/ 
CryptX-0.087_002
⭐ Starred 36 / Crypt::PK::RSA
Security Advisories (2)
CVE-2026-41564 (2026-04-23)

CryptX versions before 0.088 for Perl do not reseed the Crypt::PK PRNG state after forking. The Crypt::PK::RSA, Crypt::PK::DSA, Crypt::PK::DH, Crypt::PK::ECC, Crypt::PK::Ed25519 and Crypt::PK::X25519 modules seed a per-object PRNG state in their constructors and reuse it without fork detection. A Crypt::PK::* object created before `fork()` shares byte-identical PRNG state with every child process, and any randomized operation they perform can produce identical output, including key generation. Two ECDSA or DSA signatures from different processes are enough to recover the signing private key through nonce-reuse key recovery. This affects preforking services such as the Starman web server, where a Crypt::PK::* object loaded at startup is inherited by every worker process.

CVE-2026-41565 (2026-05-28)

CryptX versions before 0.088_001 for Perl have a stack buffer overflow in four AEAD decrypt_verify helpers. The gcm_decrypt_verify, ccm_decrypt_verify, chacha20poly1305_decrypt_verify and eax_decrypt_verify XS routines copied the caller-supplied authentication tag into a fixed 144-byte stack buffer (MAXBLOCKSIZE) without checking the supplied length. A longer tag overwrites the stack past the buffer. Version 0.088 added the clamp to gcm_decrypt_verify, and 0.088_001 added it to the other three. Any caller of an affected helper that forwards an attacker-controlled tag longer than the buffer can trigger the overflow.

NAME

Crypt::PK::RSA - Public key cryptography based on RSA

SYNOPSIS

### OO interface

#Encryption: Alice
my $pub = Crypt::PK::RSA->new('Bob_pub_rsa1.der');
my $ct = $pub->encrypt("secret message");
#
#Encryption: Bob (received ciphertext $ct)
my $priv = Crypt::PK::RSA->new('Bob_priv_rsa1.der');
my $pt = $priv->decrypt($ct);

#Signature: Alice
my $priv = Crypt::PK::RSA->new('Alice_priv_rsa1.der');
my $sig = $priv->sign_message($message);
#
#Signature: Bob (received $message + $sig)
my $pub = Crypt::PK::RSA->new('Alice_pub_rsa1.der');
$pub->verify_message($sig, $message) or die "ERROR";

#Key generation
my $pk = Crypt::PK::RSA->new();
$pk->generate_key(256, 65537);
my $private_der = $pk->export_key_der('private');
my $public_der = $pk->export_key_der('public');
my $private_pem = $pk->export_key_pem('private');
my $public_pem = $pk->export_key_pem('public');

### Functional interface

#Encryption: Alice
my $ct = rsa_encrypt('Bob_pub_rsa1.der', "secret message");
#Encryption: Bob (received ciphertext $ct)
my $pt = rsa_decrypt('Bob_priv_rsa1.der', $ct);

#Signature: Alice
my $sig = rsa_sign_message('Alice_priv_rsa1.der', $message);
#Signature: Bob (received $message + $sig)
rsa_verify_message('Alice_pub_rsa1.der', $sig, $message) or die "ERROR";

DESCRIPTION

The module provides a full featured RSA implementation.

METHODS

new

my $pk = Crypt::PK::RSA->new();
#or
my $pk = Crypt::PK::RSA->new($priv_or_pub_key_filename);
#or
my $pk = Crypt::PK::RSA->new(\$buffer_containing_priv_or_pub_key);

Support for password protected PEM keys

my $pk = Crypt::PK::RSA->new($priv_pem_key_filename, $password);
#or
my $pk = Crypt::PK::RSA->new(\$buffer_containing_priv_pem_key, $password);

generate_key

Uses Yarrow-based cryptographically strong random number generator seeded with random data taken from /dev/random (UNIX) or CryptGenRandom (Win32).

$pk->generate_key($size, $e);
# $size .. key size: 128-512 bytes (DEFAULT is 256)
# $e ..... exponent: 3, 17, 257 or 65537 (DEFAULT is 65537)

import_key

Loads private or public key in DER or PEM format.

