diff --git a/Linux/Makefile b/Linux/Makefile
index 63b1341..2288b97 100644
--- a/Linux/Makefile
+++ b/Linux/Makefile
@@ -11,7 +11,7 @@ OPENSSL = ../openssl
 CFLAGS	= -Wall -O $(WITH_DEBUG) -I $(OPENSSL)/include 
 
 LDFLAGS = -L$(OPENSSL)
-LDLIBS = -lcrypto
+LDLIBS = -lcrypto -lpthread
 
 MAN	= sscep.8
 PROG	= sscep
@@ -20,7 +20,7 @@ OBJS    = sscep.o init.o net.o sceputils.o pkcs7.o ias.o fileutils.o configurati
 all: $(PROG)_static $(PROG)_dyn
 
 $(PROG)_static: $(OBJS)
-	$(CC) $(CFLAGS) -o $(PROG)_static $(OBJS) $(OPENSSL)/libcrypto.a -ldl
+	$(CC) $(CFLAGS) -o $(PROG)_static $(OBJS) $(OPENSSL)/libcrypto.a -lpthread -ldl
 
 $(PROG)_dyn: $(OBJS)
 	$(CC) $(CFLAGS) -o $(PROG)_dyn $(OBJS) $(LDLIBS) $(LDFLAGS)
diff --git a/configuration.c b/configuration.c
index 828f961..9d5b4dc 100644
--- a/configuration.c
+++ b/configuration.c
@@ -5,19 +5,19 @@
 #define itoa _itoa
 #endif
 
-NAME_VALUE_PAIR* NAME_VALUE_PAIR_new(char *name, char *value) {
-	NAME_VALUE_PAIR *ret = OPENSSL_malloc(sizeof(NAME_VALUE_PAIR));
-	ret->name = OPENSSL_strdup(name);
-	ret->value = OPENSSL_strdup(value);
-	return ret;
-}
-
-void NAME_VALUE_PAIR_free(NAME_VALUE_PAIR *nvp) {
-	OPENSSL_free(nvp->name);
-	OPENSSL_free(nvp->value);
-	OPENSSL_free(nvp);
-}
-
+NAME_VALUE_PAIR* NAME_VALUE_PAIR_new(char *name, char *value) {
+	NAME_VALUE_PAIR *ret = OPENSSL_malloc(sizeof(NAME_VALUE_PAIR));
+	ret->name = OPENSSL_strdup(name);
+	ret->value = OPENSSL_strdup(value);
+	return ret;
+}
+
+void NAME_VALUE_PAIR_free(NAME_VALUE_PAIR *nvp) {
+	OPENSSL_free(nvp->name);
+	OPENSSL_free(nvp->value);
+	OPENSSL_free(nvp);
+}
+
 int scep_conf_init(char *filename) {
 	long err;
 	CONF *conf;
@@ -54,8 +54,6 @@ int scep_conf_load(CONF *conf) {
 	char *windir;
 #endif
 
-	int ret;
-
 	//load global scep vars
 	if((var = NCONF_get_string(conf, SCEP_CONFIGURATION_SECTION, SCEP_CONFIGURATION_PARAM_CACERTFILE)) && !c_flag) {
 		c_flag = 1;
@@ -112,23 +110,22 @@ int scep_conf_load(CONF *conf) {
 	//loading options for specific operation
 	switch(operation_flag) {
 		case SCEP_OPERATION_ENROLL:
-			ret = scep_conf_load_operation_enroll(conf);
+			scep_conf_load_operation_enroll(conf);
 			break;
 		case SCEP_OPERATION_GETCA:
-			ret = scep_conf_load_operation_getca(conf);
+			scep_conf_load_operation_getca(conf);
 			break;
 		case SCEP_OPERATION_GETCERT:
-			ret = scep_conf_load_operation_getcert(conf);
+			scep_conf_load_operation_getcert(conf);
 			break;
 		case SCEP_OPERATION_GETCRL:
-			ret = scep_conf_load_operation_getcrl(conf);
+			scep_conf_load_operation_getcrl(conf);
 			break;
 		case SCEP_OPERATION_GETNEXTCA:
-			ret = scep_conf_load_operation_getnextca(conf);
+			scep_conf_load_operation_getnextca(conf);
 			break;
 		default:
 			fprintf(stderr, "No operation specified, can't load specific settings!\n");
-			ret = -1;
 			break;
 	}
 
@@ -156,7 +153,7 @@ int scep_conf_load(CONF *conf) {
 			printf("%s: Engine Section %s found and processing it\n", pname, SCEP_CONFIGURATION_PARAM_ENGINE);
 
