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% title = "PASETO: Platform-Agnostic SEcurity TOkens" % abbr = "PASETO" % category = "info" % docname = "draft-paragon-paseto-rfc-01" % workgroup = "(No Working Group)" % keyword = ["security", "token"] % % date = 2018-04-19T16:00:00Z % % [[author]] % initials="S." % surname="Arciszewski" % fullname="Scott Arciszewski" % organization="Paragon Initiative Enterprises" % [author.address] % email = "security@paragonie.com" % [author.address.postal] % country = "United States" % [[author]] % initials="S." % surname="Haussmann" % fullname="Steven Haussmann" % organization="Rensselaer Polytechnic Institute" % [author.address] % email = "hausss@rpi.edu" % [author.address.postal] % country = "United States"

.# Abstract

Platform-Agnostic SEcurity TOkens (PASETOs) provide a cryptographically secure, compact, and URL-safe representation of claims that may be transferred between two parties. The claims are encoded in JavaScript Object Notation (JSON), version-tagged, and either encrypted using shared-key cryptography or signed using public-key cryptography.

{mainmatter}

Introduction

A Platform-Agnostic SEcurity TOken (PASETO) is a cryptographically secure, compact, and URL-safe representation of claims intended for space-constrained environments such as HTTP Cookies, HTTP Authorization headers, and URI query parameters. A PASETO encodes claims to be transmitted in a JSON [@!RFC8259] object, and is either encrypted symmetrically or signed using public-key cryptography.

Difference Between PASETO and JOSE

The key difference between PASETO and the JOSE family of standards (JWS [@!RFC7516], JWE [@!RFC7517], JWK [@!RFC7518], JWA [@!RFC7518], and JWT [@!RFC7519]) is that JOSE allows implementors and users to mix and match their own choice of cryptographic algorithms (specified by the "alg" header in JWT), while PASETO has clearly defined protocol versions to prevent unsafe configurations from being selected.

PASETO is defined in two pieces:

  1. The PASETO Message Format, defined in (#paseto-message-format)
  2. The PASETO Protocol Version, defined in (#protocol-versions)

Notation and Conventions

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [@!RFC2119].

PASETO Message Format

PASETOs consist of three or four segments, separated by a period (the ASCII character whose number, represented in hexadecimal, is 2E).

Without the Optional Footer:

version.purpose.payload

With the Optional Footer:

version.purpose.payload.footer

If no footer is provided, implementations SHOULD NOT append a trailing period to each payload.

The version is a string that represents the current version of the protocol. Currently, two versions are specified, which each possess their own ciphersuites. Accepted values: v1, v2.

The purpose is a short string describing the purpose of the token. Accepted values: local, public.

  • local: shared-key authenticated encryption
  • public: public-key digital signatures; not encrypted

The payload is a string that contains the token's data. In a local token, this data is encrypted with a symmetric cipher. In a public token, this data is unencrypted.

Any optional data can be appended to the footer. This data is authenticated through inclusion in the calculation of the authentication tag along with the header and payload. The footer MUST NOT be encrypted.

Base64 Encoding

The payload and footer in a PASETO MUST be encoded using base64url as defined in [@!RFC4648], without = padding.

In this document. b64() refers to this unpadded variant of base64url.

Authentication Padding

Multi-part messages (e.g. header, content, footer) are encoded in a specific manner before being passed to the appropriate cryptographic function.

In local mode, this encoding is applied to the additional associated data (AAD). In public mode, which is not encrypted, this encoding is applied to the components of the token, with respect to the protocol version being followed.

We will refer to this process as PAE in this document (short for Pre-Authentication Encoding).

PAE Definition

PAE() accepts an array of strings.

LE64() encodes a 64-bit unsigned integer into a little-endian binary string. The most significant bit MUST be set to 0 for interoperability with programming languages that do not have unsigned integer support.

The first 8 bytes of the output will be the number of pieces. Currently, this will be 3 or 4. This is calculated by applying LE64() to the size of the array.

Next, for each piece provided, the length of the piece is encoded via LE64() and prefixed to each piece before concatenation.

function LE64(n) {
    var str = '';
    for (var i = 0; i < 8; ++i) {
        if (i === 7) {
            n &= 127;
        }
        str += String.fromCharCode(n & 255);
        n = n >>> 8;
    }
    return str;
}
function PAE(pieces) {
    if (!Array.isArray(pieces)) {
        throw TypeError('Expected an array.');
    }
    var count = pieces.length;
    var output = LE64(count);
    for (var i = 0; i < count; i++) {
        output += LE64(pieces[i].length);
        output += pieces[i];
    }
    return output;
}

Figure: JavaScript implementation of Pre-Authentication Encoding (PAE)

As a consequence:

  • PAE([]) will always return \x00\x00\x00\x00\x00\x00\x00\x00
  • PAE(['']) will always return \x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00
  • PAE(['test']) will always return \x01\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00test
  • PAE('test') will throw a TypeError

As a result, partially controlled plaintext cannot be used to create a collision. Either the number of pieces will differ, or the length of one of the fields (which is prefixed to user-controlled input) will differ, or both.

Due to the length being expressed as an unsigned 64-bit integer, it is infeasible to encode enough data to create an integer overflow.

This is not used to encode data prior to decryption, and no decoding function is provided or specified. This merely exists to prevent canonicalization attacks.

Protocol Versions

This document defines two protocol versions, v1 and v2.

Each protocol version strictly defines the cryptographic primitives used. Changes to the primitives requires new protocol versions. Future RFCs MAY introduce new PASETO protocol versions by continuing the convention (e.g. v3, v4, ...).

Both v1 and v2 provide authentication of the entire PASETO message, including the version, purpose, payload, and footer.

The initial recommendation is to use v2, allowing for upgrades to possible future versions v3, v4, etc. when they are defined in the future.

