One document matched: draft-ietf-smime-3278bis-03.txt
Differences from draft-ietf-smime-3278bis-02.txt
S/MIME WG Sean Turner, IECA
Internet Draft Dan Brown, Certicom
Intended Status: Informational October 22, 2008
Obsoletes: 3278 (once approved)
Expires: April 22, 2009
Use of Elliptic Curve Cryptography (ECC) Algorithms
in Cryptographic Message Syntax (CMS)
draft-ietf-smime-3278bis-03.txt
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Copyright Notice
Copyright (C) The IETF Trust (2008).
Abstract
This document describes how to use Elliptic Curve Cryptography (ECC)
public-key algorithms in the Cryptographic Message Syntax (CMS). The
ECC algorithms support the creation of digital signatures and the
exchange of keys to encrypt or authenticate content. The definition
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of the algorithm processing is based on the NIST FIPS 186-3 for
digital signature, NIST SP800-56A for key agreement, RFC 3565 and RFC
3370 for key wrap and content encryption, NIST FIPS 180-3 for message
digest, and RFC 2104 and RFC 4231 for message authentication code
standards. This document will obsolete RFC 3278.
Discussion
This draft is being discussed on the 'ietf-smime' mailing list. To
subscribe, send a message to ietf-smime-request@imc.org with the
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Table of Contents
1. Introduction...................................................2
1.1. Requirements Terminology..................................3
1.2. Changes since RFC 3278....................................3
2. SignedData using ECC...........................................5
2.1. SignedData using ECDSA....................................6
3. EnvelopedData using ECC Algorithms.............................7
3.1. EnvelopedData using (ephemeral-static) ECDH...............7
3.2. EnvelopedData using 1-Pass ECMQV..........................9
4. AuthenticatedData and AuthEnvelopedData using ECC.............12
4.1. AuthenticatedData using 1-pass ECMQV.....................12
4.2. AuthEnvelopedData using 1-pass ECMQV.....................13
5. Certificates using ECC........................................14
6. SMIMECapabilities Attribute and ECC...........................14
7. ASN.1 Syntax..................................................17
7.1. Algorithm Identifiers....................................17
7.2. Other Syntax.............................................20
8. Recommended Algorithms and Elliptic Curves....................22
9. Security Considerations.......................................24
10. IANA Considerations..........................................29
11. References...................................................29
11.1. Normative...............................................29
11.2. Informative.............................................31
Appendix A ASN.1 Modules.........................................33
Appendix A.1 1988 ASN.1 Module................................33
Appendix A.2 2004 ASN.1 Module................................40
1. Introduction
The Cryptographic Message Syntax (CMS) is cryptographic algorithm
independent. This specification defines a profile for the use of
Elliptic Curve Cryptography (ECC) public key algorithms in the CMS.
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The ECC algorithms are incorporated into the following CMS content
types:
- 'SignedData' to support ECC-based digital signature methods
(ECDSA) to sign content;
- 'EnvelopedData' to support ECC-based public-key agreement
methods (ECDH and ECMQV) to generate pairwise key-encryption
keys to encrypt content-encryption keys used for content
encryption;
- 'AuthenticatedData' to support ECC-based public-key agreement
methods (ECMQV) to generate pairwise key-encryption keys to
encrypt message authenticate code (MAC) keys used for content
authentication and integrity; and,
- 'AuthEnvelopedData' to support ECC-based public-key agreement
methods (ECMQV) to generate pairwise key-encryption keys to
encrypt MAC keys used for authenticated encryption modes.
Certification of EC public keys is also described to provide public-
key distribution in support of the specified techniques.
The document will obsolete [CMS-ECC].
1.1. Requirements 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 [MUST].
1.2. Changes since RFC 3278
The following summarizes the changes:
- Abstract: The basis of the document was changed to refer to NIST
FIPP 186-3 and SP800-56A.
- Section 1: A bullet was added to address AuthEnvelopedData.
- Section 2.1: A sentence was added to indicate FIPS180-3 is used
with ECDSA. Replaced reference to ANSI X9.62 with FIPS186-3.
- Section 2.1.1: The permitted digest algorithms were expanded from
SHA-1 to SHA-1, SHA-224, SHA-256, SHA-384, and SHA-512.
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- Section 2.1.2 and 2.1.3: The bullet addressing integer "e" was
deleted.
- Section 3: Added explanation of why static-static ECDH is not
included.
- Section 3.1: The reference for DH was changed from CMS to CMS-
ALG. Provided text to indicate fields of EnvelopedData are as
in CMS.
- Section 3.1.1: The permitted digest algorithms for use with ECDH
std and cofactor methods were expanded from SHA-1 to SHA-1, SHA-
224, SHA-256, SHA-384, and SHA-512. Updated to include
description of all KeyAgreeRecipientInfo fields. Parameters for
id-ecPublicKey field changed from NULL to absent or ECPoint.
Additional information about ukm was added.
- Section 3.2: The sentence describing the advantages of 1-Pass
ECMQV was rewritten.
- Section 3.2.1: The permitted digest algorithms for use with ECMQV
were expanded from SHA-1 to SHA-1, SHA-224, SHA-256, SHA-384,
and SHA-512. Updated to include description of all fields.
Parameters for id-ecPublicKey field changed from NULL to absent
or ECPoint.
- Sections 3.2.2 and 4.1.2: The re-use of ephemeral keys paragraph
was reworded.
- Section 4.1: The sentences describing the advantages of 1-Pass
ECMQV was moved to Section 4.
- Section 4.1.2: The note about the attack was moved to Section 4.
- Section 4.2: This section was added to address AuthEnvelopedData
with ECMQV.
- Section 5: This section was moved to Section 8. The 1st
paragraph was modified to require both SignedData and
EnvelopedData. The requirements were updated for hash
algorithms and recommendations for matching curves and hash
algorithms. Also the requirements were expanded to indicate
which ECDH and ECMQV variants, key wrap algorithms, and content
encryption algorithms are required for each of the content types
used in this document.
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- Section 5 (formerly 6): This section was updated to allow for
SMIMECapabilities to be present certificates.
- Section 6 (formerly 7): The S/MIME capabilities for ECDSA with
SHA-224, SHA-256, SHA-384, and SHA-512 were added to the list of
S/MIME Capabilities. Also updated to include S/MIME
capabilities for ECDH and ECMQV using the SHA-224, SHA-256, SHA-
384, and SHA-512 algorithms as the KDF.
- Section 7.1 (formerly 8.1): Added sub-sections for digest,
signature, originator public key, key agreement, content
encryption, and message authentication code algorithms. Pointed
to algorithms and parameters in appropriate docummments for:
SHA-224, SHA-256, SHA-384, and SHA-512 as well as SHA-224, SHA-
256, SHA-384, and SHA-512 with ECDSA. Also added algorithm
identifiers for ECDH std, ECDH cofactor, and ECMQV with SHA-224,
SHA-256, SHA-384, and SHA-512 algorithms as the KDF. Changed
id-ecPublicKey parameters to be absent, NULL, and ECParameters
and if present the originator's ECParameters must match the
recipient's ECParameters.
- Section 7.2 (formerly 8.2): Updated to include AuthEnvelopedData.
Also, added text to address support requirement for compressed
and uncompressed keys, changed pointers from ANSI X9.61 to PKIX
(where ECDSA-Sig-Value is imported), changed pointers from SECG
to NIST specs, and updated example of suppPubInfo to be AES-256.
keyInfo's parameters changed from NULL to any associated
parameters (AES wraps have absent parameters).
- Section 9: Replaced text, which was a summary paragraph, with an
updated security considerations section. Paragraph referring to
definitions of SHA-224, SHA-256, SHA-384, and SHA-512 is
deleted.
- Updated references.
- Added ASN.1 modules.
- Updated acknowledgements section.
2. SignedData using ECC
This section describes how to use ECC algorithms with the CMS
SignedData format to sign data.
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2.1. SignedData using ECDSA
This section describes how to use the Elliptic Curve Digital
Signature Algorithm (ECDSA) with SignedData. ECDSA is specified in
[FIPS186-3]. The method is the elliptic curve analog of the Digital
Signature Algorithm (DSA) [FIPS186-3]. ECDSA is used with the Secure
Hash Algorithm (SHA) [FIPS180-3].
In an implementation that uses ECDSA with CMS SignedData, the
following techniques and formats MUST be used.
2.1.1. Fields of the SignedData
When using ECDSA with SignedData, the fields of SignerInfo are as in
[CMS], but with the following restrictions:
- digestAlgorithm MUST contain the algorithm identifier of the hash
algorithm (see Section 7.1) which MUST be one of the following:
id-sha1, id-sha224, id-sha256, id-sha384, or id-sha512.
- signatureAlgorithm contains the signature algorithm identifier
(see Section 7.1): ecdsa-with-SHA1, ecdsa-with-SHA224, ecdsa-
with-SHA256, ecdsa-with-SHA384, or ecdsa-with-SHA512.
- signature MUST contain the DER encoding (as an octet string) of a
value of the ASN.1 type ECDSA-Sig-Value (see Section 7.2).
When using ECDSA, the SignedData certificates field MAY include the
certificate(s) for the EC public key(s) used in the generation of the
ECDSA signatures in SignedData. ECC certificates are discussed in
Section 5.
2.1.2. Actions of the sending agent
When using ECDSA with SignedData, the sending agent uses the message
digest calculation process and signature generation process for
SignedData that are specified in [CMS]. To sign data, the sending
agent uses the signature method specified in [FIPS186-3].
The sending agent encodes the resulting signature using the
ECDSA-Sig-Value syntax (see Section 7.2) and places it in the
SignerInfo.signature field.
2.1.3. Actions of the receiving agent
When using ECDSA with SignedData, the receiving agent uses the
message digest calculation process and signature verification process
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for SignedData that are specified in [CMS]. To verify SignedData,
the receiving agent uses the signature verification method specified
in [FIPS186-3].
In order to verify the signature, the receiving agent retrieves the
integers r and s from the SignerInfo signature field of the received
message.
3. EnvelopedData using ECC Algorithms
This section describes how to use ECC algorithms with the CMS
EnvelopedData format.
This document does not specify the static-static ECDH, method C(0,2,
ECC CDH) from [SP800-56A]. Static-static ECDH is analogous to
static-static DH, which is specified in [CMS-ALG]. Ephemeral-static
ECDH and 1-Pass ECMQV were specified because they provide better
security due the originator's ephemeral contribution to the key
agreement scheme.
3.1. EnvelopedData using (ephemeral-static) ECDH
This section describes how to use the ephemeral-static Elliptic Curve
Diffie-Hellman (ECDH) key agreement algorithm with EnvelopedData,
method C(1, 1, ECC CDH) from [SP800-56A]. Ephemeral-static ECDH is
the elliptic curve analog of the ephemeral-static Diffie-Hellman key
agreement algorithm specified jointly in the documents [CMS-ALG] and
[CMS-DH].
