RSA

Pure-PHP PKCS#1 compliant implementation of RSA.

• Full name: \phpseclib\Crypt\RSA

Constants

Constant	Visibility	Type	Value
ENCRYPTION_OAEP	public		1
ENCRYPTION_PKCS1	public		2
ENCRYPTION_NONE	public		3
SIGNATURE_PSS	public		1
SIGNATURE_PKCS1	public		2
ASN1_INTEGER	public		2
ASN1_BITSTRING	public		3
ASN1_OCTETSTRING	public		4
ASN1_OBJECT	public		6
ASN1_SEQUENCE	public		48
MODE_INTERNAL	public		1
MODE_OPENSSL	public		2
PRIVATE_FORMAT_PKCS1	public		0
PRIVATE_FORMAT_PUTTY	public		1
PRIVATE_FORMAT_XML	public		2
PRIVATE_FORMAT_PKCS8	public		8
PRIVATE_FORMAT_OPENSSH	public		9
PUBLIC_FORMAT_RAW	public		3
PUBLIC_FORMAT_PKCS1	public		4
PUBLIC_FORMAT_PKCS1_RAW	public		4
PUBLIC_FORMAT_XML	public		5
PUBLIC_FORMAT_OPENSSH	public		6
PUBLIC_FORMAT_PKCS8	public		7

Properties

zero

Precomputed Zero

public \phpseclib\Math\BigInteger $zero

---

one

Precomputed One

public \phpseclib\Math\BigInteger $one

---

privateKeyFormat

Private Key Format

public int $privateKeyFormat

---

publicKeyFormat

Public Key Format

public int $publicKeyFormat

---

modulus

Modulus (ie. n)

public \phpseclib\Math\BigInteger $modulus

---

k

Modulus length

public \phpseclib\Math\BigInteger $k

---

exponent

Exponent (ie. e or d)

public \phpseclib\Math\BigInteger $exponent

---

primes

Primes for Chinese Remainder Theorem (ie. p and q)

public array $primes

---

exponents

Exponents for Chinese Remainder Theorem (ie. dP and dQ)

public array $exponents

---

coefficients

Coefficients for Chinese Remainder Theorem (ie. qInv)

public array $coefficients

---

hashName

Hash name

public string $hashName

---

hash

Hash function

public \phpseclib\Crypt\Hash $hash

---

hLen

Length of hash function output

public int $hLen

---

sLen

Length of salt

public int $sLen

---

mgfHash

Hash function for the Mask Generation Function

public \phpseclib\Crypt\Hash $mgfHash

---

mgfHLen

Length of MGF hash function output

public int $mgfHLen

---

encryptionMode

Encryption mode

public int $encryptionMode

---

signatureMode

Signature mode

public int $signatureMode

---

publicExponent

Public Exponent

public mixed $publicExponent

---

password

Password

public string $password

---

components

Components

public array $components

For use with parsing XML formatted keys. PHP's XML Parser functions use utilized - instead of PHP's DOM functions - because PHP's XML Parser functions work on PHP4 whereas PHP's DOM functions - although surperior - don't.

See Also:

• \phpseclib\Crypt\self::_start_element_handler() -

---

current

Current String

public mixed $current

For use with parsing XML formatted keys.

See Also:

• \phpseclib\Crypt\self::_character_handler() - * \phpseclib\Crypt\self::_stop_element_handler() -

---

configFile

OpenSSL configuration file name.

public mixed $configFile

Set to null to use system configuration file.

See Also:

• \phpseclib\Crypt\self::createKey() -

---

comment

Public key comment field.

public string $comment

---

Methods

__construct

The constructor

public __construct(): \phpseclib\Crypt\RSA

If you want to make use of the openssl extension, you'll need to set the mode manually, yourself. The reason \phpseclib\Crypt\RSA doesn't do it is because OpenSSL doesn't fail gracefully. openssl_pkey_new(), in particular, requires openssl.cnf be present somewhere and, unfortunately, the only real way to find out is too late.

