diff --git a/doc/standardisation/draft-ietf-krb-wg-gssapi-cfx-02.txt b/doc/standardisation/draft-ietf-krb-wg-gssapi-cfx-02.txt new file mode 100644 index 000000000..96fe594f4 --- /dev/null +++ b/doc/standardisation/draft-ietf-krb-wg-gssapi-cfx-02.txt @@ -0,0 +1,883 @@ + + + + Larry Zhu +Internet Draft Karthik Jaganathan +Updates: 1964 Microsoft +Category: Standards Track Sam Hartman +draft-ietf-krb-wg-gssapi-cfx-02.txt MIT + September 29, 2003 + Expires: March 29, 2004 + + The Kerberos Version 5 GSS-API Mechanism: Version 2 + +Status of this Memo + + This document is an Internet-Draft and is in full conformance with + all provisions of Section 10 of [RFC-2026]. + + Internet-Drafts are working documents of the Internet Engineering + Task Force (IETF), its areas, and its working groups. Note that + other groups may also distribute working documents as Internet- + Drafts. 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." + + The list of current Internet-Drafts can be accessed at + http://www.ietf.org/ietf/1id-abstracts.txt. + + The list of Internet-Draft Shadow Directories can be accessed at + http://www.ietf.org/shadow.html. + +Abstract + + This memo defines protocols, procedures, and conventions to be + employed by peers implementing the Generic Security Service + Application Program Interface (GSS-API as specified in [RFC-2743]) + when using the Kerberos Version 5 mechanism (as specified in + [KRBCLAR]). + + [RFC-1964] is updated and incremental changes are proposed in + response to recent developments such as the introduction of Kerberos + crypto framework [KCRYPTO]. These changes support the inclusion of + new cryptosystems based on crypto profiles [KCRYPTO], by defining + new per-message and context-deletion tokens along with their + encryption and checksum algorithms. + +Conventions used in this document + + 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 [RFC-2119]. + +1. Introduction + + + +Zhu Internet Draft 1 + Kerberos Version 5 GSS-API September 2003 + + + [KCRYPTO] defines a generic framework for describing encryption and + checksum types to be used with the Kerberos protocol and associated + protocols. + + [RFC-1964] describes the GSS-API mechanism for Kerberos Version 5. + It defines the format of context initiation, per-message and context + deletion tokens and uses algorithm identifiers for each cryptosystem + in per message and context deletion tokens. + + The approach taken in this document obviates the need for algorithm + identifiers. This is accomplished by using the same encryption and + checksum algorithms specified by the crypto profile [KCRYPTO] for + the session key or subkey that is created during context + negotiation. Message layouts of the per-message and context + deletion tokens are therefore revised to remove algorithm indicators + and also to add extra information to support the generic crypto + framework [KCRYPTO]. + + Tokens transferred between GSS-API peers for security context + initiation are also described in this document. The data elements + exchanged between a GSS-API endpoint implementation and the Kerberos + KDC are not specific to GSS-API usage and are therefore defined + within [KRBCLAR] rather than within this specification. + + The new token formats specified in this memo MUST be used with all + "newer" encryption types [KRBCLAR] and MAY be used with "older" + encryption types, provided that the initiator and acceptor know, + from the context establishment, that they can both process these new + token formats. + + "Newer" encryption types are those which have been specified along + with or since the new Kerberos cryptosystem specification [KCRYPTO], + as defined in section 3.1.3 of [KRBCLAR]. + + Note that in this document, the term "little endian order" is used + for brevity to refer to the least-significant-byte-first encoding, + while the term "big endian order" is for the most-significant-byte- + first encoding. + +2. Key Derivation for Per-Message and Context Deletion Tokens + + To limit the exposure of a given key, [KCRYPTO] adopted "one-way" + "entropy-preserving" derived keys, for different purposes or key + usages, from a base key or protocol key. This document defines four + key usage values below for signing and sealing messages: + + Name Value + ------------------------------------- + KG-USAGE-ACCEPTOR-SEAL 22 + KG-USAGE-ACCEPTOR-SIGN 23 + KG-USAGE-INITIATOR-SEAL 24 + KG-USAGE-INITIATOR-SIGN 25 + + +Zhu Internet Draft 2 + Kerberos Version 5 