diff --git a/src/btstack_base64_decoder.c b/src/btstack_base64_decoder.c
new file mode 100644
index 000000000..68053e801
--- /dev/null
+++ b/src/btstack_base64_decoder.c
@@ -0,0 +1,147 @@
+/*
+ * Copyright (C) 2018 BlueKitchen GmbH
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holders nor the names of
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ * 4. Any redistribution, use, or modification is done solely for
+ *    personal benefit and not for any commercial purpose or for
+ *    monetary gain.
+ *
+ * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
+ * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * Please inquire about commercial licensing options at 
+ * contact@bluekitchen-gmbh.com
+ *
+ */
+
+/*
+ *  btstack_base64_decoder.c
+ */
+
+#include "btstack_base64_decoder.h"
+#include <string.h>
+#include <stdio.h>
+
+// map ascii char to 6-bit value
+static const uint8_t table[256] = {
+    99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
+    99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
+    99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 62, 99, 99, 99, 63,
+    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 99, 99, 99, 99, 99, 99,
+    99,  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, 99, 99, 99, 99, 99,
+    99, 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, 99, 99, 99, 99, 99,
+    99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
+    99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
+    99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
+    99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
+    99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
+    99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
+    99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99,
+    99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99, 99
+};
+
+/**
+ * @brief Initialize base99 decoder
+ * @param context
+ */
+void btstack_base64_decoder_init(btstack_base64_decoder_t * context){
+	memset(context, 0, sizeof(btstack_base64_decoder_t));
+}
+
+/**
+ * @brief Decode single byte
+ * @param context
+ * @returns value, or BTSTACK_BASE64_DECODER_COMPLETE, BTSTACK_BASE64_DECODER_INVALID
+ */
+int  btstack_base64_decoder_process_byte(btstack_base64_decoder_t * context, uint8_t c){
+
+	// handle '='
+	if (c == '='){
+		if (context->pos == 2 || context->pos == 3){
+			context->pos++;
+			return BTSTACK_BASE64_DECODER_MORE;
+		}
+	}	
+
+	// lookup
+	uint8_t value = table[c];
+
+	// invalid character
+	if (value == 99) {
+		context->pos = 99;
+	}
+
+	int result = 0;
+	switch (context->pos){
+		case 0:
+			context->value = value;	// 6 bit
+			context->pos++; 
+			result = BTSTACK_BASE64_DECODER_MORE;
+			break;
+		case 1:
+			result = (context->value << 2) | (value >> 4);
+			context->value = value;	// 4 bit
+			context->pos++; 
+			break;
+		case 2:
+			result = (context->value << 4) | (value >> 2);
+			context->value = value; // 2 bit
+			context->pos++; 
+			break;
+		case 3:
+			result = (context->value << 6) | value;
+			context->pos = 0;		// done
+			break;
+		case 99:
+			result = BTSTACK_BASE64_DECODER_INVALID;
+			break;
+	}
+	return result;
+}
+
+int btstack_base64_decoder_process_block(const uint8_t * input_data, uint32_t input_size, uint8_t * output_buffer, uint32_t output_max_size){
+	btstack_base64_decoder_t context;
+	btstack_base64_decoder_init(&context);
+	uint32_t size = 0;
+	while (input_size){
+		uint8_t data = *input_data++;
+		int result = btstack_base64_decoder_process_byte(&context, data);
+		input_size--;
+		switch (result){
+			case BTSTACK_BASE64_DECODER_MORE:
+				break;
+			case BTSTACK_BASE64_DECODER_INVALID:
+				return BTSTACK_BASE64_DECODER_INVALID;
+			default:
+				if (size >= output_max_size){
+					return BTSTACK_BASE64_DECODER_FULL;
+				}
+				output_buffer[size++] = result;
+				break;
+		}
+	}
+	return size;	
+}
diff --git a/src/btstack_base64_decoder.h b/src/btstack_base64_decoder.h
new file mode 100644
index 000000000..ac45d3cc9
--- /dev/null
+++ b/src/btstack_base64_decoder.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2018 BlueKitchen GmbH
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holders nor the names of
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ * 4. Any redistribution, use, or modification is done solely for
+ *    personal benefit and not for any commercial purpose or for
+ *    monetary gain.
