45 lines
2.1 KiB
Diff
45 lines
2.1 KiB
Diff
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From f1b9c830f145a0042e853d6462b2f9ca4016c669 Mon Sep 17 00:00:00 2001
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From: =?UTF-8?q?Juraj=20=C5=A0arinay?= <juraj@sarinay.com>
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Date: Thu, 6 Mar 2025 02:02:56 +0100
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Subject: [PATCH] Properly verify adbe.pkcs7.sha1 signatures.
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For signatures with non-empty encapsulated content
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(typically adbe.pkcs7.sha1), we only compared hash values and
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never actually checked SignatureValue within SignerInfo.
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The bug introduced by c7c0207b1cfe49a4353d6cda93dbebef4508138f
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made trivial signature forgeries possible. Fix this by calling
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NSS_CMSSignerInfo_Verify() after the hash values compare equal.
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---
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poppler/NSSCryptoSignBackend.cc | 13 +++++++++----
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1 file changed, 9 insertions(+), 4 deletions(-)
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diff --git a/poppler/NSSCryptoSignBackend.cc b/poppler/NSSCryptoSignBackend.cc
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index 521137d6b..eeea26ee3 100644
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--- a/poppler/NSSCryptoSignBackend.cc
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+++ b/poppler/NSSCryptoSignBackend.cc
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@@ -877,13 +877,18 @@ SignatureValidationStatus NSSSignatureVerification::validateSignature()
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This means it's not a detached type signature
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so the digest is contained in SignedData->contentInfo
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*/
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- if (digest.len == content_info_data->len && memcmp(digest.data, content_info_data->data, digest.len) == 0) {
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- return SIGNATURE_VALID;
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- } else {
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+ if (digest.len != content_info_data->len || memcmp(digest.data, content_info_data->data, digest.len) != 0) {
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return SIGNATURE_DIGEST_MISMATCH;
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}
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- } else if (NSS_CMSSignerInfo_Verify(CMSSignerInfo, &digest, nullptr) != SECSuccess) {
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+ auto innerHashContext = HashContext::create(hashContext->getHashAlgorithm());
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+ innerHashContext->updateHash(content_info_data->data, content_info_data->len);
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+ digest_buffer = innerHashContext->endHash();
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+ digest.data = digest_buffer.data();
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+ digest.len = digest_buffer.size();
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+ }
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+
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+ if (NSS_CMSSignerInfo_Verify(CMSSignerInfo, &digest, nullptr) != SECSuccess) {
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return NSS_SigTranslate(CMSSignerInfo->verificationStatus);
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} else {
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return SIGNATURE_VALID;
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--
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GitLab
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