elastic/elasticsearch · error · IOException

Malformed PEM file, DSA Key header is missing

Error message

Malformed PEM file, DSA Key header is missing

What it means

Thrown by removeDsaHeaders after locating the DSA PARAMETERS footer: the next line must be '-----BEGIN DSA PRIVATE KEY-----'. If it is null or any other value, the PEM is malformed and parseOpenSslDsa cannot proceed safely. Protects against feeding a mispositioned reader to the DER parser.

Source

Thrown at libs/ssl-config/src/main/java/org/elasticsearch/common/ssl/PemUtils.java:209

     * Removes the DSA Params Headers that OpenSSL adds to DSA private keys as the information in them
     * is redundant
     *
     * @throws IOException if the EC Parameter footer is missing
     */
    private static BufferedReader removeDsaHeaders(BufferedReader bReader) throws IOException {
        String line = bReader.readLine();
        while (line != null) {
            if (OPENSSL_DSA_PARAMS_FOOTER.equals(line.trim())) {
                break;
            }
            line = bReader.readLine();
        }
        if (null == line || OPENSSL_DSA_PARAMS_FOOTER.equals(line.trim()) == false) {
            throw new IOException("Malformed PEM file, DSA Parameters footer is missing");
        }
        // Verify that the key starts with the correct header before passing it to parseOpenSslDsa
        if (OPENSSL_DSA_HEADER.equals(bReader.readLine()) == false) {
            throw new IOException("Malformed PEM file, DSA Key header is missing");
        }
        return bReader;
    }

    /**
     * Creates a {@link PrivateKey} from the contents of {@code bReader} that contains an plaintext private key encoded in
     * PKCS#8
     *
     * @param bReader the {@link BufferedReader} containing the key file contents
     * @return {@link PrivateKey}
     * @throws IOException              if the file can't be read
     * @throws GeneralSecurityException if the private key can't be generated from the {@link PKCS8EncodedKeySpec}
     */
    private static PrivateKey parsePKCS8(BufferedReader bReader) throws IOException, GeneralSecurityException {
        StringBuilder sb = new StringBuilder();
        String line = bReader.readLine();
        while (line != null) {
            if (PKCS8_FOOTER.equals(line.trim())) {

View on GitHub (pinned to db6a809a66)

Solutions

1. Inspect the lines following '-----END DSA PARAMETERS-----' and confirm the next line is '-----BEGIN DSA PRIVATE KEY-----'.
2. Regenerate the DSA key from a fresh parameters file (see error 803).
3. If you only have parameters, generate the corresponding private key with 'openssl gendsa'.

// For a file starting with DSA PARAMETERS, confirm the next BEGIN line after the footer is the DSA PRIVATE KEY header (mirror of the 802 EC helper).

try { PemUtils.readPrivateKey(path, passwordSupplier); }
catch (IOException e) { if (e.getMessage().contains("DSA Key header is missing")) { /* regenerate */ } else throw e; }

When it happens

Trigger: A DSA PARAMETERS block whose footer is immediately followed by something other than a DSA PRIVATE KEY block (EOF, an unrelated PEM block, or a renamed header).

Common situations: Incorrect concatenation of PEM blocks; copy-paste errors; a parameters-only file mistakenly used as a key file; manual editing that swapped or deleted headers.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• Malformed PEM file, DSA Parameters footer is missing
• could not load ssl private key file [{}]
• Error parsing Private Key [{}], file is empty
• cannot read encrypted key [{}] without a password
• cannot read PEM private key [{}] because the file does not c

AI-assisted analysis of elastic/elasticsearch@db6a809a66 (2026-08-12). Data as JSON: /api/errors/620b85ef80aa794d. Report an issue: GitHub.