Re: Convert symmetrically encrypted content to base64
On Fri, 24 Aug 2012 15:54:50 -0400 Dave Thompson wrote: Note OpenSSL's RSA privatekey *includes* publickey. RSA publickey is n,e and naive privatekey is n,d, but OpenSSL privatekey is CRT form with n,d,e,p,q + more. There is no need to transmit the publickey separately, [..] Tiny aside: BIO_new_mem_buf will do the strlen() for you if you pass -1 for length. Just a convenience. [..] If PEM_read_* returns null (or nearly any other OpenSSL routine returns a failure indication), look at the error queue. http://www.openssl.org/support/faq.html#PROG6 and #PROG7 also if you don't get readable error. If they didn't, look very carefully at your PEM data. Commandline can do this: openssl asn1parse -in myprivkey.pem and/or: openssal rsa -in myprivkey.pem -text Thanks for your hints. After a lot of testing I figured out that my functions pem2key() and key2pem() works fine. The problem is that I lose some characters (e.g. '+' gets replaced by spaces) while sending the key over the network. But I think this problem don't belong to the mailing list. ;-) Thanks a lot! Björn -- Björn Schießle bjo...@schiessle.org www: http://schiessle.org gnupg key: 0x0x2378A753E2BF04F6 fingerprint: 244F CEB0 CB09 9524 B21F B896 2378 A753 E2BF 04F6 __ OpenSSL Project http://www.openssl.org User Support Mailing Listopenssl-users@openssl.org Automated List Manager majord...@openssl.org
Re: Convert symmetrically encrypted content to base64
Hi Christian,
On Fri, 24 Aug 2012 08:11:25 +0200 Christian Hohnstaedt wrote:
please see my comments below:
(rather Qt and memory related)
Thank you for your feedback. Now I'm trying the implement the function
which does exactly the opposite: Take the public and private key in
the PEM format from the server and import it in a RSA structure:
void Encryption::pem2key(QString publickey, QString privatekey, QString
password)
{
BIO *pubBio = BIO_new_mem_buf(publickey.toLocal8Bit().data(),
strlen(publickey.toLocal8Bit().data()));
BIO *privBio = BIO_new_mem_buf(privatekey.toLocal8Bit().data(),
strlen(privatekey.toLocal8Bit().data()));
RSA *rsa = RSA_new();
PEM_read_bio_RSAPublicKey(pubBio, rsa, 0, NULL);
PEM_read_bio_RSAPrivateKey(privBio, rsa, 0, password.toLocal8Bit().data());
Keymanager::Instance()-setRSAkey(rsa);
BIO_free_all(pubBio);
BIO_free_all(privBio);
}
The program compiles and run without a problem. But if I call the
key2pem() function with the newly imported RSA key. I get two quite
short keys back (only half a line of data). So something seems to go
wrong during import of the PEM encoded keys.
Any idea what I'm doing wrong in the pem2key() function?
Thanks!
Björn
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Convert symmetrically encrypted content to base64
Hi,
I want to generate a RSA private and public key and than encrypt the
private key symmetrically with a password to store it on a server. The
data has to be stored and transferred base64 encoded.
This is how I encrypt the private key:
EVP_CIPHER_CTX ctx;
unsigned char *key = (unsigned char*)password.toLocal8Bit().data();
unsigned char *data = (unsigned char*)privkey.toLocal8Bit().constData());
int len = strlen((char*)data)+1;
unsigned char iv[EVP_MAX_IV_LENGTH];
select_random_iv(iv, EVP_MAX_IV_LENGTH);
int c_len = len + AES_BLOCK_SIZE, f_len = 0;
unsigned char *ciphertext = (unsigned char*)malloc(c_len);
EVP_EncryptInit(ctx, EVP_aes_128_cfb(), key, iv);
EVP_EncryptUpdate(ctx, ciphertext, c_len, data, len);
EVP_EncryptFinal(ctx, ciphertext+c_len, f_len);
This works fine and if I send the encrypted data, the iv, the key and
the password directly to the decrypt function (decryptPrivateKey(...))
I can also decrypt the data again. But if I encode the data together
with the iv as base64 to store it on the server and later decode it
again the decryption fails.