+ *
+ * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
+ * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * Please inquire about commercial licensing options at 
+ * contact@bluekitchen-gmbh.com
+ *
+ */
+
+/*
+ *  btstack_base64_decoder.h
+ */
+
+#ifndef __BTSTACK_BASE_64_DECODER_H
+#define __BTSTACK_BASE_64_DECODER_H
+
+#include <stdint.h>
+
+typedef struct {
+	uint8_t pos;
+	uint8_t value;
+} btstack_base64_decoder_t;
+
+#define BTSTACK_BASE64_DECODER_MORE     -1
+#define BTSTACK_BASE64_DECODER_COMPLETE -2
+#define BTSTACK_BASE64_DECODER_INVALID  -3
+#define BTSTACK_BASE64_DECODER_FULL     -4
+
+/**
+ * @brief Initialize base64 decoder
+ * @param context
+ */
+void btstack_base64_decoder_init(btstack_base64_decoder_t * context);
+
+/**
+ * @brief Decode single byte
+ * @brief context
+ * @returns value, or BTSTACK_BASE64_DECODER_MORE, BTSTACK_BASE64_DECODER_COMPLETE, BTSTACK_BASE64_DECODER_INVALID
+ */
+int  btstack_base64_decoder_process_byte(btstack_base64_decoder_t * context, uint8_t c);
+
+/**
+ * @brief Decode block
+ * @brief input_data base64 encoded message
+ * @brief input_size
+ * @breif output_buffer
+ * @brief output_max_size
+ * @return output_size or BTSTACK_BASE64_DECODER_INVALID, BTSTACK_BASE64_DECODER_FULL
+ */
+int btstack_base64_decoder_process_block(const uint8_t * input_data, uint32_t input_size, uint8_t * output_buffer, uint32_t output_max_size);
+
+#endif
diff --git a/test/base64/.gitignore b/test/base64/.gitignore
new file mode 100644
index 000000000..95facd93a
--- /dev/null
+++ b/test/base64/.gitignore
@@ -0,0 +1 @@
+base64_decoder_test
diff --git a/test/base64/Makefile b/test/base64/Makefile
new file mode 100644
index 000000000..39faea3e0
--- /dev/null
+++ b/test/base64/Makefile
@@ -0,0 +1,27 @@
+CC=g++
+
+# Requirements: cpputest.github.io
+
+BTSTACK_ROOT =  ../..
+CPPUTEST_HOME = ${BTSTACK_ROOT}/test/cpputest
+
+CFLAGS  = -g -Wall -I. -I../ -I${BTSTACK_ROOT}/src
+LDFLAGS += -lCppUTest -lCppUTestExt
+
+VPATH += ${BTSTACK_ROOT}/src
+
+COMMON_OBJ = \
+    btstack_base64_decoder.o \
+    btstack_util.o \
+    hci_dump.o \
+
+all: base64_decoder_test
+
+base64_decoder_test: ${COMMON_OBJ} base64_decoder_test.o
+	${CC} $^ ${CFLAGS} ${LDFLAGS} -o $@
+
+test: all
+	./base64_decoder_test
+	
+clean:
+	rm -fr base64_decoder_test *.dSYM *.o
diff --git a/test/base64/base64_decoder_test.c b/test/base64/base64_decoder_test.c
new file mode 100644
index 000000000..713359f03
--- /dev/null
+++ b/test/base64/base64_decoder_test.c
@@ -0,0 +1,56 @@
+#include "CppUTest/TestHarness.h"
+#include "CppUTest/CommandLineTestRunner.h"
+#include "btstack_util.h"
+#include "btstack_base64_decoder.h"
+
+void CHECK_EQUAL_ARRAY(uint8_t * expected, uint8_t * actual, int size){
+    int i;
+    for (i=0; i<size; i++){
+        if (expected[i] != actual[i]) {
+            printf("offset %u wrong\n", i);
+            printf("expected: "); printf_hexdump(expected, size);
+            printf("actual:   "); printf_hexdump(actual, size);
+        }
+        BYTES_EQUAL(expected[i], actual[i]);
+    }
+}
+
+TEST_GROUP(Base64Decoder){
+    btstack_base64_decoder_t context;
+    void setup(void){
+        btstack_base64_decoder_init(&context);
+    }
+};
+
+TEST(Base64Decoder, InvalidChar){
+    int result = btstack_base64_decoder_process_byte(&context, (uint8_t) '@'); 
+    CHECK_EQUAL(BTSTACK_BASE64_DECODER_INVALID, result);
+}
+
+TEST(Base64Decoder, abc){
+    const uint8_t input[] = "YWJj";
+    uint8_t output[3];
+    int result = btstack_base64_decoder_process_block(input, strlen((const char*) input), output, sizeof(output)); 
+    CHECK_EQUAL(sizeof(output), result);
+    CHECK_EQUAL_ARRAY((uint8_t *) "abc", output, 3);
+}
+
+TEST(Base64Decoder, ab){
+    const uint8_t input[] = "YWI=";
+    uint8_t output[3];
+    int result = btstack_base64_decoder_process_block(input, strlen((const char*) input), output, sizeof(output)); 
+    CHECK_EQUAL(2, result);
+    CHECK_EQUAL_ARRAY((uint8_t *) "ab", output, 2);
+}
+
+TEST(Base64Decoder, a){
+    const uint8_t input[] = "YQ==";
+    uint8_t output[3];
+    int result = btstack_base64_decoder_process_block(input, strlen((const char*) input), output, sizeof(output)); 
+    CHECK_EQUAL(1, result);
+    CHECK_EQUAL_ARRAY((uint8_t *) "a", output, 1);
+}
+
+int main (int argc, const char * argv[]){
+    return CommandLineTestRunner::RunAllTests(argc, argv);
+}