---

createKey

Create public / private key pair

public createKey(int $bits = 1024, int $timeout = false, array $partial = array()): mixed

Returns an array with the following three elements: - 'privatekey': The private key. - 'publickey': The public key. - 'partialkey': A partially computed key (if the execution time exceeded $timeout). Will need to be passed back to \phpseclib\Crypt\RSA::createKey() as the third parameter for further processing.

Parameters:

Parameter	Type	Description
$bits	int
$timeout	int
$partial	array

---

_convertPrivateKey

Convert a private key to the appropriate format.

public _convertPrivateKey(\phpseclib\Crypt\Math_BigInteger $n, \phpseclib\Crypt\Math_BigInteger $e, \phpseclib\Crypt\Math_BigInteger $d, array<int,\phpseclib\Crypt\Math_BigInteger> $primes, array<int,\phpseclib\Crypt\Math_BigInteger> $exponents, array<int,\phpseclib\Crypt\Math_BigInteger> $coefficients): string

Parameters:

Parameter	Type	Description
$n	\phpseclib\Crypt\Math_BigInteger
$e	\phpseclib\Crypt\Math_BigInteger
$d	\phpseclib\Crypt\Math_BigInteger
$primes	array
$exponents	array
$coefficients	array

See Also:

• \phpseclib\Crypt\self::setPrivateKeyFormat() -

---

_convertPublicKey

Convert a public key to the appropriate format

public _convertPublicKey(\phpseclib\Crypt\Math_BigInteger $n, \phpseclib\Crypt\Math_BigInteger $e): string|array<string,\phpseclib\Crypt\Math_BigInteger>

Parameters:

Parameter	Type	Description
$n	\phpseclib\Crypt\Math_BigInteger
$e	\phpseclib\Crypt\Math_BigInteger

See Also:

• \phpseclib\Crypt\self::setPublicKeyFormat() -

---

_parseKey

Break a public or private key down into its constituant components

public _parseKey(string|array $key, int $type): array|bool

Parameters:

Parameter	Type	Description
$key	string|array
$type	int

See Also:

• \phpseclib\Crypt\self::_convertPublicKey() - * \phpseclib\Crypt\self::_convertPrivateKey() -

---

getSize

Returns the key size

public getSize(): int

More specifically, this returns the size of the modulo in bits.

---

_start_element_handler

Start Element Handler

public _start_element_handler(resource $parser, string $name, array $attribs): mixed

Called by xml_set_element_handler()

Parameters:

Parameter	Type	Description
$parser	resource
$name	string
$attribs	array

---

_stop_element_handler

Stop Element Handler

public _stop_element_handler(resource $parser, string $name): mixed

Called by xml_set_element_handler()

Parameters:

Parameter	Type	Description
$parser	resource
$name	string

---

_data_handler

Data Handler

public _data_handler(resource $parser, string $data): mixed

Called by xml_set_character_data_handler()

Parameters:

Parameter	Type	Description
$parser	resource
$data	string

---

loadKey

Loads a public or private key

public loadKey(string|\phpseclib\Crypt\RSA|array $key, bool|int $type = false): bool

Returns true on success and false on failure (ie. an incorrect password was provided or the key was malformed)

Parameters:

Parameter	Type	Description
$key	string|\phpseclib\Crypt\RSA|array
$type	bool|int	optional

---

setPassword

Sets the password

public setPassword(string $password = false): mixed

Private keys can be encrypted with a password. To unset the password, pass in the empty string or false. Or rather, pass in $password such that empty($password) && !is_string($password) is true.

Parameters:

Parameter	Type	Description
$password	string

See Also:

• \phpseclib\Crypt\self::createKey() - * \phpseclib\Crypt\self::loadKey() -

---

setPublicKey

Defines the public key

public setPublicKey(string $key = false, int $type = false): bool

Some private key formats define the public exponent and some don't. Those that don't define it are problematic when used in certain contexts. For example, in SSH-2, RSA authentication works by sending the public key along with a message signed by the private key to the server. The SSH-2 server looks the public key up in an index of public keys and if it's present then proceeds to verify the signature. Problem is, if your private key doesn't include the public exponent this won't work unless you manually add the public exponent. phpseclib tries to guess if the key being used is the public key but in the event that it guesses incorrectly you might still want to explicitly set the key as being public.

