1 files changed, 64 insertions, 0 deletions
diff --git a/genqrcode/tests/rsecc_decoder.c b/genqrcode/tests/rsecc_decoder.c
new file mode 100644
index 0000000000..982742142b
--- /dev/null
+++ b/genqrcode/tests/rsecc_decoder.c
@@ -0,0 +1,64 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "../qrspec.h"
+#include "rsecc_decoder.h"
+
+#define SYMBOL_SIZE (8)
+#define symbols ((1 << SYMBOL_SIZE) - 1)
+static const int proot = 0x11d; /* stands for x^8+x^4+x^3+x^2+1 (see pp.37 of JIS X0510:2004) */
+
+/* min/max codeword length of ECC, calculated from the specification. */
+#define min_length (2)
+#define max_length (30)
+#define max_generatorSize (max_length)
+
+static unsigned char alpha[symbols + 1];
+static unsigned char aindex[symbols + 1];
+
+void RSECC_decoder_init() {
+	int i, b;
+
+	alpha[symbols] = 0;
+	aindex[0] = symbols;
+
+	b = 1;
+	for(i = 0; i < symbols; i++) {
+		alpha[i] = (unsigned char)b;
+		aindex[b] = (unsigned char)i;
+		b <<= 1;
+		if(b & (symbols + 1)) {
+			b ^= proot;
+		}
+		b &= symbols;
+	}
+}
+
+int RSECC_decoder_checkSyndrome(int dl, unsigned char *data, int el, unsigned char *ecc)
+{
+	int i, j;
+	int s;
+
+	for(i=0; i<el; i++) {
+		s = data[0];
+		for(j=1; j<dl; j++) {
+			if(s == 0) {
+				s = data[j];
+			} else {
+				s = data[j] ^ alpha[(aindex[s] + i) % symbols];
+			}
+		}
+		for(j=0; j<el; j++) {
+			if(s == 0) {
+				s = ecc[j];
+			} else {
+				s = ecc[j] ^ alpha[(aindex[s] + i) % symbols];
+			}
+		}
+		if(s != 0) {
+			return -1;
+		}
+	}
+
+	return 0;
+}