dp
Registry Context
`dp` contains the first RSA factor's Chinese Remainder Theorem exponent in a private RSA JWK.
Technical Summary
The `dp` parameter contains the Chinese Remainder Theorem exponent of the first RSA factor and is represented as a Base64urlUInt-encoded value.
When Used
JWKs representing RSA private keys.
Normative Requirements
A JWK representing an RSA private key
RFC 7518 - Section 6.3.2
include the `d` parameter.
The parameter "d" is REQUIRED for RSA private keys.
A producer of a JWK representing an RSA private key
RFC 7518 - Section 6.3.2
include all other RSA private-key optimization parameters except `oth`.
Condition: when including `dp` or any other private-key optimization parameter
If the producer includes any of the other private key parameters, then all of the others MUST be present, with the exception of "oth".
RFC 7518 - Section 6.3.2
include `oth` only when more than two prime factors were used.
Condition: when including the `oth` parameter
"oth" ... MUST only be present when more than two prime factors were used.
Producers of JWKs representing RSA private keys
RFC 7518 - Section 6.3.2
include the `dp` parameter.
The others enable optimizations and SHOULD be included by producers of JWKs representing RSA private keys.
Validation Guidance
Verify that `dp` is represented as a Base64urlUInt-encoded value.
If `dp` is present, verify that `d` and all other RSA private-key optimization parameters except `oth` are present.
If `oth` is present, verify that the RSA key uses more than two prime factors.
Reference
Details
- Entry Id
dp- Parameter Name
dp- Parameter Description
First Factor CRT Exponent- Used With Kty Value
RSA- Parameter Information Class
Private- Change Controller
IESG- Reference
RFC7518 - Section 6.3.2.4