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ElGamal funktioniert und ist default

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This commit is contained in:
Werner Koch 1997-11-24 22:24:04 +00:00
parent a51cca90b6
commit 46900fbd43
31 changed files with 1273 additions and 409 deletions
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102
g10/seckey-cert.c
View file

@ -30,6 +30,9 @@
#include "keydb.h"
#include "cipher.h"
#if BLOWFISH_BLOCKSIZE != 8
#error unsupportted blocksize
#endif
static u16
checksum( byte *p )
@ -44,11 +47,9 @@ checksum( byte *p )
}
/****************
* Check the secret key certificate
*/
int
check_secret_key( PKT_seckey_cert *cert )
static int
check_elg( PKT_seckey_cert *cert )
{
byte iv[8];
byte *mpibuf;
@ -56,13 +57,73 @@ check_secret_key( PKT_seckey_cert *cert )
MPI temp_mpi;
int res;
u32 keyid[2];
ELG_secret_key skey;
#if BLOWFISH_BLOCKSIZE != 8
#error unsupportted blocksize
#endif
if( cert->d.elg.is_protected ) { /* remove the protection */
DEK *dek = NULL;
BLOWFISH_context *blowfish_ctx=NULL;
if( cert->pubkey_algo != PUBKEY_ALGO_RSA )
return G10ERR_PUBKEY_ALGO; /* unsupport algorithm */
switch( cert->d.elg.protect_algo ) {
case CIPHER_ALGO_NONE: log_bug(NULL); break;
case CIPHER_ALGO_BLOWFISH:
keyid_from_skc( cert, keyid );
dek = get_passphrase_hash( keyid, NULL );
m_free(dek); /* pw is in secure memory, so m_free() burns it */
memset( iv, 0, BLOWFISH_BLOCKSIZE );
blowfish_ctx = m_alloc_secure( sizeof *blowfish_ctx );
blowfish_setiv( blowfish_ctx, iv );
blowfish_decode_cfb( blowfish_ctx,
cert->d.elg.protect.blowfish.iv,
cert->d.elg.protect.blowfish.iv, 8 );
cert->d.elg.calc_csum = 0;
mpibuf = (byte*)cert->d.elg.x;
n = ((mpibuf[0] << 8) | mpibuf[1])-2;
blowfish_decode_cfb( blowfish_ctx, mpibuf+4, mpibuf+4, n );
cert->d.elg.calc_csum += checksum( mpibuf );
cert->d.elg.x = mpi_decode_buffer( mpibuf );
m_free( mpibuf );
m_free( blowfish_ctx );
cert->d.elg.is_protected = 0;
/* now let's see wether we have used the right passphrase */
if( cert->d.elg.calc_csum != cert->d.elg.csum )
return G10ERR_BAD_PASS;
skey.p = cert->d.elg.p;
skey.g = cert->d.elg.g;
skey.y = cert->d.elg.y;
skey.x = cert->d.elg.x;
res = elg_check_secret_key( &skey );
memset( &skey, 0, sizeof skey );
if( !res )
return G10ERR_BAD_PASS;
break;
default:
return G10ERR_CIPHER_ALGO; /* unsupport protection algorithm */
}
}
/* must check the checksum here, because we didn't do it when
* parsing an unprotected certificate */
if( cert->d.elg.calc_csum != cert->d.elg.csum ) {
log_error("checksum in secret key certificate is wrong\n");
log_debug("stored csum=%04hx calculated csum=%04hx\n",
cert->d.elg.csum, cert->d.elg.calc_csum );
return G10ERR_CHECKSUM;
}
return 0;
}
#ifdef HAVE_RSA_CIPHER
static int
check_rsa( PKT_seckey_cert *cert )
{
byte iv[8];
byte *mpibuf;
u16 n;
MPI temp_mpi;
int res;
u32 keyid[2];
if( cert->d.rsa.is_protected ) { /* remove the protection */
DEK *dek = NULL;
@ -73,7 +134,7 @@ check_secret_key( PKT_seckey_cert *cert )
log_bug("unprotect seckey_cert is flagged protected\n");
break;
case CIPHER_ALGO_BLOWFISH:
mpi_get_keyid( cert->d.rsa.rsa_n , keyid );
keyid_from_skc( cert, keyid );
dek = get_passphrase_hash( keyid, NULL );
m_free(dek); /* pw is in secure memory, so m_free() burns it */
@ -133,5 +194,24 @@ check_secret_key( PKT_seckey_cert *cert )
}
return 0;
}
#endif /*HAVE_RSA_CIPHER*/
/****************
* Check the secret key certificate
*/
int
check_secret_key( PKT_seckey_cert *cert )
{
if( cert->pubkey_algo == PUBKEY_ALGO_ELGAMAL )
return check_elg( cert );
#ifdef HAVE_RSA_CIPHER
else if( cert->pubkey_algo == PUBKEY_ALGO_RSA )
return check_rsa( cert );
#endif
else
return G10ERR_PUBKEY_ALGO;
}