X-Git-Url: https://git.openssl.org/gitweb/?a=blobdiff_plain;f=crypto%2Fpkcs7%2Fpk7_doit.c;h=82e145b856d92c2ba966176c9bd737abe7520fa3;hb=2218c296b4981af6f2639bbd7eabfb89437fe776;hp=655c30efa3b35da9ecb12d4f75974f7990d35854;hpb=689f9faba41dc199907d3ed8e2b126107171417d;p=openssl.git

diff --git a/crypto/pkcs7/pk7_doit.c b/crypto/pkcs7/pk7_doit.c
index 655c30efa3..82e145b856 100644
--- a/crypto/pkcs7/pk7_doit.c
+++ b/crypto/pkcs7/pk7_doit.c
@@ -204,11 +204,11 @@ static int pkcs7_decrypt_rinfo(unsigned char **pek, int *peklen,
 	unsigned char *ek = NULL;
 	size_t eklen;
 
-	int ret = 0;
+	int ret = -1;
 
 	pctx = EVP_PKEY_CTX_new(pkey, NULL);
 	if (!pctx)
-		return 0;
+		return -1;
 
 	if (EVP_PKEY_decrypt_init(pctx) <= 0)
 		goto err;
@@ -235,12 +235,19 @@ static int pkcs7_decrypt_rinfo(unsigned char **pek, int *peklen,
 	if (EVP_PKEY_decrypt(pctx, ek, &eklen,
 				ri->enc_key->data, ri->enc_key->length) <= 0)
 		{
+		ret = 0;
 		PKCS7err(PKCS7_F_PKCS7_DECRYPT_RINFO, ERR_R_EVP_LIB);
 		goto err;
 		}
 
 	ret = 1;
 
+	if (*pek)
+		{
+		OPENSSL_cleanse(*pek, *peklen);
+		OPENSSL_free(*pek);
+		}
+
 	*pek = ek;
 	*peklen = eklen;
 
@@ -422,8 +429,9 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
 	X509_ALGOR *enc_alg=NULL;
 	STACK_OF(X509_ALGOR) *md_sk=NULL;
 	STACK_OF(PKCS7_RECIP_INFO) *rsk=NULL;
-	X509_ALGOR *xalg=NULL;
 	PKCS7_RECIP_INFO *ri=NULL;
+       unsigned char *ek = NULL, *tkey = NULL;
+       int eklen = 0, tkeylen = 0;
 
 	i=OBJ_obj2nid(p7->type);
 	p7->state=PKCS7_S_HEADER;
@@ -445,7 +453,6 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
 			PKCS7err(PKCS7_F_PKCS7_DATADECODE,PKCS7_R_UNSUPPORTED_CIPHER_TYPE);
 			goto err;
 			}
-		xalg=p7->d.signed_and_enveloped->enc_data->algorithm;
 		break;
 	case NID_pkcs7_enveloped:
 		rsk=p7->d.enveloped->recipientinfo;
@@ -457,7 +464,6 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
 			PKCS7err(PKCS7_F_PKCS7_DATADECODE,PKCS7_R_UNSUPPORTED_CIPHER_TYPE);
 			goto err;
 			}
-		xalg=p7->d.enveloped->enc_data->algorithm;
 		break;
 	default:
 		PKCS7err(PKCS7_F_PKCS7_DATADECODE,PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
@@ -503,8 +509,6 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
 		int max;
 		X509_OBJECT ret;
 #endif
-		unsigned char *ek = NULL;
-		int eklen;
 
 		if ((etmp=BIO_new(BIO_f_cipher())) == NULL)
 			{
@@ -537,29 +541,28 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
 			}
 