 		//getting engine ID
-		if(var = NCONF_get_string(conf, engine_section, SCEP_CONFIGURATION_ENGINE_ID)) {
+		if((var = NCONF_get_string(conf, engine_section, SCEP_CONFIGURATION_ENGINE_ID))) {
 			if(v_flag)
 				printf("%s: Configuration: Engine ID set to %s\n", pname, var);
 			scep_conf->engine->engine_id = var;
@@ -179,7 +176,7 @@ int scep_conf_load(CONF *conf) {
 		//load capi only option
 		//TODO move
 		if(strncmp(scep_conf->engine->engine_id, "capi", 4) == 0) {
-			if(var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_CAPI_NEWKEYLOCATION)) {
+			if((var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_CAPI_NEWKEYLOCATION))) {
 				if(v_flag)
 					printf("%s: Location of the new key will be in %s\n", pname, var);
 				scep_conf->engine->new_key_location = var;
@@ -189,7 +186,7 @@ int scep_conf_load(CONF *conf) {
 				scep_conf->engine->new_key_location = "REQUEST";
 			}
 
-			if(var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_CAPI_STORELOCATION)) {
+			if((var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_CAPI_STORELOCATION))) {
 				if(v_flag)
 					printf("%s: The store used will be %s\n", pname, var);
 				if(!strncmp(var, "LOCAL_MACHINE", 13)) {
@@ -212,25 +209,25 @@ int scep_conf_load(CONF *conf) {
 		//load JKSEngine only option
 		//TODO move
 		if(strncmp(scep_conf->engine->engine_id, "jksengine", 9) == 0) {
-			if(var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_JKSENGINE_KEYSTOREPASS)) {
+			if((var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_JKSENGINE_KEYSTOREPASS))) {
 				if(v_flag)
 					printf("%s: KeyStorePass will be set to %s\n", pname, var);
 				scep_conf->engine->storepass = var;
 			}
 
-			if(var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_JKSENGINE_JCONNPATH)) {
+			if((var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_JKSENGINE_JCONNPATH))) {
 				if(v_flag)
 					printf("%s: JavaConnectorPath will be set to %s\n", pname, var);
 				scep_conf->engine->jconnpath = var;
 			}
 
-			if(var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_JKSENGINE_PROVIDER)) {
+			if((var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_JKSENGINE_PROVIDER))) {
 				if(v_flag)
 					printf("%s: KeyStoreProvider will be set to %s\n", pname, var);
 				scep_conf->engine->provider = var;
 			}
 
-			if(var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_JKSENGINE_JAVAPATH)) {
+			if((var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_JKSENGINE_JAVAPATH))) {
 				if(v_flag)
 					printf("%s: JavaPath will be set to %s\n", pname, var);
 				scep_conf->engine->javapath = var;
@@ -241,7 +238,7 @@ int scep_conf_load(CONF *conf) {
 		//TODO move
 		if(strncmp(scep_conf->engine->engine_id, "pkcs11", 6) == 0) {
 			scep_conf->engine->pin = NULL;
-			if(var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_PKCS11_PIN)) {
+			if((var = NCONF_get_string(conf, engine_special_section, SCEP_CONFIGURATION_ENGINE_PKCS11_PIN))) {
 				if(v_flag)
 					printf("%s: Setting PIN to configuration value\n", pname);
 				scep_conf->engine->pin = var;
@@ -249,7 +246,7 @@ int scep_conf_load(CONF *conf) {
 		}
 
 		//loading dynamic path variable
-		if(var = NCONF_get_string(conf, engine_section, SCEP_CONFIGURATION_ENGINE_DYNPATH)) {
+		if((var = NCONF_get_string(conf, engine_section, SCEP_CONFIGURATION_ENGINE_DYNPATH))) {
 			if(v_flag)
 				printf("%s: Setting dynamic dll path to %s\n", pname, var);
 			scep_conf->engine->dynamic_path = var;
@@ -270,7 +267,7 @@ int scep_conf_load(CONF *conf) {
 		}
 
 		//loading module path variable
-		if(var = NCONF_get_string(conf, engine_section, SCEP_CONFIGURATION_ENGINE_MODULEPATH)) {
+		if((var = NCONF_get_string(conf, engine_section, SCEP_CONFIGURATION_ENGINE_MODULEPATH))) {
 			if(v_flag)
 				printf("%s: Setting module path to %s\n", pname, var);
 			scep_conf->engine->module_path = var;
@@ -280,42 +277,42 @@ int scep_conf_load(CONF *conf) {
 				printf("%s: No module path defined, not using/loading any module\n", pname);
 		}
 
