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Class: OpenSSL::PKey::RSA

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, PKey
Instance Chain:
Inherits: OpenSSL::PKey::PKey
Defined in: ext/openssl/ossl_pkey_rsa.c,
ext/openssl/lib/openssl/pkey.rb

Overview

RSA is an asymmetric public key algorithm that has been formalized in RFC 3447. It is in widespread use in public key infrastructures (PKI) where certificates (cf. ::OpenSSL::X509::Certificate) often are issued on the basis of a public/private RSA key pair. RSA is used in a wide field of applications such as secure (symmetric) key exchange, e.g. when establishing a secure TLS/SSL connection. It is also used in various digital signature schemes.

Constant Summary

Class Method Summary

PKey - Inherited

.new

Because PKey is an abstract class, actually calling this method explicitly will raise a NotImplementedError.

Instance Attribute Summary

Instance Method Summary

::OpenSSL::Marshal - Included

PKey - Inherited

#compare?

Used primarily to check if an X509::Certificate#public_key compares to its private key.

#decrypt

Performs a public key decryption operation using pkey.

#derive

Derives a shared secret from pkey and peer_pkey.

#encrypt

Performs a public key encryption operation using pkey.

#initialize_copy,
#inspect

Returns a string describing the PKey object.

#oid

Returns the short name of the OID associated with pkey.

#private_to_der

Serializes the private key to DER-encoded PKCS #8 format.

#private_to_pem

Serializes the private key to PEM-encoded PKCS #8 format.

#public_to_der

Serializes the public key to DER-encoded X.509 SubjectPublicKeyInfo format.

#public_to_pem

Serializes the public key to PEM-encoded X.509 SubjectPublicKeyInfo format.

#sign

Hashes and signs the data using a message digest algorithm digest and a private key pkey.

#sign_raw

Signs data using a private key pkey.

#to_text

Dumps key parameters, public key, and private key components contained in the key into a human-readable text.

#verify

Verifies the signature for the data using a message digest algorithm digest and a public key pkey.

#verify_raw

Verifies the signature for the data using a public key pkey.

#verify_recover

Recovers the signed data from signature using a public key pkey.

Constructor Details

.newRSA .new(encoded_key [, passphrase]) ⇒ RSA .new(encoded_key) ⇒ RSA .new(size [, exponent]) ⇒ RSA

This method is for internal use only.

Generates or loads an RSA keypair.

If called without arguments, creates a new instance with no key components set. They can be set individually by #set_key, #set_factors, and #set_crt_params.

If called with a String, tries to parse as DER or PEM encoding of an RSA key. Note that, if passphrase is not specified but the key is encrypted with a passphrase, OpenSSL will prompt for it. See also OpenSSL::PKey.read which can parse keys of any kinds.

If called with a number, generates a new key pair. This form works as an alias of .generate.

Examples:

OpenSSL::PKey::RSA.new 2048
OpenSSL::PKey::RSA.new File.read 'rsa.pem'
OpenSSL::PKey::RSA.new File.read('rsa.pem'), 'my pass phrase'
[ GitHub ]

  
# File 'ext/openssl/ossl_pkey_rsa.c', line 76

static VALUE
ossl_rsa_initialize(int argc, VALUE *argv, VALUE self)
{
    EVP_PKEY *pkey;
    RSA *rsa;
    BIO *in = NULL;
    VALUE arg, pass;
    int type;

    TypedData_Get_Struct(self, EVP_PKEY, &ossl_evp_pkey_type, pkey);
    if (pkey)
        rb_raise(rb_eTypeError, "pkey already initialized");

    /* The RSA.new(size, generator) form is handled by lib/openssl/pkey.rb */
    rb_scan_args(argc, argv, "02", &arg, &pass);
    if (argc == 0) {
	rsa = RSA_new();
        if (!rsa)
            ossl_raise(eRSAError, "RSA_new");
        goto legacy;
    }

    pass = ossl_pem_passwd_value(pass);
    arg = ossl_to_der_if_possible(arg);
    in = ossl_obj2bio(&arg);