GSS-API September 2003 + + + When the sender is the context acceptor, KG-USAGE-ACCEPTOR-SIGN is + used as the usage number in the key derivation function for deriving + keys to be used in MIC and context deletion tokens, and KG-USAGE- + ACCEPTOR-SEAL is used for Wrap tokens; similarly when the sender is + the context initiator, KG-USAGE-INITIATOR-SIGN is used as the usage + number in the key derivation function for MIC and context deletion + tokens, KG-USAGE-INITIATOR-SEAL is used for Wrap Tokens. Even if + the Wrap token does not provide for confidentiality the same usage + values specified above are used. + + During context initiation, the acceptor MAY assert a subkey, and if + so, subsequent messages MUST use this subkey as the protocol key and + these messages MUST be flagged as "AcceptorSubkey" as described in + section 4.2.2. + +3. Quality of Protection + + The GSS-API specification [RFC-2743] provides for Quality of + Protection (QOP) values that can be used by applications to request + a certain type of encryption or signing. A zero QOP value is used + to indicate the "default" protection; applications which use the + default QOP are not guaranteed to be portable across implementations + or even inter-operate with different deployment configurations of + the same implementation. Using an algorithm that is different from + the one for which the key is defined may not be appropriate. + Therefore, when the new method in this document is used, the QOP + value is ignored. + + The encryption and checksum algorithms in per-message and context + deletion tokens are now implicitly defined by the algorithms + associated with the session key or subkey. Algorithms identifiers + as described in [RFC-1964] are therefore no longer needed and + removed from the new token headers. + +4. Definitions and Token Formats + + This section provides terms and definitions, as well as descriptions + for tokens specific to the Kerberos Version 5 GSS-API mechanism. + +4.1. Initial Context Tokens + + Per [RFC-2743], all context initiation tokens emitted by the + Kerberos V5 GSS-API mechanism will have the framing shown below: + + GSS-API DEFINITIONS ::= + + BEGIN + + MechType ::= OBJECT IDENTIFIER + -- representing Kerberos V5 mechanism + + GSSAPI-Token ::= + -- option indication (delegation, etc.) indicated within + -- mechanism-specific token + +Zhu Internet Draft 3 + Kerberos Version 5 GSS-API September 2003 + + + [APPLICATION 0] IMPLICIT SEQUENCE { + thisMech MechType, + innerToken ANY DEFINED BY thisMech + -- contents mechanism-specific + -- ASN.1 structure not required + } + + END + + The innerToken field starts with a two-byte token-identifier + (TOK_ID) expressed in big endian order, followed by a Kerberos + message. + + Here are the TOK_ID values used in the initial tokens: + + Token TOK_ID Value in Hex + ----------------------------------------- + KRB_AP_REQUEST 01 00 + KRB_AP_REPLY 02 00 + KRB_ERROR 03 00 + + Where Kerberos message KRB_AP_REQUEST, KRB_AP_REPLY, and KRB_ERROR + are defined in [KRBCLAR]. + + If an unknown token ID is received in the first context token, the + receiver MUST return GSS_S_CONTINUE_NEEDED major status, and the + returned output token MUST contain a KRB_ERROR message with the + error code KRB_AP_ERR_MSG_TYPE [KRBCLAR]. + +4.1.1. Authenticator Checksum + + The authenticator in the KRB_AP_REQ message MUST include the + optional sequence number and the checksum field. The checksum field + is used to convey service flags, channel bindings, and optional + delegation information. It MUST have a type of 0x8003. The length + of the checksum MUST be 24 bytes when delegation is not used. When + delegation is used, a ticket-granting ticket will be transferred in + a KRB_CRED message. The ticket SHOULD have its forwardable flag + set. The KRB_CRED message MUST be encrypted in the session key of + the ticket used to authenticate the context. + + The format of the authenticator checksum field is as follows. + + Byte Name Description + ----------------------------------------------------------------- + 0..3 Lgth Number of bytes in Bnd field; Currently contains + hex value 10 00 00 00 (16, represented in little- + endian order) + 4..19 Bnd Channel binding information, as describe in + section 4.1.1.2. + 20..23 Flags Four-byte context-establishment flags in little- + endian order as described in section 4.1.1.1. + 24..25 DlgOpt The Delegation Option identifier (=1) [optional] + 26..27 Dlgth The length of the Deleg field [optional] + + +Zhu Internet Draft 4 + Kerberos Version 5 GSS-API September 2003 + + + 28..n Deleg A KRB_CRED message (n = Dlgth + 29) [optional] + +4.1.1.1. Checksum Flags Field + + The checksum "Flags" field is used to convey service options or + extension negotiation information. The following context + establishment flags are defined in [RFC-2744]. + + Flag Name Value + --------------------------------- + GSS_C_DELEG_FLAG 1 + GSS_C_MUTUAL_FLAG 2 + GSS_C_REPLAY_FLAG 4 + GSS_C_SEQUENCE_FLAG 8 + GSS_C_CONF_FLAG 16 + GSS_C_INTEG_FLAG 32 + GSS_C_ANON_FLAG 64 + + Context establishment flags are exposed to the calling application. + If the calling application desires a particular service option then + it requests that option via GSS_Init_sec_context() [RFC-2743]. An + implementation that supports a particular option or extension SHOULD + then set the appropriate flag in the checksum Flags field. + + The receiver MUST ignore unknown checksum flags. + +4.1.1.2. Channel Binding Information + + Channel bindings are user-specified tags to identify a given context + to the peer application. These tags are intended to be used to + identify the particular communications channel that carries the + context. + + When using C language bindings, channel bindings are communicated to + the GSS-API using the following structure [RFC-2744]: + + typedef struct gss_channel_bindings_struct { + OM_uint32 initiator_addrtype; + gss_buffer_desc initiator_address; + OM_uint32 acceptor_addrtype; + gss_buffer_desc acceptor_address; + gss_buffer_desc application_data; + } *gss_channel_bindings_t; + + The member fields and constants used for different address types are + defined in [RFC-2744]. + + The "Bnd" field contains the MD5 hash of channel bindings, taken + over all non-null components of bindings, in order of declaration. + Integer fields within channel bindings are represented in little- + endian order for the purposes of the MD5 calculation. + + In computing the contents of the Bnd field, the following detailed + points apply: + + +Zhu Internet Draft 5 + Kerberos Version 5 GSS-API September 2003 + + + + (1) Each integer field shall be formatted into four bytes, using + little endian byte ordering, for purposes of MD5 hash computation. + + (2) All input length fields within gss_buffer_desc elements of a + gss_channel_bindings_struct even those which are zero-valued, shall + be included in the hash calculation; the value elements of + gss_buffer_desc elements shall be dereferenced, and the resulting + data shall be included within the hash computation, only for the + case of gss_buffer_desc elements having non-zero length specifiers. + + (3) If the caller passes the value GSS_C_NO_BINDINGS instead of a + valid channel binding structure, the Bnd field shall be set to 16 + zero-valued bytes. + +4.2. Per-Message and Context Deletion Tokens + + Three classes of tokens are defined in this section: "MIC" tokens, + emitted by calls to GSS_GetMIC() and consumed by calls to + GSS_VerifyMIC(), "Wrap" tokens, emitted by calls to GSS_Wrap() and + consumed by calls to GSS_Unwrap(), and context deletion tokens, + emitted by calls to GSS_Delete_sec_context() and consumed by calls + to GSS_Process_context_token(). + + The new per-message and context deletion tokens introduced here do + not include the pseudo ASN.1 header used by the initial context + tokens. These new tokens are designed to be used with newer crypto + systems that can, for example, have variable-size checksums. + +4.2.1. Sequence Number and Direction Indicator + + To distinguish intentionally-repeated messages from maliciously- + replayed ones, per-message and context deletion tokens contain a + sequence number field, which is a 64 bit integer expressed in big + endian order. One separate bit is used as the direction-indicator + in the Flags field as described in section 4.2.2, thus preventing an + adversary from sending back the same message in the reverse + direction and having it accepted. Both the sequence number and the + direction-indicator are protected by the encryption and checksum + procedures specified in section 4.2.4. + + After sending a GSS_GetMIC() or GSS_Wrap() token, the sender's + sequence numbers are incremented by one. + +4.2.2. Flags Field + + The "Flags" field is a one-byte integer used to indicate a set of + attributes. The meanings of bits in this field (the least + significant bit is bit 0) are as follows: + + Bit Name Description + --------------------------------------------------------------- + 0 SentByAcceptor When set, this flag indicates the sender + is the context acceptor. When not set, + + +Zhu Internet Draft 6 + Kerberos Version 5 GSS-API September 2003 + + + it indicates the sender is the context + initiator. + 1 Sealed When set in Wrap tokens, this flag + indicates confidentiality is provided + for. It SHALL NOT be set in MIC and + context deletion tokens. + 2 AcceptorSubkey A subkey asserted by the context acceptor + is used to protect the message. + + The rest of available bits are reserved for future use and MUST be + cleared. The receiver MUST ignore unknown flags. + +4.2.3. EC Field + + The "EC" (Extra Count) field is a two-byte integer field expressed + in big endian order. + + In Wrap tokens with confidentiality, the EC field is used to encode + the number of bytes in the filler, as described in section 4.2.4. + + In Wrap tokens without confidentiality, the EC field is used to + encode the number of bytes in the trailing checksum, as described in + section 4.2.4. + +4.2.4. Encryption and Checksum Operations + + The encryption algorithms defined by the crypto profiles provide for + integrity protection [KCRYPTO]. Therefore no separate checksum is + needed. + + The result of decryption can be longer than the original plaintext + [KCRYPTO] and the extra trailing bytes are called "crypto-system + garbage". However, given the size of any plaintext data, one can + always find the next (possibly larger) size so that, when padding + the to-be-encrypted text to that size, there will be no crypto- + system garbage added [KCRYPTO]. + + In Wrap tokens that provide for confidentiality, the first 16 bytes + of the Wrap token (the "header") are appended to the plaintext data + before encryption. Filler bytes can be inserted between the + plaintext-data and the "header", and the values and size of the + filler octets are chosen by implementations, such that there is no + crypto-system garbage present after the decryption. The resulting + Wrap token is {"header" | encrypt(plaintext-data | filler | + "header")}, where encrypt() is the encryption operation (which + provides for integrity protection) defined in the crypto profile + [KCRYPTO], and the RRC field in the to-be-encrypted header contains + the hex value 00 00. + + In Wrap tokens that do not provide for confidentiality, the checksum + is calculated first over the plaintext data, and then the first 16 + bytes of the Wrap token (the "header"). Both the EC field and the + RRC field in the token header are filled with zeroes for the purpose + of calculating the checksum. The resulting Wrap token is {"header" + + +Zhu Internet Draft 7 + Kerberos Version 5 GSS-API September 2003 + + + | plaintext-data | get_mic(plaintext-data | "header")}, where + get_mic() is the checksum operation defined in the crypto profile + [KCRYPTO]. + + The parameters for the key and the cipher-state in the encrypt() and + get_mic() operations have been omitted for brevity. + + For MIC tokens, the checksum is first calculated over the first 16 + bytes of the MIC token and then the to-be-signed plaintext data. + + The resulting Wrap and MIC tokens bind the data to the token header, + including the sequence number and the directional indicator. + + For context deletion tokens, the checksum is calculated over the + first 16 bytes of the token message. + +4.2.5. RRC Field + + The "RRC" (Right Rotation Count) field in Wrap tokens is added to + allow the data to be encrypted in-place by existing [SSPI] + applications that do not provide an additional buffer for the + trailer (the cipher text after the in-place-encrypted data) in + addition to the buffer for the header (the cipher text before the + in-place-encrypted data). The resulting Wrap token in the previous + section, excluding the first 16 bytes of the token header, is + rotated to the right by "RRC" bytes. The net result is that "RRC" + bytes of trailing octets are moved toward the header. Consider the + following as an example of this rotation operation: Assume that the + RRC value is 3 and the token before the rotation is {"header" | aa | + bb | cc | dd | ee | ff | gg | hh}, the token after rotation would be + {"header" | ff | gg | hh | aa | bb | cc | dd | ee }, where {aa | bb + | cc |...