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|
#include "system.h"
#include <gcrypt.h>
#include <rpm/rpmcrypto.h>
#include "rpmpgp_internal.h"
#include "debug.h"
static int hashalgo2gcryalgo(int hashalgo)
{
switch (hashalgo) {
case RPM_HASH_MD5:
return GCRY_MD_MD5;
case RPM_HASH_SHA1:
return GCRY_MD_SHA1;
case RPM_HASH_SHA224:
return GCRY_MD_SHA224;
case RPM_HASH_SHA256:
return GCRY_MD_SHA256;
case RPM_HASH_SHA384:
return GCRY_MD_SHA384;
case RPM_HASH_SHA512:
return GCRY_MD_SHA512;
default:
return 0;
}
}
/****************************** RSA **************************************/
struct pgpDigSigRSA_s {
gcry_mpi_t s;
};
struct pgpDigKeyRSA_s {
gcry_mpi_t n;
gcry_mpi_t e;
};
static int pgpSetSigMpiRSA(pgpDigAlg pgpsig, int num, const uint8_t *p)
{
struct pgpDigSigRSA_s *sig = pgpsig->data;
int mlen = pgpMpiLen(p);
int rc = 1;
if (!sig)
sig = pgpsig->data = xcalloc(1, sizeof(*sig));
switch (num) {
case 0:
if (!gcry_mpi_scan(&sig->s, GCRYMPI_FMT_PGP, p, mlen, NULL))
rc = 0;
break;
}
return rc;
}
static int pgpSetKeyMpiRSA(pgpDigAlg pgpkey, int num, const uint8_t *p)
{
struct pgpDigKeyRSA_s *key = pgpkey->data;
int mlen = pgpMpiLen(p);
int rc = 1;
if (!key)
key = pgpkey->data = xcalloc(1, sizeof(*key));
switch (num) {
case 0:
if (!gcry_mpi_scan(&key->n, GCRYMPI_FMT_PGP, p, mlen, NULL))
rc = 0;
break;
case 1:
if (!gcry_mpi_scan(&key->e, GCRYMPI_FMT_PGP, p, mlen, NULL))
rc = 0;
break;
}
return rc;
}
static int pgpVerifySigRSA(pgpDigAlg pgpkey, pgpDigAlg pgpsig, uint8_t *hash, size_t hashlen, int hash_algo)
{
struct pgpDigKeyRSA_s *key = pgpkey->data;
struct pgpDigSigRSA_s *sig = pgpsig->data;
gcry_sexp_t sexp_sig = NULL, sexp_data = NULL, sexp_pkey = NULL;
const char *hash_algo_name;
int rc = 1;
if (!sig || !key)
return rc;
hash_algo_name = gcry_md_algo_name(hashalgo2gcryalgo(hash_algo));
gcry_sexp_build(&sexp_sig, NULL, "(sig-val (rsa (s %M)))", sig->s);
gcry_sexp_build(&sexp_data, NULL, "(data (flags pkcs1) (hash %s %b))", hash_algo_name, (int)hashlen, (const char *)hash);
gcry_sexp_build(&sexp_pkey, NULL, "(public-key (rsa (n %M) (e %M)))", key->n, key->e);
if (sexp_sig && sexp_data && sexp_pkey)
rc = gcry_pk_verify(sexp_sig, sexp_data, sexp_pkey) == 0 ? 0 : 1;
gcry_sexp_release(sexp_sig);
gcry_sexp_release(sexp_data);
gcry_sexp_release(sexp_pkey);
return rc;
}
static void pgpFreeSigRSA(pgpDigAlg pgpsig)
{
struct pgpDigSigRSA_s *sig = pgpsig->data;
if (sig) {
gcry_mpi_release(sig->s);
pgpsig->data = _free(sig);
}
}
static void pgpFreeKeyRSA(pgpDigAlg pgpkey)
{
struct pgpDigKeyRSA_s *key = pgpkey->data;
if (key) {
gcry_mpi_release(key->n);
gcry_mpi_release(key->e);
pgpkey->data = _free(key);
}
}
/****************************** DSA **************************************/
struct pgpDigSigDSA_s {
gcry_mpi_t r;
gcry_mpi_t s;
};
struct pgpDigKeyDSA_s {
gcry_mpi_t p;
gcry_mpi_t q;
gcry_mpi_t g;
gcry_mpi_t y;
};
static int pgpSetSigMpiDSA(pgpDigAlg pgpsig, int num, const uint8_t *p)
{
struct pgpDigSigDSA_s *sig = pgpsig->data;
int mlen = pgpMpiLen(p);
int rc = 1;
if (!sig)
sig = pgpsig->data = xcalloc(1, sizeof(*sig));
switch (num) {
case 0:
if (!gcry_mpi_scan(&sig->r, GCRYMPI_FMT_PGP, p, mlen, NULL))
rc = 0;
break;
case 1:
if (!gcry_mpi_scan(&sig->s, GCRYMPI_FMT_PGP, p, mlen, NULL))
rc = 0;
break;
}
return rc;
