x509: when writing fields known to be in UTF-8 form convert to NFCtmp-uninorm-everywhere

This ensures that we always write proper UTF-8 data, uniquely encoded.

5 files changed, 95 insertions, 10 deletions

diff --git a/lib/str-unicode.c b/lib/str-unicode.c
index 7bda8cab07..20e9ca10bd 100644
--- a/lib/str-unicode.c
+++ b/lib/str-unicode.c
@@ -103,4 +103,50 @@ uint8_t *_gnutls_normalize_u8_password(const uint8_t *password)
 	return NULL;
 }
 
+uint8_t *_gnutls_normalize_u8_nfc(const uint8_t *str, size_t str_size)
+{
+	size_t nrm_size = 0;
+	size_t out_size = 0;
+	uint8_t *out = NULL;
+	uint8_t *nrm = NULL;
+
+	if (str_size == 0) {
+		return (uint8_t*)strdup("");
+	}
+
+	/* check for invalid UTF-8 */
+	if (u8_check(str, str_size) != NULL) {
+		gnutls_assert();
+		return NULL;
+	}
+
+	/* normalize to NFC */
+	nrm = u8_normalize(UNINORM_NFC, str, str_size, NULL, &nrm_size);
+	if (nrm == NULL) {
+		gnutls_assert();
+		goto fail;
+	}
+
+	out_size = nrm_size;
+
+	/* copy to output with null terminator */
+	out = gnutls_malloc(out_size+1);
+	if (out == NULL) {
+		gnutls_assert();
+		goto fail;
+	}
+
+	memcpy(out, nrm, out_size);
+	out[out_size] = 0;
+
+	gnutls_free(nrm);
+
+	return out;
+
+ fail:
+	gnutls_free(out);
+	gnutls_free(nrm);
+	return NULL;
+}
+
 #endif
diff --git a/lib/str.h b/lib/str.h
index 4e497b630a..780245b733 100644
--- a/lib/str.h
+++ b/lib/str.h
@@ -38,8 +38,10 @@
 
 #if defined(HAVE_LIBUNISTRING)
 uint8_t *_gnutls_normalize_u8_password(const uint8_t *password);
+uint8_t *_gnutls_normalize_u8_nfc(const uint8_t *str, size_t str_size);
 #else
-# define _gnutls_normalize_u8_password(password) ((uint8_t*)strdup((char*)password))
+# define _gnutls_normalize_u8_password(password) ((uint8_t*)gnutls_strdup((char*)password))
+# define _gnutls_normalize_u8_nfc(str, str_size) ((uint8_t*)gnutls_strdup((char*)str))
 #endif
 
 void _gnutls_str_cpy(char *dest, size_t dest_tot_size, const char *src);
diff --git a/lib/x509/common.c b/lib/x509/common.c
index 6d72338d42..b75cb7055e 100644
--- a/lib/x509/common.c
+++ b/lib/x509/common.c
@@ -31,6 +31,7 @@
 #include <x509_b64.h>
 #include "x509_int.h"
 #include "extras/hex.h"
+#include "str.h"
 #include <common.h>
 #include <c-ctype.h>
 
@@ -1327,6 +1328,30 @@ static int is_printable(char p)
 	return 0;
 }
 
+/* ensures that the UTF8 string we write is properly encoded */
+int _gnutls_x509_write_utf8_value(ASN1_TYPE asn_struct, const char *where,
+				  const uint8_t *data, size_t data_size)
+{
+	int ret, result;
+	uint8_t *nrm = _gnutls_normalize_u8_nfc(data, data_size);
+
+	if (nrm == NULL)
+		return gnutls_assert_val(GNUTLS_E_INVALID_UTF8_PASSWORD);
+
+	result = asn1_write_value(asn_struct, where, nrm, strlen((char*)nrm));
+	if (result != ASN1_SUCCESS) {
+		gnutls_assert();
+		ret = _gnutls_asn2err(result);
+		goto cleanup;
+	}
+
+	ret = 0;
+
+ cleanup:
+	gnutls_free(nrm);
+	return ret;
+}
+
 static int write_complex_string(ASN1_TYPE asn_struct, const char *where,
 				const struct oid_to_string *oentry,
 				const uint8_t * data, size_t data_size)
@@ -1335,7 +1360,7 @@ static int write_complex_string(ASN1_TYPE asn_struct, const char *where,
 	ASN1_TYPE c2;
 	int result;
 	const char *string_type;
-	unsigned int i;
+	unsigned int i, utf8_flag = 0;
 
 	result =
 	    asn1_create_element(_gnutls_get_pkix(), oentry->asn_desc, &c2);
@@ -1354,6 +1379,7 @@ static int write_complex_string(ASN1_TYPE asn_struct, const char *where,
 	for (i = 0; i < data_size; i++) {
 		if (!is_printable(data[i])) {
 			string_type = "utf8String";
+			utf8_flag = 1;
 			break;
 		}
 	}
@@ -1370,11 +1396,19 @@ static int write_complex_string(ASN1_TYPE asn_struct, const char *where,
 
 	_gnutls_str_cpy(tmp, sizeof(tmp), string_type);
 
-	result = asn1_write_value(c2, tmp, data, data_size);
-	if (result != ASN1_SUCCESS) {
-		gnutls_assert();
-		result = _gnutls_asn2err(result);
-		goto error;
+	if (utf8_flag) {
+		result = _gnutls_x509_write_utf8_value(c2, tmp, data, data_size);
+		if (result < 0) {
+			gnutls_assert();
+			goto error;
+		}
+	} else {
+		result = asn1_write_value(c2, tmp, data, data_size);
+		if (result != ASN1_SUCCESS) {
+			gnutls_assert();
+			result = _gnutls_asn2err(result);
+			goto error;
+		}
 	}
 
 	result =
diff --git a/lib/x509/common.h b/lib/x509/common.h
index 6716939255..73d202d173 100644
--- a/lib/x509/common.h
+++ b/lib/x509/common.h
@@ -143,6 +143,9 @@ int _gnutls_x509_read_string(ASN1_TYPE c, const char *root,
 int _gnutls_x509_write_value(ASN1_TYPE c, const char *root,
 			     const gnutls_datum_t * data);
 
+int _gnutls_x509_write_utf8_value(ASN1_TYPE asn_struct, const char *where,
+				  const uint8_t *data, size_t data_size);
+
 int _gnutls_x509_write_string(ASN1_TYPE c, const char *root,
 			      const gnutls_datum_t * data,
 			      unsigned int etype);
diff --git a/lib/x509/x509_ext.c b/lib/x509/x509_ext.c
index d503d5d394..2fa655eff4 100644
--- a/lib/x509/x509_ext.c
+++ b/lib/x509/x509_ext.c
@@ -30,6 +30,7 @@
 #include <x509_b64.h>
 #include "x509_ext_int.h"
 #include "virt-san.h"
+#include "common.h"
 #include <gnutls/x509-ext.h>
 
 #define MAX_ENTRIES 64
@@ -1975,11 +1976,10 @@ static int encode_user_notice(const gnutls_datum_t * txt,
 	}
 
 	result =
-	    asn1_write_value(c2, "explicitText.utf8String", txt->data,
+	    _gnutls_x509_write_utf8_value(c2, "explicitText.utf8String", txt->data,
 			     txt->size);
-	if (result != ASN1_SUCCESS) {
+	if (result < 0) {
 		gnutls_assert();
-		result = _gnutls_asn2err(result);
 		goto error;
 	}