If an implementation uses ECDH with CMS EnvelopedData, then the
following techniques and formats MUST be used.
The fields of EnvelopedData are as in [CMS], as ECDH is a key
agreement algorithm the RecipientInfo kari choice is used. When
using ECDH, the EnvelopedData originatorInfo field MAY include the
certificate(s) for the EC public key(s) used in the formation of the
pairwise key. ECC certificates are discussed in Section 5.
3.1.1. Fields of KeyAgreeRecipientInfo
When using ephemeral-static ECDH with EnvelopedData, the fields of
KeyAgreeRecipientInfo are as follows:
- version MUST be 3.
- originator MUST be the alternative originatorKey. The
originatorKey algorithm field MUST contain the id-ecPublicKey
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object identifier (see Section 7.1). The parameters associated
with id-ecPublicKey MUST be absent or ECParameters. NOTE: The
previous version of this document required NULL to be present,
support for this legacy form is OPTIONAL. The originatorKey
publicKey field MUST contain the value of the ASN.1 type ECPoint
(see Section 7.2), which represents the sending agent's
ephemeral EC public key. The ECPoint in uncompressed form MUST
be supported.
- ukm MAY be present or absent. However, message originators
SHOULD include the ukm. As specified in RFC 3852 [CMS],
implementations MUST support ukm message recipient processing,
so interoperability is not a concern if the ukm is present or
absent. The ukm is placed in the entityUInfo field of the ECC-
CMS-SharedInfo structure. When present, the ukm is used to
ensure that a different key-encryption key is generated, even
when the ephemeral private key is improperly used more than
once, by using the ECC-CMS-SharedInfo as an input to the key
derivation function (see Section 7.2).
- keyEncryptionAlgorithm MUST contain the key encryption algorithm
object identifier (see Section 7.1). The parameters field
contains KeyWrapAlgorithm. The KeyWrapAlgorithm is the
algorithm identifier that indicates the symmetric encryption
algorithm used to encrypt the content-encryption key (CEK) with
the key-encryption key (KEK) and any associated parameters.
Algorithm requirements are found in Section 8.
- recipientEncryptedKeys contains an identifier and an encrypted
key for each recipient. The RecipientEncryptedKey
KeyAgreeRecipientIdentifier MUST contain either the
issuerAndSerialNumber identifying the recipient's certificate or
the RecipientKeyIdentifier containing the subject key identifier
from the recipient's certificate. In both cases, the
recipient's certificate contains the recipient's static ECDH
public key. RecipientEncryptedKey EncryptedKey MUST contain the
content-encryption key encrypted with the ephemeral-static,
ECDH-generated pairwise key-encryption key using the algorithm
specified by the KeyWrapAlgorithm.
3.1.2. Actions of the sending agent
When using ephemeral-static ECDH with EnvelopedData, the sending
agent first obtains the recipient's EC public key and domain
parameters (e.g. from the recipient's certificate). The sending
agent then determines an integer "keydatalen", which is the
KeyWrapAlgorithm symmetric key-size in bits, and also a bit string
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"SharedInfo", which is the DER encoding of ECC-CMS-SharedInfo (see
Section 7.2). The sending agent then performs the key deployment and
the key agreement operation of the Elliptic Curve Diffie-Hellman
Scheme specified in [SP800-56A]. As a result the sending agent
obtains:
- an ephemeral public key, which is represented as a value of the
type ECPoint (see Section 7.2), encapsulated in a bit string and
placed in the KeyAgreeRecipientInfo originator field, and
- a shared secret bit string "K", which is used as the pairwise
key-encryption key for that recipient, as specified in [CMS].
3.1.3. Actions of the receiving agent
When using ephemeral-static ECDH with EnvelopedData, the receiving
agent determines the bit string "SharedInfo", which is the DER
encoding of ECC-CMS-SharedInfo (see Section 7.2), and the integer
"keydatalen" from the key-size, in bits, of the KeyWrapAlgorithm. The
receiving agent retrieves the ephemeral EC public key from the bit
string KeyAgreeRecipientInfo originator, with a value of the type
ECPoint (see Section 7.2) encapsulated as a bit string, and if
present, originally supplied additional user key material from the
ukm field. The receiving agent performs the key agreement operation
of the Elliptic Curve Diffie-Hellman Scheme specified in [SP800-56A].
As a result, the receiving agent obtains a shared secret bit string
"K", which is used as the pairwise key-encryption key to unwrap the
CEK.
3.2. EnvelopedData using 1-Pass ECMQV
This section describes how to use the 1-Pass elliptic curve MQV
(ECMQV) key agreement algorithm with EnvelopedData, method
C(1, 2, ECC MQV) from [SP800-56A]. Like the KEA algorithm [CMS-KEA],
1-Pass ECMQV uses three key pairs: an ephemeral key pair, a static
key pair of the sending agent, and a static key pair of the receiving
agent. Using an algorithm with the sender static key pair allows for
knowledge of the message creator, this means that authentication can,
in some circumstances, be obtained for AuthEnvelopedData and
AuthenticatedData. This means that 1-Pass ECMQV can be a common
algorithm for EnvelopedData, AuthenticatedData and AuthEnvelopedData,
while ECDH can only be used in EnvelopedData.
If an implementation uses 1-Pass ECMQV with CMS EnvelopedData, then
the following techniques and formats MUST be used.
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The fields of EnvelopedData are as in [CMS], as 1-Pass ECMQV is a key
agreement algorithm the RecipientInfo kari choice is used. When
using 1-Pass ECMQV, the EnvelopedData originatorInfo field MAY
include the certificate(s) for the EC public key(s) used in the
formation of the pairwise key. ECC certificates are discussed in
Section 5.
3.2.1. Fields of KeyAgreeRecipientInfo
When using 1-Pass ECMQV with EnvelopedData, the fields of
KeyAgreeRecipientInfo are:
- version MUST be 3.
- originator identifies the static EC public key of the sender. It
SHOULD be one of the alternatives, issuerAndSerialNumber or
subjectKeyIdentifier, and point to one of the sending agent's
certificates.
- ukm MUST be present. The ukm field is an octet string which MUST
contain the DER encoding of the type MQVuserKeyingMaterial (see
Section 7.2). The MQVuserKeyingMaterial ephemeralPublicKey
algorithm field MUST contain the id-ecPublicKey object
identifier (see Section 7.1). The parameters associated with
id-ecPublicKey MUST be absent or ECParameters. NOTE: The
previous version of this document required NULL to be present,
support for this legacy form is OPTIONAL. The
MQVuserKeyingMaterial ephemeralPublicKey publicKey field MUST
contain the DER-encoding of the ASN.1 type ECPoint (see Section
7.2) representing the sending agent's ephemeral EC public key.
The MQVuserKeyingMaterial addedukm field, if present, contains
additional user keying material from the sending agent.
- keyEncryptionAlgorithm MUST be the key encryption algorithm
identifier (see Section 7.1), with the parameters field
KeyWrapAlgorithm. The KeyWrapAlgorithm indicates the symmetric
encryption algorithm used to encrypt the CEK with the KEK
generated using the 1-Pass ECMQV algorithm and any associated
parameters. Algorithm requirements are found in Section 8.
- recipientEncryptedKeys contains an identifier and an encrypted
key for each recipient. The RecipientEncryptedKey
KeyAgreeRecipientIdentifier MUST contain either the
issuerAndSerialNumber identifying the recipient's certificate or
the RecipientKeyIdentifier containing the subject key identifier
from the recipient's certificate. In both cases, the
recipient's certificate contains the recipient's static ECMQV
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public key. RecipientEncryptedKey EncryptedKey MUST contain the
content-encryption key encrypted with the 1-Pass ECMQV-generated
pairwise key-encryption key using the algorithm specified by the
KeyWrapAlgorithm.
3.2.2. Actions of the sending agent
When using 1-Pass ECMQV with EnvelopedData, the sending agent first
obtains the recipient's EC public key and domain parameters (e.g.
from the recipient's certificate), and checks that the domain
parameters are the same as the sender's domain parameters. The
sending agent then determines an integer "keydatalen", which is the
KeyWrapAlgorithm symmetric key-size in bits, and also a bit string
"SharedInfo", which is the DER encoding of ECC-CMS-SharedInfo (see
Section 7.2). The sending agent then performs the key deployment and
key agreement operations of the Elliptic Curve MQV Scheme specified
in [SP800-56A]. As a result, the sending agent obtains:
- an ephemeral public key, which is represented as a value of type
ECPoint (see Section 7.2), encapsulated in a bit string, placed
in an MQVuserKeyingMaterial ephemeralPublicKey publicKey field
(see Section 7.2), and
- a shared secret bit string "K", which is used as the pairwise
key-encryption key for that recipient, as specified in [CMS].
In a single message, if there are multiple layers for a recipient,
then the ephemeral public key can be reused by the originator for
that recipient in each of the different layers.
3.2.3. Actions of the receiving agent
When using 1-Pass ECMQV with EnvelopedData, the receiving agent
determines the bit string "SharedInfo", which is the DER encoding of
ECC-CMS-SharedInfo (see Section 7.2), and the integer "keydatalen"
from the key-size, in bits, of the KeyWrapAlgorithm. The receiving
agent then retrieves the static and ephemeral EC public keys of the
originator, from the originator and ukm fields as described in
Section 3.2.1, and its static EC public key identified in the rid
field and checks that the domain parameters are the same as the
recipient's domain parameters. The receiving agent then performs the
key agreement operation of the Elliptic Curve MQV Scheme [SP800-56A].
As a result, the receiving agent obtains a shared secret bit string
"K" which is used as the pairwise key-encryption key to unwrap the
CEK.
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4. AuthenticatedData and AuthEnvelopedData using ECC
This section describes how to use ECC algorithms with the CMS
AuthenticatedData format. AuthenticatedData lacks non-repudiation,
and so in some instances is preferable to SignedData. (For example,
the sending agent might not want the message to be authenticated when
forwarded.)
This section also describes how to use ECC algorithms with the CMS
AuthEnvelopedData format [CMS-AUTHENV]. AuthEnvelopedData supports
authentication and encryption, and in some instances is preferable to
signing and then encrypting data.
For both AuthentictedData and AuthEnvelopedData, data origin
authentication with 1-Pass ECMQV can only be provided when there is
one and only one recipient. When there are multiple recipients, an
attack is possible where one recipient modifies the content without
other recipients noticing [BON]. A sending agent who is concerned
with such an attack SHOULD use a separate AuthenticatedData or
AuthEnvelopedData for each recipient.
