idnits 2.17.00 (12 Aug 2021) /tmp/idnits2559/draft-blake-wilson-xmldsig-ecdsa-04.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** Looks like you're using RFC 2026 boilerplate. This must be updated to follow RFC 3978/3979, as updated by RFC 4748. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- ** The document seems to lack a 1id_guidelines paragraph about Internet-Drafts being working documents. ** The document seems to lack a 1id_guidelines paragraph about the list of current Internet-Drafts. ** The document seems to lack a 1id_guidelines paragraph about the list of Shadow Directories -- however, there's a paragraph with a matching beginning. Boilerplate error? == There is 1 instance of lines with non-ascii characters in the document. == No 'Intended status' indicated for this document; assuming Proposed Standard == The page length should not exceed 58 lines per page, but there was 5 longer pages, the longest (page 7) being 74 lines Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The document seems to lack an IANA Considerations section. (See Section 2.2 of https://www.ietf.org/id-info/checklist for how to handle the case when there are no actions for IANA.) ** The document seems to lack separate sections for Informative/Normative References. All references will be assumed normative when checking for downward references. ** There is 1 instance of too long lines in the document, the longest one being 1 character in excess of 72. ** The abstract seems to contain references ([XMLDSIG]), which it shouldn't. Please replace those with straight textual mentions of the documents in question. ** The document seems to lack a both a reference to RFC 2119 and the recommended RFC 2119 boilerplate, even if it appears to use RFC 2119 keywords. RFC 2119 keyword, line 112: '...The XML namespace [XML-ns] URI that MUST be used by implementations of...' RFC 2119 keyword, line 142: '...definition of the entity Key.ANY SHOULD replace the one in [XMLDSIG]:...' RFC 2119 keyword, line 201: '...[X9.62], [FIPS-186-2] or [SEC2], the OIDs of these curves SHOULD be used...' Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the RFC 3978 Section 5.4 Copyright Line does not match the current year -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (December 2002) is 7096 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'FIPS186-2' is mentioned on line 85, but not defined == Missing Reference: 'NIST-ECC' is mentioned on line 469, but not defined -- Possible downref: Non-RFC (?) normative reference: ref. 'FIPS-180-1' -- Possible downref: Non-RFC (?) normative reference: ref. 'FIPS-186-2' -- Possible downref: Non-RFC (?) normative reference: ref. 'IEEE1363' -- Possible downref: Non-RFC (?) normative reference: ref. 'KEYS' ** Downref: Normative reference to an Informational RFC: RFC 3061 -- Possible downref: Non-RFC (?) normative reference: ref. 'SEC1' -- Possible downref: Non-RFC (?) normative reference: ref. 'SEC2' -- Possible downref: Non-RFC (?) normative reference: ref. 'XML' -- Possible downref: Non-RFC (?) normative reference: ref. 'XMLDSIG' -- Possible downref: Non-RFC (?) normative reference: ref. 'XML-ns' -- Possible downref: Non-RFC (?) normative reference: ref. 'XML-schema' Summary: 10 errors (**), 0 flaws (~~), 6 warnings (==), 12 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 INTERNET-DRAFT S. Blake-Wilson, BCI 2 G. Karlinger, CIO Austria 3 Y. Wang, UNCC 4 T. Kobayashi, NTT 5 Expires: June 2003 December 2002 7 ECDSA with XML-Signature Syntax 8 10 Status of this Memo 12 This document is an Internet-Draft and is in full conformance with all 13 provisions of Section 10 of RFC2026. Internet-Drafts are working 14 documents of the Internet Engineering Task Force (IETF), its areas, 15 and its working groups. Note that other groups may also distribute 16 working documents as Internet-Drafts. 18 Internet-Drafts are draft documents valid for a maximum of six months 19 and may be updated, replaced, or obsoleted by other documents at any 20 time. It is inappropriate to use Internet-Drafts as reference material 21 or to cite them other than as "work in progress." 23 The list of current Internet-Drafts may be found at 24 http://www.ietf.org/ietf/1id-abstracts.txt 26 The list of Internet-Draft Shadow Directories may be found at 27 http://www.ietf.org/shadow.html. 29 Abstract 31 This document specifies how to use ECDSA (Elliptic Curve Digital 32 Signature Algorithm) with XML Signatures [XMLDSIG]. The mechanism 33 specified provides integrity, message authentication, and/or signer 34 authentication services for data of any type, whether located 35 within the XML that includes the signature or included by reference. 