A secure RSA encryption is implemented with an appropriate padding scheme, which includes some randomness. See PKCS#1 or OAEP for more details. The RSA encryption encrypts message padded with ‘0’s and a string of random bit. In the process, the random string is “hidden” in the ciphertext by cryptographic hashing and XORing. On decryption, the … Read more
I believe that the issue may be that the key is not marked as exportable. There is another constructor for X509Certificate2 that takes an X509KeyStorageFlags enum. Try replacing the line: X509Certificate2 x = new X509Certificate2(@”C:\temp\certs\1\test.pfx”, “test”); With this: X509Certificate2 x = new X509Certificate2(@”C:\temp\certs\1\test.pfx”, “test”, X509KeyStorageFlags.Exportable);
It depends on the tools you can use. I doubt there is a JavaScript too that could do it directly within the browser. It also depends if it’s a one-off (always the same key) or whether you need to script it. Command-line / OpenSSL If you want to use something like OpenSSL on a unix … Read more
RSA encryption is only mean for small amounts of data, the amount of data you can encrypt is dependent on the size of the key you are using, for example for 1024 bit RSA keys, and PKCS # 1 V1.5 padding, you can encrypt 117 bytes at most, with a 2048 RSA key, you can … Read more
When you use a code like this: using (var rsa = new RSACryptoServiceProvider(1024)) { // Do something with the key… // Encrypt, export, etc. } .NET (actually Windows) stores your key in a persistent key container forever. The container is randomly generated by .NET This means: Any random RSA/DSA key you have EVER generated for … Read more
OK, I’ve worked out what’s going on. Leonidas is right, it’s not just the hash that gets encrypted (in the case of the Cipher class method), it’s the ID of the hash algorithm concatenated with the digest: DigestInfo ::= SEQUENCE { digestAlgorithm AlgorithmIdentifier, digest OCTET STRING } Which is why the encryption by the Cipher … Read more
You need some sort of format to marshal the key into. One format supported by the Go standard library can be found here: http://golang.org/pkg/crypto/x509/#MarshalPKCS1PrivateKey func MarshalPKCS1PrivateKey(key *rsa.PrivateKey) []byte The inverse function is http://golang.org/pkg/crypto/x509/#ParsePKCS1PrivateKey. func ParsePKCS1PrivateKey(der []byte) (key *rsa.PrivateKey, err error) However, it is relatively standard to encode the marshaled key into a PEM file. pemdata … Read more
ssh-keygen uses OpenSSL to generate RSA keys and store it in PEM format. The encryption you are talking about is specific to PEM. If you look at your key file, —–BEGIN RSA PRIVATE KEY—– Proc-Type: 4,ENCRYPTED DEK-Info: DES-EDE3-CBC,5B01E932988DC66B EPESt4ZVIrxnQXxxWWVa7cCR+vgNZ/4vTu4mdq6pjaW7jMZoB8HV+mA745mQkQw7 i+YtdVs/JqOeyGiw/3McxYYKZTlhyh7MvfIr1n8ZdZmcjQz+oFqMxChFU3r8BGgA “DEK-Info” header has all the information you need to decrypt the key as long as … Read more
Thanks to jwilleke, I have got a solution. To verify the RS256 signature of a JWT, it is needed to use the RSAPKCS1SignatureDeformatter class and its VerifySignature method. Here is the exact code for my sample data: string tokenStr = “eyJraWQiOiIxZTlnZGs3IiwiYWxnIjoiUlMyNTYifQ.ewogImlzcyI6ICJodHRwOi8vc2VydmVyLmV4YW1wbGUuY29tIiwKICJzdWIiOiAiMjQ4Mjg5NzYxMDAxIiwKICJhdWQiOiAiczZCaGRSa3F0MyIsCiAibm9uY2UiOiAibi0wUzZfV3pBMk1qIiwKICJleHAiOiAxMzExMjgxOTcwLAogImlhdCI6IDEzMTEyODA5NzAsCiAiY19oYXNoIjogIkxEa3RLZG9RYWszUGswY25YeENsdEEiCn0.XW6uhdrkBgcGx6zVIrCiROpWURs-4goO1sKA4m9jhJIImiGg5muPUcNegx6sSv43c5DSn37sxCRrDZZm4ZPBKKgtYASMcE20SDgvYJdJS0cyuFw7Ijp_7WnIjcrl6B5cmoM6ylCvsLMwkoQAxVublMwH10oAxjzD6NEFsu9nipkszWhsPePf_rM4eMpkmCbTzume-fzZIi5VjdWGGEmzTg32h3jiex-r5WTHbj-u5HL7u_KP3rmbdYNzlzd1xWRYTUs4E8nOTgzAUwvwXkIQhOh5TPcSMBYy6X3E7-_gr9Ue6n4ND7hTFhtjYs3cjNKIA08qm5cpVYFMFMG6PkhzLQ”; string[] tokenParts = tokenStr.Split(‘.’); RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(); rsa.ImportParameters( new RSAParameters() { Modulus … Read more
Update 03/03/2021 .NET 5 now supports this out of the box. To try the code snippet below, generate a keypair and encrypt some text at http://travistidwell.com/jsencrypt/demo/ var privateKey = @”—–BEGIN RSA PRIVATE KEY—– { the full PEM private key } —–END RSA PRIVATE KEY—–“; var rsa = RSA.Create(); rsa.ImportFromPem(privateKey.ToCharArray()); var decryptedBytes = rsa.Decrypt( Convert.FromBase64String(“{ base64-encoded … Read more