 		/* If we haven't got a certificate try each ri in turn */
-
 		if (pcert == NULL)
 			{
+			/* Always attempt to decrypt all rinfo even
+			 * after success as a defence against MMA timing
+			 * attacks.
+			 */
 			for (i=0; i<sk_PKCS7_RECIP_INFO_num(rsk); i++)
 				{
 				ri=sk_PKCS7_RECIP_INFO_value(rsk,i);
+				
 				if (pkcs7_decrypt_rinfo(&ek, &eklen,
-							ri, pkey) > 0)
-					break;
+							ri, pkey) < 0)
+					goto err;
 				ERR_clear_error();
-				ri = NULL;
-				}
-			if (ri == NULL)
-				{
-				PKCS7err(PKCS7_F_PKCS7_DATADECODE,
-				      PKCS7_R_NO_RECIPIENT_MATCHES_KEY);
-				goto err;
 				}
 			}
 		else
 			{
-			if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey) <= 0)
+			/* Only exit on fatal errors, not decrypt failure */
+			if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey) < 0)
 				goto err;
+			ERR_clear_error();
 			}
 
 		evp_ctx=NULL;
@@ -568,6 +571,19 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
 			goto err;
 		if (EVP_CIPHER_asn1_to_param(evp_ctx,enc_alg->parameter) < 0)
 			goto err;
+		/* Generate random key as MMA defence */
+		tkeylen = EVP_CIPHER_CTX_key_length(evp_ctx);
+		tkey = OPENSSL_malloc(tkeylen);
+		if (!tkey)
+			goto err;
+		if (EVP_CIPHER_CTX_rand_key(evp_ctx, tkey) <= 0)
+			goto err;
+		if (ek == NULL)
+			{
+			ek = tkey;
+			eklen = tkeylen;
+			tkey = NULL;
+			}
 
 		if (eklen != EVP_CIPHER_CTX_key_length(evp_ctx)) {
 			/* Some S/MIME clients don't use the same key
@@ -576,11 +592,16 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
 			 */
 			if(!EVP_CIPHER_CTX_set_key_length(evp_ctx, eklen))
 				{
-				PKCS7err(PKCS7_F_PKCS7_DATADECODE,
-					PKCS7_R_DECRYPTED_KEY_IS_WRONG_LENGTH);
-				goto err;
+				/* Use random key as MMA defence */
+				OPENSSL_cleanse(ek, eklen);
+				OPENSSL_free(ek);
+				ek = tkey;
+				eklen = tkeylen;
+				tkey = NULL;
 				}
 		} 
+		/* Clear errors so we don't leak information useful in MMA */
+		ERR_clear_error();
 		if (EVP_CipherInit_ex(evp_ctx,NULL,NULL,ek,NULL,0) <= 0)
 			goto err;
 
@@ -588,6 +609,13 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
 			{
 			OPENSSL_cleanse(ek,eklen);
 			OPENSSL_free(ek);
+                       ek = NULL;
+			}
+		if (tkey)
+			{
+			OPENSSL_cleanse(tkey,tkeylen);
+			OPENSSL_free(tkey);
+                       tkey = NULL;
 			}
 
 		if (out == NULL)
@@ -630,6 +658,16 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
 	if (0)
 		{
 err:
+               if (ek)
+                       {
+                       OPENSSL_cleanse(ek,eklen);
+                       OPENSSL_free(ek);
+                       }
+               if (tkey)
+                       {
+                       OPENSSL_cleanse(tkey,tkeylen);
+                       OPENSSL_free(tkey);
+                       }
 		if (out != NULL) BIO_free_all(out);
 		if (btmp != NULL) BIO_free_all(btmp);
 		if (etmp != NULL) BIO_free_all(etmp);
@@ -679,7 +717,11 @@ static int do_pkcs7_signed_attrib(PKCS7_SIGNER_INFO *si, EVP_MD_CTX *mctx)
 		}
 