37 Table of Contents 39 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 3 40 2 ECDSA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 41 3 Specifying ECDSA within XMLDSIG . . . . . . . . . . . . . . . . 3 42 3.1 Version, Namespaces and Identifiers . . . . . . . . . . . . 3 43 3.1.1 XML Schema Preamble . . . . . . . . . . . . . . . . 3 44 3.1.2 DTD Replacement . . . . . . . . . . . . . . . . . . 3 45 3.2 XML Schema Preamble and DTD Replacement . . . . . . . . . . 4 46 3.2.1 XML Schema Preamble . . . . . . . . . . . . . . . . . 4 47 3.2.2 DTD Replacement . . . . . . . . . . . . . . . . . . . 4 48 3.3 ECDSA Signatures . . . . . . . . . . . . . . . . . . . . . 4 49 3.4 ECDSA Key Values . . . . . . . . . . . . . . . . . . . . . 4 50 3.4.1 Key Value Root Element . . . . . . . . . . . . . . . 5 51 3.4.2 EC Domain Parameters . . . . . . . . . . . . . . . . 5 52 3.4.2.1 Field Parameters . . . . . . . . . . . . . 6 53 3.4.2.2 Curve Parameters . . . . . . . . . . . . . 8 54 3.4.2.3 Base Point Parameters . . . . . . . . . . . 9 55 3.4.3 EC Points . . . . . . . . . . . . . . . . . . . . . 10 56 4 Security Considerations . . . . . . . . . . . . . . . . . . . . 11 57 5 Intellectual Property Rights . . . . . . . . . . . . . . . . . . 11 58 6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 59 7 Authors' addresses . . . . . . . . . . . . . . . . . . . . . . . 13 60 8 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 13 61 9 Full Copyright Statement . . . . . . . . . . . . . . . . . . . . 13 63 Appendix A: Aggregate XML Schema . . . . . . . . . . . . . . . . . 14 64 Appendix B: Aggregate DTD . . . . . . . . . . . . . . . . . . . . . 17 66 1. Introduction 68 This document specifies how to use the Elliptic Curve Digital Signature 69 Algorithm (ECDSA) with XML signatures as specified in [XMLDSIG]. Therein 70 only two digital signature methods are defined: RSA signatures and DSA 71 (DSS) signatures. This document introduces ECDSA signatures as an 72 additional method. 74 This document uses both XML Schemas [XML-schema] (normative) and DTDs 75 [XML] (informational) for specifying the corresponding XML structures. 77 2. ECDSA 79 The Elliptic Curve Digital Signature Algorithm (ECDSA) is the elliptic 80 curve analogue of the DSA (DSS) signature method [FIPS186-2]. It is 81 defined in the ANSI X9.62 standard [X9.62]. Other compatible 82 specifications include FIPS 186-2 [FIPS186-2], IEEE 1363 [IEEE1363], 83 and SEC1 [SEC1]. [RFC3279] describes the means to carry ECDSA keys in 84 X.509 certificates. Recommended elliptic curve domain parameters for 85 use with ECDSA are given in [FIPS186-2], [SEC2], and [X9.62]. 87 Like DSA, ECDSA incorporates the use of a hash function. Currently,the 88 only hash function defined for use with ECDSA is the SHA-1 message 89 digest algorithm [FIPS-180-1]. 91 ECDSA signatures are smaller than RSA signatures of similar 92 cryptographic strength. ECDSA public keys (and certificates) are smaller 93 than similar strength DSA keys, resulting in improved communications 94 efficiency. Furthermore, on many platforms ECDSA operations can be 95 computed faster than similar strength RSA or DSA operations (see [KEYS] 96 for a security analysis of key sizes across public key algorithms). 97 These advantages of signature size, bandwidth, and computational 98 efficiency may make ECDSA an attractive choice for XMLDSIG 99 implementations. 101 3. Specifying ECDSA within XMLDSIG 103 This section specifies the details of how to use ECDSA with XML 104 Signature Syntax and Processing [XMLDSIG]. It relies heavily on the 105 syntax and namespace defined therein. 107 3.1 Version, Namespaces and Identifiers 109 No provision is made for an explicit version number in this syntax. If 110 a future version is needed, it will use a different namespace. 112 The XML namespace [XML-ns] URI that MUST be used by implementations of 113 this (dated) specification is: 114 http://www.buergerkarte.at/namespaces/ecdsa/200206030# 116 Elements in the namespace of the [XMLDSIG] specification are marked as 117 such by using the namespace prefix "dsig" in the remaining sections of 118 this document. 120 The identifier for the ECDSA signature algorithm is: 121 http://www.buergerkarte.at/namespaces/ecdsa/200206030#ecdsa-sha1 123 3.2 XML Schema Preamble and DTD Replacement 125 3.2.1 XML Schema Preamble 127 The subsequent preamble is to be used with the XML Schema definitions 128 given in the remaining sections of this document. 