$pk->import_key($priv_or_pub_key_filename);
#or
$pk->import_key(\$buffer_containing_priv_or_pub_key);

Support for password protected PEM keys

$pk->import_key($pem_filename, $password);
#or
$pk->import_key(\$buffer_containing_pem_key, $password);

Loading private or public keys form perl hash:

$pk->import_key($hashref);

# the $hashref is either a key exported via key2hash
$pk->import_key({
  e  => "10001", #public exponent
  d  => "9ED5C3D3F866E06957CA0E9478A273C39BBDA4EEAC5B...", #private exponent
  N  => "D0A5CCCAE03DF9C2F5C4C8C0CE840D62CDE279990DC6...", #modulus
  p  => "D3EF0028FFAB508E2773C659E428A80FB0E9211346B4...", #p factor of N
  q  => "FC07E46B163CAB6A83B8E467D169534B2077DCDEECAE...", #q factor of N
  qP => "88C6D406F833DF73C8B734548E0385261AD51F4187CF...", #1/q mod p CRT param
  dP => "486F142FEF0A1F53269AC43D2EE4D263E2841B60DA36...", #d mod (p - 1) CRT param
  dQ => "4597284B2968B72C4212DB7E8F24360B987B80514DA9...", #d mod (q - 1) CRT param
});

# or a hash with items corresponding to JWK (JSON Web Key)
$pk->import_key({
{
  kty => "RSA",
  n   => "0vx7agoebGcQSuuPiLJXZpt...eZu0fM4lFd2NcRwr3XPksINHaQ-G_xBniIqbw0Ls1jF44-csFCur-kEgU8awapJzKnqDKgw",
  e   => "AQAB",
  d   => "X4cTteJY_gn4FYPsXB8rdXi...FLN5EEaG6RoVH-HLKD9Mdx5ooGURknhnrRwUkC7h5fJLMWbFAKLWY2v7B6NqSzUvx0_YSf",
  p   => "83i-7IvMGXoMXCskv73TKr8...Z27zvoj6pbUQyLPBQxtPnwD20-60eTmD2ujMt5PoMrm8RmNhVWtjjMmMjOpSicFHjXOuVI",
  q   => "3dfOR9cuYq-0S-mkFLzgItg...q3hWeMuG0ouqnb3obLyuqjVZQ1dIrdgTnCdYzBcOW5r37AFXjift_NGiovonzhKpoVVS78",
  dp  => "G4sPXkc6Ya9y8oJW9_ILj4...zi_H7TkS8x5SdX3oE0oiYwxIiemTAu0UOa5pgFGyJ4c8t2VF40XRugKTP8akhFo5tA77Qe",
  dq  => "s9lAH9fggBsoFR8Oac2R_E...T2kGOhvIllTE1efA6huUvMfBcpn8lqW6vzzYY5SSF7pMd_agI3G8IbpBUb0JiraRNUfLhc",
  qi  => "GyM_p6JrXySiz1toFgKbWV...4ypu9bMWx3QJBfm0FoYzUIZEVEcOqwmRN81oDAaaBk0KWGDjJHDdDmFW3AN7I-pux_mHZG",
});

Supported key formats:

# all formats can be loaded from a file
my $pk = Crypt::PK::RSA->new($filename);

# or from a buffer containing the key
my $pk = Crypt::PK::RSA->new(\$buffer_with_key);

  • RSA public keys

    -----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDHlYKg9DeHB3/dY1D9WCyJTnl5
vEzAXpUOL9tDtdPUl96brIbbdMLooO1hKjsq98kLs1q4vOn/pxvzk0BRwhiu7Vvb
VUjAn/2HHDDL0U1utqqlMJhaffeLI3HEq5o/lSMFY7sSkZU/E4YX1yqAN0SE7xfK
B2uzcNq60sMIfp6siQIDAQAB
-----END PUBLIC KEY-----

  • RSA private keys

    -----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----

  • RSA private keys in password protected PEM format

    -----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: DES-EDE3-CBC,4D697440FF5AEF18
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-----END RSA PRIVATE KEY-----

  • PKCS#8 encoded private keys

    -----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----

  • PKCS#8 encrypted private keys - password protected keys (supported since: CryptX-0.062)

    -----BEGIN ENCRYPTED PRIVATE KEY-----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-----END ENCRYPTED PRIVATE KEY-----

  • RSA public key from X509 certificate

    -----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

  • SSH public RSA keys

    ssh-rsa AAAAB3NzaC1yc2EAAAADAQA...6mdYs5iJNGu/ltUdc=

  • SSH public RSA keys (RFC-4716 format)