 	/* Add digest */
-	EVP_DigestFinal_ex(mctx, md_data,&md_len);
+	if (!EVP_DigestFinal_ex(mctx, md_data,&md_len))
+		{
+		PKCS7err(PKCS7_F_DO_PKCS7_SIGNED_ATTRIB, ERR_R_EVP_LIB);
+		return 0;
+		}
 	if (!PKCS7_add1_attrib_digest(si, md_data, md_len))
 		{
 		PKCS7err(PKCS7_F_DO_PKCS7_SIGNED_ATTRIB, ERR_R_MALLOC_FAILURE);
@@ -763,6 +805,9 @@ int PKCS7_dataFinal(PKCS7 *p7, BIO *bio)
 			}
 		break;
 
+	default:
+		PKCS7err(PKCS7_F_PKCS7_DATAFINAL,PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
+	        goto err;
 		}
 
 	if (si_sk != NULL)
@@ -784,7 +829,8 @@ int PKCS7_dataFinal(PKCS7 *p7, BIO *bio)
 
 			/* We now have the EVP_MD_CTX, lets do the
 			 * signing. */
-			EVP_MD_CTX_copy_ex(&ctx_tmp,mdc);
+			if (!EVP_MD_CTX_copy_ex(&ctx_tmp,mdc))
+				goto err;
 
 			sk=si->auth_attr;
 
@@ -822,7 +868,8 @@ int PKCS7_dataFinal(PKCS7 *p7, BIO *bio)
 		if (!PKCS7_find_digest(&mdc, bio,
 				OBJ_obj2nid(p7->d.digest->md->algorithm)))
 			goto err;
-		EVP_DigestFinal_ex(mdc,md_data,&md_len);
+		if (!EVP_DigestFinal_ex(mdc,md_data,&md_len))
+			goto err;
 		M_ASN1_OCTET_STRING_set(p7->d.digest->digest, md_data, md_len);
 		}
 
@@ -1015,16 +1062,19 @@ int PKCS7_signatureVerify(BIO *bio, PKCS7 *p7, PKCS7_SIGNER_INFO *si,
 
 	/* mdc is the digest ctx that we want, unless there are attributes,
 	 * in which case the digest is the signed attributes */
-	EVP_MD_CTX_copy_ex(&mdc_tmp,mdc);
+	if (!EVP_MD_CTX_copy_ex(&mdc_tmp,mdc))
+		goto err;
 
 	sk=si->auth_attr;
 	if ((sk != NULL) && (sk_X509_ATTRIBUTE_num(sk) != 0))
 		{
 		unsigned char md_dat[EVP_MAX_MD_SIZE], *abuf = NULL;
-                unsigned int md_len, alen;
+                unsigned int md_len;
+		int alen;
 		ASN1_OCTET_STRING *message_digest;
 
-		EVP_DigestFinal_ex(&mdc_tmp,md_dat,&md_len);
+		if (!EVP_DigestFinal_ex(&mdc_tmp,md_dat,&md_len))
+			goto err;
 		message_digest=PKCS7_digest_from_attributes(sk);
 		if (!message_digest)
 			{
@@ -1049,11 +1099,19 @@ for (ii=0; ii<md_len; ii++) printf("%02X",md_dat[ii]); printf(" calc\n");
 			goto err;
 			}
 
-		EVP_VerifyInit_ex(&mdc_tmp,EVP_get_digestbynid(md_type), NULL);
+		if (!EVP_VerifyInit_ex(&mdc_tmp,EVP_get_digestbynid(md_type), NULL))
+			goto err;
 
 		alen = ASN1_item_i2d((ASN1_VALUE *)sk, &abuf,
 						ASN1_ITEM_rptr(PKCS7_ATTR_VERIFY));
-		EVP_VerifyUpdate(&mdc_tmp, abuf, alen);
+		if (alen <= 0) 
+			{
+			PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY,ERR_R_ASN1_LIB);
+			ret = -1;
+			goto err;
+			}
+		if (!EVP_VerifyUpdate(&mdc_tmp, abuf, alen))
+			goto err;
 
 		OPENSSL_free(abuf);
 		}