Do note that when a new key is loaded the index will be cleared.

Returns true on success, false on failure

Parameters:

Parameter	Type	Description
$key	string	optional
$type	int	optional

See Also:

• \phpseclib\Crypt\self::getPublicKey() -

---

setPrivateKey

Defines the private key

public setPrivateKey(string $key = false, int $type = false): bool

If phpseclib guessed a private key was a public key and loaded it as such it might be desirable to force phpseclib to treat the key as a private key. This function will do that.

Do note that when a new key is loaded the index will be cleared.

Returns true on success, false on failure

Parameters:

Parameter	Type	Description
$key	string	optional
$type	int	optional

See Also:

• \phpseclib\Crypt\self::getPublicKey() -

---

getPublicKey

Returns the public key

public getPublicKey(int $type = self::PUBLIC_FORMAT_PKCS8): mixed

The public key is only returned under two circumstances - if the private key had the public key embedded within it or if the public key was set via setPublicKey(). If the currently loaded key is supposed to be the public key this function won't return it since this library, for the most part, doesn't distinguish between public and private keys.

Parameters:

Parameter	Type	Description
$type	int	optional

See Also:

• \phpseclib\Crypt\self::getPublicKey() -

---

getPublicKeyFingerprint

Returns the public key's fingerprint

public getPublicKeyFingerprint(string $algorithm = 'md5'): mixed

The public key's fingerprint is returned, which is equivalent to running ssh-keygen -lf rsa.pub. If there is no public key currently loaded, false is returned. Example output (md5): "c1:b1:30:29:d7:b8:de:6c:97:77:10:d7:46:41:63:87" (as specified by RFC 4716)

Parameters:

Parameter	Type	Description
$algorithm	string	The hashing algorithm to be used. Valid options are 'md5' and 'sha256'. False is returned for invalid values.

---

getPrivateKey

Returns the private key

public getPrivateKey(int $type = self::PUBLIC_FORMAT_PKCS1): mixed

The private key is only returned if the currently loaded key contains the constituent prime numbers.

Parameters:

Parameter	Type	Description
$type	int	optional

See Also:

• \phpseclib\Crypt\self::getPublicKey() -

---

_getPrivatePublicKey

Returns a minimalistic private key

public _getPrivatePublicKey(int $mode = self::PUBLIC_FORMAT_PKCS8): mixed

Returns the private key without the prime number constituants. Structurally identical to a public key that hasn't been set as the public key

Parameters:

Parameter	Type	Description
$mode	int	optional

See Also:

• \phpseclib\Crypt\self::getPrivateKey() -

---

__toString

__toString() magic method

public __toString(): string

---

__clone

__clone() magic method

public __clone(): \phpseclib\Crypt\Crypt_RSA

---

_generateMinMax

Generates the smallest and largest numbers requiring $bits bits

public _generateMinMax(int $bits): array

Parameters:

Parameter	Type	Description
$bits	int

---

_decodeLength

DER-decode the length

public _decodeLength(string& $string): int

DER supports lengths up to (28)127, however, we'll only support lengths up to (28)4. See {@link http://itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf#p=13} for more information.

Parameters:

Parameter	Type	Description
$string	string

---

_encodeLength

DER-encode the length

public _encodeLength(int $length): string

DER supports lengths up to (28)127, however, we'll only support lengths up to (28)4. See {@link http://itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf#p=13} for more information.

Parameters:

Parameter	Type	Description
$length	int

---

_string_shift

String Shift

public _string_shift(string& $string, int $index = 1): string

Inspired by array_shift

Parameters:

Parameter	Type	Description
$string	string
$index	int

---

setPrivateKeyFormat

Determines the private key format

public setPrivateKeyFormat(int $format): mixed

Parameters:

Parameter	Type	Description
$format	int

See Also:

• \phpseclib\Crypt\self::createKey() -

---

setPublicKeyFormat

Determines the public key format

public setPublicKeyFormat(int $format): mixed

Parameters:

Parameter	Type	Description
$format	int

See Also:

• \phpseclib\Crypt\self::createKey() -

---

setHash

Determines which hashing function should be used

public setHash(string $hash): mixed

Used with signature production / verification and (if the encryption mode is self::ENCRYPTION_OAEP) encryption and decryption. If $hash isn't supported, sha1 is used.