130 131 139 3.2.2 DTD Replacement 141 In order to include ECDSA in XML-signature syntax, the following 142 definition of the entity Key.ANY SHOULD replace the one in [XMLDSIG]: 144 146 3.3 ECDSA Signatures 148 The input to the ECDSA algorithm is the canonicalized represenation of 149 the dsig:SignedInfo element as specified in Section 3 of [XMLDSIG]. 151 The output of the ECDSA algorithm consists of a pair of integers usually 152 referred by the pair (r, s). The signature value (text value of element 153 dsig:SignatureValue - see section 4.2 of [XMLDSIG]) consists of the 154 base64 encoding of the concatenation of two octet-streams that 155 respectively result from the octet-encoding of the values r and s. This 156 concatenation is described in section E3.1 of [IEEE1363]. 158 3.4 ECDSA Key Values 160 The syntax used for ECDSA key values closely follows the ASN.1 syntax 161 defined in ANSI X9.62 [X9.62]. 163 3.4.1 Key Value Root Element 165 The element ECDSAKeyValue is used for encoding ECDSA public keys. For 166 use with XMLDSIG simply use this element inside dsig:KeyValue, such as 167 the predefined elements dsig:RSAKeyValue or dsig:DSAKeyValue. 169 The element consists of an optional subelement DomainParameters and the 170 mandatory subelement PublicKey. If Domainparameters is missing in an 171 instance, this means that the application knows about them from other 172 means (implicitly). 174 Schema Definition: 176 178 179 180 182 183 184 186 DTD Definition: 188 189 190 191 192 193 195 3.4.2 EC Domain Parameters 197 Domain parameters can be encoded either explicitly using element 198 ExplicitParams, or by reference using element NamedCurve. The latter 199 simply consists of an attribute named URN, which bears a uniform 200 ressource name as its value. For the named curves of standards like 201 [X9.62], [FIPS-186-2] or [SEC2], the OIDs of these curves SHOULD be used 202 in this attribute, e. g. URN="urn:oid:1.2.840.10045.3.1.1". The 203 mechanism for encoding OIDs in URNs is shown in [RFC3061]. 205 Schema Definition: 207 208 209 211 212 213 214 215 216 217 219 DTD Definition: 221 222 223 225 The element ExplicitParams is used for explicit encoding of domain 226 parameters. It contains three subelements: FieldParams describes the 227 underlying field, CurveParams describes the elliptic curve, and 228 BasePointParams describes the base point of the elliptic curve. 230 Schema Definition: 232 233 234 235 236 238 239 241 DTD Definition: 243 245 3.4.2.1 Field Parameters 247 The element FieldParams is used for encoding field parameters. The 248 corresponding XML Schema type FieldParamsType is declared abstract and 249 will be extended by specialized types for prime field, characteristic 250 two field and odd characteristic extension fields parameters. 252 The XML Schema type PrimeFieldParamsType is derived from FieldParamsType 253 and is used for for encoding prime field parameters. The type contains 254 as its single subelement P, the order of the prime field. 256 The XML Schema type CharTwoFieldParamsType is derived from 257 FieldParamsType as well and is used for encoding parameters of a 258 characteristic two field. It is again an abstract type and will be 259 extended by specialized types for trinomial base fields and pentanomial 260 base fields. F2m Gaussian Normal Base fields are not supported by this 261 specification to relieve interoperability. Common to both specialized 262 types is the element M, the extension degree of the field. 264 The XML Schema type TnBFieldParamsType is derived from 265 CharTwoFieldParamsType and is used for encoding trinomial base fields. 266 It adds the single element K, which represents the integer k, where 267 x^m + x^k + 1 is the reduction polynomial. 269 The XML Schema type PnBFieldParamsType is derived from 270 CharTwoFieldParamsType as well and is used for encoding pentanomial base 271 fields. It adds the three elements K1, K2 and K3, which represent the 272 integers k1, k2 and k3 respectively, where x^m + x^k3 + x^k2 + x^k1 + 1 273 is the reduction polynomial. 275 The XML Schema type OddCharExtensionFieldParamsType is derived from 276 FieldParamsType as well and is used for encoding parameters of a 277 odd characteristic extension field. 278 The type contains two elements M, the extension degree of the field, 279 and W, which represent the integers w, 280 where x^m - w is the reduction polynomial. 