Method: privatekeysign
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Unwraps a wrapped private key and then signs the digest provided by the client.
HTTP request
POST https://KACLS_URL/privatekeysign
Replace KACLS_URL with the Key Access Control List
Service (KACLS) URL.
Path parameters
None.
Request body
The request body contains data with the following structure:
| JSON representation |
{
"authentication": string,
"authorization": string,
"algorithm": string,
"digest": string,
"rsa_pss_salt_length": integer,
"reason": string,
"wrapped_private_key": string
}
|
| Fields |
authentication |
string
A JWT issued by the identity provider (IdP) asserting who the user is. See authentication tokens.
|
authorization |
string
A JWT asserting that the user is allowed to unwrap a key for resource_name. See authorization tokens.
|
algorithm |
string
The algorithm that was used to encrypt the Data Encryption Key (DEK) in envelope encryption.
|
digest |
string
Base64-encoded message digest. The digest of the DER encoded SignedAttributes. This value is unpadded. Max size: 128B
|
rsa_pss_salt_length |
integer
(Optional) The salt length to use, if the signature algorithm is RSASSA-PSS. If the signature algorithm is not RSASSA-PSS, this field is ignored.
|
reason |
string (UTF-8)
A passthrough JSON string providing additional context about the operation. The JSON provided should be sanitized before being displayed. Max size: 1 KB.
|
wrapped_private_key |
string
The base64-encoded wrapped private key. Max size: 8 KB.
The format of the private key or the wrapped private key is up to the Key Access Control List Service (KACLS) implementation. On the client and on the Gmail side, this is treated as an opaque blob.
|
Response body
If successful, this method returns a base64-encoded signature.
If the operation fails, a
structured error reply
is returned.
| JSON representation |
{
"signature": string
}
|
| Fields |
signature |
string
A base64-encoded signature.
|
Example
This example provides a sample request and response for the privatekeysign
method.
Request
{
"wrapped_private_key": "wHrlNOTI9mU6PBdqiq7EQA...",
"digest": "EOBc7nc+7JdIDeb0DVTHriBAbo/dfHFZJgeUhOyo67o=",
"authorization": "eyJhbGciOi...",
"authentication": "eyJhbGciOi...",
"algorithm": "SHA256withRSA",
"reason": "sign"
}
Response
{
"signature": "LpyCSy5ddy82PIp/87JKaMF4Jmt1KdrbfT1iqpB7uhVd3OwZiu+oq8kxIzB7Lr0iX4aOcxM6HiUyMrGP2PG8x0HkpykbUKQxBVcfm6SLdsqigT9ho5RYw20M6ZXNWVRetFSleKex4SRilTRny38e2ju/lUy0KDaCt1hDUT89nLZ1wsO3D1F3xk8J7clXv5fe7GPRd1ojo82Ny0iyVO7y7h1lh2PACHUFXOMzsdURYFCnxhKAsadccCxpCxKh5x8p78PdoenwY1tnT3/X4O/4LAGfT4fo98Frxy/xtI49WDRNZi6fsL6BQT4vS/WFkybBX9tXaenCqlRBDyZSFhatPQ=="
}
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Last updated 2025-08-04 UTC.
