# Warning: openssl_private_decrypt(): key parameter is not a valid private key in /var/www/app/src/Crypto/Decryptor.php on line 34

- **ID:** `php/openssl-invalid-key-format`
- **Domain:** php
- **Category:** runtime_error
- **Verification:** ai_generated
- **Fix Rate:** 82%

## Root Cause

The private key provided to openssl_private_decrypt() is malformed, missing header/footer, or in an unsupported format (e.g., PKCS#1 instead of PKCS#8).

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| PHP 8.1 | active | — | — |
| PHP 8.2 | active | — | — |
| PHP 8.3 | active | — | — |
| OpenSSL 1.1.1 | active | — | — |
| OpenSSL 3.0 | active | — | — |

## Workarounds

1. **Convert the private key from PKCS#1 to PKCS#8 format using OpenSSL command: `openssl pkcs8 -topk8 -inform PEM -outform PEM -in private.pem -out private_pkcs8.pem -nocrypt`** (85% success)
   ```
   Convert the private key from PKCS#1 to PKCS#8 format using OpenSSL command: `openssl pkcs8 -topk8 -inform PEM -outform PEM -in private.pem -out private_pkcs8.pem -nocrypt`
   ```
2. **Ensure the key string includes the correct header and footer (e.g., '-----BEGIN PRIVATE KEY-----' and '-----END PRIVATE KEY-----') and no extra whitespace or line breaks.** (75% success)
   ```
   Ensure the key string includes the correct header and footer (e.g., '-----BEGIN PRIVATE KEY-----' and '-----END PRIVATE KEY-----') and no extra whitespace or line breaks.
   ```
3. **Use `openssl_pkey_get_private()` to validate the key before passing it to decryption functions; if it returns false, log the OpenSSL error with `openssl_error_string()`.** (90% success)
   ```
   Use `openssl_pkey_get_private()` to validate the key before passing it to decryption functions; if it returns false, log the OpenSSL error with `openssl_error_string()`.
   ```

## Dead Ends

- **** — The extension is already installed and functional; the error is about key content, not extension availability. (70% fail)
- **** — Memory and time settings do not affect key parsing logic. (90% fail)
- **** — The error occurs after the key is loaded; permissions affect file reading, not key validation. (80% fail)