-		// If there is a section specified in 'engine_section/cmds', store all those commands IN ORDER
-		char *cmds_section;
-		if(cmds_section = NCONF_get_string(conf, engine_section, SCEP_CONFIGURATION_ENGINE_CMDS)) {
-			if(!NCONF_get_section(conf, cmds_section)) {
-				fprintf(stderr, "%s: Section %s defined but not found!\n", pname, cmds_section);
-				exit(SCEP_PKISTATUS_FILE);
-			}
-
-			// A cmds section was specified. Read all values in there and store for later passing to the engine
-			if(d_flag)
-				printf("%s: Engine Cmds Section %s found and processing it\n", pname, cmds_section);
-
-			STACK_OF(CONF_VALUE) *section;
-			section = NCONF_get_section(conf, cmds_section);
-			int number_of_cmds = sk_CONF_VALUE_num(section);
-			if(d_flag)
-				printf("%s: There are %d engine commands\n", pname, number_of_cmds);
-			scep_conf->engine->cmds = OPENSSL_malloc((number_of_cmds+1) * sizeof(NAME_VALUE_PAIR*));
-
-			int i;
-			for(i=0; i<number_of_cmds; i++) {
-				CONF_VALUE* conf_value;
-				conf_value = sk_CONF_VALUE_value(section, i);
-				if(d_flag)
-					printf("%s: Engine cmd: %s = %s\n", pname, conf_value->name, conf_value->value);
-				scep_conf->engine->cmds[i] = NAME_VALUE_PAIR_new(conf_value->name, conf_value->value);
-			}
-
-			// NULL terminate the array to indicate where it ends
-			scep_conf->engine->cmds[number_of_cmds] = NULL;
-		} else {
-			scep_conf->engine->cmds = NULL;
-			if(v_flag)
-				printf("%s: No engine cmds section defined\n", pname);
-		}
-
+		// If there is a section specified in 'engine_section/cmds', store all those commands IN ORDER
+		char *cmds_section;
+		if((cmds_section = NCONF_get_string(conf, engine_section, SCEP_CONFIGURATION_ENGINE_CMDS))) {
+			if(!NCONF_get_section(conf, cmds_section)) {
+				fprintf(stderr, "%s: Section %s defined but not found!\n", pname, cmds_section);
+				exit(SCEP_PKISTATUS_FILE);
+			}
+
+			// A cmds section was specified. Read all values in there and store for later passing to the engine
+			if(d_flag)
+				printf("%s: Engine Cmds Section %s found and processing it\n", pname, cmds_section);
+
+			STACK_OF(CONF_VALUE) *section;
+			section = NCONF_get_section(conf, cmds_section);
+			int number_of_cmds = sk_CONF_VALUE_num(section);
+			if(d_flag)
+				printf("%s: There are %d engine commands\n", pname, number_of_cmds);
+			scep_conf->engine->cmds = OPENSSL_malloc((number_of_cmds+1) * sizeof(NAME_VALUE_PAIR*));
+
+			int i;
+			for(i=0; i<number_of_cmds; i++) {
+				CONF_VALUE* conf_value;
+				conf_value = sk_CONF_VALUE_value(section, i);
+				if(d_flag)
+					printf("%s: Engine cmd: %s = %s\n", pname, conf_value->name, conf_value->value);
+				scep_conf->engine->cmds[i] = NAME_VALUE_PAIR_new(conf_value->name, conf_value->value);
+			}
+
+			// NULL terminate the array to indicate where it ends
+			scep_conf->engine->cmds[number_of_cmds] = NULL;
+		} else {
+			scep_conf->engine->cmds = NULL;
+			if(v_flag)
+				printf("%s: No engine cmds section defined\n", pname);
+		}
+
 	}
 
 
@@ -552,7 +549,7 @@ void scep_dump_conf() {
 				printf("Option: %s, Flag: %i, Value: %s\n", names[i], flags[i], chars[i]);
 		}
 	} else {
-		fprintf(stderr, "Length of Arrays does not match! Flags: %i, Chars: %i, Names: %i\n",
+		fprintf(stderr, "Length of Arrays does not match! Flags: %li, Chars: %li, Names: %li\n",
 			sizeof(flags)/sizeof(int),
 			sizeof(chars)/sizeof(char *),
 			sizeof(names)/sizeof(char *)
diff --git a/fileutils.c b/fileutils.c
index e7fc047..a96db03 100644
--- a/fileutils.c
+++ b/fileutils.c
@@ -63,7 +63,7 @@ compare_subject(X509 * cert)
 	char buffer[1024];
 	int rc = X509_NAME_cmp(X509_get_subject_name(cert), X509_REQ_get_subject_name(request));
 	if(d_flag) {
-		fprintf(stderr, "Subject of the returned certificate: %s\n", X509_get_subject_name(cert));
+		fprintf(stderr, "Subject of the returned certificate: %s\n", X509_NAME_oneline(X509_get_subject_name(cert), NULL, 0));
 		fprintf(stderr, "Subject of the request: %s\n",
 				X509_NAME_oneline(X509_REQ_get_subject_name(request), buffer, sizeof(buffer))
 			);
diff --git a/ias.c b/ias.c
index bf1fb11..ec7a9ad 100644
--- a/ias.c
+++ b/ias.c
@@ -14,47 +14,12 @@
 #include "sscep.h"
 #include "ias.h"
 
