X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/39cc1c879e3d75b3cafd79e4e139a7f6673dd349..700d8687944db0a48535f818b59b6c9859952c61:/client/crypto/asn1utils.c?ds=sidebyside

diff --git a/client/crypto/asn1utils.c b/client/crypto/asn1utils.c
new file mode 100644
index 00000000..2a3fe698
--- /dev/null
+++ b/client/crypto/asn1utils.c
@@ -0,0 +1,63 @@
+//-----------------------------------------------------------------------------
+// Copyright (C) 2018 Merlok
+//
+// This code is licensed to you under the terms of the GNU GPL, version 2 or,
+// at your option, any later version. See the LICENSE.txt file for the text of
+// the license.
+//-----------------------------------------------------------------------------
+// asn.1 utils
+//-----------------------------------------------------------------------------
+
+#include "asn1utils.h"
+#include <mbedtls/asn1.h>
+
+int ecdsa_asn1_get_signature(uint8_t *signature, size_t signaturelen, uint8_t *rval, uint8_t *sval) {
+	if (!signature || !signaturelen || !rval || !sval)
+		return 1;
+
+	int res = 0;
+	unsigned char *p = signature;
+	const unsigned char *end = p + signaturelen;
+	size_t len;
+	mbedtls_mpi xmpi;
+
+	if ((res = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) == 0) {
+		mbedtls_mpi_init(&xmpi);
+		res = mbedtls_asn1_get_mpi(&p, end, &xmpi);
+		if (res) {
+			mbedtls_mpi_free(&xmpi);
+			goto exit;
+		}
+		
+		res = mbedtls_mpi_write_binary(&xmpi, rval, 32);
+		mbedtls_mpi_free(&xmpi);
+		if (res) 
+			goto exit;
+
+		mbedtls_mpi_init(&xmpi);
+		res = mbedtls_asn1_get_mpi(&p, end, &xmpi);
+		if (res) {
+			mbedtls_mpi_free(&xmpi);
+			goto exit;
+		}
+		
+		res = mbedtls_mpi_write_binary(&xmpi, sval, 32);
+		mbedtls_mpi_free(&xmpi);
+		if (res) 
+			goto exit;
+
+		// check size
+		if (end != p)
+			return 2;
+		}
+
+exit:
+	return res;
+}
+
+int asn1_print(uint8_t *asn1buf, int level) {
+	
+	return 0;
+}
+
+