mirror of
https://github.com/Telecominfraproject/wlan-ap.git
synced 2025-10-30 18:07:52 +00:00
109 lines
3.5 KiB
Diff
109 lines
3.5 KiB
Diff
From a0541334a6394f8237a4393b7372693cd7e96f15 Mon Sep 17 00:00:00 2001
|
|
From: Jouni Malinen <j@w1.fi>
|
|
Date: Sat, 13 Mar 2021 18:19:31 +0200
|
|
Subject: ASN.1: Validate DigestAlgorithmIdentifier parameters
|
|
|
|
The supported hash algorithms do not use AlgorithmIdentifier parameters.
|
|
However, there are implementations that include NULL parameters in
|
|
addition to ones that omit the parameters. Previous implementation did
|
|
not check the parameters value at all which supported both these cases,
|
|
but did not reject any other unexpected information.
|
|
|
|
Use strict validation of digest algorithm parameters and reject any
|
|
unexpected value when validating a signature. This is needed to prevent
|
|
potential forging attacks.
|
|
|
|
Signed-off-by: Jouni Malinen <j@w1.fi>
|
|
---
|
|
src/tls/pkcs1.c | 21 +++++++++++++++++++++
|
|
src/tls/x509v3.c | 20 ++++++++++++++++++++
|
|
2 files changed, 41 insertions(+)
|
|
|
|
--- a/src/tls/pkcs1.c
|
|
+++ b/src/tls/pkcs1.c
|
|
@@ -244,6 +244,8 @@ int pkcs1_v15_sig_ver(struct crypto_publ
|
|
os_free(decrypted);
|
|
return -1;
|
|
}
|
|
+ wpa_hexdump(MSG_MSGDUMP, "PKCS #1: DigestInfo",
|
|
+ hdr.payload, hdr.length);
|
|
|
|
pos = hdr.payload;
|
|
end = pos + hdr.length;
|
|
@@ -265,6 +267,8 @@ int pkcs1_v15_sig_ver(struct crypto_publ
|
|
os_free(decrypted);
|
|
return -1;
|
|
}
|
|
+ wpa_hexdump(MSG_MSGDUMP, "PKCS #1: DigestAlgorithmIdentifier",
|
|
+ hdr.payload, hdr.length);
|
|
da_end = hdr.payload + hdr.length;
|
|
|
|
if (asn1_get_oid(hdr.payload, hdr.length, &oid, &next)) {
|
|
@@ -273,6 +277,23 @@ int pkcs1_v15_sig_ver(struct crypto_publ
|
|
os_free(decrypted);
|
|
return -1;
|
|
}
|
|
+ wpa_hexdump(MSG_MSGDUMP, "PKCS #1: Digest algorithm parameters",
|
|
+ next, da_end - next);
|
|
+
|
|
+ /*
|
|
+ * RFC 5754: The correct encoding for the SHA2 algorithms would be to
|
|
+ * omit the parameters, but there are implementation that encode these
|
|
+ * as a NULL element. Allow these two cases and reject anything else.
|
|
+ */
|
|
+ if (da_end > next &&
|
|
+ (asn1_get_next(next, da_end - next, &hdr) < 0 ||
|
|
+ !asn1_is_null(&hdr) ||
|
|
+ hdr.payload + hdr.length != da_end)) {
|
|
+ wpa_printf(MSG_DEBUG,
|
|
+ "PKCS #1: Unexpected digest algorithm parameters");
|
|
+ os_free(decrypted);
|
|
+ return -1;
|
|
+ }
|
|
|
|
if (!asn1_oid_equal(&oid, hash_alg)) {
|
|
char txt[100], txt2[100];
|
|
--- a/src/tls/x509v3.c
|
|
+++ b/src/tls/x509v3.c
|
|
@@ -1964,6 +1964,7 @@ int x509_check_signature(struct x509_cer
|
|
os_free(data);
|
|
return -1;
|
|
}
|
|
+ wpa_hexdump(MSG_MSGDUMP, "X509: DigestInfo", hdr.payload, hdr.length);
|
|
|
|
pos = hdr.payload;
|
|
end = pos + hdr.length;
|
|
@@ -1985,6 +1986,8 @@ int x509_check_signature(struct x509_cer
|
|
os_free(data);
|
|
return -1;
|
|
}
|
|
+ wpa_hexdump(MSG_MSGDUMP, "X509: DigestAlgorithmIdentifier",
|
|
+ hdr.payload, hdr.length);
|
|
da_end = hdr.payload + hdr.length;
|
|
|
|
if (asn1_get_oid(hdr.payload, hdr.length, &oid, &next)) {
|
|
@@ -1992,6 +1995,23 @@ int x509_check_signature(struct x509_cer
|
|
os_free(data);
|
|
return -1;
|
|
}
|
|
+ wpa_hexdump(MSG_MSGDUMP, "X509: Digest algorithm parameters",
|
|
+ next, da_end - next);
|
|
+
|
|
+ /*
|
|
+ * RFC 5754: The correct encoding for the SHA2 algorithms would be to
|
|
+ * omit the parameters, but there are implementation that encode these
|
|
+ * as a NULL element. Allow these two cases and reject anything else.
|
|
+ */
|
|
+ if (da_end > next &&
|
|
+ (asn1_get_next(next, da_end - next, &hdr) < 0 ||
|
|
+ !asn1_is_null(&hdr) ||
|
|
+ hdr.payload + hdr.length != da_end)) {
|
|
+ wpa_printf(MSG_DEBUG,
|
|
+ "X509: Unexpected digest algorithm parameters");
|
|
+ os_free(data);
|
|
+ return -1;
|
|
+ }
|
|
|
|
if (x509_sha1_oid(&oid)) {
|
|
if (signature->oid.oid[6] != 5 /* sha-1WithRSAEncryption */) {
|