[null,null,["Last updated 2025-08-04 UTC."],[[["\u003cp\u003eUnwraps a wrapped private key and uses it to sign a provided digest.\u003c/p\u003e\n"],["\u003cp\u003eRequires authentication and authorization tokens for security.\u003c/p\u003e\n"],["\u003cp\u003eAccepts the signing algorithm, digest, salt length (for RSASSA-PSS), reason, and the wrapped private key in the request body.\u003c/p\u003e\n"],["\u003cp\u003eReturns a base64-encoded signature upon successful operation.\u003c/p\u003e\n"],["\u003cp\u003eProvides a structured error reply if the operation fails.\u003c/p\u003e\n"]]],["The `privatekeysign` method unwraps a private key and signs a client-provided digest. It requires a POST request to the `/privatekeysign` endpoint with a JSON body. The body includes `authentication`, `authorization`, `algorithm`, `digest`, `rsa_pss_salt_length` (optional), `reason`, and the `wrapped_private_key`. Upon success, a JSON response containing a base64-encoded `signature` is returned; otherwise, a structured error reply is returned.\n"],null,["# Method: privatekeysign\n\nUnwraps a wrapped private key and then signs the digest provided by the client.\n\n### HTTP request\n\n`POST https://`\u003cvar translate=\"no\"\u003eKACLS_URL\u003c/var\u003e`/privatekeysign`\n\nReplace \u003cvar translate=\"no\"\u003eKACLS_URL\u003c/var\u003e with the Key Access Control List\nService (KACLS) URL.\n\n### Path parameters\n\nNone.\n\n### Request body\n\nThe request body contains data with the following structure:\n\n| JSON representation ||\n|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|\n| ``` { \"authentication\": string, \"authorization\": string, \"algorithm\": string, \"digest\": string, \"rsa_pss_salt_length\": integer, \"reason\": string, \"wrapped_private_key\": string } ``` |\n\n| Fields ||\n|-----------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `authentication` | `string` A JWT issued by the identity provider (IdP) asserting who the user is. See [authentication tokens](/workspace/cse/reference/authentication-tokens). |\n| `authorization` | `string` A JWT asserting that the user is allowed to unwrap a key for `resource_name`. See [authorization tokens](/workspace/cse/reference/authorization-tokens). |\n| `algorithm` | `string` The algorithm that was used to encrypt the Data Encryption Key (DEK) in envelope encryption. |\n| `digest` | `string` Base64-encoded message digest. The digest of the DER encoded `SignedAttributes`. This value is unpadded. Max size: 128B |\n| `rsa_pss_salt_length` | `integer` (Optional) The salt length to use, if the signature algorithm is RSASSA-PSS. If the signature algorithm is not RSASSA-PSS, this field is ignored. |\n| `reason` | `string (UTF-8)` A passthrough JSON string providing additional context about the operation. The JSON provided should be sanitized before being displayed. Max size: 1 KB. |\n| `wrapped_private_key` | `string` The base64-encoded wrapped private key. Max size: 8 KB. The format of the private key or the wrapped private key is up to the Key Access Control List Service (KACLS) implementation. On the client and on the Gmail side, this is treated as an opaque blob. |\n\n### Response body\n\nIf successful, this method returns a base64-encoded signature.\n\nIf the operation fails, a\n[structured error reply](/workspace/cse/reference/structured-errors)\nis returned.\n\n| JSON representation ||\n|---------------------------------|---|\n| ``` { \"signature\": string } ``` |\n\n| Fields ||\n|-------------|--------------------------------------|\n| `signature` | `string` A base64-encoded signature. |\n\n### Example\n\nThis example provides a sample request and response for the `privatekeysign`\nmethod.\n\n#### Request\n\n {\n \"wrapped_private_key\": \"wHrlNOTI9mU6PBdqiq7EQA...\",\n \"digest\": \"EOBc7nc+7JdIDeb0DVTHriBAbo/dfHFZJgeUhOyo67o=\",\n \"authorization\": \"eyJhbGciOi...\",\n \"authentication\": \"eyJhbGciOi...\",\n \"algorithm\": \"SHA256withRSA\",\n \"reason\": \"sign\"\n }\n\n#### Response\n\n {\n \"signature\": \"LpyCSy5ddy82PIp/87JKaMF4Jmt1KdrbfT1iqpB7uhVd3OwZiu+oq8kxIzB7Lr0iX4aOcxM6HiUyMrGP2PG8x0HkpykbUKQxBVcfm6SLdsqigT9ho5RYw20M6ZXNWVRetFSleKex4SRilTRny38e2ju/lUy0KDaCt1hDUT89nLZ1wsO3D1F3xk8J7clXv5fe7GPRd1ojo82Ny0iyVO7y7h1lh2PACHUFXOMzsdURYFCnxhKAsadccCxpCxKh5x8p78PdoenwY1tnT3/X4O/4LAGfT4fo98Frxy/xtI49WDRNZi6fsL6BQT4vS/WFkybBX9tXaenCqlRBDyZSFhatPQ==\"\n }"]]