PASETO Protocol Guidelines

When defining future protocol versions, the following rules SHOULD or MUST be followed:

  1. Everything in a token MUST be authenticated. Attackers should never be allowed the opportunity to alter messages freely. * If encryption is specified, unauthenticated modes (e.g. AES-CBC without a MAC) are forbidden. * The nonce or initialization vector must be covered by the authentication tag, not just the ciphertext.
  2. Some degree of nonce-misuse resistance SHOULD be provided: * Supporting larger nonces (longer than 128-bit) is sufficient for satisfying this requirement, provided the nonce is generated by a cryptographically secure random number generator, such as /dev/urandom on Linux. * Key-splitting and including an additional HKDF salt as part of the nonce is sufficient for this requirement. * Hashing the plaintext payload with the random nonce is an acceptable strategy for mitigating random number generator failures, but a secure random number generator SHOULD be used even with this safeguard in place.
  3. Non-deterministic, stateful, and otherwise dangerous signature schemes (e.g. ECDSA without deterministic signatures as in [@!RFC6979], XMSS) are forbidden from all PASETO protocols.
  4. Public-key cryptography MUST be IND-CCA2 secure to be considered for inclusion. This means that RSA with PKCS1v1.5 padding and unpadded RSAMUST NOT* ever be used in a PASETO protocol.

PASETO Protocol Version v1

Version v1 is a compatibility mode composed of cryptographic primitives likely available on legacy systems. v1 SHOULD NOT be used when all systems are able to use v2. v1 MAY be used when compatibility requirements include systems unable to use cryptographic primitives from v2.

v1 messages MUST use a purpose value of either local or public.

v1.local

v1.local messages SHALL be encrypted and authenticated with AES-256-CTR (AES-CTR from [@!RFC3686] with a 256-bit key) and HMAC-SHA-384 ([@!RFC4231]), using an Encrypt-then-MAC construction.

Encryption and authentication keys are split from the original key and half the nonce, facilitated by HKDF [@!RFC5869] using SHA384.

Refer to the operations defined in v1.Encrypt and v1.Decrypt for a formal definition.

v1.public

v1.public messages SHALL be signed using RSASSA-PSS as defined in [@!RFC8017], with 2048-bit private keys. These messages provide authentication but do not prevent the contents from being read, including by those without either the public key or the private key. Refer to the operations defined in v1.Sign and v1.Verify for a formal definition.

Version v1 Algorithms

v1.GetNonce

Given a message (m) and a nonce (n):

  1. Calculate HMAC-SHA384 of the message m with n as the key.
  2. Return the leftmost 32 bytes of step 1.

v1.Encrypt

Given a message m, key k, and optional footer f (which defaults to empty string):

  1. Set header h to v1.local.
  2. Generate 32 random bytes from the OS's CSPRNG.
  3. Optionally, calculate GetNonce() of m and the output of step 2 to get the nonce, n. * This step is to ensure that an RNG failure does not result in a nonce-misuse condition that breaks the security of our stream cipher. * If this step is omitted, the output of step 2 is n instead.
  4. Split the key (k) into an Encryption key (Ek) and an Authentication key (Ak), using the leftmost 16 bytes of n as the HKDF salt. (See below for pseudocode.) For encryption keys, theinfoparameter for HKDFMUST* be set to paseto-encryption-key. For authentication keys, theinfoparameter for HKDFMUST* be set to paseto-auth-key-for-aead. The output lengthMUST* be 32 for both keys.
  5. Encrypt the message using AES-256-CTR, using Ek as the key and the rightmost 16 bytes of n as the nonce. We'll call this c. (See below for pseudocode.)
  6. Pack h, n, c, and f together (in that order) using PAE (see (#authentication-padding)). We'll call this preAuth.
  7. Calculate HMAC-SHA-384 of the output of preAuth, using Ak as the authentication key. We'll call this t.
  8. If f is: * Empty: return h || b64(n || c || t) * Non-empty: return h || b64(n || c || t) || . || b64(f) * ...where || means "concatenate"

Example code:

Ek = hkdf_sha384(
   len = 32
   ikm = k,
   info = "paseto-encryption-key",
   salt = n[0:16]
);
Ak = hkdf_sha384(
   len = 32
   ikm = k,
   info = "paseto-auth-key-for-aead",
   salt = n[0:16]
);

Figure: Step 4: Key splitting with HKDF-SHA384 as per [@!RFC5869].

c = aes256ctr_encrypt(
    plaintext = m,
    nonce = n[16:]
    key = Ek
);

Figure: Step 5: PASETO v1 encryption (calculating c)

v1.Decrypt

Given a message m, key k, and optional footer f (which defaults to empty string):

  1. If f is not empty, implementations MAY verify that the value appended to the token matches some expected string f, provided they do so using a constant-time string compare function.
  2. Verify that the message begins with v1.local., otherwise throw an exception. This constant will be referred to as h.
  3. Decode the payload (m sans h, f, and the optional trailing period between m and f) from b64 to raw binary. Set: * n to the leftmost 32 bytes * t to the rightmost 48 bytes * c to the middle remainder of the payload, excluding n and t
  4. Split the key (k) into an Encryption key (Ek) and an Authentication key (Ak), using the leftmost 16 bytes of n as the HKDF salt. (See below for pseudocode.) For encryption keys, theinfoparameter for HKDFMUST* be set to paseto-encryption-key. For authentication keys, theinfoparameter for HKDFMUST* be set to paseto-auth-key-for-aead. The output lengthMUST* be 32 for both keys.
  5. Pack h, n, c, and f together (in that order) using PAE (see (#authentication-padding)). We'll call this preAuth.
  6. Recalculate HMAC-SHA-384 of preAuth using Ak as the key. We'll call this t2.
  7. Compare t with t2 using a constant-time string compare function. If they are not identical, throw an exception.
  8. Decrypt c using AES-256-CTR, using Ek as the key and the rightmost 16 bytes of n as the nonce, and return this value.