Using an algorithm with the sender static key pair allows for
knowledge of the message creator, this means that authentication can,
in some circumstances, be obtained for AuthEnvelopedData and
AuthenticatedData. This means that 1-Pass ECMQV can be a common
algorithm for EnvelopedData, AuthenticatedData, and AuthEnvelopedData
while ECDH can only be used in EnvelopedData.
4.1. AuthenticatedData using 1-pass ECMQV
This section describes how to use the 1-Pass elliptic curve MQV
(ECMQV) key agreement algorithm with AuthenticatedData. ECMQV is
method C(1, 2, ECC MQV) from [SP800-56A].
When using ECMQV with AuthenticatedData, the fields of
AuthenticatedData are as in [CMS], but with the following
restrictions:
- macAlgorithm MUST contain the algorithm identifier of the message
authentication code algorithm (see Section 7.1) which MUST be
one of the following: hmac-SHA1, id-hmacWITHSHA224, id-
hmacWITHSHA256, id-hmacWITHSHA384, or id-hmacWITHSHA512.
- digestAlgorithm MUST contain the algorithm identifier of the hash
algorithm (see Section 7.1) which MUST be one of the following:
id-sha1, id-sha224, id-sha256, id-sha384, and id-sha512.
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As 1-Pass ECMQV is a key agreement algorithm, the RecipientInfo kari
choice is used in the AuthenticatedData. When using 1-Pass ECMQV,
the AuthenticatedData originatorInfo field MAY include the
certificate(s) for the EC public key(s) used in the formation of the
pairwise key. ECC certificates are discussed in Section 5.
4.1.1. Fields of the KeyAgreeRecipientInfo
The AuthenticatedData KeyAgreeRecipientInfo fields are used in the
same manner as the fields for the corresponding EnvelopedData
KeyAgreeRecipientInfo fields of Section 3.2.1 of this document.
4.1.2. Actions of the sending agent
The sending agent uses the same actions as for EnvelopedData with
1-Pass ECMQV, as specified in Section 3.2.2 of this document.
In a single message, if there are multiple layers for a recipient,
then the ephemeral public key can be reused by the originator for
that recipient in each of the different layers.
4.1.3. Actions of the receiving agent
The receiving agent uses the same actions as for EnvelopedData with
1-Pass ECMQV, as specified in Section 3.2.3 of this document.
4.2. AuthEnvelopedData using 1-pass ECMQV
This section describes how to use the 1-Pass elliptic curve MQV
(ECMQV) key agreement algorithm with AuthEnvelopedData. ECMQV is
method C(1, 2, ECC MQV) from [SP800-56A].
When using ECMQV with AuthEnvelopedData, the fields of
AuthenticatedData are as in [CMS-AUTHENV], but with the following
restriction:
- macAlgorithm MUST contain the algorithm identifier of the message
authentication code algorithm (see Section 7.1) which MUST be
one of the following: hmac-SHA1, id-hmacWITHSHA224, id-
hmacWITHSHA256, id-hmacWITHSHA384, or id-hmacWITHSHA512.
As 1-Pass ECMQV is a key agreement algorithm, the RecipientInfo kari
choice is used. When using 1-Pass ECMQV, the AuthEnvelopedData
originatorInfo field MAY include the certificate(s) for the EC public
key(s) used in the formation of the pairwise key. ECC certificates
are discussed in Section 5.
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4.2.1. Fields of the KeyAgreeRecipientInfo
The AuthEnvelopedData KeyAgreeRecipientInfo fields are used in the
same manner as the fields for the corresponding EnvelopedData
KeyAgreeRecipientInfo fields of Section 3.2.1 of this document.
4.2.2. Actions of the sending agent
The sending agent uses the same actions as for EnvelopedData with 1-
Pass ECMQV, as specified in Section 3.2.2 of this document.
In a single message, if there are multiple layers for a recipient,
then the ephemeral public key can be reused by the originator for
that recipient in each of the different layers.
4.2.3. Actions of the receiving agent
The receiving agent uses the same actions as for EnvelopedData with
1-Pass ECMQV, as specified in Section 3.2.3 of this document.
5. Certificates using ECC
Internet X.509 certificates [PKI] can be used in conjunction with
this specification to distribute agents' public keys. The use of ECC
algorithms and keys within X.509 certificates is specified in [PKI-
ALG].
6. SMIMECapabilities Attribute and ECC
A sending agent MAY announce to receiving agents that it supports one
or more of the ECC algorithms specified in this document by using the
SMIMECapabilities signed attribute [MSG] in either a signed message
or a certificate [CERTCAP].
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The SMIMECapability value to indicate support for one of the ECDSA
signature algorithms is a SEQUENCE with the capabilityID field
containing the object identifier ecdsa-with-SHA* (where * is 1, 224,
256, 384, or 512) with NULL parameters. The DER encodings are:
ecdsa-with-SHA1: 30 0b 06 07 2a 86 48 ce 3d 04 01 05 00
ecdsa-with-SHA224: 30 0c 06 08 2a 86 48 ce 3d 04 03 01 05 00
ecdsa-with-SHA256: 30 0c 06 08 2a 86 48 ce 3d 04 03 02 05 00
ecdsa-with-SHA384: 30 0c 06 08 2a 86 48 ce 3d 04 03 03 05 00
ecdsa-with-SHA512: 30 0c 06 08 2a 86 48 ce 3d 04 03 04 05 00
NOTE: The S/MIME Capabilities indicates that parameters for ECDSA
with SHA-* are NULL (where * is 1, 224, 256, 384, or 512), however,
the parameters are absent when used to generate a digital signature.
The SMIMECapability value to indicate support for
a) the standard ECDH key agreement algorithm,
b) the cofactor ECDH key agreement algorithm, or
c) the 1-Pass ECMQV key agreement algorithm
is a SEQUENCE with the capabilityID field containing the object
identifier
a) dhSinglePass-stdDH-sha*kdf-scheme,
b) dhSinglePass-cofactorDH-sha*kdf-scheme, or
c) mqvSinglePass-sha*kdf-scheme
respectively (where * is 1, 224, 256, 384, or 512) with the
parameters present. The parameters indicate the supported key-
encryption algorithm with the KeyWrapAlgorithm algorithm identifier.
Example DER encodings that indicate some capabilities are as follows
(KA is key agreement, KDF is key derivation function, and Wrap is key
wrap algorithm):
KA=ECDH standard KDF=SHA-1 Wrap=Triple-DES
30 1c
06 09 2b 81 05 10 86 48 3f 00 02
30 0f
06 0b 2a 86 48 86 f7 0d 01 09 10 03 06
05 00
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KA=ECDH standard KDF=SHA-256 Wrap=AES-128
30 17
06 06 2b 81 04 01 0B 01
30 0d
06 09 60 86 48 01 65 03 04 01 05
05 00
KA=ECDH standard KDF=SHA-384 Wrap=AES-256
30 17
06 06 2b 81 04 01 0B 02
30 0d
06 09 60 86 48 01 65 03 04 01 2D
05 00
KA=ECDH cofactor KDF=SHA-1 Wrap=Triple-DES
30 1c
06 09 2b 81 05 10 86 48 3f 00 03
30 0f
06 0b 2a 86 48 86 f7 0d 01 09 10 03 06
05 00
KA=ECDH cofactor KDF=SHA-256 Wrap=AES-128
30 17
06 06 2b 81 04 01 0E 01
30 0d
06 09 60 86 48 01 65 03 04 01 05
05 00
KA=ECDH cofactor KDF=SHA-384 Wrap=AES-256
30 17
06 06 2b 81 04 01 0E 02
30 0d
06 09 60 86 48 01 65 03 04 01 2D
05 00
KA=ECMQV 1-Pass KDF=SHA-1 Wrap=Triple-DES
30 1c
06 09 2b 81 05 10 86 48 3f 00 10
30 0f
06 0b 2a 86 48 86 f7 0d 01 09 10 03 06
05 00
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KA=ECMQV 1-Pass KDF=SHA-256 Wrap=AES-128
30 17
06 06 2b 81 04 01 0F 01
30 0d
06 09 60 86 48 01 65 03 04 01 05
05 00
KA=ECMQV 1-Pass KDF=SHA-384 Wrap=AES-256
30 17
06 06 2b 81 04 01 0F 02
30 0d
06 09 60 86 48 01 65 03 04 01 2D
05 00
NOTE: The S/MIME Capabilities indicates that parameters for the key
wrap algorithm AES-* (where * is 128, 192, or 256) are NULL; however,
the parameters are absent when used to encrypt/decrypt a content
encryption key.
7. ASN.1 Syntax
The ASN.1 syntax used in this document is gathered in this section
for reference purposes.
7.1. Algorithm Identifiers
This section provides the object identifiers for the algorithms used
in this document along with any associated parameters.
7.1.1. Digest Algorithms
Digest algorithm object identifiers are used in the SignedData
digestAlgorithms and digestAlgorithm fields and the AuthenticatedData
digestAlgorithm field. The digest algorithms used in this document
are: SHA-1, SHA-224, SHA-256, SHA-384, and SHA-512. The object
identifiers and parameters associated with these algorithms are found
in [CMS-ALG] and [CMS-SHA2].
7.1.2. Originator Public Key
The KeyAgreeRecipientInfo originator field use the following object
identifier to indicate an elliptic curve public key:
id-ecPublicKey OBJECT IDENTIFIER ::= {
ansi-x9-62 keyType(2) 1 }
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where
ansi-x9-62 OBJECT IDENTIFIER ::= {
iso(1) member-body(2) us(840) 10045 }
When the object identifier id-ecPublicKey is used here with an
algorithm identifier, the associated parameters MUST be either absent
or ECParameters. Implementations MUST accept id-ecPublicKey with
absent, and ECParameters parameters. If ECParameters is present, its
value MUST match the recipients ECParameters. Implementations SHOULD
generate absent parameters for the id-ecPublicKey object identifier
in the KeyAgreeRecipientInfo originator field.
NOTE: [CMS-ECC] indicated the parameters were NULL. Support for NULL
parameters is OPTIONAL.
7.1.3. Signature Algorithms
Signature algorithm identifiers are used in the SignedData
signatureAlgorithm and signature field. The signature algorithms
used in this document are ECDSA with SHA-1, ECDSA with SHA-224, ECDSA
with SHA-256, ECDSA with SHA-384, and ECDSA with SHA-512. The object
identifiers and parameters associated with these algorithms are found
in [PKI-ALG].
NOTE: [CMS-ECC] indicated the parameters were NULL. Support for NULL
parameters is OPTIONAL.