Parameters:

Parameter	Type	Description
$hash	string

---

setMGFHash

Determines which hashing function should be used for the mask generation function

public setMGFHash(string $hash): mixed

The mask generation function is used by self::ENCRYPTION_OAEP and self::SIGNATURE_PSS and although it's best if Hash and MGFHash are set to the same thing this is not a requirement.

Parameters:

Parameter	Type	Description
$hash	string

---

setSaltLength

Determines the salt length

public setSaltLength(int $sLen): mixed

To quote from {@link http://tools.ietf.org/html/rfc3447#page-38}:

Typical salt lengths in octets are hLen (the length of the output of the hash function Hash) and 0.

Parameters:

Parameter	Type	Description
$sLen	int

---

_i2osp

Integer-to-Octet-String primitive

public _i2osp(\phpseclib\Math\BigInteger $x, int $xLen): string

See {@link http://tools.ietf.org/html/rfc3447#section-4.1}.

Parameters:

Parameter	Type	Description
$x	\phpseclib\Math\BigInteger
$xLen	int

---

_os2ip

Octet-String-to-Integer primitive

public _os2ip(int|string|resource $x): \phpseclib\Math\BigInteger

See {@link http://tools.ietf.org/html/rfc3447#section-4.2}.

Parameters:

Parameter	Type	Description
$x	int|string|resource

---

_exponentiate

Exponentiate with or without Chinese Remainder Theorem

public _exponentiate(\phpseclib\Math\BigInteger $x): \phpseclib\Math\BigInteger

See {@link http://tools.ietf.org/html/rfc3447#section-5.1.1}.

Parameters:

Parameter	Type	Description
$x	\phpseclib\Math\BigInteger

---

_blind

Performs RSA Blinding

public _blind(\phpseclib\Math\BigInteger $x, \phpseclib\Math\BigInteger $r, int $i): \phpseclib\Math\BigInteger

Protects against timing attacks by employing RSA Blinding. Returns $x->modPow($this->exponents[$i], $this->primes[$i])

Parameters:

Parameter	Type	Description
$x	\phpseclib\Math\BigInteger
$r	\phpseclib\Math\BigInteger
$i	int

---

_equals

Performs blinded RSA equality testing

public _equals(string $x, string $y): bool

Protects against a particular type of timing attack described.

See {@link http://codahale.com/a-lesson-in-timing-attacks/}

Thanks for the heads up singpolyma!

Parameters:

Parameter	Type	Description
$x	string
$y	string

---

_rsaep

RSAEP

public _rsaep(\phpseclib\Math\BigInteger $m): \phpseclib\Math\BigInteger

See {@link http://tools.ietf.org/html/rfc3447#section-5.1.1}.

Parameters:

Parameter	Type	Description
$m	\phpseclib\Math\BigInteger

---

_rsadp

RSADP

public _rsadp(\phpseclib\Math\BigInteger $c): \phpseclib\Math\BigInteger

See {@link http://tools.ietf.org/html/rfc3447#section-5.1.2}.

Parameters:

Parameter	Type	Description
$c	\phpseclib\Math\BigInteger

---

_rsasp1

RSASP1

public _rsasp1(\phpseclib\Math\BigInteger $m): \phpseclib\Math\BigInteger

See {@link http://tools.ietf.org/html/rfc3447#section-5.2.1}.

Parameters:

Parameter	Type	Description
$m	\phpseclib\Math\BigInteger

---

_rsavp1

RSAVP1

public _rsavp1(\phpseclib\Math\BigInteger $s): \phpseclib\Math\BigInteger

See {@link http://tools.ietf.org/html/rfc3447#section-5.2.2}.