    /* First try RSAPublicKey format */
    rsa = d2i_RSAPublicKey_bio(in, NULL);
    if (rsa)
        goto legacy;
    OSSL_BIO_reset(in);
    rsa = PEM_read_bio_RSAPublicKey(in, NULL, NULL, NULL);
    if (rsa)
        goto legacy;
    OSSL_BIO_reset(in);

    /* Use the generic routine */
    pkey = ossl_pkey_read_generic(in, pass);
    BIO_free(in);
    if (!pkey)
        ossl_raise(eRSAError, "Neither PUB key nor PRIV key");

    type = EVP_PKEY_base_id(pkey);
    if (type != EVP_PKEY_RSA) {
        EVP_PKEY_free(pkey);
        rb_raise(eRSAError, "incorrect pkey type: %s", OBJ_nid2sn(type));
    }
    RTYPEDDATA_DATA(self) = pkey;
    return self;

  legacy:
    BIO_free(in);
    pkey = EVP_PKEY_new();
    if (!pkey || EVP_PKEY_assign_RSA(pkey, rsa) != 1) {
        EVP_PKEY_free(pkey);
        RSA_free(rsa);
        ossl_raise(eRSAError, "EVP_PKEY_assign_RSA");
    }
    RTYPEDDATA_DATA(self) = pkey;
    return self;
}

Class Method Details

.generate(size, exponent = 65537) ⇒ RSA

Generates an RSA keypair.

See also OpenSSL::PKey.generate_key.

size

The desired key size in bits.

exponent

An odd Integer, normally 3, 17, or 65537.

[ GitHub ]

  
# File 'ext/openssl/lib/openssl/pkey.rb', line 343

def generate(size, exp = 0x10001, &blk)
  OpenSSL::PKey.generate_key("RSA", {
    "rsa_keygen_bits" => size,
    "rsa_keygen_pubexp" => exp,
  }, &blk)
end

Instance Attribute Details

#private?Boolean (readonly)

Does this keypair contain a private key?

[ GitHub ]

  
# File 'ext/openssl/ossl_pkey_rsa.c', line 193

static VALUE
ossl_rsa_is_private(VALUE self)
{
    RSA *rsa;

    GetRSA(self, rsa);

    return RSA_PRIVATE(self, rsa) ? Qtrue : Qfalse;
}

#public?Boolean (readonly)

The return value is always true since every private key is also a public key.

[ GitHub ]

  
# File 'ext/openssl/ossl_pkey_rsa.c', line 174

static VALUE
ossl_rsa_is_public(VALUE self)
{
    RSA *rsa;

    GetRSA(self, rsa);
    /*
     * This method should check for n and e.  BUG.
     */
    (void)rsa;
    return Qtrue;
}

Instance Method Details

#export([cipher, pass_phrase]) ⇒ PEM-format String #to_pem([cipher, pass_phrase]) ⇒ PEM-format String #to_s([cipher, pass_phrase]) ⇒ PEM-format String

Alias for #to_s.

#initialize_copy(other)

[ GitHub ]

  
# File 'ext/openssl/ossl_pkey_rsa.c', line 139

static VALUE
ossl_rsa_initialize_copy(VALUE self, VALUE other)
{
    EVP_PKEY *pkey;
    RSA *rsa, *rsa_new;

    TypedData_Get_Struct(self, EVP_PKEY, &ossl_evp_pkey_type, pkey);
    if (pkey)
        rb_raise(rb_eTypeError, "pkey already initialized");
    GetRSA(other, rsa);

    rsa_new = (RSA *)ASN1_dup((i2d_of_void *)i2d_RSAPrivateKey,
                              (d2i_of_void *)d2i_RSAPrivateKey,
                              (char *)rsa);
    if (!rsa_new)
	ossl_raise(eRSAError, "ASN1_dup");

    pkey = EVP_PKEY_new();
    if (!pkey || EVP_PKEY_assign_RSA(pkey, rsa_new) != 1) {
        RSA_free(rsa_new);
        ossl_raise(eRSAError, "EVP_PKEY_assign_RSA");
    }
    RTYPEDDATA_DATA(self) = pkey;

    return self;
}

#paramsHash

THIS METHOD IS INSECURE, PRIVATE INFORMATION CAN LEAK OUT!!!

