Add secure DSA nonce flag.

[openssl.git] / crypto / dsa / dsa_sign.c

diff --git a/crypto/dsa/dsa_sign.c b/crypto/dsa/dsa_sign.c
index 92098e2149ea57b7e9565cf9cf19c8f34e7603f4..b7e4caab2aff91ac2d37ced1621f080ef717ce78 100644 (file)
--- a/crypto/dsa/dsa_sign.c
+++ b/crypto/dsa/dsa_sign.c
@@ -58,162 +58,26 @@
 
 /* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */
 
-#include <stdio.h>
-#include "cryptlib.h"
-#include "bn.h"
-#include "dsa.h"
-#include "rand.h"
-#include "asn1.h"
-
-DSA_SIG * DSA_do_sign(dgst,dlen,dsa)
-unsigned char *dgst;
-int dlen;
-DSA *dsa;
-       {
-       BIGNUM *kinv=NULL,*r=NULL,*s=NULL;
-       BIGNUM m;
-       BIGNUM xr;
-       BN_CTX *ctx=NULL;
-       int i,reason=ERR_R_BN_LIB;
-       DSA_SIG *ret=NULL;
-
-       BN_init(&m);
-       BN_init(&xr);
-       s=BN_new();
-       if (s == NULL) goto err;
-
-       i=BN_num_bytes(dsa->q); /* should be 20 */
-       if ((dlen > i) || (dlen > 50))
-               {
-               reason=DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE;
-               goto err;
-               }
-
-       ctx=BN_CTX_new();
-       if (ctx == NULL) goto err;
-
-       if ((dsa->kinv == NULL) || (dsa->r == NULL))
-               {
-               if (!DSA_sign_setup(dsa,ctx,&kinv,&r)) goto err;
-               }
-       else
-               {
-               kinv=dsa->kinv;
-               dsa->kinv=NULL;
-               r=dsa->r;
-               dsa->r=NULL;
-               }
-
-       if (BN_bin2bn(dgst,dlen,&m) == NULL) goto err;
-
-       /* Compute  s = inv(k) (m + xr) mod q */
-       if (!BN_mod_mul(&xr,dsa->priv_key,r,dsa->q,ctx)) goto err;/* s = xr */
-       if (!BN_add(s, &xr, &m)) goto err;              /* s = m + xr */
-       if (BN_cmp(s,dsa->q) > 0)
-               BN_sub(s,s,dsa->q);
-       if (!BN_mod_mul(s,s,kinv,dsa->q,ctx)) goto err;
-
-       ret=DSA_SIG_new();
-       if (ret == NULL) goto err;
-       ret->r = r;
-       ret->s = s;
-       
-err:
-       if (!ret)
-               {
-               DSAerr(DSA_F_DSA_DO_SIGN,reason);
-               BN_free(r);
-               BN_free(s);
-               }
-       if (ctx != NULL) BN_CTX_free(ctx);
-       BN_clear_free(&m);
-       BN_clear_free(&xr);
-       return(ret);
-       }
+#define OPENSSL_FIPSAPI
 
-/* data has already been hashed (probably with SHA or SHA-1). */
+#include "cryptlib.h"
+#include <openssl/dsa.h>
+#include <openssl/rand.h>
+#include <openssl/bn.h>
 
-int DSA_sign(type,dgst,dlen,sig,siglen,dsa)
-int type;
-unsigned char *dgst;
-int dlen;
-unsigned char *sig;    /* out */
-unsigned int *siglen;  /* out */
-DSA *dsa;
+DSA_SIG * DSA_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
        {
-       DSA_SIG *s;
-       s=DSA_do_sign(dgst,dlen,dsa);
-       if (s == NULL)
-               {
-               *siglen=0;
-               return(0);
-               }
-       *siglen=i2d_DSA_SIG(s,&sig);
-       DSA_SIG_free(s);
-       return(1);
+       return dsa->meth->dsa_do_sign(dgst, dlen, dsa);
        }
 
-int DSA_sign_setup(dsa,ctx_in,kinvp,rp)
-DSA *dsa;
-BN_CTX *ctx_in;
-BIGNUM **kinvp;
-BIGNUM **rp;
+int DSA_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp)
        {
-       BN_CTX *ctx;
-       BIGNUM k,*kinv=NULL,*r=NULL;
-       int ret=0;
-
-       if (ctx_in == NULL)
-               {
-               if ((ctx=BN_CTX_new()) == NULL) goto err;
-               }
-       else
-               ctx=ctx_in;
-
-       BN_init(&k);
-       if ((r=BN_new()) == NULL) goto err;
-       kinv=NULL;
-
-       /* Get random k */
-       for (;;)
+       if (dsa->flags & DSA_FLAG_NONCE_FROM_HASH)
                {
-               if (!BN_rand(&k, BN_num_bits(dsa->q), 1, 0)) goto err;
-               if (BN_cmp(&k,dsa->q) >= 0)
-                       BN_sub(&k,&k,dsa->q);
-               if (!BN_is_zero(&k)) break;
+               /* One cannot precompute the DSA nonce if it is required to
+                * depend on the message. */
+               DSAerr(DSA_F_DSA_SIGN_SETUP, DSA_R_NONCE_CANNOT_BE_PRECOMPUTED);
+               return 0;
                }
-
-       if ((dsa->method_mont_p == NULL) && (dsa->flags & DSA_FLAG_CACHE_MONT_P))
-               {
-               if ((dsa->method_mont_p=(char *)BN_MONT_CTX_new()) != NULL)
-                       if (!BN_MONT_CTX_set((BN_MONT_CTX *)dsa->method_mont_p,
-                               dsa->p,ctx)) goto err;
-               }
-
-       /* Compute r = (g^k mod p) mod q */
-       if (!BN_mod_exp_mont(r,dsa->g,&k,dsa->p,ctx,
-               (BN_MONT_CTX *)dsa->method_mont_p)) goto err;
-       if (!BN_mod(r,r,dsa->q,ctx)) goto err;
-
-       /* Compute  part of 's = inv(k) (m + xr) mod q' */
-       if ((kinv=BN_mod_inverse(NULL,&k,dsa->q,ctx)) == NULL) goto err;
-
-       if (*kinvp != NULL) BN_clear_free(*kinvp);
-       *kinvp=kinv;
-       kinv=NULL;
-       if (*rp != NULL) BN_clear_free(*rp);
-       *rp=r;
-       ret=1;
-err:
-       if (!ret)
-               {
-               DSAerr(DSA_F_DSA_SIGN_SETUP,ERR_R_BN_LIB);
-               if (kinv != NULL) BN_clear_free(kinv);
-               if (r != NULL) BN_clear_free(r);
-               }
-       if (ctx_in == NULL) BN_CTX_free(ctx);
-       if (kinv != NULL) BN_clear_free(kinv);
-       BN_clear_free(&k);
-       return(ret);
+       return dsa->meth->dsa_sign_setup(dsa, ctx_in, kinvp, rp, NULL, 0);
        }
-