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ring perform raw RSA encryption on data

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Joker answered on May 19, 2022 Popularity 2/10 Helpfulness 1/10

answer ring perform raw RSA encryption on data

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ring perform raw RSA encryption on data

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/* encrypt a file using AES key and then encrypt the AES key using an RSA public key using PKCS1 padding */
/* we manually add PKCS1 padding and then perform raw RSA encryption */
try
        /* read Alice public key */
        rsaPublicKeyPEM = Read("alice_public_key.pem")
        rsaPublicKey = rsa_import_pem(rsaPublicKeyPEM)

        /* encrypt file with random AES-128 key */
        cData = Read ("secret_document.txt")
        cKey = RandBytes(16)
        cIV = RandBytes(16)
        cEncryptedData = Encrypt(cData,cKey,cIV,"aes128")

        /* encrypt the AES-128 key with the RSA public key */

        /* calculate the modulus length */
        rsaKeyParams = rsa_export_params(rsaPublicKey)
        modulusLen = rsaKeyParams[:bits]/ 8

        /* we manually add PKCS1 padding */
        paddingSize = modulusLen - Len(cKey) - 2 - 1
        paddingStr = space (paddingSize)

        /* encryption case. Add random bytes */
        for i=1 to paddingSize
                paddingStr[i] = Char (1 + Random(254))
        next

        paddedData = Char(0) + Char(2) + paddingStr + Char (0) + cKey

        cEncryptedKey = rsa_encrypt_raw(rsaPublicKey,paddedData)

        /* store IV, encrypted AES key and encrypted data in a file to be sent to Alice*/
        Write("raw_encrypted_document.enc", cIV + cEncryptedKey + cEncryptedData)

catch
        See "Unexpected error occured: " + cCatchError + nl
done

Popularity 2/10 Helpfulness 1/10 Language whatever

Source: ring-lang.github.io

Tags: encryption raw ring rsa whatever

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Contributed on May 19 2022

Joker

0 Answers Avg Quality 2/10

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ring perform raw RSA encryption on data

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rsa_encrypt_raw(pRsaKey,cPlainData) ---> return a string containing the raw RSA encryption of cPlainData

Popularity 2/10 Helpfulness 1/10 Language whatever

Source: ring-lang.github.io

Tags: whatever encryption rsa raw ring

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Contributed on May 19 2022

Joker

0 Answers Avg Quality 2/10

ring perform raw RSA decryption of data

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rsa_decrypt_raw(pRsaKey,cEncryptedData) ---> return a string containing the decryption of cEncryptedData

Popularity 1/10 Helpfulness 1/10 Language whatever

Source: ring-lang.github.io

Tags: rsa whatever raw ring

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Contributed on May 19 2022

Joker

0 Answers Avg Quality 2/10

ring perform raw RSA decryption of data

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/* decrypt a file by first decrypting AES key that was used to encrypt it
 * and then decrypt the whole content using the AES key
 /* We decrypt AES using rsa_decrypt_raw and then remove padding manually
 */
try
        /* read Alice private key */
        rsaKeyPEM = Read("alice_private_key.pem")
        rsaKey = rsa_import_pem(rsaKeyPEM)

        /* calculate the modulus length */
        rsaKeyParams = rsa_export_params(rsaKey)
        modulusLen = rsaKeyParams[:bits]/ 8

        /* read encrypted file */
        cEncryptedContent = Read ("encrypted_document.enc")

        /* IV is the first 16 bytes if the file */
        cIV = substr(cEncryptedContent, 1, 16)

        /* encrypted key follows IV and its length is modulusLen */
        cEncryptedKey = substr(cEncryptedContent, 17, modulusLen)

        /* encrypted data follows the key */
        cEncryptedData = substr(cEncryptedContent, 17 + modulusLen)

        /* decrypt the AES-128 key */
        cPaddedKey = rsa_decrypt_raw(rsaKey,cEncryptedKey)

        /* remove PKCS1 padding */
        paddedInputLength = len(cPaddedKey)
        cKey = ""
        if paddedInputLength > 11 AND Ascii(cPaddedKey[1]) = 0 AND Ascii(cPaddedKey[2]) = 2
                zeroFound = false
                for j = 3 to paddedInputLength
                        if Ascii(cPaddedKey[j]) = 0
                                i = j
                                zeroFound = true
                                exit
                        ok
                next

                if zeroFound
                        if i = paddedInputLength
                                /* unpadded data is empty */
                                Raise("Empty data recovered from padding")
                        else
                                cKey = substr(cPaddedKey,i+1)
                        ok
                else
                        Raise ("Invalid data padding")
                ok
        else
                Raise("the decrypted data is invalid")
        ok

        /* decrypt the data using the AES-128 key */

        cPlainData = Decrypt(cEncryptedData,cKey,cIV,"aes128")

        /* store the decrypted data to a file */
        Write("decrypted_document.txt", cPlainData)

catch
        See "Unexpected error occured: " + cCatchError + nl
done

Popularity 1/10 Helpfulness 1/10 Language whatever

Source: ring-lang.github.io

Tags: ring rsa whatever raw

Link to this answer
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Contributed on May 19 2022

Joker

0 Answers Avg Quality 2/10

ring perform raw RSA encryption on data

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