diff options
Diffstat (limited to 'app/openssl/crypto/pkcs7/pk7_doit.c')
-rw-r--r-- | app/openssl/crypto/pkcs7/pk7_doit.c | 101 |
1 files changed, 76 insertions, 25 deletions
diff --git a/app/openssl/crypto/pkcs7/pk7_doit.c b/app/openssl/crypto/pkcs7/pk7_doit.c index 3bf1a367..77fda3b8 100644 --- a/app/openssl/crypto/pkcs7/pk7_doit.c +++ b/app/openssl/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; @@ -423,6 +430,8 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert) STACK_OF(X509_ALGOR) *md_sk=NULL; STACK_OF(PKCS7_RECIP_INFO) *rsk=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; @@ -500,8 +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) { @@ -534,29 +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 sucess 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; @@ -565,6 +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 @@ -573,11 +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; @@ -585,6 +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) @@ -627,6 +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); @@ -676,7 +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); @@ -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); } @@ -1015,7 +1062,8 @@ 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)) @@ -1025,7 +1073,8 @@ int PKCS7_signatureVerify(BIO *bio, PKCS7 *p7, PKCS7_SIGNER_INFO *si, 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) { @@ -1050,7 +1099,8 @@ 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)); @@ -1060,7 +1110,8 @@ for (ii=0; ii<md_len; ii++) printf("%02X",md_dat[ii]); printf(" calc\n"); ret = -1; goto err; } - EVP_VerifyUpdate(&mdc_tmp, abuf, alen); + if (!EVP_VerifyUpdate(&mdc_tmp, abuf, alen)) + goto err; OPENSSL_free(abuf); } |