Example code:

Ek = hkdf_sha384(
   len = 32
   ikm = k,
   info = "paseto-encryption-key",
   salt = n[0:16]
);
Ak = hkdf_sha384(
   len = 32
   ikm = k,
   info = "paseto-auth-key-for-aead",
   salt = n[0:16]
);

Figure: Step 4: Key splitting with HKDF-SHA384 as per [@!RFC5869].

return aes256ctr_decrypt(
   cipherext = c,
   nonce = n[16:]
   key = Ek
);

Figure: Step 8: PASETO v1 decryption

v1.Sign

Given a message m, 2048-bit RSA secret key sk, and optional footer f (which defaults to empty string):

  1. Set h to v1.public.
  2. Pack h, m, and f together (in that order) using PAE (see (#authentication-padding)). We'll call this m2.
  3. Sign m2 using RSA with the private key sk. We'll call this sig. The padding mode MUST be RSASSA-PSS [@!RFC8017]; PKCS1v1.5 is explicitly forbidden. The public exponent e MUST be 65537. The mask generating function MUST be MGF1+SHA384. The hash function MUST be SHA384. (See below for pseudocode.)
  4. If f is: * Empty: return h || b64(m || sig) * Non-empty: return h || b64(m || sig) || . || b64(f) * ...where || means "concatenate"
sig = crypto_sign_rsa(
   message = m2,
   private_key = sk,
   padding_mode = "pss",
   public_exponent = 65537,
   hash = "sha384"
   mgf = "mgf1+sha384"
);

Figure: Pseudocode: RSA signature algorithm used in PASETO v1

v1.Verify

Given a signed message sm, RSA public key pk, and optional footer f (which defaults to empty string):

  1. If f is not empty, implementations MAY verify that the value appended to the token matches some expected string f, provided they do so using a constant-time string compare function.
  2. Verify that the message begins with v1.public., otherwise throw an exception. This constant will be referred to as h.
  3. Decode the payload (sm sans h, f, and the optional trailing period between m and f) from b64 to raw binary. Set: * s to the rightmost 256 bytes * m to the leftmost remainder of the payload, excluding s
  4. Pack h, m, and f together (in that order) using PAE (see (#authentication-padding)). We'll call this m2.
  5. Use RSA to verify that the signature is valid for the message. The padding mode MUST be RSASSA-PSS [@!RFC8017]; PKCS1v1.5 is explicitly forbidden. The public exponent e MUST be 65537. The mask generating function MUST be MGF1+SHA384. The hash function MUST be SHA384. (See below for pseudocode.)
  6. If the signature is valid, return m. Otherwise, throw an exception.
valid = crypto_sign_rsa_verify(
    signature = s,
    message = m2,
    public_key = pk,
    padding_mode = "pss",
    public_exponent = 65537,
    hash = "sha384"
    mgf = "mgf1+sha384"
);

Figure: Pseudocode: RSA signature validation for PASETO v1

PASETO Protocol Version v2

Version v2 is the RECOMMENDED protocol version. v2 SHOULD be used in preference to v1. Applications using PASETO SHOULD only support v2 messages, but MAY support v1 messages if the cryptographic primitives used in v2 are not available on all machines.

v2 messages MUST use a purpose value of either local or public.

v2.local

v2.local messages MUST be encrypted with XChaCha20-Poly1305, a variant of ChaCha20-Poly1305 [@!RFC7539] defined in (#aeadxchacha20poly1305). Refer to the operations defined in v2.Encrypt and v2.Decrypt for a formal definition.

v2.public

v2.public messages MUST be signed using Ed25519 [@!RFC8032] public key signatures. These messages provide authentication but do not prevent the contents from being read, including by those without either the public key or the private key. Refer to the operations defined in v2.Sign and v2.Verify for a formal definition.

Version v2 Algorithms

v2.Encrypt

Given a message m, key k, and optional footer f.

  1. Set header h to v2.local.
  2. Generate 24 random bytes from the OS's CSPRNG.
  3. Optionally, calculate BLAKE2b of the message m with the output of step 2 as the key, with an output length of 24. This will be our nonce, n. * This step is to ensure that an RNG failure does not result in a nonce-misuse condition that breaks the security of our stream cipher. * If this step is omitted, the output of step 2 is n instead.
  4. Pack h, n, and f together (in that order) using PAE (see (#authentication-padding)). We'll call this preAuth.
  5. Encrypt the message using XChaCha20-Poly1305, using an AEAD interface such as the one provided in libsodium. (See below for pseudocode.)
  6. If f is: * Empty: return h || b64(n || c) * Non-empty: return h || b64(n || c) || . || b64(f) * ...where || means "concatenate"
c = crypto_aead_xchacha20poly1305_encrypt(
    message = m
    aad = preAuth
    nonce = n
    key = k
);

Figure: Step 5: PASETO v2 encryption (calculating c)

v2.Decrypt

Given a message m, key k, and optional footer f.

  1. If f is not empty, implementations MAY verify that the value appended to the token matches some expected string f, provided they do so using a constant-time string compare function.
  2. Verify that the message begins with v2.local., otherwise throw an exception. This constant will be referred to as h.
  3. Decode the payload (m sans h, f, and the optional trailing period between m and f) from base64url to raw binary. Set: * n to the leftmost 24 bytes * c to the middle remainder of the payload, excluding n.
  4. Pack h, n, and f together (in that order) using PAE (see (#authentication-padding)). We'll call this preAuth
  5. Decrypt c using XChaCha20-Poly1305, store the result in p. (See below for pseudocode.)
  6. If decryption failed, throw an exception. Otherwise, return p.
p = crypto_aead_xchacha20poly1305_decrypt(
    ciphertext = c
    aad = preAuth
    nonce = n
    key = k
);

Figure: Step 8: PASETO v2 decryption

v2.Sign

Given a message m, Ed25519 secret key sk, and optional footer f (which defaults to empty string):

  1. Set h to v2.public.
  2. Pack h, m, and f together (in that order) using PAE (see (#authentication-padding)). We'll call this m2.
  3. Sign m2 using Ed25519 sk. We'll call this sig. (See below for pseudocode.)
  4. If f is: * Empty: return h || b64(m || sig) * Non-empty: return h || b64(m || sig) || . || b64(f) * ...where || means "concatenate"
sig = crypto_sign_detached(
    message = m2,
    private_key = sk
);

Figure: Step 3: Generating an Ed25519 with libsodium

v2.Verify

Given a signed message sm, public key pk, and optional footer f (which defaults to empty string):

  1. If f is not empty, implementations MAY verify that the value appended to the token matches some expected string f, provided they do so using a constant-time string compare function.
  2. Verify that the message begins with v2.public., otherwise throw an exception. This constant will be referred to as h.
  3. Decode the payload (sm sans h, f, and the optional trailing period between m and f) from base64url to raw binary. Set: * s to the rightmost 64 bytes * m to the leftmost remainder of the payload, excluding s
  4. Pack h, m, and f together (in that order) using PAE (see (#authentication-padding)). We'll call this m2.
  5. Use Ed25519 to verify that the signature is valid for the message: (See below for pseudocode.)
  6. If the signature is valid, return m. Otherwise, throw an exception.
valid = crypto_sign_verify_detached(
    signature = s,
    message = m2,
    public_key = pk
);

Figure: Step 5: Validating the Ed25519 signature using libsodium.