    ---- BEGIN SSH2 PUBLIC KEY ----
Comment: "768-bit RSA, converted from OpenSSH"
AAAAB3NzaC1yc2EAAAADAQABAAAAYQDYebeGQFCnlQiNRE7r9UEbjr+DQMTdw1ZHGB2w6x
D/DzKem8761GdCpqsLrGaw2D7aSIoP1B5Sz870YoVWHn6Ao7Hvm17V3Kxfn4B01GNQTM5+
L26mdYs5iJNGu/ltUdc=
---- END SSH2 PUBLIC KEY ----

  • RSA private keys in JSON Web Key (JWK) format

    See http://tools.ietf.org/html/draft-ietf-jose-json-web-key

    {
  "kty":"RSA",
  "n":"0vx7agoebGcQSuuPiLJXZpt...eZu0fM4lFd2NcRwr3XPksINHaQ-G_xBniIqbw0Ls1jF44-csFCur-kEgU8awapJzKnqDKgw",
  "e":"AQAB",
  "d":"X4cTteJY_gn4FYPsXB8rdXi...FLN5EEaG6RoVH-HLKD9Mdx5ooGURknhnrRwUkC7h5fJLMWbFAKLWY2v7B6NqSzUvx0_YSf",
  "p":"83i-7IvMGXoMXCskv73TKr8...Z27zvoj6pbUQyLPBQxtPnwD20-60eTmD2ujMt5PoMrm8RmNhVWtjjMmMjOpSicFHjXOuVI",
  "q":"3dfOR9cuYq-0S-mkFLzgItg...q3hWeMuG0ouqnb3obLyuqjVZQ1dIrdgTnCdYzBcOW5r37AFXjift_NGiovonzhKpoVVS78",
  "dp":"G4sPXkc6Ya9y8oJW9_ILj4...zi_H7TkS8x5SdX3oE0oiYwxIiemTAu0UOa5pgFGyJ4c8t2VF40XRugKTP8akhFo5tA77Qe",
  "dq":"s9lAH9fggBsoFR8Oac2R_E...T2kGOhvIllTE1efA6huUvMfBcpn8lqW6vzzYY5SSF7pMd_agI3G8IbpBUb0JiraRNUfLhc",
  "qi":"GyM_p6JrXySiz1toFgKbWV...4ypu9bMWx3QJBfm0FoYzUIZEVEcOqwmRN81oDAaaBk0KWGDjJHDdDmFW3AN7I-pux_mHZG",
}

    BEWARE: For JWK support you need to have JSON module installed.

  • RSA public keys in JSON Web Key (JWK) format

    {
  "kty":"RSA",
  "n": "0vx7agoebGcQSuuPiLJXZp...tN9nndrQmbXEps2aiAFbWhM78LhWx4cbbfAAtVT86zwu1RK7aPFFxuhDR1L6tSoc_BJECP",
  "e":"AQAB",
}

    BEWARE: For JWK support you need to have JSON module installed.

export_key_der

my $private_der = $pk->export_key_der('private');
#or
my $public_der = $pk->export_key_der('public');

export_key_pem

my $private_pem = $pk->export_key_pem('private');
#or
my $public_pem = $pk->export_key_pem('public');
#or
my $public_pem = $pk->export_key_pem('public_x509');

With parameter 'public' uses header and footer lines:

-----BEGIN RSA PUBLIC KEY------
-----END RSA PUBLIC KEY------

With parameter 'public_x509' uses header and footer lines:

-----BEGIN PUBLIC KEY------
-----END PUBLIC KEY------

Support for password protected PEM keys

my $private_pem = $pk->export_key_pem('private', $password);
#or
my $private_pem = $pk->export_key_pem('private', $password, $cipher);

# supported ciphers: 'DES-CBC'
#                    'DES-EDE3-CBC'
#                    'SEED-CBC'
#                    'CAMELLIA-128-CBC'
#                    'CAMELLIA-192-CBC'
#                    'CAMELLIA-256-CBC'
#                    'AES-128-CBC'
#                    'AES-192-CBC'
#                    'AES-256-CBC' (DEFAULT)

export_key_jwk

Since: CryptX-0.022

Exports public/private keys as a JSON Web Key (JWK).

my $private_json_text = $pk->export_key_jwk('private');
#or
my $public_json_text = $pk->export_key_jwk('public');

Also exports public/private keys as a perl HASH with JWK structure.

my $jwk_hash = $pk->export_key_jwk('private', 1);
#or
my $jwk_hash = $pk->export_key_jwk('public', 1);

BEWARE: For JWK support you need to have JSON module installed.

export_key_jwk_thumbprint

Since: CryptX-0.031

Exports the key's JSON Web Key Thumbprint as a string.

