static int s_decrypt_ciphertext_for_recipient()

in source/kms.c [2568:2604]

• 32 lines of code
• 4 McCabe index (conditional complexity)

static int s_decrypt_ciphertext_for_recipient(
    struct aws_allocator *allocator,
    struct aws_byte_buf *ciphertext_for_recipient,
    struct aws_rsa_keypair *keypair,
    struct aws_byte_buf *plaintext) {
    AWS_PRECONDITION(aws_allocator_is_valid(allocator));
    AWS_PRECONDITION(aws_byte_buf_is_valid(ciphertext_for_recipient));
    AWS_PRECONDITION(keypair != NULL);

    struct aws_byte_buf encrypted_symm_key, decrypted_symm_key, iv, ciphertext_out;
    int rc = aws_cms_parse_enveloped_data(ciphertext_for_recipient, &encrypted_symm_key, &iv, &ciphertext_out);
    if (rc != AWS_OP_SUCCESS) {
        fprintf(stderr, "Cannot parse CMS enveloped data.\n");
        return AWS_OP_ERR;
    }

    rc = aws_attestation_rsa_decrypt(allocator, keypair, &encrypted_symm_key, &decrypted_symm_key);
    if (rc != AWS_OP_SUCCESS) {
        aws_byte_buf_clean_up(&encrypted_symm_key);
        aws_byte_buf_clean_up(&iv);
        aws_byte_buf_clean_up(&ciphertext_out);
        return rc;
    }

    rc = aws_cms_cipher_decrypt(&ciphertext_out, &decrypted_symm_key, &iv, plaintext);
    if (rc != AWS_OP_SUCCESS) {
        fprintf(stderr, "Cannot decrypt CMS encrypted content\n");
        return rc;
    }

    aws_byte_buf_clean_up(&encrypted_symm_key);
    aws_byte_buf_clean_up(&decrypted_symm_key);
    aws_byte_buf_clean_up(&iv);
    aws_byte_buf_clean_up(&ciphertext_out);

    return rc;
}