first commit, SM2-DSA only

demos/maurice/example4.c

@@ -0,0 +1,123 @@
+/* NOCW */
+/*
+        Please read the README file for condition of use, before
+        using this software.
+
+        Maurice Gittens  <mgittens@gits.nl>   January 1997
+
+*/
+
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <openssl/evp.h>
+
+#define STDIN     	0
+#define STDOUT    	1
+#define BUFLEN	  	512 
+
+static const char *usage = "Usage: example4 [-d]\n";
+
+void do_encode(void);
+void do_decode(void);
+
+int main(int argc, char *argv[])
+{
+	if ((argc == 1))	
+	{
+		do_encode();
+	}	
+	else if ((argc == 2) && !strcmp(argv[1],"-d"))
+	{
+		do_decode();
+	}
+	else
+	{
+		fprintf(stderr,"%s", usage);
+		exit(1);
+	}
+
+	return 0;		
+}
+
+void do_encode()
+{
+	char buf[BUFLEN];
+	char ebuf[BUFLEN+24];
+	unsigned int ebuflen;
+	EVP_ENCODE_CTX ectx;
+        
+	EVP_EncodeInit(&ectx);
+
+	while(1)
+	{
+		int readlen = read(STDIN, buf, sizeof(buf));
+	
+		if (readlen <= 0)
+		{
+			if (!readlen)
+			   break;
+			else
+			{
+				perror("read");
+				exit(1);
+			}
+		}
+
+		EVP_EncodeUpdate(&ectx, ebuf, &ebuflen, buf, readlen);
+
+		write(STDOUT, ebuf, ebuflen);
+	}
+
+        EVP_EncodeFinal(&ectx, ebuf, &ebuflen); 
+
+	write(STDOUT, ebuf, ebuflen);
+}
+
+void do_decode()
+{
+ 	char buf[BUFLEN];
+ 	char ebuf[BUFLEN+24];
+	unsigned int ebuflen;
+	EVP_ENCODE_CTX ectx;
+        
+	EVP_DecodeInit(&ectx);
+
+	while(1)
+	{
+		int readlen = read(STDIN, buf, sizeof(buf));
+		int rc;	
+	
+		if (readlen <= 0)
+		{
+			if (!readlen)
+			   break;
+			else
+			{
+				perror("read");
+				exit(1);
+			}
+		}
+
+		rc = EVP_DecodeUpdate(&ectx, ebuf, &ebuflen, buf, readlen);
+		if (rc <= 0)
+		{
+			if (!rc)
+			{
+				write(STDOUT, ebuf, ebuflen);
+				break;
+			}
+
+			fprintf(stderr, "Error: decoding message\n");
+			return;
+		}
+
+		write(STDOUT, ebuf, ebuflen);
+	}
+
+        EVP_DecodeFinal(&ectx, ebuf, &ebuflen); 
+
+	write(STDOUT, ebuf, ebuflen); 
+}
+