contain one and only one Increasing-number option, which MUST be - constructed as explained in Section 10.1.3. In addition, if client - authentication is needed, then the ORO option in the Reply message - contains the code of the certificate option to indicate the request - of the client certificate information. + server's certificate information, it SHOULD first check the hash, + signature, encryption algorithms sets that the client supports. The + server selects one hash, signature, encryption algorithm from the + acknowledged algorithms sets for the future communication. If the + hash algorithm is fixed according to the signature algorithm, then + the hash algorithm field is set to zero. And then, the server + replies with a Reply message to the client. The Reply message MUST + contain the requested Certificate option, which MUST be constructed + as explained in Section 10.1.2, and Server Identifier option. In + addition, the Reply message MUST contain one and only one Signature + option, which MUST be constructed as explained in Section 10.1.3. + Besides, the Reply message SHOULD contain one and only one + Increasing-number option, which MUST be constructed as explained in + Section 10.1.4. Upon the receipt of Encrypted-Query message, the server MUST drop the message if the other DHCPv6 option is contained except Server - Identifier option and Encrypted-message option. Then, the server - checks the Server Identifier option if the Encrypted-Query message - contains it. The DHCPv6 server drops the message that is not for it, - thus not paying cost to decrypt messages. It decrypts the Encrypted- - message option using its private key if it is the target server. If - the decryption fails, the server SHOULD send an encrypted Reply - message with a DecryptionFail error status code, defined in - Section 10.3, back to the client. + Identifier option, Encryption Key Tag option, Encrypted-message + option. Then, the server checks the Server Identifier option if it + is contained. The DHCPv6 server drops the message that is not for + it, thus not paying cost to decrypt messages. If it is the target + server, according to the Encryption Key Tag option, the server + identifies the used public/private key pair and decrypts the + Encrypted-message option using the corresponding private key. If the + server does not find the corresponding private key, then it tries all + the private keys and establishes the relationship between the + encryption key tag and the private key. If the decryption fails, the + server discards the received message. If secure DHCPv6 server needs client authentication and decrypted message is a Solicit/Information-request message which contains the information for client authentication, the secure DHCPv6 server discards the received message that meets any of the following conditions: o the Signature option is missing, o multiple Signature options are present, o the Certificate option is missing. - In such failure, the server SHOULD send an encrypted Reply message - with an UnspecFail (value 1, [RFC3315]) error status code to the - client. - - The server SHOULD first check the support of the hash function, - signature algorithm, encryption algorithm that the client supports. - If the hash algorithm field is zero, then the corresponding hash - algorithm is fixed according to the signature algorithm. If the - check fails, the server SHOULD reply with an AlgorithmNotSupported - error status code, defined in Section 10.3, back to the client. - Because the server does not support the acknowledged algorithm, the - Reply message with the AlgorithmNotSupported error status code is - encrypted with the mandatory algorithm. If all the algorithms are - supported, the server then uses the acknowledged algorithms in the - future communication. + For the signature failure, the server SHOULD send an encrypted Reply + message with an UnspecFail (value 1, [RFC3315]) error status code to + the client. The server validates the client's certificate through the local pre- configured trusted certificates list. A certificate that finds a match in the local trust certificates list is treated as verified. The message that fails authentication validation MUST be dropped. In - such failure, the DHCPv6 server replies with an AuthenticationFail - error status code, defined in Section 10.3, back to the client. The - Reply message with the AuthenticationFail error status code is also - encrypted. At this point, the server has either recognized the - authentication of the client, or decided to drop the message. + such failure, the DHCPv6 server replies with an encrypted Reply + message with an AuthenticationFail error status code, defined in + Section 10.3, back to the client. At this point, the server has + either recognized the authentication of the client, or decided to + drop the message. If the decrypted message contains the Increasing-number option, the server checks it according to the rule defined in Section 9.1. If the check fails, an encrypted Reply message with a ReplayDetected error status code, defined in Section 10.3, should be sent back to the client. In addition, a Increasing-number option is carried to indicate the server's stored number for the client to use. According to the server's local policy, the