If you don't know what this is, see RFC 7638 https://tools.ietf.org/html/rfc7638.

my $thumbprint = $pk->export_key_jwk_thumbprint('SHA256');

encrypt

my $pk = Crypt::PK::RSA->new($pub_key_filename);
my $ct = $pk->encrypt($message);
#or
my $ct = $pk->encrypt($message, $padding);
#or
my $ct = $pk->encrypt($message, 'oaep', $hash_name, $lparam);

# $padding .................... 'oaep' (DEFAULT), 'v1.5' or 'none' (INSECURE)
# $hash_name (only for oaep) .. 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $lparam (only for oaep) ..... DEFAULT is empty string

decrypt

my $pk = Crypt::PK::RSA->new($priv_key_filename);
my $pt = $pk->decrypt($ciphertext);
#or
my $pt = $pk->decrypt($ciphertext, $padding);
#or
my $pt = $pk->decrypt($ciphertext, 'oaep', $hash_name, $lparam);

# $padding .................... 'oaep' (DEFAULT), 'v1.5' or 'none' (INSECURE)
# $hash_name (only for oaep) .. 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $lparam (only for oaep) ..... DEFAULT is empty string

sign_message

my $pk = Crypt::PK::RSA->new($priv_key_filename);
my $signature = $priv->sign_message($message);
#or
my $signature = $priv->sign_message($message, $hash_name);
#or
my $signature = $priv->sign_message($message, $hash_name, $padding);
#or
my $signature = $priv->sign_message($message, $hash_name, 'pss', $saltlen);

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

verify_message

my $pk = Crypt::PK::RSA->new($pub_key_filename);
my $valid = $pub->verify_message($signature, $message);
#or
my $valid = $pub->verify_message($signature, $message, $hash_name);
#or
my $valid = $pub->verify_message($signature, $message, $hash_name, $padding);
#or
my $valid = $pub->verify_message($signature, $message, $hash_name, 'pss', $saltlen);

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

sign_hash

my $pk = Crypt::PK::RSA->new($priv_key_filename);
my $signature = $priv->sign_hash($message_hash);
#or
my $signature = $priv->sign_hash($message_hash, $hash_name);
#or
my $signature = $priv->sign_hash($message_hash, $hash_name, $padding);
#or
my $signature = $priv->sign_hash($message_hash, $hash_name, 'pss', $saltlen);
#or
my $signature = $priv->sign_hash($message_hash, $hash_name, 'pss', $saltlen, $mgf_hash_name);

# $hash_name ................. 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................... 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (pss only) ........ DEFAULT is 12
# $mgf_hash_name (pss only) .. MGF hash function name (DEFAULT: the $hash_name value)

verify_hash

my $pk = Crypt::PK::RSA->new($pub_key_filename);
my $valid = $pub->verify_hash($signature, $message_hash);
#or
my $valid = $pub->verify_hash($signature, $message_hash, $hash_name);
#or
my $valid = $pub->verify_hash($signature, $message_hash, $hash_name, $padding);
#or
my $valid = $pub->verify_hash($signature, $message_hash, $hash_name, 'pss', $saltlen);
#or
my $valid = $pub->verify_hash($signature, $message_hash, $hash_name, 'pss', $saltlen, $mgf_hash_name);

# $hash_name ................. 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................... 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (pss only) ........ DEFAULT is 12
# $mgf_hash_name (pss only) .. MGF hash function name (DEFAULT: the $hash_name value)

is_private

my $rv = $pk->is_private;
# 1 .. private key loaded
# 0 .. public key loaded
# undef .. no key loaded

size

my $size = $pk->size;
# returns key size in bytes or undef if no key loaded

key2hash

my $hash = $pk->key2hash;

# returns hash like this (or undef if no key loaded):
{
  type => 1,   # integer: 1 .. private, 0 .. public
  size => 256, # integer: key size in bytes
  # all the rest are hex strings
  e  => "10001", #public exponent
  d  => "9ED5C3D3F866E06957CA0E9478A273C39BBDA4EEAC5B...", #private exponent
  N  => "D0A5CCCAE03DF9C2F5C4C8C0CE840D62CDE279990DC6...", #modulus
  p  => "D3EF0028FFAB508E2773C659E428A80FB0E9211346B4...", #p factor of N
  q  => "FC07E46B163CAB6A83B8E467D169534B2077DCDEECAE...", #q factor of N
  qP => "88C6D406F833DF73C8B734548E0385261AD51F4187CF...", #1/q mod p CRT param
  dP => "486F142FEF0A1F53269AC43D2EE4D263E2841B60DA36...", #d mod (p - 1) CRT param
  dQ => "4597284B2968B72C4212DB7E8F24360B987B80514DA9...", #d mod (q - 1) CRT param
}