Payload Processing

All PASETO payloads MUST be a JSON object [@!RFC8259].

If non-UTF-8 character sets are desired for some fields, implementors are encouraged to use Base64url encoding to preserve the original intended binary data, but still use UTF-8 for the actual payloads.

Type Safety with Cryptographic Keys

PASETO library implementations MUST implement some means of preventing type confusion bugs between different cryptography keys. For example:

  • Prepending each key in memory with a magic byte to serve as a type indicator (distinct for every combination of version and purpose).
  • In object-oriented programming languages, using separate classes for each cryptography key object that may share an interface or common base class.

Cryptographic keys MUST require the user to state a version and a purpose for which they will be used. Furthermore, given a cryptographic key, it MUST NOT be possible for a user to use this key for any version and purpose combination other than that which was specified during the creation of this key.

Registered Claims

The following keys are reserved for use within PASETO. Users SHOULD NOT write arbitrary/invalid data to any keys in a top-level PASETO in the list below:

| Key | Name | Type | Example | | ---- | ----------| ------ | ----------------------------------- | | iss | Issuer | string | {"iss":"paragonie.com"} | | sub | Subject | string | {"sub":"test"} | | aud | Audience | string | {"aud":"pie-hosted.com"} | | exp | Expiration | DtTime | {"exp":"2039-01-01T00:00:00+00:00"} | | nbf | Not Before | DtTime | {"nbf":"2038-04-01T00:00:00+00:00"} | | iat | Issued At | DtTime | {"iat":"2038-03-17T00:00:00+00:00"} | | jti | Token ID | string | {"jti":"87IFSGFgPNtQNNuw0AtuLttP"} | | kid | Key-ID | string | {"kid":"stored-in-the-footer"} |

In the table above, DtTime means an ISO 8601 compliant DateTime string. See [#keyid-support] for special rules about kid claims.

Any other claims can be freely used. These keys are only reserved in the top-level JSON object.

The keys in the above table are case-sensitive.

Implementors (i.e. library designers) SHOULD provide some means to discourage setting invalid/arbitrary data to these reserved claims.

For example: Storing any string that isn't a valid ISO 8601 DateTime in the exp claim should result in an exception or error state (depending on the programming language in question).

Key-ID Support

Some systems need to support key rotation, but since the payloads of a local token are always encrypted, it is impractical to store the key id in the payload.

Instead, users should store Key-ID claims (kid) in the unencrypted footer.

For example, a footer of {"kid":"gandalf0"} can be read without needing to first decrypt the token (which would in turn allow the user to know which key to use to decrypt the token).

Implementations SHOULD provide a means to extract the footer from a PASETO before authentication and decryption. This is possible for local tokens because the contents of the footer are not encrypted. However, the authenticity of the footer is only assured after the authentication tag is verified.

While a key identifier can generally be safely used for selecting the cryptographic key used to decrypt and/or verify payloads before verification, provided that the kid is a public number that is associated with a particular key which is not supplied by attackers, any other fields stored in the footer MUST be distrusted until the payload has been verified.

IMPORTANT: Key identifiers MUST be independent of the actual keys used by PASETO.

A fingerprint of the key is allowed as long as it is impractical for an attacker to recover the key from said fingerprint.

For example, the user MUST NOT store the public key in the footer for a public token and have the recipient use the provided public key. Doing so would allow an attacker to replace the public key with one of their own choosing, which will cause the recipient to accept any signature for any message as valid, therefore defeating the security goals of public-key cryptography.

Instead, it's recommended that implementors and users use a unique identifier for each key (independent of the cryptographic key's contents) that is used in a database or other key-value store to select the appropriate cryptographic key. These search operations MUST fail closed if no valid key is found for the given key identifier.

AEAD_XChaCha20_Poly1305

XChaCha20-Poly1305 is a variant of the ChaCha20-Poly1305 AEAD construction as defined in [@!RFC7539] that uses a 192-bit nonce instead of a 64-bit nonce.

The algorithm for XChaCha20-Poly1305 is as follows:

  1. Calculate a subkey from the first 16 bytes of the nonce and the key, using HChaCha20 ((#hchacha20)).
  2. Use the subkey and remaining 8 bytes of the nonce (prefixed with 4 NUL bytes) with AEAD_CHACHA20_POLY1305 from [@!RFC7539] as normal.

XChaCha20-Poly1305 implementations already exist in libsodium, Monocypher, xsecretbox, and a standalone Go library.

Motivation for XChaCha20-Poly1305

As long as ChaCha20-Poly1305 is a secure AEAD cipher and ChaCha is a secure pseudorandom function (PRF), XChaCha20-Poly1305 is secure.

The nonce used by the original ChaCha20-Poly1305 is too short to safely use with random strings for long-lived keys.

With XChaCha20-Poly1305, users can safely generate a random 192-bit nonce for each message and not worry about nonce-reuse vulnerabilities.

HChaCha20

HChaCha20 is an intermediary step towards XChaCha20 based on the construction and security proof used to create XSalsa20, an extended-nonce Salsa20 variant used in NaCl.

HChaCha20 is initialized the same way as the ChaCha cipher, except that HChaCha20 uses a 128-bit nonce and has no counter.

Consider the two figures below, where each non-whitespace character represents one nibble of information about the ChaCha states (all numbers little-endian):

cccccccc  cccccccc  cccccccc  cccccccc
kkkkkkkk  kkkkkkkk  kkkkkkkk  kkkkkkkk
kkkkkkkk  kkkkkkkk  kkkkkkkk  kkkkkkkk
bbbbbbbb  nnnnnnnn  nnnnnnnn  nnnnnnnn

Figure: ChaCha20 State: c=constant k=key b=blockcount n=nonce

cccccccc  cccccccc  cccccccc  cccccccc
kkkkkkkk  kkkkkkkk  kkkkkkkk  kkkkkkkk
kkkkkkkk  kkkkkkkk  kkkkkkkk  kkkkkkkk
nnnnnnnn  nnnnnnnn  nnnnnnnn  nnnnnnnn

Figure: HChaCha20 State: c=constant k=key n=nonce

After initialization, proceed through the ChaCha rounds as usual.