| hh} is used to indicate the byte sequence. + + The RRC field is expressed as a two-byte integer in big endian + order. + + The rotation count value is chosen by the sender based on + implementation details, and the receiver MUST be able to interpret + all possible rotation count values. + +4.2.6. Message Layouts + + Per-message and context deletion token messages start with a two- + byte token identifier (TOK_ID) field, expressed in big endian order. + These tokens are defined separately in subsequent sub-sections. + +4.2.6.1. MIC Tokens + + Use of the GSS_GetMIC() call yields a token, separate from the user + data being protected, which can be used to verify the integrity of + that data as received. The token has the following format: + + +Zhu Internet Draft 8 + Kerberos Version 5 GSS-API September 2003 + + + Byte no Name Description + ----------------------------------------------------------------- + 0..1 TOK_ID Identification field. Tokens emitted by + GSS_GetMIC() contain the hex value 04 04 + expressed in big endian order in this field. + 2 Flags Attributes field, as described in section + 4.2.2. + 3..7 Filler Contains five bytes of hex value FF. + 8..15 SND_SEQ Sequence number field in clear text, + expressed in big endian order. + 16..last SGN_CKSUM Checksum of byte 0..15 and the "to-be- + signed" data, where the checksum algorithm + is defined by the crypto profile for the + session key or subkey. + + The Filler field is included in the checksum calculation for + simplicity. This is common to both MIC and context deletion token + checksum calculations. + +4.2.6.2. Wrap Tokens + + Use of the GSS_Wrap() call yields a token, which consists of a + descriptive header, followed by a body portion that contains either + the input user data in plaintext concatenated with the checksum, or + the input user data encrypted. The GSS_Wrap() token has the + following format: + + Byte no Name Description + --------------------------------------------------------------- + 0..1 TOK_ID Identification field. Tokens emitted by + GSS_Wrap() contain the the hex value 05 04 + expressed in big endian order in this field. + 2 Flags Attributes field, as described in section + 4.2.2. + 3 Filler Contains the hex value FF. + 4..5 EC Contains the "extra count" field, in big + endian order as described in section 4.2.3. + 6..7 RRC Contains the "right rotation count" in big + endian order, as described in section 4.2.5. + 8..15 SND_SEQ Sequence number field in clear text, + expressed in big endian order. + 16..last Data Encrypted data for Wrap tokens with + confidentiality, or plaintext data followed + by the checksum for Wrap tokens without + confidentiality, as described in section + 4.2.4, where the encryption or checksum + algorithm is defined by the crypto profile + for the session key or subkey. + +4.2.6.3. Context Deletion Tokens + + The token emitted by GSS_Delete_sec_context() is based on the packet + format for tokens emitted by GSS_GetMIC(). The context-deletion + token has the following format: + + +Zhu Internet Draft 9 + Kerberos Version 5 GSS-API September 2003 + + + Byte no Name Description + ----------------------------------------------------------------- + 0..1 TOK_ID Identification field. Tokens emitted by + GSS_Delete_sec_context() contain the hex + value 04 05 expressed in big endian order in + this field. + 2 Flags Attributes field, as described in section + 4.2.2. + 3..7 Filler Contains five bytes of hex value FF. + 8..15 SND_SEQ Sequence number field in clear text, + expressed in big endian order. + 16..N SGN_CKSUM Checksum of byte 0..15, where the checksum + algorithm is defined by the crypto profile + for the session key or subkey. + +5. Parameter Definitions + + This section defines parameter values used by the Kerberos V5 GSS- + API mechanism. It defines interface elements in support of + portability, and assumes use of C language bindings per [RFC-2744]. + +5.1. Minor Status Codes + + This section recommends common symbolic names for minor_status + values to be returned by the Kerberos V5 GSS-API mechanism. Use of + these definitions will enable independent implementers to enhance + application portability across different implementations of the + mechanism defined in this specification. (In all cases, + implementations of GSS_Display_status() will enable callers to + convert minor_status indicators to text representations.) Each + implementation should make available, through include files or other + means, a facility to translate these symbolic names into the + concrete values which a particular GSS-API implementation uses to + represent the minor_status values specified in this section. + + It is recognized that