Crypto Key Generate Rsa Modulus 1024 Means

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Aug 03, 2007 Modulus Length. When you generate RSA keys, you will be prompted to enter a modulus length. A longer modulus could offer stronger security but takes longer to generate (see Table 24 for sample times) and takes longer to use. (The Cisco IOS software does not support a modulus greater than 2048 bits.).

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RSA is the most widespread and used public key algorithm. Its security isbased on the difficulty of factoring large integers. The algorithm haswithstood attacks for more than 30 years, and it is therefore consideredreasonably secure for new designs.

Foghorn(config)#crypto key generate rsa The name for the keys will be: foghorn.thetechfirm.com Choose the size of the key modulus in the range of 360 to 2048 for your. By 2020, the main practical threat to systems still using 1024-bit RSA to protect commercial assets often is not factorization of a public modulus; but rather, penetration of the IT infrastructure by other means, such as hacking, and trust in digital certificates issued to entities that should not be trusted. With 2048 bits or more we are safe. Is it possible to encrypt a message with a private key in python using pycryptodome or any other library? I know that you are not supposed to encrypt with the private key and decrypt with the public key, but my purpose is to encrypt with the private one so the receiver could be.

The algorithm can be used for both confidentiality (encryption) andauthentication (digital signature). It is worth noting that signing anddecryption are significantly slower than verification and encryption.

The cryptographic strength is primarily linked to the length of the RSA modulus n.In 2017, a sufficient length is deemed to be 2048 bits. For more information,see the most recent ECRYPT report.

Both RSA ciphertexts and RSA signatures are as large as the RSA modulus n (256bytes if n is 2048 bit long).

The module Crypto.PublicKey.RSA provides facilities for generating new RSA keys,reconstructing them from known components, exporting them, and importing them.

As an example, this is how you generate a new RSA key pair, save it in a filecalled mykey.pem, and then read it back:

Crypto.PublicKey.RSA.generate(bits, randfunc=None, e=65537)

Create a new RSA key pair.

The algorithm closely follows NIST FIPS 186-4 in itssections B.3.1 and B.3.3. The modulus is the product oftwo non-strong probable primes.Each prime passes a suitable number of Miller-Rabin testswith random bases and a single Lucas test.

Parameters:
  • bits (integer) – Key length, or size (in bits) of the RSA modulus.It must be at least 1024, but 2048 is recommended.The FIPS standard only defines 1024, 2048 and 3072.
  • randfunc (callable) – Function that returns random bytes.The default is Crypto.Random.get_random_bytes().
  • e (integer) – Public RSA exponent. It must be an odd positive integer.It is typically a small number with very few ones in itsbinary representation.The FIPS standard requires the public exponent to beat least 65537 (the default).

Returns: an RSA key object (RsaKey, with private key).

Crypto.PublicKey.RSA.construct(rsa_components, consistency_check=True)

Construct an RSA key from a tuple of valid RSA components.

The modulus n must be the product of two primes.The public exponent e must be odd and larger than 1.

In case of a private key, the following equations must apply:

[begin{split}begin{align}p*q &= n e*d &equiv 1 ( text{mod lcm} [(p-1)(q-1)]) p*u &equiv 1 ( text{mod } q)end{align}end{split}]
Parameters:
  • rsa_components (tuple) –

    A tuple of integers, with at least 2 and nomore than 6 items. The items come in the following order:

    1. RSA modulus n.
    2. Public exponent e.
    3. Private exponent d.Only required if the key is private.
    4. First factor of n (p).Optional, but the other factor q must also be present.
    5. Second factor of n (q). Optional.
    6. CRT coefficient q, that is (p^{-1} text{mod }q). Optional.
  • consistency_check (boolean) – If True, the library will verify that the provided componentsfulfil the main RSA properties.
Raises:

Fl studio free for mac. ValueError – when the key being imported fails the most basic RSA validity checks.

Returns: An RSA key object (RsaKey).

Crypto.PublicKey.RSA.import_key(extern_key, passphrase=None)

Import an RSA key (public or private).

Parameters:
  • extern_key (string or byte string) –

    The RSA key to import.