Parameters:

Parameter	Type	Description
$s	\phpseclib\Math\BigInteger

---

_mgf1

MGF1

public _mgf1(string $mgfSeed, int $maskLen): string

See {@link http://tools.ietf.org/html/rfc3447#appendix-B.2.1}.

Parameters:

Parameter	Type	Description
$mgfSeed	string
$maskLen	int

---

_rsaes_oaep_encrypt

RSAES-OAEP-ENCRYPT

public _rsaes_oaep_encrypt(string $m, string $l = ''): string

See {@link http://tools.ietf.org/html/rfc3447#section-7.1.1} and {http://en.wikipedia.org/wiki/Optimal_Asymmetric_Encryption_Padding OAES}.

Parameters:

Parameter	Type	Description
$m	string
$l	string

---

_rsaes_oaep_decrypt

RSAES-OAEP-DECRYPT

public _rsaes_oaep_decrypt(string $c, string $l = ''): string

See {@link http://tools.ietf.org/html/rfc3447#section-7.1.2}. The fact that the error messages aren't distinguishable from one another hinders debugging, but, to quote from RFC3447#section-7.1.2:

Note. Care must be taken to ensure that an opponent cannot distinguish the different error conditions in Step 3.g, whether by error message or timing, or, more generally, learn partial information about the encoded message EM. Otherwise an opponent may be able to obtain useful information about the decryption of the ciphertext C, leading to a chosen-ciphertext attack such as the one observed by Manger [36].

As for $l... to quote from {@link http://tools.ietf.org/html/rfc3447#page-17}:

Both the encryption and the decryption operations of RSAES-OAEP take the value of a label L as input. In this version of PKCS #1, L is the empty string; other uses of the label are outside the scope of this document.

Parameters:

Parameter	Type	Description
$c	string
$l	string

---

_raw_encrypt

Raw Encryption / Decryption

public _raw_encrypt(string $m): string

Doesn't use padding and is not recommended.

Parameters:

Parameter	Type	Description
$m	string

---

_rsaes_pkcs1_v1_5_encrypt

RSAES-PKCS1-V1_5-ENCRYPT

public _rsaes_pkcs1_v1_5_encrypt(string $m): string

See {@link http://tools.ietf.org/html/rfc3447#section-7.2.1}.

Parameters:

Parameter	Type	Description
$m	string

---

_rsaes_pkcs1_v1_5_decrypt

RSAES-PKCS1-V1_5-DECRYPT

public _rsaes_pkcs1_v1_5_decrypt(string $c): string

See {@link http://tools.ietf.org/html/rfc3447#section-7.2.2}.

For compatibility purposes, this function departs slightly from the description given in RFC3447. The reason being that RFC2313#section-8.1 (PKCS#1 v1.5) states that ciphertext's encrypted by the private key should have the second byte set to either 0 or 1 and that ciphertext's encrypted by the public key should have the second byte set to 2. In RFC3447 (PKCS#1 v2.1), the second byte is supposed to be 2 regardless of which key is used. For compatibility purposes, we'll just check to make sure the second byte is 2 or less. If it is, we'll accept the decrypted string as valid.

As a consequence of this, a private key encrypted ciphertext produced with \phpseclib\Crypt\RSA may not decrypt with a strictly PKCS#1 v1.5 compliant RSA implementation. Public key encrypted ciphertext's should but not private key encrypted ciphertext's.

Parameters:

Parameter	Type	Description
$c	string

---

_emsa_pss_encode

EMSA-PSS-ENCODE

public _emsa_pss_encode(string $m, int $emBits): mixed

See {@link http://tools.ietf.org/html/rfc3447#section-9.1.1}.

Parameters:

Parameter	Type	Description
$m	string
$emBits	int

---

_emsa_pss_verify

EMSA-PSS-VERIFY

public _emsa_pss_verify(string $m, string $em, int $emBits): string

See {@link http://tools.ietf.org/html/rfc3447#section-9.1.2}.

