openssl public key der to pem

To convert an OpenSSL public key in DER format to PEM format in Assembly language, you can use the following steps:

1. Load the DER-encoded public key into a memory buffer.
2. Initialize the OpenSSL library.
3. Create an EVP_PKEY structure to hold the public key.
4. Use the d2i_PUBKEY function to convert the DER-encoded key to an EVP_PKEY structure.
5. Create a memory BIO (BIO_s_mem) to hold the PEM-encoded key.
6. Use the PEM_write_bio_PUBKEY function to write the PEM-encoded key to the memory BIO.
7. Retrieve the PEM-encoded key from the memory BIO.
8. Clean up and free any allocated resources.

Please note that Assembly language is not commonly used for OpenSSL operations, and it may be more practical to perform this conversion in a higher-level language like C or Python.

Note: The above steps are provided as a general guideline. For specific implementation details and code examples, it is recommended to refer to the OpenSSL documentation and relevant programming resources.