Currently, RSA code, when using no padding scheme, simply checks that input

[openssl.git] / crypto / rsa / rsa_eay.c

diff --git a/crypto/rsa/rsa_eay.c b/crypto/rsa/rsa_eay.c
index 6a68770031d6d651b3903d24a8529ce2eda2715e..f325050c1c91e6cbc7dc32bf1bb4d770cfc7a8a2 100644 (file)
--- a/crypto/rsa/rsa_eay.c
+++ b/crypto/rsa/rsa_eay.c
@@ -120,7 +120,7 @@ static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
        case RSA_PKCS1_PADDING:
                i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
                break;
-#ifndef NO_SHA
+#ifndef OPENSSL_NO_SHA
        case RSA_PKCS1_OAEP_PADDING:
                i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
                break;
@@ -329,7 +329,7 @@ static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
        case RSA_PKCS1_PADDING:
                r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
                break;
-#ifndef NO_SHA
+#ifndef OPENSSL_NO_SHA
         case RSA_PKCS1_OAEP_PADDING:
                r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
                 break;
@@ -453,7 +453,7 @@ err:
 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa)
        {
        const RSA_METHOD *meth;
-       BIGNUM r1,m1;
+       BIGNUM r1,m1,vrfy;
        int ret=0;
        BN_CTX *ctx;
 
@@ -461,6 +461,7 @@ static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa)
        if ((ctx=BN_CTX_new()) == NULL) goto err;
        BN_init(&m1);
        BN_init(&r1);
+       BN_init(&vrfy);
 
        if (rsa->flags & RSA_FLAG_CACHE_PRIVATE)
                {
@@ -541,10 +542,28 @@ static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa)
        if (!BN_mul(&r1,r0,rsa->q,ctx)) goto err;
        if (!BN_add(r0,&r1,&m1)) goto err;
 
+       if (rsa->e && rsa->n)
+               {
+               if (!meth->bn_mod_exp(&vrfy,r0,rsa->e,rsa->n,ctx,NULL)) goto err;
+               /* If 'I' was greater than (or equal to) rsa->n, the operation
+                * will be equivalent to using 'I mod n'. However, the result of
+                * the verify will *always* be less than 'n' so we don't check
+                * for absolute equality, just congruency. */
+               if (!BN_sub(&vrfy, &vrfy, I)) goto err;
+               if (!BN_mod(&vrfy, &vrfy, rsa->n, ctx)) goto err;
+               if (vrfy.neg)
+                       if (!BN_add(&vrfy, &vrfy, rsa->n)) goto err;
+               if (!BN_is_zero(&vrfy))
+                       /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
+                        * miscalculated CRT output, just do a raw (slower)
+                        * mod_exp and return that instead. */
+                       if (!meth->bn_mod_exp(r0,I,rsa->d,rsa->n,ctx,NULL)) goto err;
+               }
        ret=1;
 err:
        BN_clear_free(&m1);
        BN_clear_free(&r1);
+       BN_clear_free(&vrfy);
        BN_CTX_free(ctx);
        return(ret);
        }