    The following formats are supported for an RSA public key:

    • X.509 certificate (binary or PEM format)
    • X.509 subjectPublicKeyInfo DER SEQUENCE (binary or PEMencoding)
    • PKCS#1RSAPublicKey DER SEQUENCE (binary or PEM encoding)
    • An OpenSSH line (e.g. the content of ~/.ssh/id_ecdsa, ASCII)

    The following formats are supported for an RSA private key:

    • PKCS#1 RSAPrivateKey DER SEQUENCE (binary or PEM encoding)
    • PKCS#8PrivateKeyInfo or EncryptedPrivateKeyInfoDER SEQUENCE (binary or PEM encoding)
    • OpenSSH (text format, introduced in OpenSSH 6.5)

    For details about the PEM encoding, see RFC1421/RFC1423.

  • passphrase (string or byte string) – For private keys only, the pass phrase that encrypts the key.

Returns: An RSA key object (RsaKey).

Raises:ValueError/IndexError/TypeError – When the given key cannot be parsed (possibly because the passphrase is wrong).
class Crypto.PublicKey.RSA.RsaKey(**kwargs)

Class defining an actual RSA key.Do not instantiate directly.Use generate(), construct() or import_key() instead.

Variables:
  • n (integer) – RSA modulus
  • e (integer) – RSA public exponent
  • d (integer) – RSA private exponent
  • p (integer) – First factor of the RSA modulus
  • q (integer) – Second factor of the RSA modulus
  • u – Chinese remainder component ((p^{-1} text{mod } q))
exportKey(format='PEM', passphrase=None, pkcs=1, protection=None, randfunc=None)

Export this RSA key.

Parameters:
  • format (string) –

    The format to use for wrapping the key:

    • ’PEM’. (Default) Text encoding, done according to RFC1421/RFC1423.
    • ’DER’. Binary encoding.
    • ’OpenSSH’. Textual encoding, done according to OpenSSH specification.Only suitable for public keys (not private keys).
  • passphrase (string) – (For private keys only) The pass phrase used for protecting the output.
  • pkcs (integer) –

    (For private keys only) The ASN.1 structure to use forserializing the key. Note that even in case of PEMencoding, there is an inner ASN.1 DER structure.

    With pkcs=1 (default), the private key is encoded in asimple PKCS#1 structure (RSAPrivateKey).

    With pkcs=8, the private key is encoded in a PKCS#8 structure(PrivateKeyInfo). Git ssh key generate windows.

    Note

    /how-is-surrogate-key-generated.html. This parameter is ignored for a public key.For DER and PEM, an ASN.1 DER SubjectPublicKeyInfostructure is always used.

  • protection (string) –

    (For private keys only)The encryption scheme to use for protecting the private key.

    If None (default), the behavior depends on format:

    • For ‘DER’, the PBKDF2WithHMAC-SHA1AndDES-EDE3-CBCscheme is used. The following operations are performed:
      1. A 16 byte Triple DES key is derived from the passphraseusing Crypto.Protocol.KDF.PBKDF2() with 8 bytes salt,and 1 000 iterations of Crypto.Hash.HMAC.
      2. The private key is encrypted using CBC.
      3. The encrypted key is encoded according to PKCS#8.
    • For ‘PEM’, the obsolete PEM encryption scheme is used.It is based on MD5 for key derivation, and Triple DES for encryption.

    Specifying a value for protection is only meaningful for PKCS#8(that is, pkcs=8) and only if a pass phrase is present too.

    The supported schemes for PKCS#8 are listed in theCrypto.IO.PKCS8 module (see wrap_algo parameter).

  • randfunc (callable) – A function that provides random bytes. Only used for PEM encoding.The default is Crypto.Random.get_random_bytes().
Returns:

the encoded key

Return type:

byte string

Raises:

ValueError – when the format is unknown or when you try to encrypt a privatekey with DER format and PKCS#1.

Warning

If you don’t provide a pass phrase, the private key will beexported in the clear!

export_key(format='PEM', passphrase=None, pkcs=1, protection=None, randfunc=None)

Export this RSA key.

Parameters:
  • format (string) –

    The format to use for wrapping the key:

    • ’PEM’. (Default) Text encoding, done according to RFC1421/RFC1423.
    • ’DER’. Binary encoding.
    • ’OpenSSH’. Textual encoding, done according to OpenSSH specification.Only suitable for public keys (not private keys).
  • passphrase (string) – (For private keys only) The pass phrase used for protecting the output.
  • pkcs (integer) –

    (For private keys only) The ASN.1 structure to use forserializing the key. Note that even in case of PEMencoding, there is an inner ASN.1 DER structure.

    With pkcs=1 (default), the private key is encoded in asimple PKCS#1 structure (RSAPrivateKey).

    With pkcs=8, the private key is encoded in a PKCS#8 structure(PrivateKeyInfo).