Stores all parameters of key to the hash. The hash has keys ‘n’, ‘e’, ‘d’, ‘p’, ‘q’, ‘dmp1’, ‘dmq1’, ‘iqmp’.

Don’t use :-)) (It’s up to you)

[ GitHub ]

  
# File 'ext/openssl/ossl_pkey_rsa.c', line 453

static VALUE
ossl_rsa_get_params(VALUE self)
{
    RSA *rsa;
    VALUE hash;
    const BIGNUM *n, *e, *d, *p, *q, *dmp1, *dmq1, *iqmp;

    GetRSA(self, rsa);
    RSA_get0_key(rsa, &n, &e, &d);
    RSA_get0_factors(rsa, &p, &q);
    RSA_get0_crt_params(rsa, &dmp1, &dmq1, &iqmp);

    hash = rb_hash_new();
    rb_hash_aset(hash, rb_str_new2("n"), ossl_bn_new(n));
    rb_hash_aset(hash, rb_str_new2("e"), ossl_bn_new(e));
    rb_hash_aset(hash, rb_str_new2("d"), ossl_bn_new(d));
    rb_hash_aset(hash, rb_str_new2("p"), ossl_bn_new(p));
    rb_hash_aset(hash, rb_str_new2("q"), ossl_bn_new(q));
    rb_hash_aset(hash, rb_str_new2("dmp1"), ossl_bn_new(dmp1));
    rb_hash_aset(hash, rb_str_new2("dmq1"), ossl_bn_new(dmq1));
    rb_hash_aset(hash, rb_str_new2("iqmp"), ossl_bn_new(iqmp));

    return hash;
}

#private_decrypt(string) ⇒ String #private_decrypt(string, padding) ⇒ String

Decrypt string, which has been encrypted with the public key, with the private key. padding defaults to PKCS1_PADDING.

Deprecated in version 3.0. Consider using PKey#encrypt and PKey#decrypt instead.

[ GitHub ]

  
# File 'ext/openssl/lib/openssl/pkey.rb', line 435

def private_decrypt(data, padding = PKCS1_PADDING)
  n or raise OpenSSL::PKey::RSAError, "incomplete RSA"
  private? or raise OpenSSL::PKey::RSAError, "private key needed."
  begin
    decrypt(data, {
      "rsa_padding_mode" => translate_padding_mode(padding),
    })
  rescue OpenSSL::PKey::PKeyError
    raise OpenSSL::PKey::RSAError, $!.message
  end
end

#private_encrypt(string) ⇒ String #private_encrypt(string, padding) ⇒ String

Encrypt string with the private key. padding defaults to PKCS1_PADDING. The encrypted string output can be decrypted using #public_decrypt.

Deprecated in version 3.0. Consider using PKey#sign_raw and PKey#verify_raw, and PKey#verify_recover instead.

[ GitHub ]

  
# File 'ext/openssl/lib/openssl/pkey.rb', line 372

def private_encrypt(string, padding = PKCS1_PADDING)
  n or raise OpenSSL::PKey::RSAError, "incomplete RSA"
  private? or raise OpenSSL::PKey::RSAError, "private key needed."
  begin
    sign_raw(nil, string, {
      "rsa_padding_mode" => translate_padding_mode(padding),
    })
  rescue OpenSSL::PKey::PKeyError
    raise OpenSSL::PKey::RSAError, $!.message
  end
end

#public_decrypt(string) ⇒ String #public_decrypt(string, padding) ⇒ String

Decrypt string, which has been encrypted with the private key, with the public key. padding defaults to PKCS1_PADDING.

