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Diffstat (limited to 'botan/doc/examples/rsa_enc.cpp')
| -rw-r--r-- | botan/doc/examples/rsa_enc.cpp | 151 |
1 files changed, 0 insertions, 151 deletions
diff --git a/botan/doc/examples/rsa_enc.cpp b/botan/doc/examples/rsa_enc.cpp deleted file mode 100644 index f9b8c55..0000000 --- a/botan/doc/examples/rsa_enc.cpp +++ /dev/null @@ -1,151 +0,0 @@ -/* - Grab an RSA public key from the file given as an argument, grab a message - from another file, and encrypt the message. - - Algorithms used: - RSA with EME1(SHA-1) padding to encrypt the master key - CAST-128 in CBC mode with PKCS#7 padding to encrypt the message. - HMAC with SHA-1 is used to authenticate the message - - The keys+IV used are derived from the master key (the thing that's encrypted - with RSA) using KDF2(SHA-1). The 3 outputs of KDF2 are parameterized by P, - where P is "CAST", "IV" or "MAC", in order to make each key/IV unique. - - The format is: - 1) First line is the master key, encrypted with the recipients public key - using EME1(SHA-1), and then base64 encoded. - 2) Second line is the first 96 bits (12 bytes) of the HMAC(SHA-1) of - the _plaintext_ - 3) Following lines are base64 encoded ciphertext (CAST-128 as described), - each broken after ~72 characters. - -Written by Jack Lloyd (lloyd@randombit.net), June 3, 2002 - Updated to use KDF2, September 8, 2002 - Updated to read X.509 keys, October 21, 2002 - -This file is in the public domain -*/ - -#include <iostream> -#include <fstream> -#include <string> -#include <memory> - -#include <botan/botan.h> -#include <botan/look_pk.h> -#include <botan/rsa.h> -using namespace Botan; - -std::string b64_encode(const SecureVector<byte>&); -SymmetricKey derive_key(const std::string&, const SymmetricKey&, u32bit); - -int main(int argc, char* argv[]) - { - if(argc != 3) - { - std::cout << "Usage: " << argv[0] << " keyfile messagefile" << std::endl; - return 1; - } - - std::ifstream message(argv[2]); - if(!message) - { - std::cout << "Couldn't read the message file." << std::endl; - return 1; - } - - Botan::LibraryInitializer init; - - std::string output_name(argv[2]); - output_name += ".enc"; - std::ofstream ciphertext(output_name.c_str()); - if(!ciphertext) - { - std::cout << "Couldn't write the ciphertext to " << output_name - << std::endl; - return 1; - } - - try { - std::auto_ptr<X509_PublicKey> key(X509::load_key(argv[1])); - RSA_PublicKey* rsakey = dynamic_cast<RSA_PublicKey*>(key.get()); - if(!rsakey) - { - std::cout << "The loaded key is not a RSA key!\n"; - return 1; - } - - AutoSeeded_RNG rng; - - std::auto_ptr<PK_Encryptor> encryptor(get_pk_encryptor(*rsakey, - "EME1(SHA-1)")); - - /* Generate the master key (the other keys are derived from this) - - Basically, make the key as large as can be encrypted by this key, up - to a limit of 256 bits. For 512 bit keys, the master key will be >160 - bits. A >600 bit key will use the full 256 bit master key. - - In theory, this is not enough, because we derive 16+16+8=40 bytes of - secrets (if you include the IV) using the master key, so they are not - statistically indepedent. Practically speaking I don't think this is - a problem. - */ - SymmetricKey masterkey(rng, - std::min(32U, encryptor->maximum_input_size())); - - SymmetricKey cast_key = derive_key("CAST", masterkey, 16); - SymmetricKey mac_key = derive_key("MAC", masterkey, 16); - SymmetricKey iv = derive_key("IV", masterkey, 8); - - SecureVector<byte> encrypted_key = - encryptor->encrypt(masterkey.bits_of(), rng); - - ciphertext << b64_encode(encrypted_key) << std::endl; - - Pipe pipe(new Fork( - new Chain( - get_cipher("CAST-128/CBC/PKCS7", cast_key, iv, - ENCRYPTION), - new Base64_Encoder(true) // true == do linebreaking - ), - new Chain( - new MAC_Filter("HMAC(SHA-1)", mac_key, 12), - new Base64_Encoder - ) - ) - ); - - pipe.start_msg(); - message >> pipe; - pipe.end_msg(); - - /* Write the MAC as the second line. That way we can pull it off right - from the start, and feed the rest of the file right into a pipe on the - decrypting end. - */ - - ciphertext << pipe.read_all_as_string(1) << std::endl; - ciphertext << pipe.read_all_as_string(0); - } - catch(std::exception& e) - { - std::cout << "Exception: " << e.what() << std::endl; - } - return 0; - } - -std::string b64_encode(const SecureVector<byte>& in) - { - Pipe pipe(new Base64_Encoder); - pipe.process_msg(in); - return pipe.read_all_as_string(); - } - -SymmetricKey derive_key(const std::string& param, - const SymmetricKey& masterkey, - u32bit outputlength) - { - std::auto_ptr<KDF> kdf(get_kdf("KDF2(SHA-1)")); - return kdf->derive_key(outputlength, masterkey.bits_of(), param); - } |