Parameters:

Parameter	Type	Description
$m	string
$em	string
$emBits	int

---

_rsassa_pss_sign

RSASSA-PSS-SIGN

public _rsassa_pss_sign(string $m): string

See {@link http://tools.ietf.org/html/rfc3447#section-8.1.1}.

Parameters:

Parameter	Type	Description
$m	string

---

_rsassa_pss_verify

RSASSA-PSS-VERIFY

public _rsassa_pss_verify(string $m, string $s): string

See {@link http://tools.ietf.org/html/rfc3447#section-8.1.2}.

Parameters:

Parameter	Type	Description
$m	string
$s	string

---

_emsa_pkcs1_v1_5_encode

EMSA-PKCS1-V1_5-ENCODE

public _emsa_pkcs1_v1_5_encode(string $m, int $emLen): string

See {@link http://tools.ietf.org/html/rfc3447#section-9.2}.

Parameters:

Parameter	Type	Description
$m	string
$emLen	int

---

_emsa_pkcs1_v1_5_encode_without_null

EMSA-PKCS1-V1_5-ENCODE (without NULL)

public _emsa_pkcs1_v1_5_encode_without_null(string $m, int $emLen): string

Quoting https://tools.ietf.org/html/rfc8017#page-65,

"The parameters field associated with id-sha1, id-sha224, id-sha256, id-sha384, id-sha512, id-sha512/224, and id-sha512/256 should generally be omitted, but if present, it shall have a value of type NULL"

Parameters:

Parameter	Type	Description
$m	string
$emLen	int

---

_rsassa_pkcs1_v1_5_sign

RSASSA-PKCS1-V1_5-SIGN

public _rsassa_pkcs1_v1_5_sign(string $m): string

See {@link http://tools.ietf.org/html/rfc3447#section-8.2.1}.

Parameters:

Parameter	Type	Description
$m	string

---

_rsassa_pkcs1_v1_5_verify

RSASSA-PKCS1-V1_5-VERIFY

public _rsassa_pkcs1_v1_5_verify(string $m, string $s): string

See {@link http://tools.ietf.org/html/rfc3447#section-8.2.2}.

Parameters:

Parameter	Type	Description
$m	string
$s	string

---

setEncryptionMode

Set Encryption Mode

public setEncryptionMode(int $mode): mixed

Valid values include self::ENCRYPTION_OAEP and self::ENCRYPTION_PKCS1.

Parameters:

Parameter	Type	Description
$mode	int

---

setSignatureMode

Set Signature Mode

public setSignatureMode(int $mode): mixed

Valid values include self::SIGNATURE_PSS and self::SIGNATURE_PKCS1

Parameters:

Parameter	Type	Description
$mode	int

---

setComment

Set public key comment.

public setComment(string $comment): mixed

Parameters:

Parameter	Type	Description
$comment	string

---

getComment

Get public key comment.

public getComment(): string

---

encrypt

Encryption

public encrypt(string $plaintext): string

Both self::ENCRYPTION_OAEP and self::ENCRYPTION_PKCS1 both place limits on how long $plaintext can be. If $plaintext exceeds those limits it will be broken up so that it does and the resultant ciphertext's will be concatenated together.

Parameters:

Parameter	Type	Description
$plaintext	string

See Also:

• \phpseclib\Crypt\self::decrypt() -

---

decrypt

Decryption

public decrypt(string $ciphertext): string

Parameters:

Parameter	Type	Description
$ciphertext	string

See Also:

• \phpseclib\Crypt\self::encrypt() -

---

sign

Create a signature

public sign(string $message): string

Parameters:

Parameter	Type	Description
$message	string

See Also:

• \phpseclib\Crypt\self::verify() -

---

verify

Verifies a signature

public verify(string $message, string $signature): bool

Parameters:

Parameter	Type	Description
$message	string
$signature	string

See Also:

• \phpseclib\Crypt\self::sign() -

---

_extractBER

Extract raw BER from Base64 encoding

public _extractBER(string $str): string

Parameters:

Parameter	Type	Description
$str	string

---

---

Automatically generated on 2025-03-18