282 Schema Definition: 284 286 287 288 289 290 291 292 293 294 296 297 298 299 300 301 302 303 304 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 326 327 328 329 330 331 332 333 334 335 336 338 DTD Definition: 340 341 342 343 344 345 346 348 3.4.2.2 Curve Parameters 350 The element CurveParams is used for encoding parameters of the elliptic 351 curve. The corresponding XML Schema type CurveParamsType bears the 352 elements A and B representing the coefficients a and b of the elliptic 353 curve, while the optional element Seed contains the value used to derive 354 the coefficients of a randomly generated elliptic curve, according to 355 the algorithm specified in annex A3.3 of [X9.62]. 357 Schema Definition: 359 360 361 362 363 364 365 367 DTD Definition: 369 370 371 372 373 374 376 3.4.2.3 Base Point Parameters 378 The element BasePointParams is used for encoding parameters regarding 379 the base point of the elliptic curve. BasePoint represents the base 380 point itself, Order provides the order of the base point, and Cofactor 381 optionally provides the cofactor of the base point. 383 Schema Definition: 385 386 387 388 389 391 392 394 DTD Definition: 396 397 398 399 401 3.4.3 EC Points 403 The XML Schema type ECPointType is used for encoding a point on the 404 elliptic curve. It consists of the subelements X and Y, providing the 405 x and y coordinates of the point. Point compression representation is 406 not supported by this specification for the sake of simple design. 408 The point at infinity is encoded by omitting both elements X and Y. 410 The subelements X and Y are of type FieldElemType. This is an abstract 411 type for encoding elements of the elliptic curveËs underlying field and 412 is extended by specialized types for prime field elements and 413 characteristic two field elements. 415 The XML Schema type PrimeFieldElemType is used for encoding prime field 416 elements. It contains a single attribute named Value, whose value 417 represents the field element as an integer. 419 The XML Schema type CharTwoFieldElemType is used for encoding 420 characteristic two field elements. It Contains a single attribute named 421 Value, whose value represents the field element as an octet string. The 422 octet string must be composed as shown in paragraph 2 of section 4.3.3 423 of [X9.62]. 425 Schema Definition: 427 428 429 430 431 432 434 436 437 438 439 441 442 443 445 446 447 448 450 451 452 453 454 455 456 458 459 460 462 4. Security Considerations 464 Implementers should ensure that appropriate security measures are in 465 place when they deploy ECDSA within XMLDSIG. In particular, the security 466 of ECDSA requires the careful selection of both key sizes and elliptic 467 curve domain parameters. Selection guidelines for these parameters and 468 some specific recommended curves that are considered safe are provided 469 in [X9.62], [NIST-ECC], and [SEC2]. For further security discussion, 470 see [XMLDSIG]. 472 5. Intellectual Property Rights 474 The IETF has been notified of intellectual property rights claimed in 475 regard to the specification contained in this document. 476 For more information, consult the online list of claimed rights 477 (http://www.ietf.org/ipr.html). 479 The IETF takes no position regarding the validity or scope of any 480 intellectual property or other rights that might be claimed to 481 pertain to the implementation or use of the technology described in 482 this document or the extent to which any license under such rights 483 might or might not be available; neither does it represent that it 484 has made any effort to identify any such rights. Information on the 485 IETF's procedures with respect to rights in standards-track and 486 standards-related documentation can be found in BCP-11. Copies of 487 claims of rights made available for publication and any assurances of 488 licenses to be made available, or the result of an attempt made to 489 obtain a general license or permission for the use of such 490 proprietary rights by implementers or users of this specification can 491 be obtained from the IETF Secretariat. 493 6. References 495 [FIPS-180-1] Federal Information Processing Standards Publication 496 (FIPS PUB) 180-1, Secure Hash Standard, April 1995. 498 [FIPS-186-2] Federal Information Processing Standards Publication 499 (FIPS PUB) 186-2, Digital Signature Standard. January 500 2000. 502 [IEEE1363] Institute for Electrical and Electronics Engineers (IEEE) 503 Standard 1363-2000, Standard Specifications for Public Key 504 Cryptography. January 2000. 506 [KEYS] Lenstra, A.K. and Verheul, E.R., Selecting Cryptographic Key 507 Sizes. October 1999. Presented at Public Key Cryptography 508 Conference, Melbourne, Australia, January 2000. 