7.1.4. Key Agreement Algorithms
Key agreement algorithms are used in EnvelopedData,
AuthenticatedData, and AuthEnvelopedData in the KeyAgreeRecipientInfo
keyEncryptionAlgorithm field. The following object identifiers
indicate the key agreement algorithms used in this document [SP800-
56A]:
dhSinglePass-stdDH-sha1kdf-scheme OBJECT IDENTIFIER ::= {
x9-63-scheme 2 }
dhSinglePass-stdDH-sha224kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 11 0 }
dhSinglePass-stdDH-sha256kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 11 1 }
dhSinglePass-stdDH-sha384kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 11 2 }
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dhSinglePass-stdDH-sha512kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 11 3 }
dhSinglePass-cofactorDH-sha1kdf-scheme OBJECT IDENTIFIER ::= {
x9-63-scheme 3 }
dhSinglePass-cofactorDH-sha224kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 14 0 }
dhSinglePass-cofactorDH-sha256kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 14 1 }
dhSinglePass-cofactorDH-sha384kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 14 2 }
dhSinglePass-cofactorDH-sha512kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 14 3 }
mqvSinglePass-sha1kdf-scheme OBJECT IDENTIFIER ::= {
x9-63-scheme 16 }
mqvSinglePass-sha224kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 15 0 }
mqvSinglePass-sha256kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 15 1 }
mqvSinglePass-sha384kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 15 2 }
mqvSinglePass-sha512kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 15 3 }
where
x9-63-scheme OBJECT IDENTIFIER ::= {
iso(1) identified-organization(3) tc68(133) country(16)
x9(840) x9-63(63) schemes(0) }
and
secg-scheme OBJECT IDENTIFIER ::= {
iso(1) identified-organization(3) certicom(132) schemes(1) }
When the object identifiers are used here within an algorithm
identifier, the associated parameters field contains KeyWrapAlgorithm
to indicate the key wrap algorithm and any associated parameters.
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7.1.5. Key Wrap Algorithms
Key wrap algorithms are used as part of the parameters in the key
agreement algorithm. The key wrap algorithms used in this document
are Triple-DES, AES-128, AES-192, and AES-256. The object
identifiers and parameters for these algorithms are found in [CMS-
ALG] and [CMS-AES].
7.1.6. Content Encryption Algorithms
Content encryption algorithms are used in EnvelopedData and
AuthEnvelopedData in the EncryptedContentInfo
contentEncryptionAlgorithm field. The content encryption algorithms
used with EnvelopedData in this document are 3-Key Triple DES in CBC
mode, AES-128 in CBC mode, AES-192 in CBC mode, and AES-256 in CBC
mode. The object identifiers and parameters associated with these
algorithms are found in [CMS-ALG] and [CMS-AES]. The content
encryption algorithms used with AuthEnvelopedData in this document
are AES-128 in CCM mode, AES-192 in CCM mode, AES-256 in CCM mode,
AES-128 in GCM mode, AES-192 in GCM mode, and AES-256 in GCM mode.
The object identifiers and parameters associated with these
algorithms are found in [CMS-AESCG].
7.1.7. Message Authentication Code Algorithms
Message authentication code algorithms are used in AuthenticatedData
and AuthEnvelopedData in the macAlgorithm field. The message
authentication code algorithms used in this document are HMAC with
SHA-1, HMAC with SHA-224, HMAC with SHA-256, HMAC with SHA-384, and
HMAC with SHA-512. The object identifiers and parameters associated
with these algorithms are found in [HMAC-SHA1] and [HMAC-SHA2].
7.2. Other Syntax
The following additional syntax is used here.
When using ECDSA with SignedData, ECDSA signatures are encoded using
the type:
ECDSA-Sig-Value ::= SEQUENCE {
r INTEGER,
s INTEGER }
ECDSA-Sig-Value is specified in [PKI-ALG]. Within CMS, ECDSA-Sig-
Value is DER-encoded and placed within a signature field of
SignedData.
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When using ECDH and ECMQV with EnvelopedData, AuthenticatedData, and
AuthEnvelopedData, ephemeral and static public keys are encoded using
the type ECPoint. Implementations MUST support uncompressed keys and
MAY support compressed keys.
ECPoint ::= OCTET STRING
When using ECMQV with EnvelopedData, AuthenticatedData, and
AuthEnvelopedData, the sending agent's ephemeral public key and
additional keying material are encoded using the type:
MQVuserKeyingMaterial ::= SEQUENCE {
ephemeralPublicKey OriginatorPublicKey,
addedukm [0] EXPLICIT UserKeyingMaterial OPTIONAL }
The ECPoint syntax is used to represent the ephemeral public key and
is placed in the ephemeralPublicKey.publicKey field. The additional
user keying material is placed in the addedukm field. Then the
MQVuserKeyingMaterial value is DER-encoded and placed within the ukm
field of EnvelopedData, AuthenticatedData, or AuthEnvelopedData.
When using ECDH or ECMQV with EnvelopedData, AuthenticatedData, or
AuthEnvelopedData, the key-encryption keys are derived by using the
type:
ECC-CMS-SharedInfo ::= SEQUENCE {
keyInfo AlgorithmIdentifier,
entityUInfo [0] EXPLICIT OCTET STRING OPTIONAL,
suppPubInfo [2] EXPLICIT OCTET STRING }
The fields of ECC-CMS-SharedInfo are as follows:
keyInfo contains the object identifier of the key-encryption
algorithm (used to wrap the CEK) and associated parameters. In
this specification, 3DES wrap has NULL parameters while the AES
wraps have absent parameters.
entityUInfo optionally contains additional keying material
supplied by the sending agent. When used with ECDH and CMS, the
entityUInfo field contains the octet string ukm. When used with
ECMQV and CMS, the entityUInfo contains the octet string addedukm
(encoded in MQVuserKeyingMaterial).
suppPubInfo contains the length of the generated KEK, in bits,
represented as a 32 bit number, as in [CMS-DH] and [CMS-AES].
(E.g. for AES-256 it would be 00 00 01 00.)
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Within CMS, ECC-CMS-SharedInfo is DER-encoded and used as input to
the key derivation function, as specified in [SP800-56A].
Note that ECC-CMS-SharedInfo differs from the OtherInfo specified in
[CMS-DH]. Here, a counter value is not included in the keyInfo field
because the key derivation function specified in [SP800-56A] ensures
that sufficient keying data is provided.
8. Recommended Algorithms and Elliptic Curves
It is RECOMMEND that implementations of this specification support
SignedData and EnvelopedData. Support for AuthenticatedData and
AuthEnvelopedData is OPTIONAL.
In order to encourage interoperability, implementations SHOULD use
the elliptic curve domain parameters specified by [PKI-ALG].
Implementations that support SignedData with ECDSA:
- MUST support ECDSA with SHA-256; and,
- MAY support ECDSA with SHA-1, ECDSA with SHA-224, ECDSA with SHA-
384, and ECDSA with SHA-512. Other digital signature algorithms
MAY also be supported.
When using ECDSA, it is RECOMMENDED that the P-224 curve be used with
SHA-224, the P-256 curve be used with SHA-256, the P-384 curve be
used with SHA-384, and the P-521 curve be used with SHA-512.
If EnvelopedData is supported, then ephemeral-static ECDH standard
primitive MUST be supported. Support for ephemeral-static ECDH co-
factor is OPTIONAL and support for 1-Pass ECMQV is also OPTIONAL.
Implementations that support EnvelopedData with the ephemeral-static
ECDH standard primitive:
- MUST support the dhSinglePass-stdDH-sha256kdf-scheme key
agreement algorithm, the id-aes128-wrap key wrap algorithm, and
the id-aes128-cbc content encryption algorithm; and,
- MAY support the dhSinglePass-stdDH-sha1kdf-scheme, dhSinglePass-
stdDH-sha224kdf-scheme, dhSinglePass-stdDH-sha384kdf-scheme and
dhSinglePass-stdDH-sha512kdf-scheme key agreement algorithms,
the id-alg-CMS3DESwrap, id-aes192-wrap, and id-aes256-wrap key
wrap algorithms and the des-ede3-cbc, id-aes192-cbc and id-
aes256-cbc content encryption algorithms. Other algorithms MAY
also be supported.
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Implementations that support EnvelopedData with the ephemeral-static
ECDH cofactor primitive:
- MUST support the dhSinglePass-cofactorDH-sha256kdf-scheme key
agreement algorithm, the id-aes128-wrap key wrap algorithm, and
the id-aes128-cbc content encryption algorithm; and,
- MAY support the dhSinglePass-cofactorDH-sha1kdf-scheme,
dhSinglePass-cofactorDH-sha224kdf-scheme, dhSinglePass-
cofactorDH-sha384kdf-scheme, and dhSinglePass-cofactorDH-
sha512kdf-scheme key agreement, the id-alg-CMS3DESwrap, id-
aes192-wrap, and id-aes256-wrap key wrap algorithms and the des-
ede3-cbc, id-aes192-cbc and id-aes256-cbc content encryption
algorithms. Other algorithms MAY also be supported.
Implementations that support EnvelopedData with 1-Pass ECMQV:
- MUST support the mqvSinglePass-sha256kdf-scheme key agreement
algorithm, the id-aes128-wrap key wrap algorithm, and the id-
aes128-cbc content encryption algorithm; and,
- MAY support mqvSinglePass-sha1kdf-scheme, mqvSinglePass-
sha224kdf-scheme, mqvSinglePass-sha384kdf-scheme, and
mqvSinglePass-sha512kdf-scheme key agreement algorithms, the id-
alg-CMS3DESwrap, id-aes192-wrap, and id-aes256-wrap key wrap
algorithms and the des-ede3-cbc, id-aes192-cbc and id-aes256-cbc
content encryption algorithms. Other algorithms MAY also be
supported.
Implementations that support AuthenticatedData with 1-Pass ECMQV:
- MUST support the mqvSinglePass-sha256kdf-scheme key agreement,
the id-aes128-wrap key wrap, the id-sha256 message digest, and
id-hmacWithSHA256 message authentication code algorithms; and,
- MAY support the mqvSinglePass-sha1kdf-scheme, mqvSinglePass-
sha224kdf-scheme, mqvSinglePass-sha384kdf-scheme, mqvSinglePass-
sha512kdf-scheme key agreement algorithms, the id-alg-
CMS3DESwrap, id-aes192-wrap, and id-aes256-wrap key wrap
algorithms, the id-sha1, id-sha224, id-sha384, and id-sha512,
message digest algorithms, and the hmac-SHA1, id-hmacWithSHA224,
id-hmacWithSHA384, id-hmacWithSHA512 message authentication code
algorithms. Other algorithms MAY also be supported.
