adding base64_decode function that will be needed for SAM as mentioned in #85

include/ua_base64.h

@@ -0,0 +1,19 @@
+/*
+ * ua_base64.h
+ *
+ *  Created on: Jun 10, 2014
+ *      Author: sten
+ */
+
+#ifndef UA_BASE64_H_
+#define UA_BASE64_H_
+
+#include "ua_basictypes.h"
+
+/** @brief calculates the upper bound for the binary data that is encoded in base64 encoded string */
+UA_Int32 UA_base64_getDecodedSizeUB(UA_String* const base64EncodedData);
+
+/** @brief decodes base64 encoded string into target, target should be at least of the size returned by UA_base64_getDecodedSizeUB */
+UA_Int32 UA_base64_decode(UA_String* const base64EncodedData, UA_Byte* target);
+
+#endif /* UA_BASE64_H_ */

src/Makefile.am

@@ -7,6 +7,7 @@ libopen62541_la_SOURCES = opcua.c \
 						  ua_namespace_0.c \
 						  util/ua_list.c \
 						  util/ua_indexedList.c \
+						  util/ua_base64.c \
 						  ua_transport.c \
 						  ua_transport_binary.c \
 						  ua_transport_binary_secure.c \

src/util/ua_base64.c

@@ -0,0 +1,141 @@
+/*
+begin library headers
+*/
+
+/*
+cdecode.h - c header for a base64 decoding algorithm
+
+This is part of the libb64 project, and has been placed in the public domain.
+For details, see http://sourceforge.net/projects/libb64
+*/
+#ifndef BASE64_CDECODE_H
+#define BASE64_CDECODE_H
+
+typedef enum
+{
+	step_a, step_b, step_c, step_d
+} base64_decodestep;
+
+typedef struct
+{
+	base64_decodestep step;
+	char plainchar;
+} base64_decodestate;
+
+void base64_init_decodestate(base64_decodestate* state_in);
+
+int base64_decode_value(char value_in);
+
+int base64_decode_block(const char* code_in, const int length_in, char* plaintext_out, base64_decodestate* state_in);
+
+#endif /* BASE64_CDECODE_H */
+
+/*
+end library headers
+*/
+
+#include "ua_base64.h"
+
+UA_Int32 UA_base64_getDecodedSizeUB(UA_String* const base64EncodedData){
+	//note that base64-encoded data length is always divisible by 4
+	return base64EncodedData->length * 3 / 4;
+}
+
+UA_Int32 UA_base64_decode(UA_String* const base64EncodedData, UA_Byte* target){
+	base64_decodestate state;
+	base64_init_decodestate(&state);
+	//FIXME: The (void*)(char*) was was perfomed to get rid of "differ in signedness" warnings. Can be a potential problem since the library code expects 'char' but we have 'unsigned char' in UA_String
+	base64_decode_block((void*)(char*)(base64EncodedData->data), base64EncodedData->length, (void*)(char*)target, &state);
+	return UA_NO_ERROR;
+}
+
+/*
+begin library code
+*/
+
+/*
+cdecoder.c - c source to a base64 decoding algorithm implementation
+
+This is part of the libb64 project, and has been placed in the public domain.
+For details, see http://sourceforge.net/projects/libb64
+*/
+
+int base64_decode_value(char value_in)
+{
+	static const char decoding[] = {62,-1,-1,-1,63,52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-2,-1,-1,-1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1,-1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51};
+	static const char decoding_size = sizeof(decoding);
+	value_in -= 43;
+	if (value_in < 0 || value_in > decoding_size) return -1;
+	return decoding[(int)value_in];
+}
+
+void base64_init_decodestate(base64_decodestate* state_in)
+{
+	state_in->step = step_a;
+	state_in->plainchar = 0;
+}
+
+int base64_decode_block(const char* code_in, const int length_in, char* plaintext_out, base64_decodestate* state_in)
+{
+	const char* codechar = code_in;
+	char* plainchar = plaintext_out;
+	char fragment;
+	
+	*plainchar = state_in->plainchar;
+	
+	switch (state_in->step)
+	{
+		while (1)
+		{
+	case step_a:
+			do {
+				if (codechar == code_in+length_in)
+				{
+					state_in->step = step_a;
+					state_in->plainchar = *plainchar;
+					return plainchar - plaintext_out;
+				}
+				fragment = (char)base64_decode_value(*codechar++);
+			} while (fragment < 0);
+			*plainchar    = (fragment & 0x03f) << 2;
+	case step_b:
+			do {
+				if (codechar == code_in+length_in)
+				{
+					state_in->step = step_b;
+					state_in->plainchar = *plainchar;
+					return plainchar - plaintext_out;
+				}
+				fragment = (char)base64_decode_value(*codechar++);
+			} while (fragment < 0);
+			*plainchar++ |= (fragment & 0x030) >> 4;
+			*plainchar    = (fragment & 0x00f) << 4;
+	case step_c:
+			do {
+				if (codechar == code_in+length_in)
+				{
+					state_in->step = step_c;
+					state_in->plainchar = *plainchar;
+					return plainchar - plaintext_out;
+				}
+				fragment = (char)base64_decode_value(*codechar++);
+			} while (fragment < 0);
+			*plainchar++ |= (fragment & 0x03c) >> 2;
+			*plainchar    = (fragment & 0x003) << 6;
+	case step_d:
+			do {
+				if (codechar == code_in+length_in)
+				{
+					state_in->step = step_d;
+					state_in->plainchar = *plainchar;
+					return plainchar - plaintext_out;
+				}
+				fragment = (char)base64_decode_value(*codechar++);
+			} while (fragment < 0);
+			*plainchar++   |= (fragment & 0x03f);
+		}
+	}
+	/* control should not reach here */
+	return plainchar - plaintext_out;
+}
+