Deprecated in version 3.0. Consider using PKey#sign_raw and PKey#verify_raw, and PKey#verify_recover instead.

[ GitHub ]

  
# File 'ext/openssl/lib/openssl/pkey.rb', line 394

def public_decrypt(string, padding = PKCS1_PADDING)
  n or raise OpenSSL::PKey::RSAError, "incomplete RSA"
  begin
    verify_recover(nil, string, {
      "rsa_padding_mode" => translate_padding_mode(padding),
    })
  rescue OpenSSL::PKey::PKeyError
    raise OpenSSL::PKey::RSAError, $!.message
  end
end

#public_encrypt(string) ⇒ String #public_encrypt(string, padding) ⇒ String

Encrypt string with the public key. padding defaults to PKCS1_PADDING. The encrypted string output can be decrypted using #private_decrypt.

Deprecated in version 3.0. Consider using PKey#encrypt and PKey#decrypt instead.

[ GitHub ]

  
# File 'ext/openssl/lib/openssl/pkey.rb', line 415

def public_encrypt(data, padding = PKCS1_PADDING)
  n or raise OpenSSL::PKey::RSAError, "incomplete RSA"
  begin
    encrypt(data, {
      "rsa_padding_mode" => translate_padding_mode(padding),
    })
  rescue OpenSSL::PKey::PKeyError
    raise OpenSSL::PKey::RSAError, $!.message
  end
end

#public_keyRSA

Returns a new RSA instance that carries just the public key components.

This method is provided for backwards compatibility. In most cases, there is no need to call this method.

For the purpose of serializing the public key, to PEM or DER encoding of X.509 SubjectPublicKeyInfo format, check PKey#public_to_pem and PKey#public_to_der.

[ GitHub ]

  
# File 'ext/openssl/lib/openssl/pkey.rb', line 327

def public_key
  OpenSSL::PKey.read(public_to_der)
end

#set_crt_params(dmp1, dmq1, iqmp) ⇒ self

Sets dmp1, dmq1, iqmp for the RSA instance. They are calculated by d mod (p - 1), d mod (q - 1) and q^(-1) mod p respectively.

[ GitHub ]

#set_factors(p, q) ⇒ self

Sets p, q for the RSA instance.

[ GitHub ]

#set_key(n, e, d) ⇒ self

Sets n, e, d for the RSA instance.

[ GitHub ]

#sign_pss(digest, data, salt_length:, mgf1_hash:) ⇒ String

Signs data using the Probabilistic Signature Scheme (RSA-PSS) and returns the calculated signature.

RSAError will be raised if an error occurs.

See #verify_pss for the verification operation.

Parameters

digest

A String containing the message digest algorithm name.

data

A String. The data to be signed.

salt_length

The length in octets of the salt. Two special values are reserved: :digest means the digest length, and :max means the maximum possible length for the combination of the private key and the selected message digest algorithm.

mgf1_hash

The hash algorithm used in MGF1 (the currently supported mask generation function (MGF)).

Example

data = "Sign me!"
pkey = OpenSSL::PKey::RSA.new(2048)
signature = pkey.sign_pss("SHA256", data, salt_length: :max, mgf1_hash: "SHA256")
pub_key = OpenSSL::PKey.read(pkey.public_to_der)
puts pub_key.verify_pss("SHA256", signature, data,
                        salt_length: :auto, mgf1_hash: "SHA256") # => true
[ GitHub ]

