PKCS#7: Fix NULL dereference with missing EncryptedContent.

CVE-2015-1790

Reviewed-by: Rich Salz <rsalz@openssl.org>
This commit is contained in:
Emilia Kasper 2015-05-12 19:00:30 +02:00 committed by Dr. Stephen Henson
parent fa57f74a39
commit 582f1f41d4

View file

@ -359,12 +359,19 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
switch (i) {
case NID_pkcs7_signed:
/*
* p7->d.sign->contents is a PKCS7 structure consisting of a contentType
* field and optional content.
* data_body is NULL if that structure has no (=detached) content
* or if the contentType is wrong (i.e., not "data").
*/
data_body = PKCS7_get_octet_string(p7->d.sign->contents);
md_sk = p7->d.sign->md_algs;
break;
case NID_pkcs7_signedAndEnveloped:
rsk = p7->d.signed_and_enveloped->recipientinfo;
md_sk = p7->d.signed_and_enveloped->md_algs;
/* data_body is NULL if the optional EncryptedContent is missing. */
data_body = p7->d.signed_and_enveloped->enc_data->enc_data;
enc_alg = p7->d.signed_and_enveloped->enc_data->algorithm;
evp_cipher = EVP_get_cipherbyobj(enc_alg->algorithm);
@ -377,6 +384,7 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
case NID_pkcs7_enveloped:
rsk = p7->d.enveloped->recipientinfo;
enc_alg = p7->d.enveloped->enc_data->algorithm;
/* data_body is NULL if the optional EncryptedContent is missing. */
data_body = p7->d.enveloped->enc_data->enc_data;
evp_cipher = EVP_get_cipherbyobj(enc_alg->algorithm);
if (evp_cipher == NULL) {
@ -390,6 +398,12 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
goto err;
}
/* Detached content must be supplied via in_bio instead. */
if (data_body == NULL && in_bio == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATADECODE, PKCS7_R_NO_CONTENT);
goto err;
}
/* We will be checking the signature */
if (md_sk != NULL) {
for (i = 0; i < sk_X509_ALGOR_num(md_sk); i++) {
@ -557,7 +571,7 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
etmp = NULL;
}
#if 1
if (PKCS7_is_detached(p7) || (in_bio != NULL)) {
if (in_bio != NULL) {
bio = in_bio;
} else {
# if 0