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path: root/openssl/crypto/pkcs7/pk7_doit.c
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Diffstat (limited to 'openssl/crypto/pkcs7/pk7_doit.c')
-rw-r--r--openssl/crypto/pkcs7/pk7_doit.c89
1 files changed, 64 insertions, 25 deletions
diff --git a/openssl/crypto/pkcs7/pk7_doit.c b/openssl/crypto/pkcs7/pk7_doit.c
index 3bf1a367b..fae8eda46 100644
--- a/openssl/crypto/pkcs7/pk7_doit.c
+++ b/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;
@@ -500,8 +507,8 @@ 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;
+ unsigned char *ek = NULL, *tkey = NULL;
+ int eklen, tkeylen;
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;
@@ -586,6 +610,11 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
OPENSSL_cleanse(ek,eklen);
OPENSSL_free(ek);
}
+ if (tkey)
+ {
+ OPENSSL_cleanse(tkey,tkeylen);
+ OPENSSL_free(tkey);
+ }
if (out == NULL)
out=etmp;
@@ -676,7 +705,11 @@ 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 +817,8 @@ 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 +856,8 @@ 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 +1050,8 @@ 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 +1061,8 @@ 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 +1087,8 @@ 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 +1098,8 @@ 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);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-25 21:15:39 +0000