isisd: fix #10505 using base64 encoding

Using base64 instead of the raw string to encode
the binary data.

Signed-off-by: whichbug <whichbug@github.com>

1 files changed, 193 insertions, 0 deletions

diff --git a/lib/base64.c b/lib/base64.c
new file mode 100644
index 0000000000..e3f238969b
--- /dev/null
+++ b/lib/base64.c
@@ -0,0 +1,193 @@
+/*
+ * This is part of the libb64 project, and has been placed in the public domain.
+ * For details, see http://sourceforge.net/projects/libb64
+ */
+
+#include "base64.h"
+
+static const int CHARS_PER_LINE = 72;
+static const char *ENCODING =
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+void base64_init_encodestate(struct base64_encodestate *state_in)
+{
+	state_in->step = step_A;
+	state_in->result = 0;
+	state_in->stepcount = 0;
+}
+
+char base64_encode_value(char value_in)
+{
+	if (value_in > 63)
+		return '=';
+	return ENCODING[(int)value_in];
+}
+
+int base64_encode_block(const char *plaintext_in, int length_in, char *code_out,
+			struct base64_encodestate *state_in)
+{
+	const char *plainchar = plaintext_in;
+	const char *const plaintextend = plaintext_in + length_in;
+	char *codechar = code_out;
+	char result;
+	char fragment;
+
+	result = state_in->result;
+
+	switch (state_in->step) {
+		while (1) {
+			case step_A:
+				if (plainchar == plaintextend) {
+					state_in->result = result;
+					state_in->step = step_A;
+					return codechar - code_out;
+				}
+				fragment = *plainchar++;
+				result = (fragment & 0x0fc) >> 2;
+				*codechar++ = base64_encode_value(result);
+				result = (fragment & 0x003) << 4;
+				/* fall through */
+			case step_B:
+				if (plainchar == plaintextend) {
+					state_in->result = result;
+					state_in->step = step_B;
+					return codechar - code_out;
+				}
+				fragment = *plainchar++;
+				result |= (fragment & 0x0f0) >> 4;
+				*codechar++ = base64_encode_value(result);
+				result = (fragment & 0x00f) << 2;
+				/* fall through */
+			case step_C:
+				if (plainchar == plaintextend) {
+					state_in->result = result;
+					state_in->step = step_C;
+					return codechar - code_out;
+				}
+				fragment = *plainchar++;
+				result |= (fragment & 0x0c0) >> 6;
+				*codechar++ = base64_encode_value(result);
+				result  = (fragment & 0x03f) >> 0;
+				*codechar++ = base64_encode_value(result);
+
+				++(state_in->stepcount);
+				if (state_in->stepcount == CHARS_PER_LINE/4) {
+					*codechar++ = '\n';
+					state_in->stepcount = 0;
+				}
+		}
+	}
+	/* control should not reach here */
+	return codechar - code_out;
+}
+
+int base64_encode_blockend(char *code_out, struct base64_encodestate *state_in)
+{
+	char *codechar = code_out;
+
+	switch (state_in->step) {
+	case step_B:
+		*codechar++ = base64_encode_value(state_in->result);
+		*codechar++ = '=';
+		*codechar++ = '=';
+		break;
+	case step_C:
+		*codechar++ = base64_encode_value(state_in->result);
+		*codechar++ = '=';
+		break;
+	case step_A:
+		break;
+	}
+	*codechar++ = '\n';
+
+	return codechar - code_out;
+}
+
+
+signed char base64_decode_value(signed char value_in)
+{
+	static const signed 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
+	};
+	value_in -= 43;
+	if (value_in < 0 || value_in >= 80)
+		return -1;
+	return decoding[(int)value_in];
+}
+
+void base64_init_decodestate(struct base64_decodestate *state_in)
+{
+	state_in->step = step_a;
+	state_in->plainchar = 0;
+}
+
+int base64_decode_block(const char *code_in, int length_in, char *plaintext_out,
+			struct base64_decodestate *state_in)
+{
+	const char *codec = code_in;
+	char *plainc = plaintext_out;
+	signed char fragmt;
+
+	*plainc = state_in->plainchar;
+
+	switch (state_in->step) {
+		while (1) {
+			case step_a:
+				do {
+					if (codec == code_in+length_in) {
+						state_in->step = step_a;
+						state_in->plainchar = *plainc;
+						return plainc - plaintext_out;
+					}
+					fragmt = base64_decode_value(*codec++);
+				} while (fragmt < 0);
+				*plainc = (fragmt & 0x03f) << 2;
+				/* fall through */
+			case step_b:
+				do {
+					if (codec == code_in+length_in) {
+						state_in->step = step_b;
+						state_in->plainchar = *plainc;
+						return plainc - plaintext_out;
+					}
+					fragmt = base64_decode_value(*codec++);
+				} while (fragmt < 0);
+				*plainc++ |= (fragmt & 0x030) >> 4;
+				*plainc = (fragmt & 0x00f) << 4;
+				/* fall through */
+			case step_c:
+				do {
+					if (codec == code_in+length_in) {
+						state_in->step = step_c;
+						state_in->plainchar = *plainc;
+						return plainc - plaintext_out;
+					}
+					fragmt = base64_decode_value(*codec++);
+				} while (fragmt < 0);
+				*plainc++ |= (fragmt & 0x03c) >> 2;
+				*plainc = (fragmt & 0x003) << 6;
+				/* fall through */
+			case step_d:
+				do {
+					if (codec == code_in+length_in) {
+						state_in->step = step_d;
+						state_in->plainchar = *plainc;
+						return plainc - plaintext_out;
+					}
+					fragmt = base64_decode_value(*codec++);
+				} while (fragmt < 0);
+				*plainc++   |= (fragmt & 0x03f);
+		}
+	}
+	/* control should not reach here */
+	return plainc - plaintext_out;
+}