Implementations that support AuthEnvelopedData with 1-Pass ECMQV:
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- MUST support the mqvSinglePass-sha256kdf-scheme key agreement,
the id-aes128-wrap key wrap, the id-aes128-ccm authenticated-
content encryption, and the id-hmacWithSHA256 message
authentication code algorithms; and,
- MAY support the mqvSinglePass-sha1kdf-scheme, mqvSinglePass-
sha224kdf-scheme, mqvSinglePass-sha384kdf-scheme, and
mqvSinglePass-sha512kdf-scheme key agreement algorithms, the id-
alg-CMS3DESwrap, id-aes192-wrap, and id-aes256-wrap key wrap
algorithms, the id-aes192-ccm and id-aes256-ccm authenticated-
content encryption algorithms, and hmac-SHA1, id-hmacWithSHA224,
id-hmacWithSHA384, id-hmacWithSHA512 message authentication code
algorithms. Other algorithms MAY also be supported.
9. Security Considerations
Cryptographic algorithms will be broken or weakened over time.
Implementers and users need to check that the cryptographic
algorithms listed in this document continue to provide the expected
level of security. The IETF from time to time may issue documents
dealing with the current state of the art.
Cryptographic algorithms rely on random number. See [RANDOM] for
guidance on generation of random numbers.
Receiving agents that validate signatures and sending agents that
encrypt messages need to be cautious of cryptographic processing
usage when validating signatures and encrypting messages using keys
larger than those mandated in this specification. An attacker could
send keys and/or certificates with keys which would result in
excessive cryptographic processing, for example keys larger than
those mandated in this specification, which could swamp the
processing element. Agents which use such keys without first
validating the certificate to a trust anchor are advised to have some
sort of cryptographic resource management system to prevent such
attacks.
Using secret keys of an appropriate size is crucial to the security
of a Diffie-Hellman exchange. For elliptic curve groups, the size of
the secret key must be equal to the size of n (the order of the group
generated by the point g). Using larger secret keys provides
absolutely no additional security, and using smaller secret keys is
likely to result in dramatically less security. (See [SP800-56A] for
more information on selecting secret keys.)
This specification is based on [CMS], [CMS-AES], [CMS-AESCG], [CMS-
ALG], [CMS-AUTHENV], [CMS-DH], [CMS_SHA2], [FIPS180-3], [FIPS186-3],
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[HMAC-SHA1], and [HMAC-SHA2], and the appropriate security
considerations of those documents apply.
In addition, implementors of AuthenticatedData and AuthEnvelopedData
should be aware of the concerns expressed in [BON] when using
AuthenticatedData and AuthEnvelopedData to send messages to more than
one recipient. Also, users of MQV should be aware of the
vulnerability in [K].
When implementing EnvelopedData, AuthenticatedData, and
AuthEnvelopedData, there are five algorithm related choices that need
to be made:
1) What is the public key size?
2) What is the KDF?
3) What is the key wrap algorithm?
4) What is the content encryption algorithm?
5) What is the curve?
Consideration must be given to strength of the security provided by
each of these choices. Security is measured in bits, where a strong
symmetric cipher with a key of X bits is said to provide X bits of
security. It is recommended that the bits of security provided by
each are roughly equivalent. The following table provides comparable
minimum bits of security [SP800-57] for the ECDH/ECMQV key sizes,
KDFs, key wrapping algorithms, and content encryption algorithms. It
also lists curves [PKI-ALG] for the key sizes.
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Minimum | ECDH or | Key | Key | Content | Curves
Bits of | ECQMV | Derivation | Wrap | Encryption |
Security | Key Size | Function | Alg. | Alg. |
---------+----------+------------+----------+-------------+----------
80 | 160-223 | SHA-1 | 3DES | 3DES CBC | sect163k1
| | SHA-224 | AES-128 | AES-128 CBC | secp163r2
| | SHA-256 | AES-192 | AES-192 CBC | secp192r1
| | SHA-384 | AES-256 | AES-256 CBC |
| | SHA-512 | | |
---------+----------+------------+----------+-------------+---------
112 | 224-255 | SHA-1 | 3DES | 3DES CBC | secp224r1
| | SHA-224 | AES-128 | AES-128 CBC | sect233k1
| | SHA-256 | AES-192 | AES-192 CBC | sect233r1
| | SHA-384 | AES-256 | AES-256 CBC |
| | SHA-512 | | |
---------+----------+------------+----------+-------------+---------
128 | 256-383 | SHA-1 | AES-128 | AES-128 CBC | secp256r1
| | SHA-224 | AES-192 | AES-192 CBC | sect283k1
| | SHA-256 | AES-256 | AES-256 CBC | sect283r1
| | SHA-384 | | |
| | SHA-512 | | |
---------+----------+------------+----------+-------------+---------
192 | 384-511 | SHA-224 | AES-192 | AES-192 CBC | secp384r1
| | SHA-256 | AES-256 | AES-256 CBC | sect409k1
| | SHA-384 | | | sect409r1
| | SHA-512 | | |
---------+----------+------------+----------+-------------+---------
256 | 512+ | SHA-256 | AES-256 | AES-256 CBC | secp521r1
| | SHA-384 | | | sect571k1
| | SHA-512 | | | sect571r1
---------+----------+------------+----------+-------------+---------
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To promote interoperability, the following choices are RECOMMENDED:
Minimum | ECDH or | Key | Key | Content | Curve
Bits of | ECQMV | Derivation | Wrap | Encryption |
Security | Key Size | Function | Alg. | Alg. |
---------+----------+------------+----------+-------------+----------
80 | 192 | SHA-256 | 3DES | 3DES CBC | secp192r1
---------+----------+------------+----------+-------------+----------
112 | 224 | SHA-256 | 3DES | 3DES CBC | secp224r1
---------+----------+------------+----------+-------------+----------
128 | 256 | SHA-256 | AES-128 | AES-128 CBC | secp256r1
---------+----------+------------+----------+-------------+----------
192 | 384 | SHA-384 | AES-256 | AES-256 CBC | secp384r1
---------+----------+------------+----------+-------------+----------
256 | 512 | SHA-512 | AES-256 | AES-256 CBC | secp521r1
---------+----------+------------+----------+-------------+----------
When implementing SignedData, there are three algorithm related
choices that need to be made:
1) What is the public key size?
2) What is the hash algorithm?
3) What is the curve?
Consideration must be given to the bits of security provided by each
of these choices. Security is measured in bits, where a strong
symmetric cipher with a key of X bits is said to provide X bits of
security. It is recommended that the bits of security provided by
each choice are roughly equivalent. The following table provides
comparable minimum bits of security [SP800-57] for the ECDSA key
sizes and message digest algorithms. It also lists curves [PKI-ALG]
for the key sizes.
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Minimum | ECDSA | Message | Curve
Bits of | Key Size | Digest |
Security | | Algorithm |
---------+----------+-----------+-----------
80 | 160-223 | SHA-1 | sect163k1
| | SHA-224 | secp163r2
| | SHA-256 | secp192r1
| | SHA-384 |
| | SHA-512 |
---------+----------+-----------+-----------
112 | 224-255 | SHA-224 | secp224r1
| | SHA-256 | sect233k1
| | SHA-384 | sect233r1
| | SHA-512 |
---------+----------+-----------+-----------
128 | 256-383 | SHA-256 | secp256r1
| | SHA-384 | sect283k1
| | SHA-512 | sect283r1
---------+----------+-----------+-----------
192 | 384-511 | SHA-384 | secp384r1
| | SHA-512 | sect409k1
| | | sect409r1
---------+----------+-----------+-----------
256 | 512+ | SHA-512 | secp521r1
| | | sect571k1
| | | sect571r1
---------+----------+-----------+-----------
To promote interoperability, the following choices are RECOMMENDED:
Minimum | ECDSA | Message | Curve
Bits of | Key Size | Digest |
Security | | Algorithm |
---------+----------+-----------+-----------
80 | 192 | SHA-256 | sect192r1
---------+----------+-----------+-----------
112 | 224 | SHA-256 | secp224r1
---------+----------+-----------+-----------
128 | 256 | SHA-256 | secp256r1
---------+----------+-----------+-----------
192 | 384 | SHA-384 | secp384r1
---------+----------+-----------+-----------
256 | 512+ | SHA-512 | secp521r1
---------+----------+-----------+-----------
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10. IANA Considerations
This document makes extensive use of object identifiers to register
originator public key types and algorithms. The algorithms object
identifiers are registered in the ANSI X9.62, ANSI X9.63, NIST, RSA,
and SECG arcs. Additionally, object identifiers are used to identify
the ASN.1 modules found in Appendix A. These are defined in an arc
delegated by IANA to the SMIME Working Group. No further action by
IANA is necessary for this document or any anticipated updates.
11. References
11.1. Normative
[CMS] Housley, R., "Cryptographic Message Syntax", RFC
3852, July 2004.
[CMS-AES] Schaad, J., "Use of the Advanced Encryption Standard
(AES) Encryption Algorithm in Cryptographic Message
Syntax (CMS)", RFC 3565, July 2003.
[CMS-AESCG] Housley, R., "Using AES-CCM and AES-GCM Authenticated
Encryption in the Cryptographic Message Syntax
(CMS)", RFC 5084, November 2007.
[CMS-ALG] Housley, R., "Cryptographic Message Syntax (CMS)
Algorithms", RFC 3370, August 2002.
[CMS-AUTHENV] Housley, R. "Cryptographic Message Syntax (CMS)
Authenticated-Enveloped-Data Content Type", RFC 5083,
November 2007.
[CMS-DH] Rescorla, E., "Diffie-Hellman Key Agreement Method",
RFC 2631, June 1999.
[CMS-SHA2] Turner, S., "Using SHA2 Algorithms with Cryptographic
Message Syntax", work-in-progress.
[FIPS180-3] National Institute of Standards and Technology
(NIST), FIPS Publication 180-3: Secure Hash Standard,
(draft) June 2003.
[FIPS186-3] National Institute of Standards and Technology
(NIST), FIPS Publication 186-3: Digital Signature
Standard, (draft) March 2006.
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[HMAC-SHA1] Krawczyk, M., Bellare, M., and R. Canetti, "HMAC:
Keyed-Hashing for Message Authentication", RFC 2104,
February 1997.
[HMAC-SHA2] Nystrom, M., "Identifiers and Test Vectors for HMAC-
SHA-224, HMAC-SHA-256, HMAC-SHA-384, and HMAC-SHA-
512", RFC 4231, December 2005.
[MUST] Bradner, S., "Key Words for Use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[MSG] Ramsdell, B., and S. Turner, "S/MIME Version 3.2
Message Specification", draft-ietf-smime-3851bis,
work-in-progress.
[PKI] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation
List (CRL) Profile", RFC 5280, May 2008.
[PKI-ALG] Turner, S., Brown, D., Yiu, K., Housley, R., and W.
