On Thu, Nov 07, 2002 at 08:56:53PM +0100, [EMAIL PROTECTED] wrote:
> 
> Hello!
> 
> I generate a private key using:
> openssl genrsa -out xxx.key 1024
> It contains the private key, but I can get the public key this way:
> openssl rsa -in xxx.key -pubout -out yyy.pub
> 
> I can get the private key in a C program using 
> PEM_read_PrivateKey(..), but I can't find 
> PEM_read_PublicKey(..) function. 

PEM_read_RSA_PUBKEY(...);

> 
> So the question is, how could I get the public_key into an EVP_PKEY 
> structure from the generated key file. I would use DSA keys too, so I 
> would prefer EVP_PKEY struct.
> 
> Thanks:
>     Peter
> 
> ps.: is it possible, that the private key file contains the public key 
> too?

struct
               {
               BIGNUM *n;              // public modulus
               BIGNUM *e;              // public exponent
               BIGNUM *d;              // private exponent
               BIGNUM *p;              // secret prime factor
               BIGNUM *q;              // secret prime factor
               BIGNUM *dmp1;           // d mod (p-1)
               BIGNUM *dmq1;           // d mod (q-1)
               BIGNUM *iqmp;           // q^-1 mod p
               // ...
               };
        RSA

Read the private key and delete d, p, q, dmp1, dmq1, iqmp
and you have a public key :-)

(man 3 RSA)


Christian
>   
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