FUNCTIONS

rsa_encrypt

RSA based encryption. See method "encrypt" below.

my $ct = rsa_encrypt($pub_key_filename, $message);
#or
my $ct = rsa_encrypt(\$buffer_containing_pub_key, $message);
#or
my $ct = rsa_encrypt($pub_key, $message, $padding);
#or
my $ct = rsa_encrypt($pub_key, $message, 'oaep', $hash_name, $lparam);

# $padding .................... 'oaep' (DEFAULT), 'v1.5' or 'none' (INSECURE)
# $hash_name (only for oaep) .. 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $lparam (only for oaep) ..... DEFAULT is empty string

rsa_decrypt

RSA based decryption. See method "decrypt" below.

my $pt = rsa_decrypt($priv_key_filename, $ciphertext);
#or
my $pt = rsa_decrypt(\$buffer_containing_priv_key, $ciphertext);
#or
my $pt = rsa_decrypt($priv_key, $ciphertext, $padding);
#or
my $pt = rsa_decrypt($priv_key, $ciphertext, 'oaep', $hash_name, $lparam);

# $padding .................... 'oaep' (DEFAULT), 'v1.5' or 'none' (INSECURE)
# $hash_name (only for oaep) .. 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $lparam (only for oaep) ..... DEFAULT is empty string

rsa_sign_message

Generate RSA signature. See method "sign_message" below.

my $sig = rsa_sign_message($priv_key_filename, $message);
#or
my $sig = rsa_sign_message(\$buffer_containing_priv_key, $message);
#or
my $sig = rsa_sign_message($priv_key, $message, $hash_name);
#or
my $sig = rsa_sign_message($priv_key, $message, $hash_name, $padding);
#or
my $sig = rsa_sign_message($priv_key, $message, $hash_name, 'pss', $saltlen);

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

rsa_verify_message

Verify RSA signature. See method "verify_message" below.

rsa_verify_message($pub_key_filename, $signature, $message) or die "ERROR";
#or
rsa_verify_message(\$buffer_containing_pub_key, $signature, $message) or die "ERROR";
#or
rsa_verify_message($pub_key, $signature, $message, $hash_name) or die "ERROR";
#or
rsa_verify_message($pub_key, $signature, $message, $hash_name, $padding) or die "ERROR";
#or
rsa_verify_message($pub_key, $signature, $message, $hash_name, 'pss', $saltlen) or die "ERROR";

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

rsa_sign_hash

Generate RSA signature. See method "sign_hash" below.

my $sig = rsa_sign_hash($priv_key_filename, $message_hash);
#or
my $sig = rsa_sign_hash(\$buffer_containing_priv_key, $message_hash);
#or
my $sig = rsa_sign_hash($priv_key, $message_hash, $hash_name);
#or
my $sig = rsa_sign_hash($priv_key, $message_hash, $hash_name, $padding);
#or
my $sig = rsa_sign_hash($priv_key, $message_hash, $hash_name, 'pss', $saltlen);

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

rsa_verify_hash

Verify RSA signature. See method "verify_hash" below.

rsa_verify_hash($pub_key_filename, $signature, $message_hash) or die "ERROR";
#or
rsa_verify_hash(\$buffer_containing_pub_key, $signature, $message_hash) or die "ERROR";
#or
rsa_verify_hash($pub_key, $signature, $message_hash, $hash_name) or die "ERROR";
#or
rsa_verify_hash($pub_key, $signature, $message_hash, $hash_name, $padding) or die "ERROR";
#or
rsa_verify_hash($pub_key, $signature, $message_hash, $hash_name, 'pss', $saltlen) or die "ERROR";

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

OpenSSL interoperability

### let's have:
# RSA private key in PEM format - rsakey.priv.pem
# RSA public key in PEM format  - rsakey.pub.pem
# data file to be signed or encrypted - input.data

Encrypt by OpenSSL, decrypt by Crypt::PK::RSA

Create encrypted file (from commandline):

openssl rsautl -encrypt -inkey rsakey.pub.pem -pubin -out input.encrypted.rsa -in input.data

