From 36c820a9d99792d6816c2e537a36a3ec21bab592 Mon Sep 17 00:00:00 2001
From: Armin Novak <armin.novak@thincast.com>
Date: Wed, 17 Jul 2019 14:00:29 +0200
Subject: [PATCH] Extract whole certificate chain to PEM format.

---
 libfreerdp/crypto/crypto.c | 20 ++++++++++++++++++--
 libfreerdp/crypto/tls.c    | 17 ++++++++++++++++-
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/libfreerdp/crypto/crypto.c b/libfreerdp/crypto/crypto.c
index 727c62c..58def01 100644
--- a/libfreerdp/crypto/crypto.c
+++ b/libfreerdp/crypto/crypto.c
@@ -754,13 +754,27 @@ char* crypto_cert_issuer(X509* xcert)
 	return crypto_print_name(X509_get_issuer_name(xcert));
 }
 
+static int verify_cb (int ok, X509_STORE_CTX *csc)
+{
+	if (ok != 1)
+	{
+		int err = X509_STORE_CTX_get_error(csc);
+		int derr = X509_STORE_CTX_get_error_depth(csc);
+		X509* where = X509_STORE_CTX_get_current_cert(csc);
+		const char* what = X509_verify_cert_error_string(err);
+
+		WLog_WARN(TAG, "Certificate verification failure '%s (%d)' at stack position %d", what, err, derr);
+		WLog_WARN(TAG, "%s", crypto_cert_subject(where));
+	}
+	return ok;
+}
+
 BOOL x509_verify_certificate(CryptoCert cert, const char* certificate_store_path)
 {
 	X509_STORE_CTX* csc;
 	BOOL status = FALSE;
 	X509_STORE* cert_ctx = NULL;
 	X509_LOOKUP* lookup = NULL;
-	X509* xcert = cert->px509;
 	cert_ctx = X509_STORE_new();
 
 	if (cert_ctx == NULL)
@@ -773,6 +787,7 @@ BOOL x509_verify_certificate(CryptoCert cert, const char* certificate_store_path
 	                    | OPENSSL_INIT_ADD_ALL_DIGESTS \
 	                    | OPENSSL_INIT_LOAD_CONFIG, NULL);
 #endif
+
 	lookup = X509_STORE_add_lookup(cert_ctx, X509_LOOKUP_file());
 
 	if (lookup == NULL)
@@ -797,10 +812,11 @@ BOOL x509_verify_certificate(CryptoCert cert, const char* certificate_store_path
 
 	X509_STORE_set_flags(cert_ctx, 0);
 
-	if (!X509_STORE_CTX_init(csc, cert_ctx, xcert, cert->px509chain))
+	if (!X509_STORE_CTX_init(csc, cert_ctx, cert->px509, cert->px509chain))
 		goto end;
 
 	X509_STORE_CTX_set_purpose(csc, X509_PURPOSE_SSL_SERVER);
+	X509_STORE_CTX_set_verify_cb(csc, verify_cb);
 
 	if (X509_verify_cert(csc) == 1)
 		status = TRUE;
diff --git a/libfreerdp/crypto/tls.c b/libfreerdp/crypto/tls.c
index 7351f9c..8a02ed0 100644
--- a/libfreerdp/crypto/tls.c
+++ b/libfreerdp/crypto/tls.c
@@ -1226,7 +1226,7 @@ static BOOL accept_cert(rdpTls* tls, const BYTE* pem, UINT32 length)
 static BOOL tls_extract_pem(CryptoCert cert, BYTE** PublicKey, DWORD* PublicKeyLength)
 {
 	BIO* bio;
-	int status;
+	int status, count, x;
 	size_t offset;
 	size_t length = 0;
 	BOOL rc = FALSE;
@@ -1256,6 +1256,21 @@ static BOOL tls_extract_pem(CryptoCert cert, BYTE** PublicKey, DWORD* PublicKeyL
 		goto fail;
 	}
 
+	if (cert->px509chain)
+	{
+		count = sk_BIO_num(cert->px509chain);
+		for (x=0; x<count; x++)
+		{
+			X509* c = sk_BIO_value(cert->px509chain, x);
+			status = PEM_write_bio_X509(bio, c);
+			if (status < 0)
+			{
+				WLog_ERR(TAG, "PEM_write_bio_X509 failure: %d", status);
+				goto fail;
+			}
+		}
+	}
+
 	offset = 0;
 	length = 2048;
 	pemCert = (BYTE*) malloc(length + 1);
-- 
2.7.4