// Get signature.
	newSignature := getSignature(signingKey, formValues.Get("Policy"))

	// Verify signature.
	if !compareSignatureV4(newSignature, formValues.Get(xhttp.AmzSignature)) {
		return cred, ErrSignatureDoesNotMatch
	}

	// Success.
	return cred, ErrNone
}

// doesPresignedSignatureMatch - Verify query headers with presigned signature

	signature := calculateSignatureV2(stringToSign, cred.SecretKey)
	return signature
}

// compareSignatureV2 returns true if and only if both signatures
// are equal. The signatures are expected to be base64 encoded strings
// according to the AWS S3 signature V2 spec.
func compareSignatureV2(sig1, sig2 string) bool {
	// Decode signature string to binary byte-sequence representation is required

			return n, cr.err
		}
	}

	// Now, we read the signature of the following payload and expect:
	//   chunk-signature=" + <signature-as-hex> + "\r\n"
	//
	// The signature is 64 bytes long (hex-encoded SHA256 hash) and
	// starts with a 16 byte header: len("chunk-signature=") + 64 == 80.
	var signature [80]byte
	_, err = io.ReadFull(cr.reader, signature[:])
	if err == io.EOF {
		err = io.ErrUnexpectedEOF
	}

			},
			expected: ErrInvalidAccessKeyID,
		},
		// (2) It should fail with a bad signature.
		{
			form: http.Header{
				"X-Amz-Credential": []string{fmt.Sprintf(credentialTemplate, accessKey, now.Format(yyyymmdd), globalMinioDefaultRegion)},
				"X-Amz-Date":       []string{now.Format(iso8601Format)},
				"X-Amz-Signature":  []string{"invalidsignature"},
				"Policy":           []string{"policy"},
			},

	if aec != ErrNone {
		return psv, aec
	}

	// Save signature.
	preSignV4Values.Signature, aec = parseSignature("Signature=" + query.Get(xhttp.AmzSignature))
	if aec != ErrNone {
		return psv, aec
	}

	// Return structured form of signature query string.
	return preSignV4Values, ErrNone
}

// Parses signature version '4' header of the following form.
//

			extractedSignedHeaders[http.CanonicalHeaderKey(header)] = r.TransferEncoding
		case "content-length":
			// Signature-V4 spec excludes Content-Length from signed headers list for signature calculation.
			// But some clients deviate from this rule. Hence we consider Content-Length for signature
			// calculation to be compatible with such clients.
			extractedSignedHeaders.Set(header, strconv.FormatInt(r.ContentLength, 10))

			// validating the extraction/parsing of signature field.
			if !compareSignatureV4(testCase.expectedAuthField.Signature, parsedAuthField.Signature) {
				t.Errorf("Test %d: Parsed Signature field mismatch: Expected \"%s\", got \"%s\"", i+1, testCase.expectedAuthField.Signature, parsedAuthField.Signature)
			}

			// validating the extracted signed headers.

		{"X-Amz-Content-Sha256", unsignedPayload, "X-Amz-Credential", "", true},

		// Test case - 4.
		// Enabling PreSigned Signature v4, but X-Amz-Content-Sha256 not set has to be skipped.
		{"", "", "X-Amz-Credential", "", true},

		// Test case - 5.
		// Enabling PreSigned Signature v4, but X-Amz-Content-Sha256 set and its not UNSIGNED-PAYLOAD, we shouldn't skip.

  val extensions: List<Extension>,
) {
  /**
   * Returns the standard name of this certificate's signature algorithm as specified by
   * [Signature.getInstance]. Typical values are like "SHA256WithRSA".
   */
  val signatureAlgorithmName: String
    get() {
      return when (signature.algorithm) {
        ObjectIdentifiers.SHA256_WITH_RSA_ENCRYPTION -> "SHA256WithRSA"

    } else {
      // Everything else requires Android API 21+.
      signature(rootProject.libs.signature.android.apilevel21) { artifact { type = "signature" } }
    }

    // OkHttp requires Java 8+.
    signature(rootProject.libs.codehaus.signature.java18) { artifact { type = "signature" } }
  }

  tasks.withType<KotlinCompile> {
    kotlinOptions {
      jvmTarget = JavaVersion.VERSION_1_8.toString()