message without an Increasing- - number option MAY be acceptable or rejected. If the server rejects - such a message, the server processes it as the increasing number - check fails. + number option MAY be acceptable or rejected. The Signature field verification MUST show that the signature has - been calculated as specified in Section 10.1.2. If the signature + been calculated as specified in Section 10.1.3. If the signature check fails, the DHCPv6 server SHOULD send an encrypted Reply message with a SignatureFail error status code. Only the clients that get through both the signature verification and increasing number check (if there is a Increasing-number option) are accepted as authenticated clients and continue to be handled their message as defined in [RFC3315]. Once the client has been authenticated, the DHCPv6 server sends the Encrypted-response message to the DHCPv6 client. The Encrypted- response message MUST only contain the Encrypted-message option, - which MUST be constructed as explained in Section 10.1.4. The + which MUST be constructed as explained in Section 10.1.6. The encryption text SHOULD be formatted as explain in [RFC5652]. The Encrypted-message option contains the encrypted DHCPv6 message that is encrypted using the authenticated client's public key. To provide the replay protection, the Increasing-number option can be contained in the encrypted DHCPv6 message. 8. Relay Agent Behavior When a DHCPv6 relay agent receives an Encrypted-query or Encrypted- response message, it may not recognize this message. The unknown @@ -632,337 +609,384 @@ of server certs available locally. In this way, the client can be confident of a quick response, and therefore treat the lack of a quick response as an indication that no authenticated DHCP servers exist. 9. Processing Rules 9.1. Increasing Number Check In order to check the Increasing-number option, defined in - Section 10.1.3, the client/server has one stable stored number for + Section 10.1.4, the client/server has one stable stored number for replay attack detection. The server should keep a record of the increasing number forever. And the client keeps a record of the - increasing number during the transaction with the DHCPv6 server. In - addition, the client can forget the increasing number information - after the transaction is finished. + increasing number during the DHCPv6 configuration process with the + DHCPv6 server. And the client can forget the increasing number + information after the transaction is finished. It is essential to remember that the increasing number is finite. All arithmetic dealing with sequence numbers must be performed modulo 2^64. This unsigned arithmetic preserves the relationship of sequence numbers as they cycle from 2^64 - 1 to 0 again. In order to check the Increasing-number option, the following - comparison is needed. The symbol means "less or equal" (modulo - 2^64). + comparison is needed. NUM.STO = the stored number in the client/server NUM.REC = the acknowledged number from the received message The Increasing-number option in the received message passes the increasing number check if NUM.REC is more than NUM.STO. And then, the value of NUM.STO is changed into the value of NUM.REC. - The increasing number check fails if NUM.REC is equal or less than - NUM.STO + The increasing number check fails if NUM.REC is equal with or less + than NUM.STO 10. Extensions for Secure DHCPv6 - This section describes the extensions to DHCPv6. Four new DHCPv6 - options, two new DHCPv6 messages and five new status codes are + This section describes the extensions to DHCPv6. Six new DHCPv6 + options, two new DHCPv6 messages and six new status codes are defined. 10.1. New DHCPv6 Options +10.1.1. Algorithm Option -10.1.1. Certificate Option - - The Certificate option carries the certificate(s) of the client/ - server. The format of the Certificate option is described as - follows: + The Algorithm option carries the algorithms sets for algorithm + agility, which is sent from the client to server. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | OPTION_CERTIFICATE | option-len | + | OPTION_SIGNATURE | option-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . EA-id List . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | | - . Certificate List(variable length) . - | | + . SA-id List . + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + . HA-id List . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - Figure 2: Certificate Option + Figure 2: Algorithm Option - o option-code: OPTION_CERTIFICATE (TBA1). + o option-code: OPTION_SIGNATURE (TBA1). - o option-len: length of EA-id List + length of Certificate List in - octets. + o option-len: length of EA-id List + length of SA-id List + length + of HA-id List in octets. - o EA-id List: The format of the EA-id List field is shown in - Figure 3. + o EA-id: The format of the EA-id List field is shown in Figure 3. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | EA-num | EA-id | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . ... . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | EA-id | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ EA-num The number of the following EA-ids. EA-id Encryption Algorithm id. The encryption algorithm is used for the encrypted DHCPv6 configuration process. This design is adopted in order to provide encryption algorithm agility. The value is from the Encryption Algorithm for Secure DHCPv6 registry in IANA. A registry of the initial assigned values - is defined in Section 12. + is defined in Section 12. The mandatory encryption + algorithms MUST be included. Figure 3: EA-id List Field - o Certificate List: The format of the Certificate List Field is - shown in Figure 4. + o SA-id List: The format of the SA-id List field is shown in + Figure 4. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | cert-len | cert-data | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - . ...cert-data(variable length)(cont) . +| SA-num | SA-id | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - . . . ... . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | cert-len | cert-data | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - . ...cert-data(variable length)(cont) . - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - - cert-len The length of the certificate. +| SA-id | ++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - Cert-data A variable-length field containing certificates. The - encoding of certificate and certificate data MUST - be in format as defined in Section 3.6, [RFC7296]. - The support of X.509 certificate is mandatory. +SA-num The number of the following SA-ids. - Figure 4: Certificate List Field +SA-id Signature Algorithm id. This design is adopted in + order to provide signature algorithm agility. The + value is from the Signature Algorithm for Secure + DHCPv6 registry in IANA. The support of RSASSA-PKCS1-v1_5 + is mandatory. A registry of the initial assigned + values is defined in Section 12. The mandatory + signature algorithms MUST be included. -10.1.2. Signature option + Figure 4: SA-id List Field - The Signature option allows a signature that is signed by the private - key to be attached to a DHCPv6 message. The Signature option could - be in any place within the DHCPv6 message while it is logically - created after the entire DHCPv6 header and options. It protects the - entire DHCPv6 header and options, including itself. The format of - the Signature option is described as follows: + o HA-id List: The format of the HA-id List field is shown in + Figure 5. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | OPTION_SIGNATURE | option-len | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - . SA-id List . - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - . HA-id List . + | HA-num | HA-id | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | | - . Signature (variable length) . - . . + . ... . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | HA-id | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - Figure 5: Signature Option + HA-num The number of the following HA-ids. - o option-code: OPTION_SIGNATURE (TBA2). + HA-id Hash Algorithm id. This design is adopted in order to + provide hash algorithm agility. The value is from the + Hash Algorithm for Secure DHCPv6 registry in IANA. The + support of SHA-256 is mandatory. A registry of the + initial assigned values is defined in Section 12. + The mandatory hash algorithms MUST be included. - o option-len: length of SA-id list + length of HA-id list + length - of Signature field in octets. + Figure 5: HA-id List Field - o SA-id List: The format of the SA-id List field is shown in - Figure 6. +10.1.2. Certificate Option + + The Certificate option carries the certificate of the client/server. + The format of the Certificate option is described as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | SA-num | SA-id | + | OPTION_CERTIFICATE | option-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - . ... . + | EA-id | SA-id | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + . Certificate . + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | SA-id | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - SA-num The number of the following SA-ids. + Figure 6: Certificate Option - SA-id Signature Algorithm id. The signature algorithm is - used for computing the signature result. This - design is adopted in order to provide signature - algorithm agility. The value is from the Signature - Algorithm for Secure DHCPv6 registry in IANA. The - support of RSASSA-PKCS1-v1_5 is mandatory. A - registry of the initial assigned values is defined - in Section 12. + o option-code: OPTION_CERTIFICATE (TBA2). - Figure 6: EA-id List Field + o option-len: 4 + length of Certificate in octets. - o HA-id List: The format of the HA-id List field is shown in - Figure 7. + o EA-id: Encryption Algorithm id. The encryption algorithm is used + for the encrypted DHCPv6 configuration process. This design is + adopted in order to provide encryption algorithm agility. The + value is from the Encryption Algorithm for Secure DHCPv6 registry + in IANA. A registry of the initial assigned values is defined in + Section 12. If the value of EA-id is 0, then the certificate is + not used for encryption. + + o SA-id: Signature Algorithm id. The signature algorithm is used + for computing the signature result. The value is from the + Signature Algorithm for Secure DHCPv6 registry in IANA. A + registry of the initial assigned values is defined in Section 