509 http://www.cryptosavvy.com/ 511 [RFC3061] Mealling, M., RFC 3061, A URN Namespace of Object 512 Identifiers. IETF Informational RFC, February 2001. 513 http://www.ietf.org/rfc/rfc3061.txt 515 [RFC3279] Bassham, L., Housley, R., and Polk, W., RFC 3279, Algorithms 516 and Identifiers for the Internet X.509 Public Key 517 Infrastructure Certificate and Certificate Revocation List 518 (CRL) Profile. IETF Proposed Standard, April 2002. 519 http://www.ietf.org/rfc/rfc3279.txt 521 [SEC1] Standards for Efficient Cryptography Group, SEC 1: Elliptic 522 Curve Cryptography, Version 1.0, September 2000. 523 http://www.secg.org 525 [SEC2] Standards for Efficient Cryptography Group, SEC 2: Recommended 526 Elliptic Curve Domain Parameters, Version 1.0, September 2000. 527 http://www.secg.org 529 [X9.62] American National Standards Institute. ANSI X9.62-1998, 530 Public Key Cryptography for the Financial Services Industry: 531 The Elliptic Curve Digital Signature Algorithm. January 1999. 533 [XML] Bray, T., Maler, E., Paoli, J. , and Sperberg-McQueen, C. M., 534 Extensible Markup Language (XML) 1.0 (Second Edition), W3C 535 Recommendation, October 2000. 536 http://www.w3.org/TR/2000/REC-xml-20001006 538 [XMLDSIG] Eastlake, D., Reagle, J., and Solo, D., XML-Signature 539 Syntax and Processing. W3C Recommendation, February 2002. 540 http://www.w3.org/TR/2002/REC-xmldsig-core-20020212/ 542 [XML-ns] Bray, T., Hollander, D., and Layman, A., Namespaces in XML, 543 W3C Recommendation, January 1999. 544 http://www.w3.org/TR/1999/REC-xml-names-19990114/ 546 [XML-schema] Beech, D., Maloney, M., Mendelsohn, N., and Thompson, 547 H., XML Schema Part 1: Structures, W3C Recommendation, 548 May 2001. 549 http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/ 550 Biron, P., and Malhotra, A., ML Schema Part 2: 551 Datatypes, W3C Recommendation, May 2001. 552 http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/ 554 7. Authors' Addresses 556 Simon Blake-Wilson 557 BCI 558 96 Spadina Ave, Unit 606 559 Toronto, ON, M5V 2J6, Canada 560 e-mail: sblakewilson@bcisse.com 562 Gregor Karlinger 563 Chief Information Office Austria 564 Parkring 10/I/5 565 1010 Wien, Austria 566 e-mail: gregor.karlinger@cio.gv.at 568 Tetsutaro Kobayashi 569 NTT Laboratories 570 1-1 Hikarinooka, Yokosuka, 239-0847, Japan 571 Phone: +81-468-59-3712 572 FAX: +81-468-59-3365 573 email: kotetsu@isl.ntt.co.jp 575 Yongge Wang 576 University of North Carolina at Charlotte 577 9201 University City Blvd 578 Charlotte, NC 28223, USA 579 e-mail: yonwang@uncc.edu 581 8. Acknowledgements 583 The authors would like to acknowledge the many helpful comments of 584 Wolfgang Bauer, Donald Eastlake, Tom Gindin, Chris Hawk, Joseph M. 585 Reagle Jr., and Francois Rousseau. 587 9. Full Copyright Statement 589 Copyright (C) The Internet Society (1999). All Rights Reserved. 591 This document and translations of it may be copied and furnished to 592 others, and derivative works that comment on or otherwise explain 593 it or assist in its implementation may be prepared, copied, 594 published and distributed, in whole or in part, without restriction 595 of any kind, provided that the above copyright notice and this 596 paragraph are included on all such copies and derivative works. 597 However, this document itself may not be modified in any way, such 598 as by removing the copyright notice or references to the Internet 599 Society or other Internet organizations, except as needed for the 600 purpose of developing Internet standards in which case the procedures 601 for copyrights defined in the Internet Standards process must be 602 followed, or as required to translate it into languages other than 603 English. 605 The limited permissions granted above are perpetual and will not be 606 revoked by the Internet Society or its successors or assigns. 608 This document and the information contained herein is provided on an 609 "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING 610 TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING 611 BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION 612 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF 613 MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 615 Appendix A: Aggregate XML Schema 617 618 627 629 630 631 632 634 635 636 637 639 640 641 643 644 645 646 647 648 649 650 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 706 707 708 709 710 711 712 713 714 715 716 717 718 719 721 722 724 726 727 728 729 730 731 732 734 735 736 737 738 740 741 742 743 744 745 746 748 749 750 751 752 753 754 756 757 758 759 761 Appendix A: Aggregate DTD 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790