Polk, "Elliptic Curve Cryptography Subject Public Key
Information", draft-ietf-pkix-ecc-subpubkeyinfo,
work-in-progress.
[RANDOM] Eastlake 3rd, D., Crocker, S., and J. Schiller,
"Randomness Recommendations for Security", RFC 4086,
June 2005.
[RSAOAEP] Schaad, J., Kaliski, B., and R. Housley, "Additional
Algorithms and Identifiers for RSA Cryptography for
use in the Internet X.509 Public Key Infrastructure
Certificate and Certificate Revocation List (CRL)
Profile", RFC 4055, June 2005.
[SP800-56A] National Institute of Standards and Technology
(NIST), Special Publication 800-56A: Recommendation
Pair-Wise Key Establishment Schemes Using Discrete
Logarithm Cryptography (Revised), March 2007.
[X.208] ITU-T Recommendation X.208 (1988) | ISO/IEC 8824-
1:1988. Specification of Abstract Syntax Notation One
(ASN.1).
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11.2. Informative
[BON] D. Boneh, "The Security of Multicast MAC",
Presentation at Selected Areas of Cryptography 2000,
Center for Applied Cryptographic Research, University
of Waterloo, 2000. Paper version available from
http://crypto.stanford.edu/~dabo/papers/mmac.ps
[CERTCAP] Santesson, S., "X.509 Certificate Extension for
Secure/Multipurpose Internet Mail Extensions (S/MIME)
Capabilities", RFC 4262, December 2005.
[CMS-ECC] Blake-Wilson, S., Brown, D., and P. Lambert, "Use of
Elliptic Curve Cryptography (ECC) Algorithms in
Cryptographic Message Syntax (CMS)", RFC 3278, April
2002.
[CMS-KEA] Pawling, J., "CMS KEA and SKIPJACK Conventions", RFC
2876, July 2000.
[CMS-ASN] Hoffman, P., and J. Schaad, "New ASN.1 Modules for
CMS", draft-ietf-smime-new-asn1, work-in-progress.
[K] B. Kaliski, "MQV Vulnerability", Posting to ANSI X9F1
and IEEE P1363 newsgroups, 1998.
[PKI-ASN] Hoffman, P., and J. Schaad, "New ASN.1 Modules for
PKIX", draft-ietf-pkix-new-asn1, work-in-progress.
[SP800-57] National Institute of Standards and Technology
(NIST), Special Publication 800-57: Recommendation
for Key Management - Part 1 (Revised), March 2007.
[X.680] ITU-T Recommendation X.680 (2002) | ISO/IEC 8824-
1 :2002. Information Technology - Abstract Syntax
Notation One.
[X.681] ITU-T Recommendation X.680 (2002) | ISO/IEC 8824-
2 :2002. Information Technology - Abstract Syntax
Notation One: Information Object Specification.
[X.682] ITU-T Recommendation X.682 (2002) | ISO/IEC 8824-
3 :2002. Information Technology - Abstract Syntax
Notation One: Constraint Specification.
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[X.683] ITU-T Recommendation X.683 (2002) | ISO/IEC 8824-
4:2002. Information Technology - Abstract Syntax
Notation One: Parameterization of ASN.1
Specifications, 2002.
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Appendix A ASN.1 Modules
Appendix A.1 provides the normative ASN.1 definitions for the
structures described in this specification using ASN.1 as defined in
[X.208].
Appendix A.2 provides an informative ASN.1 definitions for the
structures described in this specification using ASN.1 as defined in
[X.680], [X.681], [X.682], and [X.683]. This appendix contains the
same information as Appendix A.1 in a more recent (and precise) ASN.1
notation, however Appendix A.1 takes precedence in case of conflict.
Appendix A.1 1988 ASN.1 Module
SMIMEECCAlgs-1988
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) modules(0) TBA }
DEFINITIONS IMPLICIT TAGS ::=
BEGIN
-- EXPORTS ALL
IMPORTS
-- From [PKI]
AlgorithmIdentifier
FROM PKIX1Explicit88
{ iso(1) identified-organization(3) dod(6)
internet(1) security(5) mechanisms(5) pkix(7) mod(0)
pkix1-explicit(18) }
-- From [RSAOAEP]
id-sha224, id-sha256, id-sha384, id-sha512
FROM PKIX1-PSS-OAEP-Algorithms
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-pkix1-rsa-pkalgs(33) }
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-- From [PKI-ALG]
id-sha1, ecdsa-with-SHA1, ecdsa-with-SHA224,
ecdsa-with-SHA256, ecdsa-with-SHA384, ecdsa-with-SHA512,
id-ecPublicKey, ECDSA-Sig-Value, ECPoint
FROM PKIXAlgs-2008
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0) TBA }
-- From [CMS]
OriginatorPublicKey, UserKeyingMaterial
FROM CryptographicMessageSyntax2004
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) modules(0) cms-2004(24) }
-- From [CMS-ALG]
hMAC-SHA1, des-ede3-cbc, id-alg-CMS3DESwrap, CBCParameter
FROM CryptographicMessageSyntaxAlgorithms
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) modules(0) cmsalg-2001(16) }
-- From [CMS-AES]
id-aes128-CBC, id-aes192-CBC, id-aes256-CBC, AES-IV,
id-aes128-wrap, id-aes192-wrap, id-aes256-wrap
FROM CMSAesRsaesOaep
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) modules(0) id-mod-cms-aes(19) }
-- From [CMS-AESCG]
id-aes128-CCM, id-aes192-CCM, id-aes256-CCM, CCMParameters
id-aes128-GCM, id-aes192-GCM, id-aes256-GCM, GCMParameters
FROM CMS-AES-CCM-and-AES-GCM
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) modules(0) id-mod-cms-aes(32) }
;
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--
-- ECDSA with SHA-1, SHA-224, SHA-256, SHA-384, and SHA-512
-- Algorithms.
--
-- ecdsa-with-SHA1 Parameters are NULL
-- ecdsa-with-SHA224 Parameters are absent
-- ecdsa-with-SHA256 Parameters are absent
-- ecdsa-with-SHA384 Parameters are absent
-- ecdsa-with-SHA512 Parameters are absent
-- ECDSA Signature Value
-- Contents of SignatureValue OCTET STRING
-- ECDSA-Sig-Value ::= SEQUENCE {
-- r INTEGER,
-- s INTEGER
-- }
--
-- Key Agreement Algorithms
--
x9-63-scheme OBJECT IDENTIFIER ::= {
iso(1) identified-organization(3) tc68(133) country(16) x9(840)
x9-63(63) schemes(0) }
secg-scheme OBJECT IDENTIFIER ::= {
iso(1) identified-organization(3) certicom(132) schemes(1) }
--
-- Diffie-Hellman Single Pass, Standard, with KDFs
--
-- Parameters are always present and indicate the key wrap algorithm
-- with KeyWrapAlgorithm
dhSinglePass-stdDH-sha1kdf-scheme OBJECT IDENTIFIER ::= {
x9-63-scheme 2 }
dhSinglePass-stdDH-sha224kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 11 0 }
dhSinglePass-stdDH-sha256kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 11 1 }
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dhSinglePass-stdDH-sha384kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 11 2 }
dhSinglePass-stdDH-sha512kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 11 3 }
--
-- Diffie-Hellman Single Pass, Cofactor, with KDFs
--
dhSinglePass-cofactorDH-sha1kdf-scheme OBJECT IDENTIFIER ::= {
x9-63-scheme 3 }
dhSinglePass-cofactorDH-sha224kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 14 0 }
dhSinglePass-cofactorDH-sha256kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 14 1 }
dhSinglePass-cofactorDH-sha384kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 14 2 }
dhSinglePass-cofactorDH-sha512kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 14 3 }
--
-- MQV Single Pass, Cofactor, with KDFs
--
mqvSinglePass-sha1kdf-scheme OBJECT IDENTIFIER ::= {
x9-63-scheme 16 }
mqvSinglePass-sha224kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 15 0 }
mqvSinglePass-sha256kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 15 1 }
mqvSinglePass-sha384kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 15 2 }
mqvSinglePass-sha512kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 15 3 }
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--
-- Key Wrap Algorithms
--
KeyWrapAlgorithm ::= AlgorithmIdentifier
-- id-alg-CMS3DESwrap Parameters are NULL
-- id-aes128-wrap Parameters are absent
-- id-aes192-wrap Parameters are absent
-- id-aes256-wrap Parameters are absent
--
-- Content Encryption Algorithms
--
-- des-ede3-cbc Parameters are CBCParameter
-- id-aes128-CBC Parameters are AES-IV
-- id-aes192-CBC Parameters are AES-IV
-- id-aes256-CBC Parameters are AES-IV
-- id-aes128-CCM Parameters are CCMParameters
-- id-aes192-CCM Parameters are CCMParameters
-- id-aes256-CCM Parameters are CCMParameters
-- id-aes128-GCM Parameters are GCMParameters
-- id-aes192-GCM Parameters are GCMParameters
-- id-aes256-GCM Parameters are GCMParameters
--
-- Message Digest Algorithms
--
-- HMAC with SHA-1
-- Parameters SHOULD be absent, MAY be NULL
-- hMAC-SHA1
-- HMAC with SHA-224, HMAC with SHA-256, HMAC with SHA-384,
-- and HMAC with SHA-512
-- Parameters are absent
id-hmacWithSHA224 OBJECT IDENTIFIER ::= {
iso(1) member-body(2) us(840) rsadsi(113549)
digestAlgorithm(2) 8 }
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id-hmacWithSHA256 OBJECT IDENTIFIER ::= {
iso(1) member-body(2) us(840) rsadsi(113549)
digestAlgorithm(2) 9 }
id-hmacWithSHA384 OBJECT IDENTIFIER ::= {
iso(1) member-body(2) us(840) rsadsi(113549)
digestAlgorithm(2) 10 }
id-hmacWithSHA512 OBJECT IDENTIFIER ::= {
iso(1) member-body(2) us(840) rsadsi(113549)
digestAlgorithm(2) 11 }
--
-- Originator Public Key Algorithms
--
-- id-ecPublicKey Parameters are absent, NULL, or ECParameters
-- Format for both ephemeral and static public keys
