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PHP openssl_pkey_get_details() Function: Usage and Examples

Returns information about an asymmetric key including its type, public component and key length.

1 views Published Oct 17, 2026 Updated Oct 17, 2026 Know-Stuff

Returns information about an asymmetric key including its type, public component and key length.

Before using it, identify which data, connection or runtime state the operation reads or changes. This avoids examples that appear to work but apply to a different context.

What Is openssl_pkey_get_details() in PHP?


Returns information about an asymmetric key including its type, public component and key length.

Syntax:

<?php

// Signature for reference only
openssl_pkey_get_details(OpenSSLAsymmetricKey $key) : array|false

Parameters and Return Value


  • $key — Required OpenSSLAsymmetricKey argument supplied to this operation.

The declared return type is array|false.

Example 1: Basic Usage


<?php

$privateKey = openssl_pkey_new(["private_key_bits"=>2048]);
$keyDetails = openssl_pkey_get_details($privateKey);
echo $keyDetails["bits"];

Returns information about an asymmetric key including its type, public component and key length.

Example 2: Another Case


<?php

$privateKey = openssl_pkey_new(["private_key_bits"=>2048]);
$keyDetails = openssl_pkey_get_details($privateKey);
echo $keyDetails["type"] === OPENSSL_KEYTYPE_RSA ? "RSA" : "Other";

The second sample illustrates a different way to inspect or handle this operation. Configure the underlying session, socket, key material or connection first.

Practical Example


<?php

$privateKey = openssl_pkey_new(["private_key_bits"=>2048]);
$keyDetails = openssl_pkey_get_details($privateKey);
$publicKeyPem = $keyDetails["key"];
if ($publicKeyPem === "") { throw new RuntimeException("Public key missing"); }

The practical example is a teaching scenario. Change sample configuration and credentials before using a similar design in an application.

Important Behavior and Edge Cases


  • Use trusted certificate and key material; never print private keys or disclose secrets in logs.
  • Relevant PHP environment: openssl. Ensure the required extension and operating-system capabilities are present.
  • Check results and release resources where necessary; successful syntax alone does not guarantee a successful operation.

Comparison With Related Functions


OptionWhen to Use It
openssl_pkey_get_detailsReturns information about an asymmetric key including its type, public component and key length.
openssl_pkey_get_detailsUse this related operation for its different responsibilities; do not assume identical inputs or return values.

Common Beginner Mistakes


MistakeCorrect Approach
Confusing public and private keysUse the appropriate key type for each operation and never disclose secret key data.
Assuming every algorithm is safe for every purposeChoose modern algorithms and protocol combinations supported by your deployment.
Printing certificate and key material to visitorsKeep cryptographic diagnostics restricted and redact secrets.

Key Takeaways


  • Returns information about an asymmetric key including its type, public component and key length.
  • Use trusted certificate and key material; never print private keys or disclose secrets in logs.
  • Validate inputs and handle failure conditions before integrating this operation into a production workflow.

Returns information about an asymmetric key including its type, public component and key length. Use the appropriate runtime and treat any environment-dependent output as an example, not a guaranteed result.

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