Decrypt file (Perl code):

use Crypt::PK::RSA;
use Crypt::Misc 'read_rawfile';

my $pkrsa = Crypt::PK::RSA->new("rsakey.priv.pem");
my $encfile = read_rawfile("input.encrypted.rsa");
my $plaintext = $pkrsa->decrypt($encfile, 'v1.5');
print $plaintext;

Encrypt by Crypt::PK::RSA, decrypt by OpenSSL

Create encrypted file (Perl code):

use Crypt::PK::RSA;
use Crypt::Misc 'write_rawfile';

my $plaintext = 'secret message';
my $pkrsa = Crypt::PK::RSA->new("rsakey.pub.pem");
my $encrypted = $pkrsa->encrypt($plaintext, 'v1.5');
write_rawfile("input.encrypted.rsa", $encrypted);

Decrypt file (from commandline):

openssl rsautl -decrypt -inkey rsakey.priv.pem -in input.encrypted.rsa

Sign by OpenSSL, verify by Crypt::PK::RSA

Create signature (from commandline):

openssl dgst -sha1 -sign rsakey.priv.pem -out input.sha1-rsa.sig input.data

Verify signature (Perl code):

use Crypt::PK::RSA;
use Crypt::Digest 'digest_file';
use Crypt::Misc 'read_rawfile';

my $pkrsa = Crypt::PK::RSA->new("rsakey.pub.pem");
my $signature = read_rawfile("input.sha1-rsa.sig");
my $valid = $pkrsa->verify_hash($signature, digest_file("SHA1", "input.data"), "SHA1", "v1.5");
print $valid ? "SUCCESS" : "FAILURE";

Sign by Crypt::PK::RSA, verify by OpenSSL

Create signature (Perl code):

use Crypt::PK::RSA;
use Crypt::Digest 'digest_file';
use Crypt::Misc 'write_rawfile';

my $pkrsa = Crypt::PK::RSA->new("rsakey.priv.pem");
my $signature = $pkrsa->sign_hash(digest_file("SHA1", "input.data"), "SHA1", "v1.5");
write_rawfile("input.sha1-rsa.sig", $signature);

Verify signature (from commandline):

openssl dgst -sha1 -verify rsakey.pub.pem -signature input.sha1-rsa.sig input.data

Keys generated by Crypt::PK::RSA

Generate keys (Perl code):

use Crypt::PK::RSA;
use Crypt::Misc 'write_rawfile';

my $pkrsa = Crypt::PK::RSA->new;
$pkrsa->generate_key(256, 65537);
write_rawfile("rsakey.pub.der",  $pkrsa->export_key_der('public'));
write_rawfile("rsakey.priv.der", $pkrsa->export_key_der('private'));
write_rawfile("rsakey.pub.pem",  $pkrsa->export_key_pem('public_x509'));
write_rawfile("rsakey.priv.pem", $pkrsa->export_key_pem('private'));
write_rawfile("rsakey-passwd.priv.pem", $pkrsa->export_key_pem('private', 'secret'));

Use keys by OpenSSL:

openssl rsa -in rsakey.priv.der -text -inform der
openssl rsa -in rsakey.priv.pem -text
openssl rsa -in rsakey-passwd.priv.pem -text -inform pem -passin pass:secret
openssl rsa -in rsakey.pub.der -pubin -text -inform der
openssl rsa -in rsakey.pub.pem -pubin -text

Keys generated by OpenSSL

Generate keys:

openssl genrsa -out rsakey.priv.pem 1024
openssl rsa -in rsakey.priv.pem -out rsakey.priv.der -outform der
openssl rsa -in rsakey.priv.pem -out rsakey.pub.pem -pubout
openssl rsa -in rsakey.priv.pem -out rsakey.pub.der -outform der -pubout
openssl rsa -in rsakey.priv.pem -passout pass:secret -des3 -out rsakey-passwd.priv.pem

Load keys (Perl code):

use Crypt::PK::RSA;

my $pkrsa = Crypt::PK::RSA->new;
$pkrsa->import_key("rsakey.pub.der");
$pkrsa->import_key("rsakey.priv.der");
$pkrsa->import_key("rsakey.pub.pem");
$pkrsa->import_key("rsakey.priv.pem");
$pkrsa->import_key("rsakey-passwd.priv.pem", "secret");

SEE ALSO