}
static int pgpSetKeyMpiDSA(pgpDigAlg pgpkey, int num, const uint8_t *p)
{
struct pgpDigKeyDSA_s *key = pgpkey->data;
int mlen = pgpMpiLen(p);
int rc = 1;
if (!key)
key = pgpkey->data = xcalloc(1, sizeof(*key));
switch (num) {
case 0:
if (!gcry_mpi_scan(&key->p, GCRYMPI_FMT_PGP, p, mlen, NULL))
rc = 0;
break;
case 1:
if (!gcry_mpi_scan(&key->q, GCRYMPI_FMT_PGP, p, mlen, NULL))
rc = 0;
break;
case 2:
if (!gcry_mpi_scan(&key->g, GCRYMPI_FMT_PGP, p, mlen, NULL))
rc = 0;
break;
case 3:
if (!gcry_mpi_scan(&key->y, GCRYMPI_FMT_PGP, p, mlen, NULL))
rc = 0;
break;
}
return rc;
}
static int pgpVerifySigDSA(pgpDigAlg pgpkey, pgpDigAlg pgpsig, uint8_t *hash, size_t hashlen, int hash_algo)
{
struct pgpDigKeyDSA_s *key = pgpkey->data;
struct pgpDigSigDSA_s *sig = pgpsig->data;
gcry_sexp_t sexp_sig = NULL, sexp_data = NULL, sexp_pkey = NULL;
int rc = 1;
size_t qlen;
if (!sig || !key)
return rc;
qlen = (mpi_get_nbits(key->q) + 7) / 8;
if (qlen < 20)
qlen = 20; /* sanity */
if (hashlen > qlen)
hashlen = qlen; /* dsa2: truncate hash to qlen */
gcry_sexp_build(&sexp_sig, NULL, "(sig-val (dsa (r %M) (s %M)))", sig->r, sig->s);
gcry_sexp_build(&sexp_data, NULL, "(data (flags raw) (value %b))", (int)hashlen, (const char *)hash);
gcry_sexp_build(&sexp_pkey, NULL, "(public-key (dsa (p %M) (q %M) (g %M) (y %M)))", key->p, key->q, key->g, key->y);
if (sexp_sig && sexp_data && sexp_pkey)
rc = gcry_pk_verify(sexp_sig, sexp_data, sexp_pkey) == 0 ? 0 : 1;
gcry_sexp_release(sexp_sig);
gcry_sexp_release(sexp_data);
gcry_sexp_release(sexp_pkey);
return rc;
}
static void pgpFreeSigDSA(pgpDigAlg pgpsig)
{
struct pgpDigSigDSA_s *sig = pgpsig->data;
if (sig) {
gcry_mpi_release(sig->r);
gcry_mpi_release(sig->s);
pgpsig->data = _free(sig);
}
}
static void pgpFreeKeyDSA(pgpDigAlg pgpkey)
{
struct pgpDigKeyDSA_s *key = pgpkey->data;
if (key) {
gcry_mpi_release(key->p);
gcry_mpi_release(key->q);
gcry_mpi_release(key->g);
gcry_mpi_release(key->y);
pgpkey->data = _free(key);
}
}
/****************************** EDDSA **************************************/
struct pgpDigSigEDDSA_s {
gcry_mpi_t r;
gcry_mpi_t s;
};
struct pgpDigKeyEDDSA_s {
gcry_mpi_t q;
};
static int pgpSetSigMpiEDDSA(pgpDigAlg pgpsig, int num, const uint8_t *p)
{
struct pgpDigSigEDDSA_s *sig = pgpsig->data;
int mlen = pgpMpiLen(p);
int rc = 1;
if (!sig)
sig = pgpsig->data = xcalloc(1, sizeof(*sig));
switch (num) {
case 0:
if (!gcry_mpi_scan(&sig->r, GCRYMPI_FMT_PGP, p, mlen, NULL))
rc = 0;
break;
case 1:
if (!gcry_mpi_scan(&sig->s, GCRYMPI_FMT_PGP, p, mlen, NULL))
rc = 0;
break;
}
return rc;
}
static int pgpSetKeyMpiEDDSA(pgpDigAlg pgpkey, int num, const uint8_t *p)
{
struct pgpDigKeyEDDSA_s *key = pgpkey->data;
int mlen = pgpMpiLen(p);
int rc = 1;
if (!key)
key = pgpkey->data = xcalloc(1, sizeof(*key));
switch (num) {
case 0:
if (!gcry_mpi_scan(&key->q, GCRYMPI_FMT_PGP, p, mlen, NULL))
rc = 0;
break;
}
return rc;
}
static int
ed25519_zero_extend(gcry_mpi_t x, unsigned char *buf, int bufl)
{
int n = (gcry_mpi_get_nbits(x) + 7) / 8;
if (n == 0 || n > bufl)
return 1;
n = bufl - n;
if (n)
memset(buf, 0, n);
gcry_mpi_print(GCRYMPI_FMT_USG, buf + n, bufl - n, NULL, x);
return 0;
}
static int pgpVerifySigEDDSA(pgpDigAlg pgpkey, pgpDigAlg pgpsig, uint8_t *hash, size_t hashlen, int hash_algo)