this list may grow over time, and that the + need for additional minor_status codes specific to particular + implementations may arise. It is recommended, however, that + implementations should return a minor_status value as defined on a + mechanism-wide basis within this section when that code is + accurately representative of reportable status rather than using a + separate, implementation-defined code. + +5.1.1. Non-Kerberos-specific codes + + GSS_KRB5_S_G_BAD_SERVICE_NAME + /* "No @ in SERVICE-NAME name string" */ + GSS_KRB5_S_G_BAD_STRING_UID + /* "STRING-UID-NAME contains nondigits" */ + GSS_KRB5_S_G_NOUSER + /* "UID does not resolve to username" */ + GSS_KRB5_S_G_VALIDATE_FAILED + /* "Validation error" */ + GSS_KRB5_S_G_BUFFER_ALLOC + /* "Couldn't allocate gss_buffer_t data" */ + + +Zhu Internet Draft 10 + Kerberos Version 5 GSS-API September 2003 + + + GSS_KRB5_S_G_BAD_MSG_CTX + /* "Message context invalid" */ + GSS_KRB5_S_G_WRONG_SIZE + /* "Buffer is the wrong size" */ + GSS_KRB5_S_G_BAD_USAGE + /* "Credential usage type is unknown" */ + GSS_KRB5_S_G_UNKNOWN_QOP + /* "Unknown quality of protection specified" */ + +5.1.2. Kerberos-specific-codes + + GSS_KRB5_S_KG_CCACHE_NOMATCH + /* "Client principal in credentials does not match + specified name" */ + GSS_KRB5_S_KG_KEYTAB_NOMATCH + /* "No key available for specified service principal" */ + GSS_KRB5_S_KG_TGT_MISSING + /* "No Kerberos ticket-granting ticket available" */ + GSS_KRB5_S_KG_NO_SUBKEY + /* "Authenticator has no subkey" */ + GSS_KRB5_S_KG_CONTEXT_ESTABLISHED + /* "Context is already fully established" */ + GSS_KRB5_S_KG_BAD_SIGN_TYPE + /* "Unknown signature type in token" */ + GSS_KRB5_S_KG_BAD_LENGTH + /* "Invalid field length in token" */ + GSS_KRB5_S_KG_CTX_INCOMPLETE + /* "Attempt to use incomplete security context" */ + +5.2. Buffer Sizes + + All implementations of this specification shall be capable of + accepting buffers of at least 16K bytes as input to GSS_GetMIC(), + GSS_VerifyMIC(), and GSS_Wrap(), and shall be capable of accepting + the output_token generated by GSS_Wrap() for a 16K byte input buffer + as input to GSS_Unwrap(). Support for larger buffer sizes is + optional but recommended. + +6. Backwards Compatibility Considerations + + The new token formats defined in this document will only be + recognized by new implementations. To address this, implementations + can always use the explicit sign or seal algorithm in [RFC-1964] + when the key type corresponds to "older" enctypes. An alternative + approach might be to retry sending the message with the sign or seal + algorithm explicitly defined as in [RFC-1964]. However this would + require either the use of a mechanism such as [RFC-2478] to securely + negotiate the method or the use out of band mechanism to choose + appropriate mechanism. For this reason, it is RECOMMENDED that the + new token formats defined in this document SHOULD be used only if + both peers are known to support the new mechanism during context + negotiation, for example, either because of the use of "new" + enctypes or because of the use of Kerberos Version 5 extensions. + + +Zhu Internet Draft 11 + Kerberos Version 5 GSS-API September 2003 + + +7. Security Considerations + + Under the current mechanism, no negotiation of algorithm types + occurs, so server-side (acceptor) implementations cannot request + that clients not use algorithm types not understood by the server. + However, administration of the server's Kerberos data (e.g., the + service key) has to be done in communication with the KDC, and it is + from the KDC that the client will request credentials. The KDC + could therefore be given the task of limiting session keys for a + given service to types actually supported by the Kerberos and GSSAPI + software on the server. + + This does have a drawback for cases where a service principal name + is used both for GSSAPI-based and non-GSSAPI-based communication + (most notably the "host" service key), if the GSSAPI implementation + does not understand (for example) AES [AES-KRB5] but the Kerberos + implementation does. It means that AES session keys cannot be + issued for that service principal, which keeps the protection of + non-GSSAPI services weaker than necessary. KDC administrators + desiring to limit the session key types to support interoperability + with such GSSAPI implementations should carefully weigh the + reduction in protection offered by such mechanisms against the + benefits of