Once the 20 ChaCha rounds have been completed, the first 128 bits and last 128 bits of the keystream (both little-endian) are concatenated, and this 256-bit subkey is returned.

Test Vector for the HChaCha20 Block Function

  • Key = 00:01:02:03:04:05:06:07:08:09:0a:0b:0c:0d:0e:0f:10:11:12:13:14:15:16:17:18:19:1a:1b:1c:1d:1e:1f. The key is a sequence of octets with no particular structure before we copy it into the HChaCha state.
  • Nonce = (00:00:00:09:00:00:00:4a:00:00:00:00:31:41:59:27)

After setting up the HChaCha state, it looks like this:

61707865 3320646e 79622d32 6b206574
03020100 07060504 0b0a0908 0f0e0d0c
13121110 17161514 1b1a1918 1f1e1d1c
09000000 4a000000 00000000 27594131

Figure: ChaCha state with the key setup.

After running 20 rounds (10 column rounds interleaved with 10 "diagonal rounds"), the HChaCha state looks like this:

82413b42 27b27bfe d30e4250 8a877d73
4864a70a f3cd5479 37cd6a84 ad583c7b
8355e377 127ce783 2d6a07e0 e5d06cbc
a0f9e4d5 8a74a853 c12ec413 26d3ecdc

Figure: HChaCha state after 20 rounds

HChaCha20 will then return only the first and last rows, resulting in the following 256-bit key:

82413b4 227b27bfe d30e4250 8a877d73
a0f9e4d 58a74a853 c12ec413 26d3ecdc

Figure: Resultant HChaCha20 subkey

Intended Use-Cases for PASETO

Like JWTs, PASETOs are intended to be single-use tokens, as there is no built-in mechanism to prevent replay attacks within the token lifetime.

  • local tokens are intended for tamper-resistant encrypted cookies or HTTP request parameters. A resonable example would be long-term authentication cookies which re-establish a new session cookie if a user checked the "remember me on this computer" box when authenticating. To accomplish this, the server would look use the jti claim in a database lookup to find the appropriate user to associate this session with. After each new browsing session, the jti would be rotated in the database and a fresh cookie would be stored in tbe browser.
  • public tokens are intended for one-time authentication claims from a third party. For example, public PASETO would be suitable for a protocol like OpenID Connect.

Security Considerations

PASETO was designed in part to address known deficits of the JOSE standards that lead to insecure implementations.

PASETO uses versioned protocols, rather than runtime ciphersuite negotiation, to prevent insecure algorithms from being selected. Mix-and-match is not a robust strategy for usable security engineering, especially when implementations have insecure default settings.

If a severe security vulnerability is ever discovered in one of the specified versions, a new version of the protocol that is not affected should be decided by a team of cryptography engineers familiar with the vulnerability in question. This prevents users from having to rewrite and/or reconfigure their implementations to side-step the vulnerability.

PASETO implementors should only support the two most recent protocol versions (currently v1 and v2) at any given time.

PASETO users should beware that, although footers are authenticated, they are never encrypted. Therefore, sensitive information MUST NOT be stored in a footer.

Furthermore, PASETO users should beware that, if footers are employed to implement Key Identification (kid), the values stored in the footer MUST be unrelated to the actual cryptographic key used in verifying the token as discussed in (#keyid-support).

PASETO has no built-in mechanism to resist replay attacks within the token's lifetime. Users SHOULD NOT attempt to use PASETO to obviate the need for server-side data storage when designing web applications.

PASETO's cryptography features requires the availability of a secure random number generator, such as the getrandom(2) syscall on newer Linux distributions, /dev/urandom on most Unix-like systems, and CryptGenRandom on Windows computers.

The use of userspace pseudo-random number generators, even if seeded by the operating system's cryptographically secure pseudo-random number generator, is discouraged.

Implementors should use some means of identifying different key types so that they cannot be used in the wrong context. Encapsulating each key in a different class and type-hinting checking that:

  • Only symmetric cryptography keys are used for decrypting local tokens
  • Only asymmetric cryptography public keys are used for verifying public tokens

IANA Considerations

The IANA should reserve a new "PASETO Headers" registry for the purpose of this document and superseding RFCs.

This document defines a suite of string prefixes for PASETO tokens, called "PASETO Headers" (see (#paseto-message-format)), which consists of two parts:

  • version, with values v1, v2 defined above
  • purpose, with the values of local or public

These two values are concatenated with a single character separator, the ASCII period character ..

Initial values for the "PASETO Headers" registry are given below; future assignments are to be made through Expert Review [@!RFC8126], such as the [CFRG].

| Value | PASETO Header Meaning | Definition | | --------- | --------------------- | ----------- | | v1.local | Version 1, local | (#v1local) | | v1.public | Version 1, public | (#v1public) | | v2.local | Version 2, local | (#v2local) | | v2.public | Version 2, public | (#v2public) | Table: PASETO Headers and their respective meanings

[CFRG]: https://irtf.org/cfrg "Crypto Forum Research Group"

{backmatter}

PASETO Test Vectors

Note: When a nonce is given below, it refers to the value before being hashed with the message. Typically this value is provided by a secure random number generator.

