azure-security-keyvault-keys-java

Azure Key Vault 密钥（Java）

管理加密密钥，并在 Azure Key Vault 和 Managed HSM 中执行加密操作。

安装

<dependency>
    <groupId>com.azure</groupId>
    <artifactId>azure-security-keyvault-keys</artifactId>
    <version>4.9.0</version>
</dependency>

创建客户端

import com.azure.security.keyvault.keys.KeyClient;
import com.azure.security.keyvault.keys.KeyClientBuilder;
import com.azure.security.keyvault.keys.cryptography.CryptographyClient;
import com.azure.security.keyvault.keys.cryptography.CryptographyClientBuilder;
import com.azure.identity.DefaultAzureCredentialBuilder;

// Key management client
KeyClient keyClient = new KeyClientBuilder()
    .vaultUrl("https://<vault-name>.vault.azure.net")
    .credential(new DefaultAzureCredentialBuilder().build())
    .buildClient();

// Async client
KeyAsyncClient keyAsyncClient = new KeyClientBuilder()
    .vaultUrl("https://<vault-name>.vault.azure.net")
    .credential(new DefaultAzureCredentialBuilder().build())
    .buildAsyncClient();

// Cryptography client (for encrypt/decrypt/sign/verify)
CryptographyClient cryptoClient = new CryptographyClientBuilder()
    .keyIdentifier("https://<vault-name>.vault.azure.net/keys/<key-name>/<key-version>")
    .credential(new DefaultAzureCredentialBuilder().build())
    .buildClient();

密钥类型

类型	描述
RSA	RSA 密钥（2048、3072、4096 位）
RSA_HSM	HSM 中的 RSA 密钥
EC	椭圆曲线密钥
EC_HSM	HSM 中的椭圆曲线密钥
OCT	对称密钥（仅限 Managed HSM）
OCT_HSM	HSM 中的对称密钥

创建密钥

创建 RSA 密钥

import com.azure.security.keyvault.keys.models.*;

// Simple RSA key
KeyVaultKey rsaKey = keyClient.createRsaKey(new CreateRsaKeyOptions("my-rsa-key")
    .setKeySize(2048));

System.out.println("Key name: " + rsaKey.getName());
System.out.println("Key ID: " + rsaKey.getId());
System.out.println("Key type: " + rsaKey.getKeyType());

// RSA key with options
KeyVaultKey rsaKeyWithOptions = keyClient.createRsaKey(new CreateRsaKeyOptions("my-rsa-key-2")
    .setKeySize(4096)
    .setExpiresOn(OffsetDateTime.now().plusYears(1))
    .setNotBefore(OffsetDateTime.now())
    .setEnabled(true)
    .setKeyOperations(KeyOperation.ENCRYPT, KeyOperation.DECRYPT, 
                       KeyOperation.WRAP_KEY, KeyOperation.UNWRAP_KEY)
    .setTags(Map.of("environment", "production")));

// HSM-backed RSA key
KeyVaultKey hsmKey = keyClient.createRsaKey(new CreateRsaKeyOptions("my-hsm-key")
    .setKeySize(2048)
    .setHardwareProtected(true));

创建 EC 密钥

// EC key with P-256 curve
KeyVaultKey ecKey = keyClient.createEcKey(new CreateEcKeyOptions("my-ec-key")
    .setCurveName(KeyCurveName.P_256));

// EC key with other curves
KeyVaultKey ecKey384 = keyClient.createEcKey(new CreateEcKeyOptions("my-ec-key-384")
    .setCurveName(KeyCurveName.P_384));

KeyVaultKey ecKey521 = keyClient.createEcKey(new CreateEcKeyOptions("my-ec-key-521")
    .setCurveName(KeyCurveName.P_521));

// HSM-backed EC key
KeyVaultKey ecHsmKey = keyClient.createEcKey(new CreateEcKeyOptions("my-ec-hsm-key")
    .setCurveName(KeyCurveName.P_256)
    .setHardwareProtected(true));

创建对称密钥（仅限 Managed HSM）

KeyVaultKey octKey = keyClient.createOctKey(new CreateOctKeyOptions("my-symmetric-key")
    .setKeySize(256)
    .setHardwareProtected(true));

获取密钥

// Get latest version
KeyVaultKey key = keyClient.getKey("my-key");

// Get specific version
KeyVaultKey keyVersion = keyClient.getKey("my-key", "<version-id>");