  
# File 'ext/openssl/ossl_pkey_rsa.c', line 285

static VALUE
ossl_rsa_sign_pss(int argc, VALUE *argv, VALUE self)
{
    VALUE digest, data, options, kwargs[2], signature;
    static ID kwargs_ids[2];
    EVP_PKEY *pkey;
    EVP_PKEY_CTX *pkey_ctx;
    const EVP_MD *md, *mgf1md;
    EVP_MD_CTX *md_ctx;
    size_t buf_len;
    int salt_len;

    if (!kwargs_ids[0]) {
	kwargs_ids[0] = rb_intern_const("salt_length");
	kwargs_ids[1] = rb_intern_const("mgf1_hash");
    }
    rb_scan_args(argc, argv, "2:", &digest, &data, &options);
    rb_get_kwargs(options, kwargs_ids, 2, 0, kwargs);
    if (kwargs[0] == ID2SYM(rb_intern("max")))
	salt_len = -2; /* RSA_PSS_SALTLEN_MAX_SIGN */
    else if (kwargs[0] == ID2SYM(rb_intern("digest")))
	salt_len = -1; /* RSA_PSS_SALTLEN_DIGEST */
    else
	salt_len = NUM2INT(kwargs[0]);
    mgf1md = ossl_evp_get_digestbyname(kwargs[1]);

    pkey = GetPrivPKeyPtr(self);
    buf_len = EVP_PKEY_size(pkey);
    md = ossl_evp_get_digestbyname(digest);
    StringValue(data);
    signature = rb_str_new(NULL, (long)buf_len);

    md_ctx = EVP_MD_CTX_new();
    if (!md_ctx)
	goto err;

    if (EVP_DigestSignInit(md_ctx, &pkey_ctx, md, NULL, pkey) != 1)
	goto err;

    if (EVP_PKEY_CTX_set_rsa_padding(pkey_ctx, RSA_PKCS1_PSS_PADDING) != 1)
	goto err;

    if (EVP_PKEY_CTX_set_rsa_pss_saltlen(pkey_ctx, salt_len) != 1)
	goto err;

    if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkey_ctx, mgf1md) != 1)
	goto err;

    if (EVP_DigestSignUpdate(md_ctx, RSTRING_PTR(data), RSTRING_LEN(data)) != 1)
	goto err;

    if (EVP_DigestSignFinal(md_ctx, (unsigned char *)RSTRING_PTR(signature), &buf_len) != 1)
	goto err;

    rb_str_set_len(signature, (long)buf_len);

    EVP_MD_CTX_free(md_ctx);
    return signature;

  err:
    EVP_MD_CTX_free(md_ctx);
    ossl_raise(eRSAError, NULL);
}

#to_derDER-format String

Outputs this keypair in DER encoding.

[ GitHub ]

  
# File 'ext/openssl/ossl_pkey_rsa.c', line 243

static VALUE
ossl_rsa_to_der(VALUE self)
{
    if (can_export_rsaprivatekey(self))
        return ossl_pkey_export_traditional(0, NULL, self, 1);
    else
        return ossl_pkey_export_spki(self, 1);
}

#export([cipher, pass_phrase]) ⇒ PEM-format String #to_pem([cipher, pass_phrase]) ⇒ PEM-format String #to_s([cipher, pass_phrase]) ⇒ PEM-format String

Alias for #to_s.

#export([cipher, pass_phrase]) ⇒ PEM-format String #to_pem([cipher, pass_phrase]) ⇒ PEM-format String #to_s([cipher, pass_phrase]) ⇒ PEM-format String
Also known as: #export, #to_pem

Outputs this keypair in PEM encoding. If cipher and pass_phrase are given they will be used to encrypt the key. cipher must be an ::OpenSSL::Cipher instance.