Note: Signing may result in a different token each time, but the given token and public key pair should validate successfully. The private key that corresponds to this public key is as follows:

-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----

PASETO v1 Test Vectors

v1.local (Shared-Key Encryption) Test Vectors

Test Vector v1-E-1

Key:     70717273 74757677 78797a7b 7c7d7e7f
         80818283 84858687 88898a8b 8c8d8e8f
Nonce:   00000000 00000000 00000000 00000000
         00000000 00000000 00000000 00000000
Payload: {"data":"this is a signed message",
         "exp":"2019-01-01T00:00:00+00:00"}
Footer:
Token:   v1.local.WzhIh1MpbqVNXNt7-HbWvL-JwAym3Tomad9Pc2nl7wK87vGraUV
         vn2bs8BBNo7jbukCNrkVID0jCK2vr5bP18G78j1bOTbBcP9HZzqnraEdspcj
         d_PvrxDEhj9cS2MG5fmxtvuoHRp3M24HvxTtql9z26KTfPWxJN5bAJaAM6go
         s8fnfjJO8oKiqQMaiBP_Cqncmqw8

Test Vector v1-E-2

Same as v1-E-1, but with a slightly different message.

Key:     70717273 74757677 78797a7b 7c7d7e7f
         80818283 84858687 88898a8b 8c8d8e8f
Nonce:   00000000 00000000 00000000 00000000
         00000000 00000000 00000000 00000000
Payload: {"data":"this is a secret message",
         "exp":"2019-01-01T00:00:00+00:00"}
Footer:
Token:   v1.local.w_NOpjgte4bX-2i1JAiTQzHoGUVOgc2yqKqsnYGmaPaCu_KWUkR
         GlCRnOvZZxeH4HTykY7AE_jkzSXAYBkQ1QnwvKS16uTXNfnmp8IRknY76I2m
         3S5qsM8klxWQQKFDuQHl8xXV0MwAoeFh9X6vbwIqrLlof3s4PMjRDwKsxYzk
         Mr1RvfDI8emoPoW83q4Q60_xpHaw

Test Vector v1-E-3

Key:     70717273 74757677 78797a7b 7c7d7e7f
         80818283 84858687 88898a8b 8c8d8e8f
Nonce:   26f75533 54482a1d 91d47846 27854b8d
         a6b8042a 7966523c 2b404e8d bbe7f7f2
Payload: {"data":"this is a signed message",
         "exp":"2019-01-01T00:00:00+00:00"}
Footer:
Token:   v1.local.4VyfcVcFAOAbB8yEM1j1Ob7Iez5VZJy5kHNsQxmlrAwKUbOtq9c
         v39T2fC0MDWafX0nQJ4grFZzTdroMvU772RW-X1oTtoFBjsl_3YYHWnwgqzs
         0aFc3ejjORmKP4KUM339W3syBYyjKIOeWnsFQB6Yef-1ov9rvqt7TmwONUHe
         JUYk4IK_JEdUeo_uFRqAIgHsiGCg

Test Vector v1-E-4

Same as v1-E-3, but with a slightly different message.

Key:     70717273 74757677 78797a7b 7c7d7e7f
         80818283 84858687 88898a8b 8c8d8e8f
Nonce:   26f75533 54482a1d 91d47846 27854b8d
         a6b8042a 7966523c 2b404e8d bbe7f7f2
Payload: {"data":"this is a secret message",
         "exp":"2019-01-01T00:00:00+00:00"}
Footer:
Token:   v1.local.IddlRQmpk6ojcD10z1EYdLexXvYiadtY0MrYQaRnq3dnqKIWcbb
         pOcgXdMIkm3_3gksirTj81bvWrWkQwcUHilt-tQo7LZK8I6HCK1V78B9YeEq
         GNeeWXOyWWHoJQIe0d5nTdvejdt2Srz_5Q0QG4oiz1gB_wmv4U5pifedaZbH
         XUTWXchFEi0etJ4u6tqgxZSklcec

Test Vector v1-E-5

Key:     70717273 74757677 78797a7b 7c7d7e7f
         80818283 84858687 88898a8b 8c8d8e8f
Nonce:   26f75533 54482a1d 91d47846 27854b8d
         a6b8042a 7966523c 2b404e8d bbe7f7f2
Payload: {"data":"this is a signed message",
         "exp":"2019-01-01T00:00:00+00:00"}
Footer:  {"kid":"UbkK8Y6iv4GZhFp6Tx3IWLWLfNXSEvJcdT3zdR65YZxo"}
Token:   v1.local.4VyfcVcFAOAbB8yEM1j1Ob7Iez5VZJy5kHNsQxmlrAwKUbOtq9c
         v39T2fC0MDWafX0nQJ4grFZzTdroMvU772RW-X1oTtoFBjsl_3YYHWnwgqzs
         0aFc3ejjOR mKP4KUM339W3szA28OabR192eRqiyspQ6xPM35NMR-04-FhRJ
         ZEWiF0W5oWjPVtGPjeVjm2DI4YtJg.eyJraWQiOiJVYmtLOFk2aXY0R1poRn
         A2VHgzSVdMV0xmTlhTRXZKY2RUM3pkUjY1WVp4byJ9

Test Vector v1-E-6

Same as v1-E-5, but with a slightly different message.

Key:     70717273 74757677 78797a7b 7c7d7e7f
         80818283 84858687 88898a8b 8c8d8e8f
Nonce:   26f75533 54482a1d 91d47846 27854b8d
         a6b8042a 7966523c 2b404e8d bbe7f7f2
Payload: {"data":"this is a secret message",
         "exp":"2019-01-01T00:00:00+00:00"}
Footer:  {"kid":"UbkK8Y6iv4GZhFp6Tx3IWLWLfNXSEvJcdT3zdR65YZxo"}
Token:   v1.local.IddlRQmpk6ojcD10z1EYdLexXvYiadtY0MrYQaRnq3dnqKIWcbb
         pOcgXdMIkm3_3gksirTj81bvWrWkQwcUHilt-tQo7LZK8I6HCK1V78B9YeEq
         GNeeWXOyWWHoJQIe0d5nTdvcT2vnER6NrJ7xIowvFba6J4qMlFhBnYSxHEq9
         v9NlzcKsz1zscdjcAiXnEuCHyRSc.eyJraWQiOiJVYmtLOFk2aXY0R1poRnA
         2VHgzSVdMV0xmTlhTRXZKY2RUM3pkUjY1WVp4byJ9