tests/Makefile.am

@@ -3,7 +3,7 @@ TESTS=
 UNIT_TESTS=
 check_PROGRAMS=
 
-UNIT_TESTS += check_stack check_list check_indexedList check_builtin check_namespace check_memory check_services_view check_xml
+UNIT_TESTS += check_stack check_list check_indexedList check_builtin check_namespace check_memory check_services_view check_xml check_base64
 TESTS += $(UNIT_TESTS)
 check_PROGRAMS += $(UNIT_TESTS)
 

tests/check_base64.c

@@ -0,0 +1,55 @@
+#include <stdlib.h> // EXIT_SUCCESS
+#include "ua_base64.h"
+
+#include "check.h"
+
+
+START_TEST(base64_test_basic)
+{
+
+
+	//this is base64'd ASCII string "open62541"
+	UA_String encodedString = {12, (UA_Byte*)"b3BlbjYyNTQx"};
+
+	//assure that we allocate at least 9 bytes
+	ck_assert_int_ge(UA_base64_getDecodedSizeUB(&encodedString), 9);
+
+	UA_Byte* decodedData = (UA_Byte*)malloc(UA_base64_getDecodedSizeUB(&encodedString));
+	UA_base64_decode(&encodedString, decodedData);
+
+	//check the string
+	ck_assert_int_eq(decodedData[0], 'o');
+	ck_assert_int_eq(decodedData[1], 'p');
+	ck_assert_int_eq(decodedData[2], 'e');
+	ck_assert_int_eq(decodedData[3], 'n');
+	ck_assert_int_eq(decodedData[4], '6');
+	ck_assert_int_eq(decodedData[5], '2');
+	ck_assert_int_eq(decodedData[6], '5');
+	ck_assert_int_eq(decodedData[7], '4');
+	ck_assert_int_eq(decodedData[8], '1');
+}
+END_TEST
+
+Suite*base64_testSuite(void)
+{
+	Suite *s = suite_create("base64_test");
+	TCase *tc_core = tcase_create("Core");
+	tcase_add_test(tc_core, base64_test_basic);
+	suite_add_tcase(s,tc_core);
+	return s;
+}
+
+int main (void)
+{
+	int number_failed = 0;
+
+	Suite* s = base64_testSuite();
+	SRunner* sr = srunner_create(s);
+	srunner_run_all(sr,CK_NORMAL);
+	number_failed += srunner_ntests_failed(sr);
+	srunner_free(sr);
+
+	return (number_failed == 0) ? EXIT_SUCCESS : EXIT_FAILURE;
+
+}
+