interoperability. + +8. Acknowledgments + + The authors wish to acknowledge the contributions from the following + individuals: + + Ken Raeburn and Nicolas Williams corrected many of our errors in the + use of generic profiles and were instrumental in the creation of this + draft. + + The text for security considerations was contributed by Ken Raeburn. + + Sam Hartman and Ken Raeburn suggested the "floating trailer" idea, + namely the encoding of the RRC field. + + Sam Hartman and Nicolas Williams recommended the replacing our + earlier key derivation function for directional keys with different + key usage numbers for each direction as well as retaining the + directional bit for maximum compatibility. + + Paul Leach provided numerous suggestions and comments. + + Scott Field, Richard Ward, Dan Simon, and Kevin Damour also provided + valuable inputs on this draft. + + Jeffrey Hutzelman provided comments on channel bindings and suggested + many editorial changes. + + This document retains some of the text of RFC-1964 in relevant + sections. + +Zhu Internet Draft 12 + Kerberos Version 5 GSS-API September 2003 + + + +9. References + +9.1. Normative References + + [RFC-2026] Bradner, S., "The Internet Standards Process -- Revision + 3", BCP 9, RFC 2026, October 1996. + + [RFC-2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [RFC-2743] Linn, J., "Generic Security Service Application Program + Interface Version 2, Update 1", RFC 2743, January 2000. + + [RFC-2744] Wray, J., "Generic Security Service API Version 2: C- + bindings", RFC 2744, January 2000. + + [RFC-1964] Linn, J., "The Kerberos Version 5 GSS-API Mechanism", + RFC 1964, June 1996. + + [KCRYPTO] Raeburn, K., "Encryption and Checksum Specifications for + Kerberos 5", draft-ietf-krb-wg-crypto-05.txt, June, 2003. Work in + progress. + + [KRBCLAR] Neuman, C., Kohl, J., Ts'o T., Yu T., Hartman, S., + Raeburn, K., "The Kerveros Network Authentication Service (V5)", + draft-ietf-krb-wg-kerberos-clarifications-04.txt, February 2002. + Work in progress. + + [AES-KRB5] Raeburn, K., "AES Encryption for Kerberos 5", draft- + raeburn-krb-rijndael-krb-05.txt, June 2003. Work in progress. + + [RFC-2478] Baize, E., Pinkas D., "The Simple and Protected GSS-API + Negotiation Mechanism", RFC 2478, December 1998. + +9.2. Informative References + + [SSPI] Leach, P., "Security Service Provider Interface", Microsoft + Developer Network (MSDN), April 2003. + +10. Author's Address + + Larry Zhu + One Microsoft Way + Redmond, WA 98052 - USA + EMail: LZhu@microsoft.com + + Karthik Jaganathan + One Microsoft Way + Redmond, WA 98052 - USA + EMail: karthikj@microsoft.com + +Zhu Internet Draft 13 + Kerberos Version 5 GSS-API September 2003 + + + Sam Hartman + Massachusetts Institute of Technology + 77 Massachusetts Avenue + Cambridge, MA 02139 - USA + Email: hartmans@MIT.EDU + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Zhu Internet Draft 14 + Kerberos Version 5 GSS-API September 2003 + + + +Full Copyright Statement + + Copyright (C) The Internet Society (date). All Rights Reserved. + + This document and translations of it may be copied and furnished to + others, and derivative works that comment on or otherwise explain it + or assist in its implementation may be prepared, copied, published + and distributed, in whole or in part, without restriction of any + kind, provided that the above copyright notice and this paragraph + are included on all such copies and derivative works. However, this + document itself may not be modified in any way, such as by removing + the copyright notice or references to the Internet Society or other + Internet organizations, except as needed for the purpose of + developing Internet standards in which case the procedures for + copyrights defined in the Internet Standards process must be + followed, or as required to translate it into languages other than + English. + + The limited permissions granted above are perpetual and will not be + revoked by the Internet Society or its successors or assigns. + + This document and the information contained herein is provided on an + "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING + TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING + BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION + HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF + MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + + + + + + + + + + + + + + + + + + + + + + + + + + +Zhu Internet Draft 15 \ No newline at end of file