v1.public (Public-Key Authentication) Test Vectors

Test Vector v1-S-1

Token:      v1.public.eyJkYXRhIjoidGhpcyBpcyBhIHNpZ25lZCBtZXNzYWdlIiw
            iZXhwIjoiMjAxOS0wMS0wMVQwMDowMDowMCswMDowMCJ9cIZKahKeGM5k
            iAS_4D70Qbz9FIThZpxetJ6n6E6kXP_119SvQcnfCSfY_gG3D0Q2v7FEt
            m2Cmj04lE6YdgiZ0RwA41WuOjXq7zSnmmHK9xOSH6_2yVgt207h1_LphJ
            zVztmZzq05xxhZsV3nFPm2cCu8oPceWy-DBKjALuMZt_Xj6hWFFie96Sf
            Q6i85lOsTX8Kc6SQaG-3CgThrJJ6W9DC-YfQ3lZ4TJUoY3QNYdtEgAvp1
            QuWWK6xmIb8BwvkBPej5t88QUb7NcvZ15VyNw3qemQGn2ITSdpdDgwMtp
            flZOeYdtuxQr1DSGO2aQyZl7s0WYn1IjdQFx6VjSQ4yfw
Public Key: -----BEGIN PUBLIC KEY-----
            MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyaTgTt53ph3p
            5GHgwoGWwz5hRfWXSQA08NCOwe0FEgALWos9GCjNFCd723nCHxBtN1qd
            74MSh/uN88JPIbwxKheDp4kxo4YMN5trPaF0e9G6Bj1N02HnanxFLW+g
            mLbgYO/SZYfWF/M8yLBcu5Y1Ot0ZxDDDXS9wIQTtBE0ne3YbxgZJAZTU
            5XqyQ1DxdzYyC5lF6yBaR5UQtCYTnXAApVRuUI2Sd6L1E2vl9bSBumZ5
            IpNxkRnAwIMjeTJB/0AIELh0mE5vwdihOCbdV6alUyhKC1+1w/FW6HWc
            p/JG1kKC8DPIidZ78Bbqv9YFzkAbNni5eSBOsXVBKG78Zsc8owIDAQAB
            -----END PUBLIC KEY-----
Payload:    {"data":"this is a signed message",
            "exp":"2019-01-01T00:00:00+00:00"}
Footer:

Test Vector v1-S-2

Token:      v1.public.eyJkYXRhIjoidGhpcyBpcyBhIHNpZ25lZCBtZXNzYWdlIiw
            iZXhwIjoiMjAxOS0wMS0wMVQwMDowMDowMCswMDowMCJ9sBTIb0J_4mis
            AuYc4-6P5iR1rQighzktpXhJ8gtrrp2MqSSDkbb8q5WZh3FhUYuW_rg2X
            8aflDlTWKAqJkM3otjYwtmfwfOhRyykxRL2AfmIika_A-_MaLp9F0iw4S
            1JetQQDV8GUHjosd87TZ20lT2JQLhxKjBNJSwWue8ucGhTgJcpOhXcthq
            az7a2yudGyd0layzeWziBhdQpoBR6ryTdtIQX54hP59k3XCIxuYbB9qJM
            pixiPAEKBcjHT74sA-uukug9VgKO7heWHwJL4Rl9ad21xyNwaxAnwAJ7C
            0fN5oGv8Rl0dF11b3tRmsmbDoIokIM0Dba29x_T3YzOyg.eyJraWQiOiJ
            kWWtJU3lseFFlZWNFY0hFTGZ6Rjg4VVpyd2JMb2xOaUNkcHpVSEd3OVVx
            biJ9
Public Key: -----BEGIN PUBLIC KEY-----
            MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyaTgTt53ph3p
            5GHgwoGWwz5hRfWXSQA08NCOwe0FEgALWos9GCjNFCd723nCHxBtN1qd
            74MSh/uN88JPIbwxKheDp4kxo4YMN5trPaF0e9G6Bj1N02HnanxFLW+g
            mLbgYO/SZYfWF/M8yLBcu5Y1Ot0ZxDDDXS9wIQTtBE0ne3YbxgZJAZTU
            5XqyQ1DxdzYyC5lF6yBaR5UQtCYTnXAApVRuUI2Sd6L1E2vl9bSBumZ5
            IpNxkRnAwIMjeTJB/0AIELh0mE5vwdihOCbdV6alUyhKC1+1w/FW6HWc
            p/JG1kKC8DPIidZ78Bbqv9YFzkAbNni5eSBOsXVBKG78Zsc8owIDAQAB
            -----END PUBLIC KEY-----
Payload:    {"data":"this is a signed message",
            "exp":"2019-01-01T00:00:00+00:00"}
Footer:     {"kid":"dYkISylxQeecEcHELfzF88UZrwbLolNiCdpzUHGw9Uqn"}

PASETO v2 Test Vectors

v2.local (Shared-Key Encryption) Test Vectors

Test Vector v2-E-1

Key:     70717273 74757677 78797a7b 7c7d7e7f
         80818283 84858687 88898a8b 8c8d8e8f
Nonce:   00000000 00000000 00000000 00000000
         00000000 00000000
Payload: {"data":"this is a signed message",
         "exp":"2019-01-01T00:00:00+00:00"}
Footer:
Token:   v2.local.97TTOvgwIxNGvV80XKiGZg_kD3tsXM_-qB4dZGHOeN1cTkgQ4Pn
         W8888l802W8d9AvEGnoNBY3BnqHORy8a5cC8aKpbA0En8XELw2yDk2f1sVOD
         yfnDbi6rEGMY3pSfCbLWMM2oHJxvlEl2XbQ

Test Vector v2-E-2

Same as v2-E-1, but with a slightly different message.

Key:     70717273 74757677 78797a7b 7c7d7e7f
         80818283 84858687 88898a8b 8c8d8e8f
Nonce:   00000000 00000000 00000000 00000000
         00000000 00000000
Payload: {"data":"this is a secret message",
         "exp":"2019-01-01T00:00:00+00:00"}
Footer:
Token:   v2.local.CH50H-HM5tzdK4kOmQ8KbIvrzJfjYUGuu5Vy9ARSFHy9owVDMYg
         3-8rwtJZQjN9ABHb2njzFkvpr5cOYuRyt7CRXnHt42L5yZ7siD-4l-FoNsC7
         J2OlvLlIwlG06mzQVunrFNb7Z3_CHM0PK5w

Test Vector v2-E-3

Key:     70717273 74757677 78797a7b 7c7d7e7f
         80818283 84858687 88898a8b 8c8d8e8f
Nonce:   45742c97 6d684ff8 4ebdc0de 59809a97
         cda2f64c 84fda19b
Payload: {"data":"this is a signed message",
         "exp":"2019-01-01T00:00:00+00:00"}
Footer:
Token:   v2.local.5K4SCXNhItIhyNuVIZcwrdtaDKiyF81-eWHScuE0idiVqCo72bb
         jo07W05mqQkhLZdVbxEa5I_u5sgVk1QLkcWEcOSlLHwNpCkvmGGlbCdNExn6
         Qclw3qTKIIl5-O5xRBN076fSDPo5xUCPpBA

Test Vector v2-E-4

Same as v2-E-3, but with a slightly different message.

