import OpenSSL-1.0.0a

1 files changed, 34 insertions, 14 deletions

diff --git a/src/lib/libcrypto/dsa/dsa_ossl.c b/src/lib/libcrypto/dsa/dsa_ossl.c
index 412cf1d88b..4fead07e80 100644
--- a/src/lib/libcrypto/dsa/dsa_ossl.c
+++ b/src/lib/libcrypto/dsa/dsa_ossl.c
@@ -61,16 +61,15 @@
 #include <stdio.h>
 #include "cryptlib.h"
 #include <openssl/bn.h>
+#include <openssl/sha.h>
 #include <openssl/dsa.h>
 #include <openssl/rand.h>
 #include <openssl/asn1.h>
 
-#ifndef OPENSSL_FIPS
-
 static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa);
 static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp, BIGNUM **rp);
 static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
-                  DSA *dsa);
+                         DSA *dsa);
 static int dsa_init(DSA *dsa);
 static int dsa_finish(DSA *dsa);
 
@@ -135,7 +134,7 @@ static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
         BIGNUM m;
         BIGNUM xr;
         BN_CTX *ctx=NULL;
-        int i,reason=ERR_R_BN_LIB;
+        int reason=ERR_R_BN_LIB;
         DSA_SIG *ret=NULL;
 
         BN_init(&m);
@@ -150,8 +149,9 @@ static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
         s=BN_new();
         if (s == NULL) goto err;
 
-        i=BN_num_bytes(dsa->q); /* should be 20 */
-        if ((dlen > i) || (dlen > 50))
+        /* reject a excessive digest length (currently at most
+         * dsa-with-SHA256 is supported) */
+        if (dlen > SHA256_DIGEST_LENGTH)
                 {
                 reason=DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE;
                 goto err;
@@ -172,7 +172,14 @@ static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
                 dsa->r=NULL;
                 }
 
-        if (BN_bin2bn(dgst,dlen,&m) == NULL) goto err;
+        
+        if (dlen > BN_num_bytes(dsa->q))
+                /* if the digest length is greater than the size of q use the
+                 * BN_num_bits(dsa->q) leftmost bits of the digest, see
+                 * fips 186-3, 4.2 */
+                dlen = BN_num_bytes(dsa->q);
+        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 */
@@ -283,30 +290,31 @@ 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 (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);
         BN_clear_free(&kq);
         return(ret);
         }
 
 static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
-                  DSA *dsa)
+                         DSA *dsa)
         {
         BN_CTX *ctx;
         BIGNUM u1,u2,t1;
         BN_MONT_CTX *mont=NULL;
-        int ret = -1;
+        int ret = -1, i;
         if (!dsa->p || !dsa->q || !dsa->g)
                 {
                 DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_MISSING_PARAMETERS);
                 return -1;
                 }
 
-        if (BN_num_bits(dsa->q) != 160)
+        i = BN_num_bits(dsa->q);
+        /* fips 186-3 allows only different sizes for q */
+        if (i != 160 && i != 224 && i != 256)
                 {
                 DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_BAD_Q_VALUE);
                 return -1;
@@ -318,6 +326,14 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
                 return -1;
                 }
 
+        /* reject a excessive digest length (currently at most
+         * dsa-with-SHA256 is supported) */
+        if (dgst_len > SHA256_DIGEST_LENGTH)
+                {
+                DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
+                return -1;
+                }
+
         BN_init(&u1);
         BN_init(&u2);
         BN_init(&t1);
@@ -342,6 +358,11 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
         if ((BN_mod_inverse(&u2,sig->s,dsa->q,ctx)) == NULL) goto err;
 
         /* save M in u1 */
+        if (dgst_len > (i >> 3))
+                /* if the digest length is greater than the size of q use the
+                 * BN_num_bits(dsa->q) leftmost bits of the digest, see
+                 * fips 186-3, 4.2 */
+                dgst_len = (i >> 3);
         if (BN_bin2bn(dgst,dgst_len,&u1) == NULL) goto err;
 
         /* u1 = M * w mod q */
@@ -393,4 +414,3 @@ static int dsa_finish(DSA *dsa)
         return(1);
 }
 
-#endif