12. + If the value of SA-id is 0, then the certificate is not used for + signature check. + + o Certificate: A variable-length field containing certificates. The + encoding of certificate and certificate data MUST be in format as + defined in Section 3.6, [RFC7296]. The support of X.509 + certificate is mandatory. + + It should be noticed that the scenario where the values of EA-id and + SA-id are all 0, it makes no sense and MUST NOT be used. + +10.1.3. Signature option + + The Signature option allows a signature that is signed by the private + key to be attached to a DHCPv6 message. The Signature option could + be in any place within the DHCPv6 message while it is logically + created after the entire DHCPv6 header and options. It protects the + entire DHCPv6 header and options, including itself. The format of + the Signature option is described as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | HA-num | HA-id | + | OPTION_SIGNATURE | option-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - . ... . + | SA-id | HA-id | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + . Signature (variable length) . + . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | HA-id | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - HA-num The number of the following HA-ids. + Figure 7: Signature Option - HA-id Hash Algorithm id. The hash algorithm is used for - computing the signature result. This design is - adopted in order to provide hash algorithm agility. - The value is from the Hash Algorithm for Secure - DHCPv6 registry in IANA. The support of SHA-256 is - mandatory. A registry of the initial assigned values - is defined in Section 12. If the signature algorithm - and hash algorithm cannot be separated, the HA-id - field is zero. The hash algorithm is decided by the - corresponding signature algorithm. + o option-code: OPTION_SIGNATURE (TBA3). - Figure 7: HA-id List Field + o option-len: 4 + length of Signature field in octets. + + o SA-id: Signature Algorithm id. The signature algorithm is used + for computing the signature result. This design is adopted in + order to provide signature algorithm agility. The value is from + the Signature Algorithm for Secure DHCPv6 registry in IANA. The + support of RSASSA-PKCS1-v1_5 is mandatory. A registry of the + initial assigned values is defined in Section 12. + + o HA-id: Hash Algorithm id. The hash algorithm is used for + computing the signature result. This design is adopted in order + to provide hash algorithm agility. The value is from the Hash + Algorithm for Secure DHCPv6 registry in IANA. The support of + SHA-256 is mandatory. A registry of the initial assigned values + is defined in Section 12. If the hash algorithm is fixed + according to the corresponding signature algorithm, the HA-id + field is set to zero. o Signature: A variable-length field containing a digital signature. The signature value is computed with the hash algorithm and the signature algorithm, as described in HA-id and SA-id. The Signature field MUST be padded, with all 0, to the next octet boundary if its size is not a multiple of 8 bits. The padding length depends on the signature algorithm, which is indicated in the SA-id field. Note: If Secure DHCPv6 is used, the DHCPv6 message is encrypted in a way that the authentication mechanism defined in RFC3315 does not understand. So the Authentication option SHOULD NOT be used if Secure DHCPv6 is applied. -10.1.3. Increasing-number Option +10.1.4. Increasing-number Option - The Increasing-number option carries the number which is higher than - the local stored number on the client/server. It adds the anti- - replay protection to the DHCPv6 messages. It is optional. + The Increasing-number option carries the strictly increasing number + for anti-replay protection. It is optional. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OPTION_INCREASING_NUM | option-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | InreasingNum (64-bit) | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ -option-code OPTION_INCREASING_NUM (TBA3). +option-code OPTION_INCREASING_NUM (TBA4). option-len 8, in octets. IncreasingNum A strictly increasing number for the replay attack detection which is more than the local stored number. - Figure 8: Incresing-number Option + Figure 8: Increasing-number Option -10.1.4. Encrypted-message Option +10.1.5. Encryption Key Tag Option - The Encrypted-message option carries the encrypted DHCPv6 message - with the recipient's public key. + The Encryption Key Tag option carries the key identifier which is + calculated from the public key data. The Encrypted-Query message + MUST contain the Encryption Key Tag option to identify the used + public/private key pair. + + 0 1 2 3 + 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | option-code | option-len | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + . encryption key tag . + . (variable) . + . . + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Figure 9: Encryption Key Tag Option + + option-code OPTION_ENCRY_KT (TBA5). + + option-len Length of the encryption key tag. + + encryption key tag A variable length field containing the encryption + key tag sent from the client to server to identify the used + public/private key pair. The encryption key tag is calculated + from the public key data, like fingerprint of a specific public + key. + +10.1.6. Encrypted-message Option + + The Encrypted-message option carries the encrypted DHCPv6 message, + which is calculated with the recipient's public key. The format of the Encrypted-message option is: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | option-code | option-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | . encrypted DHCPv6 message . . (variable) . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - Figure 9: Encrypted-message Option + Figure 10: Encrypted-message Option - option-code OPTION_ENCRYPTED_MSG (TBA4). + option-code OPTION_ENCRYPTED_MSG (TBA6). option-len Length of the encrypted DHCPv6 message. encrypted DHCPv6 message A variable length field containing the - encrypted DHCPv6 message sent by the client or the server. In - Encrypted-Query message, it contains encrypted DHCPv6 message sent - by a client. In Encrypted-response message, it contains encrypted - DHCPv6 message sent by a server. + encrypted DHCPv6 message. In Encrypted-Query message, it contains + encrypted DHCPv6 message sent from a client to server. In + Encrypted-response message, it contains encrypted DHCPv6 message + sent from a server to client. 10.2. New DHCPv6 Messages Two new DHCPv6 messages are defined to achieve the DHCPv6 encryption: Encrypted-Query and Encrypted-Response. Both the DHCPv6 messages defined in this document share the following format: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | msg-type | transaction-id | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | . options . . (variable) . | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - Figure 10: The format of Encrypted-Query and Encrypted-Response + Figure 11: The format of Encrypted-Query and Encrypted-Response Messages msg-type Identifier of the message type. It can be either - Encrypted-Query (TBA5) or DHCPv6-Response (TBA6). + Encrypted-Query (TBA7) or DHCPv6-Response (TBA8). transaction-id The transaction ID for this message exchange. options The Encrypted-Query message MUST contain the - Encrypted-message option and MUST contain the Server - Identifier option if the message in the Encrypted- - message option has a Server Identifier option. The - Encrypted-Response message MUST only contain the - Encrypted-message option. + Encrypted-message option, Encryption Key Tag option + and Server Identifier option if the message in the + Encrypted-message option has a Server Identifier + option. The Encrypted-Response message MUST only + contain the Encrypted-message option. 10.3. Status Codes The following new status codes, see Section 5.4 of [RFC3315] are defined. - o AlgorithmNotSupported (TBD7): indicates that the DHCPv6 server - does not support algorithms that sender used. - - o AuthenticationFail (TBD8): indicates that the message from the + o AuthenticationFail (TBD9): indicates that the message from the DHCPv6 client fails authentication check. - o ReplayDetected (TBD9): indicates the message from DHCPv6 client + o ReplayDetected (TBD10): indicates the message from DHCPv6 client fails the increasing number check. - o SignatureFail (TBD10): indicates the message from DHCPv6 client + o SignatureFail (TBD11): indicates the message from DHCPv6 client fails the signature check. - o DecryptionFail (TBD11): indicates the message from DHCPv6 client - fails the DHCPv6 message decryption. - 11. Security Considerations This document provides the authentication and encryption mechanisms for DHCPv6. [RFC6273] has analyzed possible threats to the hash algorithms used in SEND. Since Secure DHCPv6 defined in this document uses the same hash algorithms in similar way to SEND, analysis results could be applied as well: current attacks on hash functions do not constitute any practical threat to the digital signatures used in the signature @@ -974,42 +998,46 @@ There are some mandatory algorithm for encryption algorithm in this document. It may be at some point that the mandatory algorithm is no longer safe to use. If the client tries more than one cert for client authentication, the server can easily get a client that implements this to enumerate its entire cert list and probably learn a lot about a client that way. 12. IANA Considerations - This document defines four new DHCPv6 [RFC3315] options. The IANA is - requested to assign values for these four options from the DHCPv6 + This document defines six new DHCPv6 [RFC3315] options. The IANA is + requested to assign values for these six options from the DHCPv6 Option Codes table of the DHCPv6 Parameters registry maintained in - http://www.iana.org/assignments/dhcpv6-parameters. The four options + http://www.iana.org/assignments/dhcpv6-parameters. The six options are: - The Certificate Option (TBA1), described in Section 10.1.1. + The Algorithm Option (TBA1), described in Section 10.1.2. - The Signature Option (TBA2), described in Section 10.1.2. + The Certificate Option (TBA2), described in Section 10.1.2. - The Increasing-number Option (TBA3),described in Section 10.1.3. + The Signature Option (TBA3), described in Section 10.1.3. - The Encrypted-message Option (TBA4), described in Section 10.1.4. + The Increasing-number Option (TBA4),described in Section 10.1.4. + + The Encryption