[ GitHub ]

  
# File 'ext/openssl/ossl_pkey_rsa.c', line 228

static VALUE
ossl_rsa_export(int argc, VALUE *argv, VALUE self)
{
    if (can_export_rsaprivatekey(self))
        return ossl_pkey_export_traditional(argc, argv, self, 0);
    else
        return ossl_pkey_export_spki(self, 0);
}

#translate_padding_mode(num) (private)

[ GitHub ]

  
# File 'ext/openssl/lib/openssl/pkey.rb', line 452

private def translate_padding_mode(num)
  case num
  when PKCS1_PADDING
    "pkcs1"
  when SSLV23_PADDING
    "sslv23"
  when NO_PADDING
    "none"
  when PKCS1_OAEP_PADDING
    "oaep"
  else
    raise OpenSSL::PKey::PKeyError, "unsupported padding mode"
  end
end

#verify_pss(digest, signature, data, salt_length:, mgf1_hash:) ⇒ Boolean

Verifies data using the Probabilistic Signature Scheme (RSA-PSS).

The return value is true if the signature is valid, false otherwise. RSAError will be raised if an error occurs.

See #sign_pss for the signing operation and an example code.

Parameters

digest

A String containing the message digest algorithm name.

data

A String. The data to be signed.

salt_length

The length in octets of the salt. Two special values are reserved: :digest means the digest length, and :auto means automatically determining the length based on the signature.

mgf1_hash

The hash algorithm used in MGF1.

[ GitHub ]

  
# File 'ext/openssl/ossl_pkey_rsa.c', line 372

static VALUE
ossl_rsa_verify_pss(int argc, VALUE *argv, VALUE self)
{
    VALUE digest, signature, data, options, kwargs[2];
    static ID kwargs_ids[2];
    EVP_PKEY *pkey;
    EVP_PKEY_CTX *pkey_ctx;
    const EVP_MD *md, *mgf1md;
    EVP_MD_CTX *md_ctx;
    int result, salt_len;

    if (!kwargs_ids[0]) {
	kwargs_ids[0] = rb_intern_const("salt_length");
	kwargs_ids[1] = rb_intern_const("mgf1_hash");
    }
    rb_scan_args(argc, argv, "3:", &digest, &signature, &data, &options);
    rb_get_kwargs(options, kwargs_ids, 2, 0, kwargs);
    if (kwargs[0] == ID2SYM(rb_intern("auto")))
	salt_len = -2; /* RSA_PSS_SALTLEN_AUTO */
    else if (kwargs[0] == ID2SYM(rb_intern("digest")))
	salt_len = -1; /* RSA_PSS_SALTLEN_DIGEST */
    else
	salt_len = NUM2INT(kwargs[0]);
    mgf1md = ossl_evp_get_digestbyname(kwargs[1]);

    GetPKey(self, pkey);
    md = ossl_evp_get_digestbyname(digest);
    StringValue(signature);
    StringValue(data);

    md_ctx = EVP_MD_CTX_new();
    if (!md_ctx)
	goto err;

    if (EVP_DigestVerifyInit(md_ctx, &pkey_ctx, md, NULL, pkey) != 1)
	goto err;

    if (EVP_PKEY_CTX_set_rsa_padding(pkey_ctx, RSA_PKCS1_PSS_PADDING) != 1)
	goto err;

    if (EVP_PKEY_CTX_set_rsa_pss_saltlen(pkey_ctx, salt_len) != 1)
	goto err;

    if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkey_ctx, mgf1md) != 1)
	goto err;

    if (EVP_DigestVerifyUpdate(md_ctx, RSTRING_PTR(data), RSTRING_LEN(data)) != 1)
	goto err;

    result = EVP_DigestVerifyFinal(md_ctx,
				   (unsigned char *)RSTRING_PTR(signature),
				   RSTRING_LEN(signature));

    switch (result) {
      case 0:
	ossl_clear_error();
	EVP_MD_CTX_free(md_ctx);
	return Qfalse;
      case 1:
	EVP_MD_CTX_free(md_ctx);
	return Qtrue;
      default:
	goto err;
    }

  err:
    EVP_MD_CTX_free(md_ctx);
    ossl_raise(eRSAError, NULL);
}