-- ECPoint ::= OCTET STRING
-- Format of KeyAgreeRecipientInfo ukm field when used with
-- ECMQV
MQVuserKeyingMaterial ::= SEQUENCE {
ephemeralPublicKey OriginatorPublicKey,
addedukm [0] EXPLICIT UserKeyingMaterial OPTIONAL
}
-- 'SharedInfo' for input to KDF when using ECDH and ECMQV with
-- EnvelopedData, AuthenticatedData, or AuthEnvelopedData
ECC-CMS-SharedInfo ::= SEQUENCE {
keyInfo AlgorithmIdentifier,
entityUInfo [0] EXPLICIT OCTET STRING OPTIONAL,
suppPubInfo [2] EXPLICIT OCTET STRING
}
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--
-- S/MIME Capabilities
--
--
-- S/MIME Capabilities: ECDSA with SHA-1, SHA-224, SHA-256, SHA-384,
-- and SHA-512 Algorithms
--
-- ecdsa-with-SHA1 Type NULL
-- ecdsa-with-SHA224 Type NULL
-- ecdsa-with-SHA256 Type NULL
-- ecdsa-with-SHA384 Type NULL
-- ecdsa-with-SHA512 Type NULL
--
-- S/MIME Capabilities: ECDH, Single Pass, Standard
--
-- dhSinglePass-stdDH-sha1kdf Type is the KeyWrapAlgorithm
-- dhSinglePass-stdDH-sha224kdf Type is the KeyWrapAlgorithm
-- dhSinglePass-stdDH-sha256kdf Type is the KeyWrapAlgorithm
-- dhSinglePass-stdDH-sha384kdf Type is the KeyWrapAlgorithm
-- dhSinglePass-stdDH-sha512kdf Type is the KeyWrapAlgorithm
--
-- S/MIME Capabilities: ECDH, Single Pass, Cofactor
--
-- dhSinglePass-cofactorDH-sha1kdf Type is the KeyWrapAlgorithm
-- dhSinglePass-cofactorDH-sha224kdf Type is the KeyWrapAlgorithm
-- dhSinglePass-cofactorDH-sha256kdf Type is the KeyWrapAlgorithm
-- dhSinglePass-cofactorDH-sha384kdf Type is the KeyWrapAlgorithm
-- dhSinglePass-cofactorDH-sha512kdf Type is the KeyWrapAlgorithm
--
-- S/MIME Capabilities: ECMQV, Single Pass, Standard
--
-- mqvSinglePass-sha1kdf Type is the KeyWrapAlgorithm
-- mqvSinglePass-sha224kdf Type is the KeyWrapAlgorithm
-- mqvSinglePass-sha256kdf Type is the KeyWrapAlgorithm
-- mqvSinglePass-sha384kdf Type is the KeyWrapAlgorithm
-- mqvSinglePass-sha512kdf Type is the KeyWrapAlgorithm
END
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Appendix A.2 2004 ASN.1 Module
SMIMEECCAlgs-2008
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) modules(0) TBA }
DEFINITIONS IMPLICIT TAGS ::=
BEGIN
-- EXPORTS ALL
IMPORTS
-- FROM [PKI-ASN]
KEY-WRAP, SIGNATURE-ALGORITHM, DIGEST-ALGORITHM, ALGORITHM,
PUBLIC-KEY, MAC-ALGORITHM, CONTENT-ENCRYPTION, KEY-AGREE
FROM AlgorithmInformation
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-algorithInformation(TBA) }
-- From [PKI-ALG]
id-ecPublicKey, ECDSA-Sig-Value, ECPoint
FROM PKIXAlgIDs-2008
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0) TBA }
-- From [PKI-ALG]
mda-sha1, sa-ecdsaWithSHA1, sa-ecdsaWithSHA224, sa-ecdsaWithSHA256,
sa-ecdsaWithSHA384, sa-ecdsaWithSHA512, ECParameters
FROM PKIXAlgs-2008
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0) TBA }
-- From [PKI-ASN]
mda-sha224, mda-sha256, mda-sha384, mda-sha512
FROM PKIX1-PSS-OAEP-Algorithms
{ iso(1) identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) id-mod(0) TBA }
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-- From [CMS]
OriginatorPublicKey, UserKeyingMaterial
FROM CryptographicMessageSyntax2004
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) modules(0) cms-2004(24) }
-- From [CMS-ASN]
maca-hMAC-SHA1, cea-des-ede3-cbc, kwa-3DESWrap, CBCParameter
FROM CryptographicMessageSyntaxAlgorithms
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) modules(0) cmsalg-2001(16) }
-- From [CMS-ASN]
cea-aes128-CBC, cea-aes192-CBC, cea-aes256-CBC, kwa-aes128-wrap,
kwa-aes192-wrap, kwa-aes256-wrap
FROM CMSAesRsaesOaep
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) modules(0) id-mod-cms-aes(19) }
-- From [CMS-ASN]
cea-aes128-ccm, cea-aes192-ccm, cea-aes256-ccm, cea-aes128-gcm,
cea-aes192-gcm, cea-aes256-gcm
FROM CMS-AES-CCM-and-AES-GCM
{ iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
smime(16) modules(0) cms-aes-ccm-and-gcm(32) }
;
-- Constrains the SignedData digestAlgorithms field
-- Constrains the SignedData SignerInfo digestAlgorithm field
-- Constrains the AuthenticatedData digestAlgorithm field
-- MessageDigestAlgorithms DIGEST-ALGORITHM ::= {
-- mda-sha1 |
-- mda-sha224 |
-- mda-sha256 |
-- mda-sha384 |
-- mda-sha512,
-- ... -- Extensible
-- }
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-- Constrains the SignedData SignerInfo signatureAlgorithm field
-- SignatureAlgorithms SIGNATURE-ALGORITHM ::= {
-- sa-ecdsaWithSHA1 |
-- sa-ecdsaWithSHA224 |
-- sa-ecdsaWithSHA256 |
-- sa-ecdsaWithSHA384 |
-- sa-ecdsaWithSHA512,
-- ... -- Extensible
-- }
-- ECDSA Signature Value
-- Contents of SignatureValue OCTET STRING
-- ECDSA-Sig-Value ::= SEQUENCE {
-- r INTEGER,
-- s INTEGER
-- }
--
-- Key Agreement Algorithms
--
-- Constrains the EnvelopedData RecipientInfo KeyAgreeRecipientInfo
-- keyEncryption Algorithm field
-- Constrains the AuthenticatedData RecipientInfo
-- KeyAgreeRecipientInfo keyEncryption Algorithm field
-- Constrains the AuthEnvelopedData RecipientInfo
-- KeyAgreeRecipientInfo keyEncryption Algorithm field
-- DH variants are not used with AuthenticatedData or
-- AuthEnvelopedData
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KeyAgreementAlgorithms KEY-AGREE ::= {
kaa-dhSinglePass-stdDH-sha1kdf |
kaa-dhSinglePass-stdDH-sha224kdf |
kaa-dhSinglePass-stdDH-sha256kdf |
kaa-dhSinglePass-stdDH-sha384kdf |
kaa-dhSinglePass-stdDH-sha512kdf |
kaa-dhSinglePass-cofactorDH-sha1kdf |
kaa-dhSinglePass-cofactorDH-sha224kdf |
kaa-dhSinglePass-cofactorDH-sha256kdf |
kaa-dhSinglePass-cofactorDH-sha384kdf |
kaa-dhSinglePass-cofactorDH-sha512kdf |
kaa-mqvSinglePass-sha1kdf |
kaa-mqvSinglePass-sha224kdf |
kaa-mqvSinglePass-sha256kdf |
kaa-mqvSinglePass-sha384kdf |
kaa-mqvSinglePass-sha512kdf,
... -- Extensible
}
x9-63-scheme OBJECT IDENTIFIER ::= {
iso(1) identified-organization(3) tc68(133) country(16) x9(840)
x9-63(63) schemes(0) }
secg-scheme OBJECT IDENTIFIER ::= {
iso(1) identified-organization(3) certicom(132) schemes(1) }
--
-- Diffie-Hellman Single Pass, Standard, with KDFs
--
-- Parameters are always present and indicate the Key Wrap Algorithm
kaa-dhSinglePass-stdDH-sha1kdf KEY-AGREE ::= {
IDENTIFIER dhSinglePass-stdDH-sha1kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
dhSinglePass-stdDH-sha1kdf-scheme OBJECT IDENTIFIER ::= {
x9-63-scheme 2 }
kaa-dhSinglePass-stdDH-sha224kdf KEY-AGREE ::= {
IDENTIFIER dhSinglePass-stdDH-sha224kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
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dhSinglePass-stdDH-sha224kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 11 0 }
kaa-dhSinglePass-stdDH-sha256kdf KEY-AGREE ::= {
IDENTIFIER dhSinglePass-stdDH-sha256kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
dhSinglePass-stdDH-sha256kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 11 1 }
kaa-dhSinglePass-stdDH-sha384kdf KEY-AGREE ::= {
IDENTIFIER dhSinglePass-stdDH-sha384kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
dhSinglePass-stdDH-sha384kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 11 2 }
kaa-dhSinglePass-stdDH-sha512kdf KEY-AGREE ::= {
IDENTIFIER dhSinglePass-stdDH-sha512kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
dhSinglePass-stdDH-sha512kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 11 3 }
--
-- Diffie-Hellman Single Pass, Cofactor, with KDFs
--
kaa-dhSinglePass-cofactorDH-sha1kdf KEY-AGREE ::= {
IDENTIFIER dhSinglePass-cofactorDH-sha1kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
dhSinglePass-cofactorDH-sha1kdf-scheme OBJECT IDENTIFIER ::= {
x9-63-scheme 3 }
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kaa-dhSinglePass-cofactorDH-sha224kdf KEY-AGREE ::= {
IDENTIFIER dhSinglePass-cofactorDH-sha224kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
dhSinglePass-cofactorDH-sha224kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 14 0 }
kaa-dhSinglePass-cofactorDH-sha256kdf KEY-AGREE ::= {
IDENTIFIER dhSinglePass-cofactorDH-sha256kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
dhSinglePass-cofactorDH-sha256kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 14 1 }
kaa-dhSinglePass-cofactorDH-sha384kdf KEY-AGREE ::= {
IDENTIFIER dhSinglePass-cofactorDH-sha384kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
dhSinglePass-cofactorDH-sha384kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 14 2 }
kaa-dhSinglePass-cofactorDH-sha512kdf KEY-AGREE ::= {
IDENTIFIER dhSinglePass-cofactorDH-sha512kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
dhSinglePass-cofactorDH-sha512kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 14 3 }
--
-- MQV Single Pass, Cofactor, with KDFs
--
kaa-mqvSinglePass-sha1kdf KEY-AGREE ::= {
IDENTIFIER mqvSinglePass-sha1kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
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mqvSinglePass-sha1kdf-scheme OBJECT IDENTIFIER ::= {
x9-63-scheme 16 }
kaa-mqvSinglePass-sha224kdf KEY-AGREE ::= {
