---
title: "Unwraps a symmetric key using the specified key that was initially used for wrapping that key."
method: POST
path: "/keys/{key-name}/{key-version}/unwrapkey"
---

# Unwraps a symmetric key using the specified key that was initially used for wrapping that key.

`POST /keys/{key-name}/{key-version}/unwrapkey`

The UNWRAP operation supports decryption of a symmetric key using the target key encryption key. This operation is the reverse of the WRAP operation. The UNWRAP operation applies to asymmetric and symmetric keys stored in Azure Key Vault since it uses the private portion of the key. This operation requires the keys/unwrapKey permission.

## Path parameters

- `key-name` string, required
- `key-version` string, required

## Query parameters

- `api-version` string, required

## Request body

- KeyOperationsParameters — The key operations parameters.
  - `alg` 'RSA-OAEP' | 'RSA-OAEP-256' | 'RSA1_5' | 'A128GCM' | 'A192GCM' | 'A256GCM' | 'A128KW' | 'A192KW' | 'A256KW' | 'A128CBC' | 'A192CBC' | 'A256CBC' | 'A128CBCPAD' | 'A192CBCPAD' | 'A256CBCPAD' | 'CKM_AES_KEY_WRAP' | 'CKM_AES_KEY_WRAP_PAD', required — An algorithm used for encryption and decryption.
  - `value` string, base64url, required — The value to operate on.
  - `iv` string, base64url — Cryptographically random, non-repeating initialization vector for symmetric algorithms.
  - `aad` string, base64url — Additional data to authenticate but not encrypt/decrypt when using authenticated crypto algorithms.
  - `tag` string, base64url — The tag to authenticate when performing decryption with an authenticated algorithm.

## Response `200`

The request has succeeded.

- KeyOperationResult — The key operation result.
  - `kid` string — Key identifier
  - `value` string, base64url — The result of the operation.
  - `iv` string, base64url — Cryptographically random, non-repeating initialization vector for symmetric algorithms.
  - `tag` string, base64url — The tag to authenticate when performing decryption with an authenticated algorithm.
  - `aad` string, base64url — Additional data to authenticate but not encrypt/decrypt when using authenticated crypto algorithms.

## Other responses

- `default` — An unexpected error response.

---

[API](https://skmtc.net/azure/apis/keyvault-keys.md) · [All operations](https://skmtc.net/azure/apis/keyvault-keys/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/azure/keyvault-keys/versions/7bedded21050/schema)