Key:     70717273 74757677 78797a7b 7c7d7e7f
         80818283 84858687 88898a8b 8c8d8e8f
Nonce:   45742c97 6d684ff8 4ebdc0de 59809a97
         cda2f64c 84fda19b
Payload: {"data":"this is a secret message",
         "exp":"2019-01-01T00:00:00+00:00"}
Footer:
Token:   v2.local.pvFdDeNtXxknVPsbBCZF6MGedVhPm40SneExdClOxa9HNR8wFv7
         cu1cB0B4WxDdT6oUc2toyLR6jA6sc-EUM5ll1EkeY47yYk6q8m1RCpqTIzUr
         Iu3B6h232h62DPbIxtjGvNRAwsLK7LcV8oQ

Test Vector v2-E-5

Key:     70717273 74757677 78797a7b 7c7d7e7f
         80818283 84858687 88898a8b 8c8d8e8f
Nonce:   45742c97 6d684ff8 4ebdc0de 59809a97
         cda2f64c 84fda19b
Payload: {"data":"this is a signed message",
         "exp":"2019-01-01T00:00:00+00:00"}
Footer:  {"kid":"UbkK8Y6iv4GZhFp6Tx3IWLWLfNXSEvJcdT3zdR65YZxo"}
Token:   v2.local.5K4SCXNhItIhyNuVIZcwrdtaDKiyF81-eWHScuE0idiVqCo72bb
         jo07W05mqQkhLZdVbxEa5I_u5sgVk1QLkcWEcOSlLHwNpCkvmGGlbCdNExn6
         Qclw3qTKIIl5-zSLIrxZqOLwcFLYbVK1SrQ.eyJraWQiOiJ6VmhNaVBCUDlm
         UmYyc25FY1Q3Z0ZUaW9lQTlDT2NOeTlEZmdMMVc2MGhhTiJ9

Test Vector v2-E-6

Same as v2-E-5, but with a slightly different message.

Key:     70717273 74757677 78797a7b 7c7d7e7f
         80818283 84858687 88898a8b 8c8d8e8f
Nonce:   45742c97 6d684ff8 4ebdc0de 59809a97
         cda2f64c 84fda19b
Payload: {"data":"this is a secret message",
         "exp":"2019-01-01T00:00:00+00:00"}
Footer:  {"kid":"UbkK8Y6iv4GZhFp6Tx3IWLWLfNXSEvJcdT3zdR65YZxo"}
Token:   v2.local.pvFdDeNtXxknVPsbBCZF6MGedVhPm40SneExdClOxa9HNR8wFv7
         cu1cB0B4WxDdT6oUc2toyLR6jA6sc-EUM5ll1EkeY47yYk6q8m1RCpqTIzUr
         Iu3B6h232h62DnMXKdHn_Smp6L_NfaEnZ-A.eyJraWQiOiJ6VmhNaVBCUDlm
         UmYyc25FY1Q3Z0ZUaW9lQTlDT2NOeTlEZmdMMVc2MGhhTiJ9

v2.public (Public-Key Authentication) Test Vectors

Test Vector v2-S-1

Token:       v2.public.eyJkYXRhIjoidGhpcyBpcyBhIHNpZ25lZCBtZXNzYWdlIi
             wiZXhwIjoiMjAxOS0wMS0wMVQwMDowMDowMCswMDowMCJ9HQr8URrGnt
             Tu7Dz9J2IF23d1M7-9lH9xiqdGyJNvzp4angPW5Esc7C5huy_M8I8_Dj
             JK2ZXC2SUYuOFM-Q_5Cw
Private Key: b4cbfb43 df4ce210 727d953e 4a713307
             fa19bb7d 9f850414 38d9e11b 942a3774
             1eb9dbbb bc047c03 fd70604e 0071f098
             7e16b28b 757225c1 1f00415d 0e20b1a2
Public Key:  1eb9dbbb bc047c03 fd70604e 0071f098
             7e16b28b 757225c1 1f00415d 0e20b1a2
Payload:     {"data":"this is a signed message",
             "exp":"2019-01-01T00:00:00+00:00"}
Footer:

Test Vector v2-S-2

Token:       v2.public.eyJkYXRhIjoidGhpcyBpcyBhIHNpZ25lZCBtZXNzYWdlIi
             wiZXhwIjoiMjAxOS0wMS0wMVQwMDowMDowMCswMDowMCJ9flsZsx_gYC
             R0N_Ec2QxJFFpvQAs7h9HtKwbVK2n1MJ3Rz-hwe8KUqjnd8FAnIJZ601
             tp7lGkguU63oGbomhoBw.eyJraWQiOiJ6VmhNaVBCUDlmUmYyc25FY1Q
             3Z0ZUaW9lQTlDT2NOeTlEZmdMMVc2MGhhTiJ9
Private Key: b4cbfb43 df4ce210 727d953e 4a713307
             fa19bb7d 9f850414 38d9e11b 942a3774
             1eb9dbbb bc047c03 fd70604e 0071f098
             7e16b28b 757225c1 1f00415d 0e20b1a2
Public Key:  1eb9dbbb bc047c03 fd70604e 0071f098
             7e16b28b 757225c1 1f00415d 0e20b1a2
Payload:     {"data":"this is a signed message",
             "exp":"2019-01-01T00:00:00+00:00"}
Footer:      {"kid":"zVhMiPBP9fRf2snEcT7gFTioeA9COcNy9DfgL1W60haN"}

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