IDENTIFIER mqvSinglePass-sha224kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
mqvSinglePass-sha224kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 15 0 }
kaa-mqvSinglePass-sha256kdf KEY-AGREE ::= {
IDENTIFIER mqvSinglePass-sha256kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
mqvSinglePass-sha256kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 15 1 }
kaa-mqvSinglePass-sha384kdf KEY-AGREE ::= {
IDENTIFIER mqvSinglePass-sha384kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
mqvSinglePass-sha384kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 15 2 }
kaa-mqvSinglePass-sha512kdf KEY-AGREE ::= {
IDENTIFIER mqvSinglePass-sha512kdf-scheme
PARAMS TYPE KeyWrapAlgorithm ARE required
UKM IS preferredPresent
}
mqvSinglePass-sha512kdf-scheme OBJECT IDENTIFIER ::= {
secg-scheme 15 3 }
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--
-- Key Wrap Algorithms
--
KeyWrapAlgorithm KEY-WRAP ::= {
kwa-3des |
kwa-aes128 |
kwa-aes192 |
kwa-aes256,
... -- Extensible
}
--
-- Content Encryption Algorithms
--
-- Constrains the EnvelopedData EncryptedContentInfo encryptedContent
-- field and the AuthEnvelopedData EncryptedContentInfo
-- contentEncryptionAlgorithm field
-- ContentEncryptionAlgorithms CONTENT-ENCRYPTION ::= {
-- cea-des-ede3-cbc |
-- cea-aes128-cbc |
-- cea-aes192-cbc |
-- cea-aes256-cbc |
-- cea-aes128-ccm |
-- cea-aes192-ccm |
-- cea-aes256-ccm |
-- cea-aes128-gcm |
-- cea-aes192-gcm |
-- cea-aes256-gcm,
-- ... -- Extensible
-- }
-- des-ede3-cbc and aes*-cbc are used with EnvelopedData and
-- EncryptedData
-- aes*-ccm are used with AuthEnvelopedData
-- aes*-gcm are used with AuthEnvelopedData
-- (where * is 128, 192, and 256)
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--
-- Message Digest Algorithms
--
-- Constrains the AuthenticatedData
-- MessageAuthenticationCodeAlgorithm field
-- Constrains the AuthEnvelopedData
-- MessageAuthenticationCodeAlgorithm field
MessageAuthenticationCodeAlgorithms MAC-ALGORITHM ::= {
maca-sha1 |
maca-sha224 |
maca-sha256 |
maca-sha384 |
maca-sha512,
... -- Extensible
}
maca-sha224 MAC-ALGORITHM ::= {
IDENTIFIER id-hmacWithSHA224
PARAMS TYPE NULL ARE preferredPresent
}
id-hmacWithSHA224 OBJECT IDENTIFIER ::= {
iso(1) member-body(2) us(840) rsadsi(113549)
digestAlgorithm(2) 8 }
maca-sha256 MAC-ALGORITHM ::= {
IDENTIFIER id-hmacWithSHA256
PARAMS TYPE NULL ARE preferredPresent
}
id-hmacWithSHA256 OBJECT IDENTIFIER ::= {
iso(1) member-body(2) us(840) rsadsi(113549)
digestAlgorithm(2) 9 }
maca-sha384 MAC-ALGORITHM ::= {
IDENTIFIER id-hmacWithSHA384
PARAMS TYPE NULL ARE preferredPresent
}
id-hmacWithSHA384 OBJECT IDENTIFIER ::= {
iso(1) member-body(2) us(840) rsadsi(113549)
digestAlgorithm(2) 10 }
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maca-sha512 MAC-ALGORITHM ::= {
IDENTIFIER id-hmacWithSHA512
PARAMS TYPE NULL ARE preferredPresent
}
id-hmacWithSHA512 OBJECT IDENTIFIER ::= {
iso(1) member-body(2) us(840) rsadsi(113549)
digestAlgorithm(2) 11 }
--
-- Originator Public Key Algorithms
--
-- Constraints on KeyAgreeRecipientInfo OriginatorIdentifierOrKey
-- OriginatorPublicKey algorithm field
-- PARAMS are NULL
OriginatorPKAlgorithms PUBLIC-KEY ::= {
opka-ec,
... -- Extensible
}
opka-ec PUBLIC-KEY ::={
IDENTIFIER id-ecPublicKey
KEY ECPoint
PARAMS TYPE CHOICE { n NULL, p ECParameters } ARE preferredAbsent
}
-- Format for both ephemeral and static public keys
-- ECPoint ::= OCTET STRING
-- Format of KeyAgreeRecipientInfo ukm field when used with
-- ECMQV
MQVuserKeyingMaterial ::= SEQUENCE {
ephemeralPublicKey OriginatorPublicKey,
addedukm [0] EXPLICIT UserKeyingMaterial OPTIONAL
}
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-- 'SharedInfo' for input to KDF when using ECDH and ECMQV with
-- EnvelopedData, AuthenticatedData, or AuthEnvelopedData
ECC-CMS-SharedInfo ::= SEQUENCE {
keyInfo AlgorithmIdentifier { KeyWrapAlgorithm },
entityUInfo [0] EXPLICIT OCTET STRING OPTIONAL,
suppPubInfo [2] EXPLICIT OCTET STRING
}
--
-- S/MIME Capabilities
--
SMIME-CAPS ::= CLASS {
&Type OPTIONAL,
&id OBJECT IDENTIFIER UNIQUE
}
WITH SYNTAX {TYPE &Type IDENTIFIED BY &id }
SMIMECapability ::= SEQUENCE {
capabilityID SMIME-CAPS.&id({SMimeCapsSet}),
parameters SMIME-CAPS.
&Type({SMimeCapsSet}{@capabilityID}) OPTIONAL
}
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SMimeCapsSet SMIME-CAPS ::= {
cap-ecdsa-with-SHA1 |
cap-ecdsa-with-SHA224 |
cap-ecdsa-with-SHA256 |
cap-ecdsa-with-SHA384 |
cap-ecdsa-with-SHA512 |
cap-dhSinglePass-stdDH-sha1kdf |
cap-dhSinglePass-stdDH-sha224kdf |
cap-dhSinglePass-stdDH-sha256kdf |
cap-dhSinglePass-stdDH-sha384kdf |
cap-dhSinglePass-stdDH-sha512kdf |
cap-dhSinglePass-cofactorDH-sha1kdf |
cap-dhSinglePass-cofactorDH-sha224kdf |
cap-dhSinglePass-cofactorDH-sha256kdf |
cap-dhSinglePass-cofactorDH-sha384kdf |
cap-dhSinglePass-cofactorDH-sha512kdf |
cap-mqvSinglePass-sha1kdf |
cap-mqvSinglePass-sha224kdf |
cap-mqvSinglePass-sha256kdf |
cap-mqvSinglePass-sha384kdf |
cap-mqvSinglePass-sha512kdf,
... -- Extensible
}
--
-- S/MIME Capabilities: ECDSA with SHA-1, SHA-224, SHA-256, SHA-384,
-- and SHA-512 Algorithms
--
cap-ecdsa-with-SHA1 SMIME-CAPS ::= {
TYPE NULL IDENTIFIED BY sa-ecdsaWithSHA1.&id }
cap-ecdsa-with-SHA224 SMIME-CAPS ::= {
TYPE NULL IDENTIFIED BY sa-ecdsaWithSHA224.&id }
cap-ecdsa-with-SHA256 SMIME-CAPS ::= {
TYPE NULL IDENTIFIED BY sa-ecdsaWithSHA256.&id }
cap-ecdsa-with-SHA384 SMIME-CAPS ::= {
TYPE NULL IDENTIFIED BY sa-ecdsaWithSHA384.&id }
cap-ecdsa-with-SHA512 SMIME-CAPS ::= {
TYPE NULL IDENTIFIED BY sa-ecdsaWithSHA512.&id }
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--
-- S/MIME Capabilities: ECDH, Single Pass, Standard
--
cap-dhSinglePass-stdDH-sha1kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm IDENTIFIED BY dhSinglePass-stdDH-sha1kdf }
cap-dhSinglePass-stdDH-sha224kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm IDENTIFIED BY dhSinglePass-stdDH-sha224kdf }
cap-dhSinglePass-stdDH-sha256kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm IDENTIFIED BY dhSinglePass-stdDH-sha256kdf }
cap-dhSinglePass-stdDH-sha384kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm IDENTIFIED BY dhSinglePass-stdDH-sha384kdf }
cap-dhSinglePass-stdDH-sha512kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm IDENTIFIED BY dhSinglePass-stdDH-sha512kdf }
--
-- S/MIME Capabilities: ECDH, Single Pass, Cofactor
--
cap-dhSinglePass-cofactorDH-sha1kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm
IDENTIFIED BY dhSinglePass-cofactorDH-sha1kdf }
cap-dhSinglePass-cofactorDH-sha224kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm
IDENTIFIED BY dhSinglePass-cofactorDH-sha224kdf }
cap-dhSinglePass-cofactorDH-sha256kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm
IDENTIFIED BY dhSinglePass-cofactorDH-sha256kdf }
cap-dhSinglePass-cofactorDH-sha384kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm
IDENTIFIED BY dhSinglePass-cofactorDH-sha384kdf }
cap-dhSinglePass-cofactorDH-sha512kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm
IDENTIFIED BY dhSinglePass-cofactorDH-sha512kdf }
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--
-- S/MIME Capabilities: ECMQV, Single Pass, Standard
--
cap-mqvSinglePass-sha1kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm IDENTIFIED BY mqvSinglePass-sha1kdf }
cap-mqvSinglePass-sha224kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm IDENTIFIED BY mqvSinglePass-sha224kdf }
cap-mqvSinglePass-sha256kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm IDENTIFIED BY mqvSinglePass-sha256kdf }
cap-mqvSinglePass-sha384kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm IDENTIFIED BY mqvSinglePass-sha384kdf }
cap-mqvSinglePass-sha512kdf SMIME-CAPS ::= {
TYPE KeyWrapAlgorithm IDENTIFIED BY mqvSinglePass-sha512kdf }
END
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Acknowledgements
The methods described in this document are based on work done by the
ANSI X9F1 working group. The authors wish to extend their thanks to
ANSI X9F1 for their assistance. The authors also wish to thank Peter
de Rooij for his patient assistance. The technical comments of
Francois Rousseau were valuable contributions.
Many thanks go out to the other authors of RFC 3278: Simon Blake-
Wilson and Paul Lambert. Without RFC 3278 this version wouldn't
exist.
The authors also wish to thank Alfred Hoenes, Paul Hoffman, Russ
Housley, and Jim Schaad for their valuable input.
Author's Addresses
Sean Turner
IECA, Inc.
3057 Nutley Street, Suite 106
Fairfax, VA 22031
USA
Email: turners@ieca.com
Daniel R. L. Brown
Certicom Corp
5520 Explorer Drive #400
Mississauga, ON L4W 5L1
CANADA
Email: dbrown@certicom.com
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Full Copyright Statement
Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
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