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SUSE:SLE-12-SP2:GA
openssl.12525
openssl-CVE-2019-1563.patch
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File openssl-CVE-2019-1563.patch of Package openssl.12525
From e21f8cf78a125cd3c8c0d1a1a6c8bb0b901f893f Mon Sep 17 00:00:00 2001 From: Bernd Edlinger <bernd.edlinger@hotmail.de> Date: Sun, 1 Sep 2019 00:16:28 +0200 Subject: [PATCH] Fix a padding oracle in PKCS7_dataDecode and CMS_decrypt_set1_pkey An attack is simple, if the first CMS_recipientInfo is valid but the second CMS_recipientInfo is chosen ciphertext. If the second recipientInfo decodes to PKCS #1 v1.5 form plaintext, the correct encryption key will be replaced by garbage, and the message cannot be decoded, but if the RSA decryption fails, the correct encryption key is used and the recipient will not notice the attack. As a work around for this potential attack the length of the decrypted key must be equal to the cipher default key length, in case the certifiate is not given and all recipientInfo are tried out. The old behaviour can be re-enabled in the CMS code by setting the CMS_DEBUG_DECRYPT flag. Reviewed-by: Matt Caswell <matt@openssl.org> (Merged from https://github.com/openssl/openssl/pull/9777) (cherry picked from commit 5840ed0cd1e6487d247efbc1a04136a41d7b3a37) --- CHANGES | 14 ++++++++++++++ crypto/cms/cms_env.c | 18 +++++++++++++++++- crypto/cms/cms_lcl.h | 2 ++ crypto/cms/cms_smime.c | 4 ++++ crypto/pkcs7/pk7_doit.c | 12 ++++++++---- 5 files changed, 45 insertions(+), 5 deletions(-) Index: openssl-1.0.1i/crypto/cms/cms_env.c =================================================================== --- openssl-1.0.1i.orig/crypto/cms/cms_env.c +++ openssl-1.0.1i/crypto/cms/cms_env.c @@ -372,6 +372,7 @@ static int cms_RecipientInfo_ktri_decryp unsigned char *ek = NULL; size_t eklen; int ret = 0; + size_t fixlen = 0; CMS_EncryptedContentInfo *ec; ec = cms->d.envelopedData->encryptedContentInfo; @@ -382,6 +383,20 @@ static int cms_RecipientInfo_ktri_decryp return 0; } + + if (cms->d.envelopedData->encryptedContentInfo->havenocert + && !cms->d.envelopedData->encryptedContentInfo->debug) { + X509_ALGOR *calg = ec->contentEncryptionAlgorithm; + const EVP_CIPHER *ciph = EVP_get_cipherbyobj(calg->algorithm); + + if (ciph == NULL) { + CMSerr(CMS_F_CMS_RECIPIENTINFO_KTRI_DECRYPT, CMS_R_UNKNOWN_CIPHER); + return 0; + } + + fixlen = EVP_CIPHER_key_length(ciph); + } + pctx = EVP_PKEY_CTX_new(ktri->pkey, NULL); if (!pctx) return 0; @@ -411,8 +426,10 @@ static int cms_RecipientInfo_ktri_decryp } if (EVP_PKEY_decrypt(pctx, ek, &eklen, - ktri->encryptedKey->data, - ktri->encryptedKey->length) <= 0) + ktri->encryptedKey->data, + ktri->encryptedKey->length) <= 0 + || eklen == 0 + || (fixlen != 0 && eklen != fixlen)) { CMSerr(CMS_F_CMS_RECIPIENTINFO_KTRI_DECRYPT, CMS_R_CMS_LIB); goto err; Index: openssl-1.0.1i/crypto/cms/cms_lcl.h =================================================================== --- openssl-1.0.1i.orig/crypto/cms/cms_lcl.h +++ openssl-1.0.1i/crypto/cms/cms_lcl.h @@ -177,6 +177,8 @@ struct CMS_EncryptedContentInfo_st size_t keylen; /* Set to 1 if we are debugging decrypt and don't fake keys for MMA */ int debug; + /* Set to 1 if we have no cert and need extra safety measures for MMA */ + int havenocert; }; struct CMS_RecipientInfo_st Index: openssl-1.0.1i/crypto/cms/cms_smime.c =================================================================== --- openssl-1.0.1i.orig/crypto/cms/cms_smime.c +++ openssl-1.0.1i/crypto/cms/cms_smime.c @@ -747,6 +747,10 @@ int CMS_decrypt(CMS_ContentInfo *cms, EV cms->d.envelopedData->encryptedContentInfo->debug = 1; else cms->d.envelopedData->encryptedContentInfo->debug = 0; + if (!cert) + cms->d.envelopedData->encryptedContentInfo->havenocert = 1; + else + cms->d.envelopedData->encryptedContentInfo->havenocert = 0; if (!pk && !cert && !dcont && !out) return 1; if (pk && !CMS_decrypt_set1_pkey(cms, pk, cert)) Index: openssl-1.0.1i/crypto/pkcs7/pk7_doit.c =================================================================== --- openssl-1.0.1i.orig/crypto/pkcs7/pk7_doit.c +++ openssl-1.0.1i/crypto/pkcs7/pk7_doit.c @@ -198,7 +198,8 @@ static int pkcs7_encode_rinfo(PKCS7_RECI static int pkcs7_decrypt_rinfo(unsigned char **pek, int *peklen, - PKCS7_RECIP_INFO *ri, EVP_PKEY *pkey) + PKCS7_RECIP_INFO *ri, EVP_PKEY *pkey, + size_t fixlen) { EVP_PKEY_CTX *pctx = NULL; unsigned char *ek = NULL; @@ -233,7 +234,9 @@ static int pkcs7_decrypt_rinfo(unsigned } if (EVP_PKEY_decrypt(pctx, ek, &eklen, - ri->enc_key->data, ri->enc_key->length) <= 0) + ri->enc_key->data, ri->enc_key->length) <= 0 + || eklen == 0 + || (fixlen != 0 && eklen != fixlen)) { ret = 0; PKCS7err(PKCS7_F_PKCS7_DECRYPT_RINFO, ERR_R_EVP_LIB); @@ -598,8 +601,8 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKE { ri=sk_PKCS7_RECIP_INFO_value(rsk,i); - if (pkcs7_decrypt_rinfo(&ek, &eklen, - ri, pkey) < 0) + if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey, + EVP_CIPHER_key_length(evp_cipher)) < 0) goto err; ERR_clear_error(); } @@ -607,7 +610,7 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKE else { /* Only exit on fatal errors, not decrypt failure */ - if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey) < 0) + if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey, 0) < 0) goto err; ERR_clear_error(); }
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