{
struct pgpDigKeyEDDSA_s *key = pgpkey->data;
struct pgpDigSigEDDSA_s *sig = pgpsig->data;
gcry_sexp_t sexp_sig = NULL, sexp_data = NULL, sexp_pkey = NULL;
int rc = 1;
unsigned char buf_r[32], buf_s[32];
if (!sig || !key)
return rc;
if (pgpkey->curve != PGPCURVE_ED25519)
return rc;
if (ed25519_zero_extend(sig->r, buf_r, 32) || ed25519_zero_extend(sig->s, buf_s, 32))
return rc;
gcry_sexp_build(&sexp_sig, NULL, "(sig-val (eddsa (r %b) (s %b)))", 32, (const char *)buf_r, 32, (const char *)buf_s, 32);
gcry_sexp_build(&sexp_data, NULL, "(data (flags eddsa) (hash-algo sha512) (value %b))", (int)hashlen, (const char *)hash);
gcry_sexp_build(&sexp_pkey, NULL, "(public-key (ecc (curve \"Ed25519\") (flags eddsa) (q %M)))", key->q);
if (sexp_sig && sexp_data && sexp_pkey)
rc = gcry_pk_verify(sexp_sig, sexp_data, sexp_pkey) == 0 ? 0 : 1;
gcry_sexp_release(sexp_sig);
gcry_sexp_release(sexp_data);
gcry_sexp_release(sexp_pkey);
return rc;
}
static void pgpFreeSigEDDSA(pgpDigAlg pgpsig)
{
struct pgpDigSigEDDSA_s *sig = pgpsig->data;
if (sig) {
gcry_mpi_release(sig->r);
gcry_mpi_release(sig->s);
pgpsig->data = _free(sig);
}
}
static void pgpFreeKeyEDDSA(pgpDigAlg pgpkey)
{
struct pgpDigKeyEDDSA_s *key = pgpkey->data;
if (key) {
gcry_mpi_release(key->q);
pgpkey->data = _free(key);
}
}
/****************************** NULL **************************************/
static int pgpSetMpiNULL(pgpDigAlg pgpkey, int num, const uint8_t *p)
{
return 1;
}
static int pgpVerifyNULL(pgpDigAlg pgpkey, pgpDigAlg pgpsig,
uint8_t *hash, size_t hashlen, int hash_algo)
{
return 1;
}
static int pgpSupportedCurve(int curve)
{
if (curve == PGPCURVE_ED25519) {
static int supported_ed25519;
if (!supported_ed25519) {
gcry_sexp_t sexp = NULL;
unsigned int nbits;
gcry_sexp_build(&sexp, NULL, "(public-key (ecc (curve \"Ed25519\")))");
nbits = gcry_pk_get_nbits(sexp);
gcry_sexp_release(sexp);
supported_ed25519 = nbits > 0 ? 1 : -1;
}
return supported_ed25519 > 0;
}
return 0;
}
pgpDigAlg pgpPubkeyNew(int algo, int curve)
{
pgpDigAlg ka = xcalloc(1, sizeof(*ka));;
switch (algo) {
case PGPPUBKEYALGO_RSA:
ka->setmpi = pgpSetKeyMpiRSA;
ka->free = pgpFreeKeyRSA;
ka->mpis = 2;
break;
case PGPPUBKEYALGO_DSA:
ka->setmpi = pgpSetKeyMpiDSA;
ka->free = pgpFreeKeyDSA;
ka->mpis = 4;
break;
case PGPPUBKEYALGO_EDDSA:
if (!pgpSupportedCurve(curve)) {
ka->setmpi = pgpSetMpiNULL;
ka->mpis = -1;
break;
}
ka->setmpi = pgpSetKeyMpiEDDSA;
ka->free = pgpFreeKeyEDDSA;
ka->mpis = 1;
ka->curve = curve;
break;
default:
ka->setmpi = pgpSetMpiNULL;
ka->mpis = -1;
break;
}
ka->verify = pgpVerifyNULL; /* keys can't be verified */
return ka;
}
pgpDigAlg pgpSignatureNew(int algo)
{
pgpDigAlg sa = xcalloc(1, sizeof(*sa));
switch (algo) {
case PGPPUBKEYALGO_RSA:
sa->setmpi = pgpSetSigMpiRSA;
sa->free = pgpFreeSigRSA;
sa->verify = pgpVerifySigRSA;
sa->mpis = 1;
break;
case PGPPUBKEYALGO_DSA:
sa->setmpi = pgpSetSigMpiDSA;
sa->free = pgpFreeSigDSA;
sa->verify = pgpVerifySigDSA;
sa->mpis = 2;
break;
case PGPPUBKEYALGO_EDDSA:
sa->setmpi = pgpSetSigMpiEDDSA;
sa->free = pgpFreeSigEDDSA;
sa->verify = pgpVerifySigEDDSA;
sa->mpis = 2;
break;
default:
sa->setmpi = pgpSetMpiNULL;
sa->verify = pgpVerifyNULL;
sa->mpis = -1;
break;
}
return sa;
}
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