如何用Java实现Microsoft Azure key vault的sha-1？

Question

我需要用Java实现一个带有Key Vault的符号，使用Sha1算法，但不被支持，如何实现呢，我尝试用bouncy castle做了de digest并用RSNULL算法使用Key Vault客户端，但结果是不正确的。

    String stringToSign = "holamund";
    byte[] digestSha1Bytes = DigestUtils.sha1(stringToSign.getBytes());
    keyOperationResult = keyVaultClient.sign("AZURE_URL_KEY",   JsonWebKeySignatureAlgorithm.RSNULL, digestSha1Bytes);

产生的输出:IOGXIIIZ5ZYM2M7OZZ/ET8UOWWTWMKESEJVVS9W9CPHZ11WKFZ/IKGX2SJ4ADHCN32QCDBOSV/KNATVPYW+EXKVX/3NRAMXUIUUUGHQF4/MUU7Y2644IWUECXQP8O1IXL8Mn7SCEB5SH0SNARK77DVFRK7A0UNZR/82WPFXMJXYYEH8K/CIFRHK/MWX6SZE+1RM6VDMKAODYRQR1LSUSSS0WZOIUVDTXNKYL55MATS5CLPWIPBHU+H4YAO1+B+NFVKJEEDDGBJHVMMO1EO/KT7HSHREOUKYR2MWKXKLZCZA3DWRP3PSI9RDIRPOC/IVFIOCWCYK44XFX0UKVHDZHZ4W==

预期输出:PhoyaoTuoTelMTBFGRPG12TJP0JDJQY1GSDMR63S8L8HMB4LSIRMALXSVRM5D2ED2D6PMDMXVA+OJUW/PXZX5RM5B3SEIIXDE5JLOOKOOC2PBKIGJI5SF7+YCSOWCSGTDXMWKTQDBCZWERHW1HS5HNJW/UBKBIMDF0RT478JXEPH9AYEHOFJANLLI5/OHZDUPS8PX9QZQIR/KYRWK32Z14DUGPCTYET5TTY7LYU4KSTEYCWEA5BOONAZAN8ENT41 S564CCPR2ZDYIRZCNNWLTQXD7InNPUFWP+RVLZHLYP3Y+IIYIU6EYJURDOTUHHZTP+MEQSD/IMTGE43FWB6W==

我试着用不同的API（如bouncy castle、java native等）做了消化，但没有用key vault符号来做正确的约定。

Answer 1

在Azure Key Vault中，rsnull算法提供了一个原始的rsa签名。为了使用原始RSA签名算法生成标准SHA1签名，您必须首先将摘要包装到要签名的ASN.1 DigestInfo结构中。以下示例显示：

import java.io.IOException;
import java.security.KeyPair;
import java.security.MessageDigest;
import java.security.Signature;
import com.microsoft.azure.keyvault.KeyVaultClient;
import com.microsoft.azure.keyvault.models.KeyBundle;
import com.microsoft.azure.keyvault.models.KeyOperationResult;
import com.microsoft.azure.keyvault.webkey.JsonWebKey;
import com.microsoft.azure.keyvault.webkey.JsonWebKeySignatureAlgorithm;

...

/**
 * @param keyVaultClient An instance of Key Vault client.
 * @param keyIdentifer The Key Identifier. This is the kid field of JsonWebKey structure.
 * @param message The message to be signed.
 */
void sampleSHA1SignatureWithAzureKeyVault(KeyVaultClient keyVaultClient, String keyIdentifer, byte[] message) throws Throwable {

    /////////////////////////////////////////
    // Signs message using Azure Key Vault //
    /////////////////////////////////////////

    // Compute SHA1 hash:
    MessageDigest md = MessageDigest.getInstance("SHA1");
    md.update(message);
    byte[] digest = md.digest();

    // Convert SHA1 digest into ASN.1:
    byte[] digestInfo = getDigestInfoForSHA1Digest(digest);

    // Call Azure Key Vault to perform the signature using the server key.
    // Note that we are passing the DigestInfo to RSNULL, instead of SHA1 digest.
    KeyOperationResult result = keyVaultClient.sign(keyIdentifer, JsonWebKeySignatureAlgorithm.RSNULL, digestInfo);
    byte[] signature = result.result();

    /////////////////////////////////////////////////////////
    // Verifies the signature locally, using java.security //
    /////////////////////////////////////////////////////////

    // Read the public key from Azure Key Vault
    KeyBundle keyBundle = keyVaultClient.getKey(keyIdentifer);

    // Initialize java.security instances with the Public Key and message.
    KeyPair kp = keyBundle.key().toRSA(false);
    Signature signImpl = Signature.getInstance("SHA1withRSA");
    signImpl.initVerify(kp.getPublic());
    signImpl.update(message);

    // Verify the signature.
    if (signImpl.verify(signature))
        System.out.println("Signature was verified.");
    else
        System.out.println("Signature verification failed.");
}

byte[] getDigestInfoForSHA1Digest(byte[] digest) {

    // Constructs an ASN.1 DigestInfo structure for the caller-specified SHA1 hash.

    // ASN.1 data:
    byte[] digestInfo = new byte[] { //
            0x30, 0x21, // SEQUENCE DigestInfo (33 bytes) (13 of header + 20 of SHA1 digest)
            0x30, 0x09, // SEQUENCE AlgorithmIdentifier (9 bytes)
            0x06, 0x05, // OBJECT IDENTIFIER algorithm (5 bytes)
            0x2b, 0x0e, 0x03, 0x02, 0x1a, // OID of SHA1 (1.3.14.3.2.26)
            0x05, 0x00, // NUL algorithm parameters (05 00 is the DER encoding for NUL)
            0x04, 0x14, // OCTET STRING digest (20 bytes)
            00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00 // SHA1, copied below
    };

    System.arraycopy(digest, 0, digestInfo, 15, digest.length);

    return digestInfo;
}