Here is how I encode the data together with the iv in base64:
char *base64Key = base64(ciphertext, strlen((char*)ciphertext));
char *base64IV = base64(iv, strlen((char*)iv));
char *iv_seperator = (char*)00iv00;
base64Key = (char*)realloc(base64Key,
strlen(base64Key)+strlen(base64IV)+6+1);
strcat(base64Key, iv_seperator);
strcat(base64Key, base64IV);
The result is a string data00iv00iv which I transfer to the
server. Now when I retrieve the data again I separate the encrypted key
and the iv, decode it and send it to the decryption function:
char *data = privkey.toLocal8Bit().data();
char keyBase64[strlen(data)+1];
char ivBase64[2000];
int separator, i;
bool isKey = true;
for(i = 0; istrlen(data); i++) {
if (data[i] == '0' data[i+1] == '0' data[i+2] == 'i' data[i+3]
== 'v' data[i+4] == '0' data[i+5] == '0') {
isKey = false;
keyBase64[i] = '\0';
i += 5;
separator = i;
} else {
if (isKey) keyBase64[i] = data[i];
else ivBase64[i-separator-1] = data[i];
}
}
ivBase64[i-separator-1] = '\0';
unsigned char *key = unbase64(keyBase64, strlen(keyBase64));
unsigned char *iv = unbase64(ivBase64, strlen(ivBase64));
return (decryptPrivateKey(key, iv, password));
This is how base64 and unbase64 looks:
char* Encryption::base64(const unsigned char *input, int length)
{
BIO *bmem, *b64;
BUF_MEM *bptr;
b64 = BIO_new(BIO_f_base64());
bmem = BIO_new(BIO_s_mem());
b64 = BIO_push(b64, bmem);
BIO_write(b64, input, length);
BIO_flush(b64);
BIO_get_mem_ptr(b64, bptr);
char *buff = (char *)malloc(bptr-length+1);
memcpy(buff, bptr-data, bptr-length);
buff[bptr-length] = 0;
BIO_free_all(b64);
return buff;
}
unsigned char* Encryption::unbase64(char *input, int length)
{
BIO *b64, *bmem;
unsigned char *buffer = (unsigned char *)malloc(length);
memset(buffer, 0, length);
b64 = BIO_new(BIO_f_base64());
bmem = BIO_new_mem_buf(input, length);
bmem = BIO_push(b64, bmem);
BIO_read(bmem, buffer, length);
BIO_free_all(bmem);
return buffer;
}
I already tried several other methods to endoce/decode base64 but
nothing really works. Maybe someone on this list can help me?
Thanks a lot!
Björn
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OpenSSL Project http://www.openssl.org
User Support Mailing Listopenssl-users@openssl.org
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Re: Convert symmetrically encrypted content to base64
Hi,
I think I did it way too complicated. I think the problem was that I
always tried to mimic some openssl php code I know, but I think the
solution I have now is much easier and standard complained:
void Encryption::generateUserKeys(QString password)
{
RSA *rsa;
EVP_PKEY *pkey;
int bits = 1024;
unsigned long exp = RSA_F4;
QMapQString, QString keypair;
rsa = RSA_generate_key(bits, exp, NULL, NULL);
pkey = EVP_PKEY_new();
EVP_PKEY_assign_RSA(pkey, rsa);
keypair = key2pem(rsa, password);
RSA_free(rsa);
sendUserKeysToServer(keypair);
}
QMapQString, QString Encryption::key2pem(RSA *rsa, QString password)
{
QMapQString, QString keypair;
BUF_MEM *bptr;
BIO *pubBio = BIO_new(BIO_s_mem());
BIO *privBio = BIO_new(BIO_s_mem());
PEM_write_bio_RSA_PUBKEY(pubBio, rsa);
PEM_write_bio_RSAPrivateKey(privBio, rsa, EVP_aes_128_cfb(),NULL,
0, 0, password.toLocal8Bit().data());
BIO_get_mem_ptr(pubBio, bptr);
char *pubKey = (char *)malloc(bptr-length+1);
memcpy(pubKey, bptr-data, bptr-length);
pubKey[bptr-length] = 0;
BIO_get_mem_ptr(privBio, bptr);
char *privKey = (char *)malloc(bptr-length+1);
memcpy(privKey, bptr-data, bptr-length);
privKey[bptr-length] = 0;
keypair[privatekey] = QString(privKey);
keypair[publickey] = QString(pubKey);
BIO_free_all(pubBio);
BIO_free_all(privBio);
return keypair;
}
Please feel free to commend on it if you think there is still something
to improve.
best wishes,
Björn
--
Björn Schießle bjo...@schiessle.org
www: http://schiessle.org
gnupg key: 0x0x2378A753E2BF04F6
fingerprint: 244F CEB0 CB09 9524 B21F B896 2378 A753 E2BF 04F6
__
OpenSSL Project http://www.openssl.org
User Support Mailing Listopenssl-users@openssl.org
Automated List Manager majord...@openssl.org
