class OpenSSL::PKey::RSA

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.

Constants

NO_PADDING
PKCS1_OAEP_PADDING
PKCS1_PADDING
SSLV23_PADDING

Public Class Methods

generate(size, exponent = 65537) → RSA

Source

# 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

Generates an RSA keypair.

Public Instance Methods

export([cipher, password]) → PEM-format String

Source

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);
}

Serializes a private or public key to a PEM-encoding.

When the key contains public components only

Serializes it into an X.509 SubjectPublicKeyInfo. The parameters cipher and password are ignored.

A PEM-encoded key will look like:

-----BEGIN PUBLIC KEY-----
[...]
-----END PUBLIC KEY-----

Consider using public_to_pem instead. This serializes the key into an X.509 SubjectPublicKeyInfo regardless of whether the key is a public key or a private key.

When the key contains private components, and no parameters are given

Serializes it into a PKCS #1 RSAPrivateKey.

A PEM-encoded key will look like:

-----BEGIN RSA PRIVATE KEY-----
[...]
-----END RSA PRIVATE KEY-----

When the key contains private components, and cipher and password are given

Serializes it into a PKCS #1 RSAPrivateKey and encrypts it in OpenSSL’s traditional PEM encryption format. cipher must be a cipher name understood by OpenSSL::Cipher.new or an instance of OpenSSL::Cipher.

An encrypted PEM-encoded key will look like:

-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: AES-128-CBC,733F5302505B34701FC41F5C0746E4C0

[...]
-----END RSA PRIVATE KEY-----

Note that this format uses MD5 to derive the encryption key, and hence will not be available on FIPS-compliant systems.

This method is kept for compatibility. This should only be used when the PKCS #1 RSAPrivateKey format is required.

Consider using public_to_pem (X.509 SubjectPublicKeyInfo) or private_to_pem (PKCS #8 PrivateKeyInfo or EncryptedPrivateKeyInfo) instead.

Also aliased as: to_pem, to_s

initialize_copy (p1)

Source

HAVE_EVP_PKEY_DUP
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;
}

params → hash

Source

static VALUE
ossl_rsa_get_params(VALUE self)
{
    OSSL_3_const 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;
}

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)

private? → true | false

Source

static VALUE
ossl_rsa_is_private(VALUE self)
{
    OSSL_3_const RSA *rsa;

    GetRSA(self, rsa);

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

Does this keypair contain a private key?

private_decrypt(string) → String

private_decrypt(string, padding) → String

Source

# File ext/openssl/lib/openssl/pkey.rb, line 439
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

Decrypt string, which has been encrypted with the public key, with the private key. padding defaults to PKCS1_PADDING, which is known to be insecure but is kept for backwards compatibility.

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

private_encrypt(string) → String

private_encrypt(string, padding) → String

Source

# File ext/openssl/lib/openssl/pkey.rb, line 373
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

Encrypt string with the private key. padding defaults to PKCS1_PADDING, which is known to be insecure but is kept for backwards compatibility. The encrypted string output can be decrypted using public_decrypt.

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

public? → true

Source

static VALUE
ossl_rsa_is_public(VALUE self)
{
    OSSL_3_const RSA *rsa;

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

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

public_decrypt(string) → String

public_decrypt(string, padding) → String

Source

# File ext/openssl/lib/openssl/pkey.rb, line 396
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

Decrypt string, which has been encrypted with the private key, with the public key. padding defaults to PKCS1_PADDING which is known to be insecure but is kept for backwards compatibility.

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

public_encrypt(string) → String

public_encrypt(string, padding) → String

Source

# File ext/openssl/lib/openssl/pkey.rb, line 418
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

Encrypt string with the public key. padding defaults to PKCS1_PADDING, which is known to be insecure but is kept for backwards compatibility. The encrypted string output can be decrypted using private_decrypt.

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

public_key → rsanew

Source

# File ext/openssl/lib/openssl/pkey.rb, line 327
def public_key
  OpenSSL::PKey.read(public_to_der)
end

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.

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.

set_factors(p, q) → self

Sets p, q for the RSA instance.

set_key(n, e, d) → self

Sets n, e, d for the RSA instance.

sign_pss(digest, data, salt_length:, mgf1_hash:) → String

Source

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);
}

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

to_der → DER-format String

Source

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);
}

Serializes a private or public key to a DER-encoding.

See to_pem for details.

This method is kept for compatibility. This should only be used when the PKCS #1 RSAPrivateKey format is required.

Consider using public_to_der or private_to_der instead.

to_pem([cipher, password]) → PEM-format String

Serializes a private or public key to a PEM-encoding.

When the key contains public components only

Serializes it into an X.509 SubjectPublicKeyInfo. The parameters cipher and password are ignored.

A PEM-encoded key will look like:

-----BEGIN PUBLIC KEY-----
[...]
-----END PUBLIC KEY-----

Consider using public_to_pem instead. This serializes the key into an X.509 SubjectPublicKeyInfo regardless of whether the key is a public key or a private key.

When the key contains private components, and no parameters are given

Serializes it into a PKCS #1 RSAPrivateKey.

A PEM-encoded key will look like:

-----BEGIN RSA PRIVATE KEY-----
[...]
-----END RSA PRIVATE KEY-----

When the key contains private components, and cipher and password are given

An encrypted PEM-encoded key will look like:

-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: AES-128-CBC,733F5302505B34701FC41F5C0746E4C0

[...]
-----END RSA PRIVATE KEY-----

Note that this format uses MD5 to derive the encryption key, and hence will not be available on FIPS-compliant systems.

This method is kept for compatibility. This should only be used when the PKCS #1 RSAPrivateKey format is required.

Consider using public_to_pem (X.509 SubjectPublicKeyInfo) or private_to_pem (PKCS #8 PrivateKeyInfo or EncryptedPrivateKeyInfo) instead.

Alias for: export

to_s([cipher, password]) → PEM-format String

Serializes a private or public key to a PEM-encoding.

When the key contains public components only

Serializes it into an X.509 SubjectPublicKeyInfo. The parameters cipher and password are ignored.

A PEM-encoded key will look like:

-----BEGIN PUBLIC KEY-----
[...]
-----END PUBLIC KEY-----

Consider using public_to_pem instead. This serializes the key into an X.509 SubjectPublicKeyInfo regardless of whether the key is a public key or a private key.

When the key contains private components, and no parameters are given

Serializes it into a PKCS #1 RSAPrivateKey.

A PEM-encoded key will look like:

-----BEGIN RSA PRIVATE KEY-----
[...]
-----END RSA PRIVATE KEY-----

When the key contains private components, and cipher and password are given

An encrypted PEM-encoded key will look like:

-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: AES-128-CBC,733F5302505B34701FC41F5C0746E4C0

[...]
-----END RSA PRIVATE KEY-----

Note that this format uses MD5 to derive the encryption key, and hence will not be available on FIPS-compliant systems.

This method is kept for compatibility. This should only be used when the PKCS #1 RSAPrivateKey format is required.

Consider using public_to_pem (X.509 SubjectPublicKeyInfo) or private_to_pem (PKCS #8 PrivateKeyInfo or EncryptedPrivateKeyInfo) instead.

Alias for: export

verify_pss(digest, signature, data, salt_length:, mgf1_hash:) → true | false

Source

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);
}

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.

Private Instance Methods

translate_padding_mode (num)

Source

# File ext/openssl/lib/openssl/pkey.rb, line 456
        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