Add a public domain base64 encode/decode implementation.

Author: jnthn

src/6model/base64.c

@@ -0,0 +1,116 @@
+/*
+
+	This code is public domain software.
+
+*/
+
+#include <stdlib.h>
+
+//  base64 encoding
+//
+//  buf:     binary input data
+//  size:    size of input (bytes)
+//  return:  base64-encoded string (null-terminated)
+//           memory for output will be allocated here, free it later
+//
+char* base64_encode(const void* buf, size_t size)
+{
+	static const char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+	char* str = (char*) malloc((size+3)*4/3 + 1);
+
+	char* p = str;
+	unsigned char* q = (unsigned char*) buf;
+	size_t i = 0;
+
+	while (i < size) {
+		int c = q[i++];
+		c *= 256;
+		if (i < size)
+            c += q[i];
+		i++;
+
+		c *= 256;
+		if (i < size)
+            c += q[i];
+		i++;
+
+		*p++ = base64[(c & 0x00fc0000) >> 18];
+		*p++ = base64[(c & 0x0003f000) >> 12];
+
+		if (i > size + 1)
+			*p++ = '=';
+		else
+			*p++ = base64[(c & 0x00000fc0) >> 6];
+
+		if (i > size)
+			*p++ = '=';
+		else
+			*p++ = base64[c & 0x0000003f];
+	}
+
+	*p = 0;
+
+	return str;
+}
+
+
+//  single base64 character conversion
+//
+static int POS(char c)
+{
+	if (c>='A' && c<='Z') return c - 'A';
+	if (c>='a' && c<='z') return c - 'a' + 26;
+	if (c>='0' && c<='9') return c - '0' + 52;
+	if (c == '+') return 62;
+	if (c == '/') return 63;
+	if (c == '=') return -1;
+    return -2;
+}
+
+//  base64 decoding
+//
+//  s:       base64 string, must be null-terminated
+//  data:    output buffer for decoded data
+//  data_len size of decoded data
+//  return:  allocated data buffer
+//
+void* base64_decode(char* s, size_t *data_len)
+{
+    char *p;
+    unsigned char *q, *data;
+    int n[4];
+
+	size_t len = strlen(s);
+	if (len % 4)
+		return NULL;
+	data = (unsigned char*) malloc(len/4*3);
+	q = (unsigned char*) data;
+
+	for (p = s; *p; ) {
+		n[0] = POS(*p++);
+		n[1] = POS(*p++);
+		n[2] = POS(*p++);
+		n[3] = POS(*p++);
+        
+        if (n[0] == -2 || n[1] == -2 || n[2] == -2 || n[3] == -2)
+            return NULL;
+
+		if (n[0] == -1 || n[1] == -1)
+			return NULL;
+
+		if (n[2] == -1 && n[3] != -1)
+			return NULL;
+
+		q[0] = (n[0] << 2) + (n[1] >> 4);
+		if (n[2] != -1)
+            q[1] = ((n[1] & 15) << 4) + (n[2] >> 2);
+		if (n[3] != -1)
+            q[2] = ((n[2] & 3) << 6) + n[3];
+		q += 3;
+	}
+
+	*data_len = q-data - (n[2]==-1) - (n[3]==-1);
+
+	return data;
+}

src/6model/base64.h

@@ -0,0 +1,2 @@
+char* base64_encode(const void* buf, size_t size);
+void* base64_decode(const char* s, size_t *data_len);

tools/build/Makefile.in

@@ -189,15 +189,15 @@ METAMODEL_SOURCE = src/6model/sixmodelobject.h src/6model/sixmodelobject.c \
                    src/6model/storage_spec.h src/6model/serialization_context.c \
                    src/6model/serialization_context.h src/6model/serialization.c \
                    src/6model/serialization.h src/guts/multi_dispatch.h \
-                   src/guts/multi_dispatch.c \
+                   src/guts/multi_dispatch.c src/6model/base64.c src/6model/base64.h \
 
 METAMODEL_OBJS   = ../6model/sixmodelobject$(O) ../6model/repr_registry$(O) \
                    ../6model/knowhow_bootstrapper$(O) ../6model/reprs/KnowHOWREPR$(O) \
                    ../6model/reprs/P6opaque$(O) ../6model/reprs/P6int$(O) \
                    ../6model/reprs/P6str$(O) ../6model/reprs/P6num$(O) \
                    ../6model/reprs/HashAttrStore$(O) ../6model/reprs/Uninstantiable$(O) \
                    ../6model/serialization_context$(O) ../6model/serialization$(O) \
-                   ../guts/multi_dispatch$(O)
+                   ../guts/multi_dispatch$(O) ../6model/base64$(O)
 
 LIBTOMMATH_BIN = $(TOM)core$(O) \
         $(TOM)_error$(O) \
@@ -697,6 +697,7 @@ $(OPS_DIR)/$(OPS)$(LOAD_EXT): $(OPS_DIR)/$(OPS_SOURCE) $(DYNPMC)
 	cd src/6model/reprs && $(CC) -c @cc_o_out@Uninstantiable$(O) -I../../../$(PMC_DIR) $(CINCLUDES) $(CFLAGS) Uninstantiable.c
 	cd src/6model && $(CC) -c @cc_o_out@serialization_context$(O) -I../../$(PMC_DIR) $(CINCLUDES) $(CFLAGS) serialization_context.c
 	cd src/6model && $(CC) -c @cc_o_out@serialization$(O) -I../../$(PMC_DIR) $(CINCLUDES) $(CFLAGS) serialization.c
+	cd src/6model && $(CC) -c @cc_o_out@base64$(O) -I../../$(PMC_DIR) $(CINCLUDES) $(CFLAGS) base64.c
 	cd src/guts && $(CC) -c @cc_o_out@multi_dispatch$(O) -I../../$(PMC_DIR) $(CINCLUDES) $(CFLAGS) multi_dispatch.c
 	cd 3rdparty/sha1 && $(CC) -c @cc_o_out@sha1$(O) $(CINCLUDES) $(CFLAGS) sha1.c
 	cd $(OPS_DIR) && $(LD) @ld_out@$(OPS)$(LOAD_EXT) $(OPS)$(O) $(METAMODEL_OBJS) ../../3rdparty/sha1/sha1$(O) $(LINKARGS)