Key Tag Option (TBA5),described in Section 10.1.5. + + The Encrypted-message Option (TBA6), described in Section 10.1.6. The IANA is also requested to assign value for these two messages from the DHCPv6 Message Types table of the DHCPv6 Parameters registry maintained in http://www.iana.org/assignments/dhcpv6-parameters. The two messages are: - The Encrypted-Query Message (TBA5), described in Section 10.2. + The Encrypted-Query Message (TBA7), described in Section 10.2. - The Encrypted-Response Message (TBA6), described in Section 10.2. + The Encrypted-Response Message (TBA8), described in Section 10.2. The IANA is also requested to add three new registry tables to the DHCPv6 Parameters registry maintained in http://www.iana.org/assignments/dhcpv6-parameters. The three tables are the Hash Algorithm for Secure DHCPv6 table, the Signature Algorithm for Secure DHCPv6 table and the Encryption Algorithm for Secure DHCPv6 table. Initial values for these registries are given below. Future assignments are to be made through Standards Action [RFC5226]. @@ -1025,62 +1053,80 @@ SigAlg-Combined | ox00 | this document SHA-256 | 0x01 | this document SHA-512 | 0x02 | this document Signature Algorithm for Secure DHCPv6. The values in this table are 8-bit unsigned integers. The following initial values are assigned for Signature Algorithm for Secure DHCPv6 in this document: Name | Value | RFCs -------------------+---------+-------------- + Non-SigAlg | 0x00 | this document RSASSA-PKCS1-v1_5 | 0x01 | this document Encryption algorithm for Secure DHCPv6. The values in this table are 8-bit unsigned integers. The following initial values are assigned for encryption algorithm for Secure DHCPv6 in this document: Name | Value | RFCs -------------------+---------+-------------- + Non-EncryAlg | 0x00 | this document RSA | 0x01 | this document IANA is requested to assign the following new DHCPv6 Status Codes, defined in Section 10.3, in the DHCPv6 Parameters registry maintained in http://www.iana.org/assignments/dhcpv6-parameters: Code | Name | Reference ---------+-----------------------+-------------- - TBD7 | AlgorithmNotSupported | this document - TBD8 | AuthenticationFail | this document - TBD9 | ReplayDetected | this document - TBD10 | SignatureFail | this document - TBD11 | DecryptionFail | this document + TBD9 | AuthenticationFail | this document + TBD10 | ReplayDetected | this document + TBD11 | SignatureFail | this document 13. Acknowledgements The authors would like to thank Tomek Mrugalski, Bernie Volz, Jianping Wu, Randy Bush, Yiu Lee, Sean Shen, Ralph Droms, Jari Arkko, Sean Turner, Stephen Farrell, Christian Huitema, Stephen Kent, Thomas Huth, David Schumacher, Francis Dupont, Gang Chen, Suresh Krishnan, Fred Templin, Robert Elz, Nico Williams, Erik Kline, Alan DeKok, - Bernard Aboba, Sam Hartman, Qi Sun, Zilong Liu and other members of - the IETF DHC working group for their valuable comments. + Bernard Aboba, Sam Hartman, Zilong Liu and other members of the IETF + DHC working group for their valuable comments. This document was produced using the xml2rfc tool [RFC2629]. 14. Change log [RFC Editor: Please remove] + draft-ietf-dhc-sedhcpv6-18: Add the Algorithm option. The algorithm + option contains the EA-id List, SA-id List, HA-id List, and then the + certificate and signature options do not contain the algorithm list; + Add the Encryption Key Tag option to identify the used public/private + key pair; Delete the AlgorithmNotSupported error status code; Delete + some description on that secure DHCPv6 exchanges the server selection + method; Delete the DecryptionFail error status code; For the case + where the client's certificate is missed, then the server discards + the received message. Add the assumption that: For DHCPv6 client, + just one certificate is used for the DHCPv6 configuration. Add the + statement that: For the first Encrypted-Query message, the server + needs to try all the possible private keys and then records the + relationship between the public key and the encryption key tag. + + draft-ietf-dhc-sedhcpv6-17: Change the format of the certificate + option according to the comments from Bernie. + + draft-ietf-dhc-sedhcpv6-16: For the algorithm agility part, the + provider can offer multiple EA-id, SA-id, HA-id and then receiver + choose one from the algorithm set. + draft-ietf-dhc-sedhcpv6-15: Increasing number option only contains the strictly increasing number; Add some description about why - encryption is needed in Security Issues of DHCPv6 part; For the - algorithm agility part, the provider can offer multiple EA-id, SA-id, - HA-id and then receiver choose one from the algorithm set. - + encryption is needed in Security Issues of DHCPv6 part; draft-ietf-dhc-sedhcpv6-14: For the deployment part, Tofu is out of scope and take Opportunistic security into consideration; Increasing number option is changed into 64 bits; Increasing number check is a separate section; IncreasingnumFail error status code is changed into ReplayDetected error status code; Add the section of "caused change to RFC3315"; draft-ietf-dhc-sedhcpv6-13: Change the Timestamp option into Increasing-number option and the corresponding check method; Delete the OCSP stampling part for the certificate check; Add the scenario