// Get only key properties (no key material)
KeyProperties keyProps = keyClient.getKey("my-key").getProperties();

更新密钥属性

KeyVaultKey key = keyClient.getKey("my-key");

// Update properties
key.getProperties()
    .setEnabled(false)
    .setExpiresOn(OffsetDateTime.now().plusMonths(6))
    .setTags(Map.of("status", "archived"));

KeyVaultKey updatedKey = keyClient.updateKeyProperties(key.getProperties(),
    KeyOperation.ENCRYPT, KeyOperation.DECRYPT);

列出密钥

import com.azure.core.util.paging.PagedIterable;

// List all keys
for (KeyProperties keyProps : keyClient.listPropertiesOfKeys()) {
    System.out.println("Key: " + keyProps.getName());
    System.out.println("  Enabled: " + keyProps.isEnabled());
    System.out.println("  Created: " + keyProps.getCreatedOn());
}

// List key versions
for (KeyProperties version : keyClient.listPropertiesOfKeyVersions("my-key")) {
    System.out.println("Version: " + version.getVersion());
    System.out.println("Created: " + version.getCreatedOn());
}

删除密钥

import com.azure.core.util.polling.SyncPoller;

// Begin delete (soft-delete enabled vaults)
SyncPoller<DeletedKey, Void> deletePoller = keyClient.beginDeleteKey("my-key");

// Wait for deletion
DeletedKey deletedKey = deletePoller.poll().getValue();
System.out.println("Deleted: " + deletedKey.getDeletedOn());

deletePoller.waitForCompletion();

// Recovery is an ALTERNATIVE to purge: a purged key cannot be recovered.
// Purge requires separate explicit authorization and may be blocked by purge protection.

// Recover the soft-deleted key
SyncPoller<KeyVaultKey, Void> recoverPoller = keyClient.beginRecoverDeletedKey("my-key");
recoverPoller.waitForCompletion();

加密操作

请先确认保管库／租户、密钥操作和资源授权。禁用、删除或清除等破坏性操作可能导致依赖数据无法访问；执行写入前，请盘点使用方并确认恢复方案。密钥轮换后，后续解密／验证时请使用返回的带版本密钥 ID 以及密文／签名。切勿记录已解密的生产明文或导入的私钥组件。备份 Blob 属于敏感的加密材料，且恢复受限，并非通用导出内容：请将其写入经批准的私有存储，且不要覆盖现有备份。请固定 Java SDK 版本，并确认所选保管库／HSM 和算法支持相应方法。

加密／解密

import com.azure.security.keyvault.keys.cryptography.models.*;

CryptographyClient cryptoClient = new CryptographyClientBuilder()
    .keyIdentifier("https://<vault>.vault.azure.net/keys/<key-name>")
    .credential(new DefaultAzureCredentialBuilder().build())
    .buildClient();

byte[] plaintext = "Hello, World!".getBytes(StandardCharsets.UTF_8);

// Encrypt
EncryptResult encryptResult = cryptoClient.encrypt(EncryptionAlgorithm.RSA_OAEP, plaintext);
byte[] ciphertext = encryptResult.getCipherText();
System.out.println("Ciphertext length: " + ciphertext.length);

// Decrypt
DecryptResult decryptResult = cryptoClient.decrypt(EncryptionAlgorithm.RSA_OAEP, ciphertext);
String decrypted = new String(decryptResult.getPlainText(), StandardCharsets.UTF_8);
System.out.println("Decrypted: " + decrypted);

签名／验证

import java.security.MessageDigest;

// Create digest of data
byte[] data = "Data to sign".getBytes(StandardCharsets.UTF_8);
MessageDigest md = MessageDigest.getInstance("SHA-256");
byte[] digest = md.digest(data);

// Sign
SignResult signResult = cryptoClient.sign(SignatureAlgorithm.RS256, digest);
byte[] signature = signResult.getSignature();

// Verify
VerifyResult verifyResult = cryptoClient.verify(SignatureAlgorithm.RS256, digest, signature);
System.out.println("Valid signature: " + verifyResult.isValid());

包装／解包密钥

// Key to wrap (e.g., AES key)
byte[] keyToWrap = new byte[32];  // 256-bit key
new SecureRandom().nextBytes(keyToWrap);

// Wrap
WrapResult wrapResult = cryptoClient.wrapKey(KeyWrapAlgorithm.RSA_OAEP, keyToWrap);
byte[] wrappedKey = wrapResult.getEncryptedKey();

