comments

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

diff --git a/crypto/rsa/rsa_eay.c b/crypto/rsa/rsa_eay.c
index 35db9e5687ce1e69047ccb5a2bf2d8de26b249ae..83891df316fe7c74c939373985de7afb76ddc67c 100644 (file)
--- a/crypto/rsa/rsa_eay.c
+++ b/crypto/rsa/rsa_eay.c
@@ -79,15 +79,17 @@ static int RSA_eay_finish(RSA *rsa);
 static RSA_METHOD rsa_pkcs1_eay_meth={
        "Eric Young's PKCS#1 RSA",
        RSA_eay_public_encrypt,
-       RSA_eay_public_decrypt,
-       RSA_eay_private_encrypt,
+       RSA_eay_public_decrypt, /* signature verification */
+       RSA_eay_private_encrypt, /* signing */
        RSA_eay_private_decrypt,
        RSA_eay_mod_exp,
        BN_mod_exp_mont, /* XXX probably we should not use Montgomery if  e == 3 */
        RSA_eay_init,
        RSA_eay_finish,
-       0,
+       0, /* flags */
        NULL,
+       0, /* rsa_sign */
+       0  /* rsa_verify */
        };
 
 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
@@ -120,7 +122,7 @@ 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;
@@ -139,6 +141,13 @@ static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
 
        if (BN_bin2bn(buf,num,&f) == NULL) goto err;
        
+       if (BN_ucmp(&f, rsa->n) >= 0)
+               {       
+               /* usually the padding functions would catch this */
+               RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
+               goto err;
+               }
+
        if ((rsa->_method_mod_n == NULL) && (rsa->flags & RSA_FLAG_CACHE_PUBLIC))
                {
                BN_MONT_CTX* bn_mont_ctx;
@@ -186,6 +195,7 @@ err:
        return(r);
        }
 
+/* signing */
 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
             unsigned char *to, RSA *rsa, int padding)
        {
@@ -223,6 +233,13 @@ static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
        if (i <= 0) goto err;
 
        if (BN_bin2bn(buf,num,&f) == NULL) goto err;
+       
+       if (BN_ucmp(&f, rsa->n) >= 0)
+               {       
+               /* usually the padding functions would catch this */
+               RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
+               goto err;
+               }
 
        if ((rsa->flags & RSA_FLAG_BLINDING) && (rsa->blinding == NULL))
                RSA_blinding_on(rsa,ctx);
@@ -299,6 +316,12 @@ static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
        /* make data into a big number */
        if (BN_bin2bn(from,(int)flen,&f) == NULL) goto err;
 
+       if (BN_ucmp(&f, rsa->n) >= 0)
+               {
+               RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
+               goto err;
+               }
+
        if ((rsa->flags & RSA_FLAG_BLINDING) && (rsa->blinding == NULL))
                RSA_blinding_on(rsa,ctx);
        if (rsa->flags & RSA_FLAG_BLINDING)
@@ -329,7 +352,7 @@ 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;
@@ -359,6 +382,7 @@ err:
        return(r);
        }
 
+/* signature verification */
 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
             unsigned char *to, RSA *rsa, int padding)
        {
@@ -392,6 +416,13 @@ static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
                }
 
        if (BN_bin2bn(from,flen,&f) == NULL) goto err;
+
+       if (BN_ucmp(&f, rsa->n) >= 0)
+               {
+               RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
+               goto err;
+               }
+
        /* do the decrypt */
        if ((rsa->_method_mod_n == NULL) && (rsa->flags & RSA_FLAG_CACHE_PUBLIC))
                {
@@ -453,7 +484,7 @@ 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 +492,7 @@ 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)
                {
@@ -496,7 +528,7 @@ static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa)
                        if (!BN_MONT_CTX_set(bn_mont_ctx,rsa->q,ctx))
                                {
                                BN_MONT_CTX_free(bn_mont_ctx);
-                                       goto err;
+                               goto err;
                                }
                        if (rsa->_method_mod_q == NULL) /* other thread may have finished first */
                                {
@@ -541,10 +573,28 @@ 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);
        }