    Note

    This parameter is ignored for a public key.For DER and PEM, an ASN.1 DER SubjectPublicKeyInfostructure is always used.

  • protection (string) –

    (For private keys only)The encryption scheme to use for protecting the private key.

    If None (default), the behavior depends on format:

    • For ‘DER’, the PBKDF2WithHMAC-SHA1AndDES-EDE3-CBCscheme is used. The following operations are performed:
      1. A 16 byte Triple DES key is derived from the passphraseusing Crypto.Protocol.KDF.PBKDF2() with 8 bytes salt,and 1 000 iterations of Crypto.Hash.HMAC.
      2. The private key is encrypted using CBC.
      3. The encrypted key is encoded according to PKCS#8.
    • For ‘PEM’, the obsolete PEM encryption scheme is used.It is based on MD5 for key derivation, and Triple DES for encryption.

    Specifying a value for protection is only meaningful for PKCS#8(that is, pkcs=8) and only if a pass phrase is present too.

    The supported schemes for PKCS#8 are listed in theCrypto.IO.PKCS8 module (see wrap_algo parameter).

  • randfunc (callable) – A function that provides random bytes. Only used for PEM encoding.The default is Crypto.Random.get_random_bytes().
Returns:

the encoded key

Return type:

byte string

Raises:

ValueError – when the format is unknown or when you try to encrypt a privatekey with DER format and PKCS#1.

Warning

If you don’t provide a pass phrase, the private key will beexported in the clear!

has_private()

Whether this is an RSA private key

publickey()

A matching RSA public key.

Returns:a new RsaKey object
size_in_bits()

Size of the RSA modulus in bits

size_in_bytes()

The minimal amount of bytes that can hold the RSA modulus

Crypto.PublicKey.RSA.oid = '1.2.840.113549.1.1.1'

Object ID for the RSA encryption algorithm. This OID often indicatesa generic RSA key, even when such key will be actually used for digitalsignatures.

Telnet versus SSH

Many people continue to use Telnet for sensitive applications or access to critical systems. Telnet is CLEARTEXT, so all the data, including the login id is visible is someone intercepts that session

Here’s what this looks like using Wireshark an Open Source Protocol Analyzer when we use the Follow TCP Stream feature in Wireshark.

The next characters are red (the character I typed) and blue (the characters echoed back)

You clearly see the User Verification Prompt.Here's the telnet trace file.

Below you can see me typing in my username;

In this screenshot below you can see me entering the commandenable and the the enable password.

How to Enable SSH Version 1 on Cisco

Before you can enable SSH you need to assign individual (or group) user IDs and passwords.

These are just login id's and are required regardless if you use Telnet or SSH.

To enable locally administered user IDs, use the following set of configuration commands. I would not suggest using the nopassword parameter.

Put your own data in the italized text.

Now when you telnet into the device you should see the Username prompt

User Access Verification
Username: fortunato
Password:
foghorn>

Cisco Generate Crypto Key

Now that you have login id's created you can turn on SSH version 1.

To enable SSH, use the following set of configuration commands. I would not suggest using the nopassword parameter.

Put your own data in the italized text.

foghorn#configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

foghorn(config)#crypto key generate rsa

% Please define a domain-name first.! common mistake when you do not the IP domain-name created

foghorn(config)#ip domain-name thetechfirm.com

foghorn(config)#crypto key generate rsa

The name for the keys will be: foghorn.thetechfirm.com

Choose the size of the key modulus in the range of 360 to 2048 for your

General Purpose Keys. Choosing a key modulus greater than 512 may take a few minutes.

How many bits in the modulus [512]: 1024

% Generating 1024 bit RSA keys .[OK]

foghorn(config)#ip ssh time-out 120

foghorn(config)#ip ssh authentication-retries 5

foghorn(config)#end

Now we'll try to capture the SSH login and as you can see the login data is no longer in clear text. Here's the SSH 1 trace file.

The moral of the story is not to use Cleartext logins if the device or application is sensitive.

Crypto Key Generate Rsa Modulus 1024 Means Meaning

To upgrade to even more secure SSH version 2, type in the following commands

foghorn(config)#ip ssh version 2
foghorn(config)#no ip ssh version 1
foghorn(config)#end

the SSH version 2 trace files are here

Crypto Key Generate Rsa Modulus 1024 Means 1

In this write up I used;

Crypto Key Generate Rsa Modulus 1024 Means In Hindi

  • Wireshark Protocol Analyzer(free)

  • Putty Telnet/SSH Client(free)

  • Cisco Switch(not free)