// Unwrap
UnwrapResult unwrapResult = cryptoClient.unwrapKey(KeyWrapAlgorithm.RSA_OAEP, wrappedKey);
byte[] unwrappedKey = unwrapResult.getKey();

备份与恢复

// Backup
byte[] backup = keyClient.backupKey("my-key");

// Save backup to file
Files.write(Paths.get("key-backup.blob"), backup);

// Restore
byte[] backupData = Files.readAllBytes(Paths.get("key-backup.blob"));
KeyVaultKey restoredKey = keyClient.restoreKeyBackup(backupData);

密钥轮换

// Rotate to new version
KeyVaultKey rotatedKey = keyClient.rotateKey("my-key");
System.out.println("New version: " + rotatedKey.getProperties().getVersion());

// Set rotation policy
KeyRotationPolicy policy = new KeyRotationPolicy()
    .setExpiresIn("P90D")  // Expire after 90 days
    .setLifetimeActions(Arrays.asList(
        new KeyRotationLifetimeAction(KeyRotationPolicyAction.ROTATE)
            .setTimeBeforeExpiry("P30D")));  // Rotate 30 days before expiry

keyClient.updateKeyRotationPolicy("my-key", policy);

// Get rotation policy
KeyRotationPolicy currentPolicy = keyClient.getKeyRotationPolicy("my-key");

导入密钥

import com.azure.security.keyvault.keys.models.ImportKeyOptions;
import com.azure.security.keyvault.keys.models.JsonWebKey;

// Import existing key material
JsonWebKey jsonWebKey = new JsonWebKey()
    .setKeyType(KeyType.RSA)
    .setN(modulus)
    .setE(exponent)
    .setD(privateExponent)
    // ... other RSA components
    ;

ImportKeyOptions importOptions = new ImportKeyOptions("imported-key", jsonWebKey)
    .setHardwareProtected(false);

KeyVaultKey importedKey = keyClient.importKey(importOptions);

加密算法

算法	密钥类型	描述
RSA1_5	RSA	RSAES-PKCS1-v1_5
RSA_OAEP	RSA	使用 OAEP 的 RSAES（推荐）
RSA_OAEP_256	RSA	使用 SHA-256 和 OAEP 的 RSAES
A128GCM	OCT	128 位 AES-GCM
A256GCM	OCT	256 位 AES-GCM
A128CBC	OCT	128 位 AES-CBC
A256CBC	OCT	256 位 AES-CBC

签名算法

算法	密钥类型	哈希
RS256	RSA	SHA-256
RS384	RSA	SHA-384
RS512	RSA	SHA-512
PS256	RSA	SHA-256（PSS）
ES256	EC P-256	SHA-256
ES384	EC P-384	SHA-384
ES512	EC P-521	SHA-512

错误处理

import com.azure.core.exception.HttpResponseException;
import com.azure.core.exception.ResourceNotFoundException;

try {
    KeyVaultKey key = keyClient.getKey("non-existent-key");
} catch (ResourceNotFoundException e) {
    System.out.println("Key not found: " + e.getMessage());
} catch (HttpResponseException e) {
    System.out.println("HTTP error " + e.getResponse().getStatusCode());
    System.out.println("Message: " + e.getMessage());
}

环境变量

AZURE_KEYVAULT_URL=https://<vault-name>.vault.azure.net

最佳实践

1. 生产环境使用 HSM 密钥 - 对敏感密钥设置 setHardwareProtected(true)
2. 启用软删除 - 防止意外删除
3. 密钥轮换 - 设置自动轮换策略
4. 最小权限 - 为不同操作使用单独的密钥
5. 尽可能在本地执行加密 - 使用 CryptographyClient 和本地密钥材料，减少往返调用

触发短语

• “Key Vault keys Java”、“cryptographic keys Java”
• “encrypt decrypt Java”、“sign verify Java”
• “RSA key”、“EC key”、“HSM key”
• “key rotation”、“wrap unwrap key”

适用场景

当需要执行概述中所述的工作流或操作时，可使用此技能。

限制

• 仅当任务与上述描述的范围明确匹配时，才使用此技能。
• 不要将输出视为环境特定验证、测试或专家审查的替代品。
• 如果缺少必要的输入、权限、安全边界或成功标准，请暂停并请求澄清。