-int i2d_pkcs7_issuer_and_subject(pkcs7_issuer_and_subject *a,
-	     unsigned char **pp) {
+ASN1_SEQUENCE(PKCS7_ISSUER_AND_SUBJECT) = {
+        ASN1_SIMPLE(PKCS7_ISSUER_AND_SUBJECT, subject, X509_NAME),
+        ASN1_SIMPLE(PKCS7_ISSUER_AND_SUBJECT, issuer, X509_NAME),
+} ASN1_SEQUENCE_END(PKCS7_ISSUER_AND_SUBJECT)
 
-	M_ASN1_I2D_vars(a);
-	M_ASN1_I2D_len(a->issuer,i2d_X509_NAME);
-	M_ASN1_I2D_len(a->subject,i2d_X509_NAME);
-	M_ASN1_I2D_seq_total();
-	M_ASN1_I2D_put(a->issuer,i2d_X509_NAME);
-	M_ASN1_I2D_put(a->subject,i2d_X509_NAME);
-	M_ASN1_I2D_finish();
-}
-
-pkcs7_issuer_and_subject *
-d2i_pkcs7_issuer_and_subject(pkcs7_issuer_and_subject **a,
-		unsigned char **pp, long length) {
-
-	M_ASN1_D2I_vars(a, pkcs7_issuer_and_subject *,
-		pkcs7_issuer_and_subject_new);
-	M_ASN1_D2I_Init();
-	M_ASN1_D2I_start_sequence();
-	M_ASN1_D2I_get(ret->issuer,d2i_X509_NAME);
-	M_ASN1_D2I_get(ret->subject,d2i_X509_NAME);
-	M_ASN1_D2I_Finish(a,pkcs7_issuer_and_subject_free, 99);
-}
-
-pkcs7_issuer_and_subject *pkcs7_issuer_and_subject_new(void) {
-
-	pkcs7_issuer_and_subject *ret=NULL;
-	ASN1_CTX c;
-	M_ASN1_New_Malloc(ret,pkcs7_issuer_and_subject);
-	M_ASN1_New(ret->issuer,X509_NAME_new);
-	M_ASN1_New(ret->subject,X509_NAME_new);
-	return(ret);
-	M_ASN1_New_Error(199);
-}
-
-void pkcs7_issuer_and_subject_free(pkcs7_issuer_and_subject *a) {
-
-	if (a == NULL) return;
-	X509_NAME_free(a->issuer);
-	M_ASN1_INTEGER_free(a->subject);
-	OPENSSL_free(a);
-}
+IMPLEMENT_ASN1_FUNCTIONS(PKCS7_ISSUER_AND_SUBJECT);
+IMPLEMENT_ASN1_PRINT_FUNCTION(PKCS7_ISSUER_AND_SUBJECT);
 
+IMPLEMENT_ASN1_PRINT_FUNCTION(PKCS7_ISSUER_AND_SERIAL);
\ No newline at end of file
diff --git a/ias.h b/ias.h
index 470d908..b3d1f5a 100644
--- a/ias.h
+++ b/ias.h
@@ -7,17 +7,7 @@
 
 /* Macros */
 
-#define i2d_pkcs7_issuer_and_subject_bio(bp, ias) \
-	ASN1_i2d_bio(i2d_pkcs7_issuer_and_subject, bp, (unsigned char *)ias)
-#define i2d_PKCS7_ISSUER_AND_SERIAL_bio(bp, ias)  \
-	ASN1_i2d_bio(i2d_PKCS7_ISSUER_AND_SERIAL, bp, (unsigned char *)ias)
-
-/* Routines */
-int i2d_pkcs7_issuer_and_subject(pkcs7_issuer_and_subject *, unsigned char **);
-pkcs7_issuer_and_subject *
-d2i_pkcs7_issuer_and_subject(pkcs7_issuer_and_subject **, unsigned char **,
-	long length);
-pkcs7_issuer_and_subject *pkcs7_issuer_and_subject_new(void);
-void pkcs7_issuer_and_subject_free(pkcs7_issuer_and_subject *);
-
+DECLARE_ASN1_FUNCTIONS(PKCS7_ISSUER_AND_SUBJECT);
+DECLARE_ASN1_PRINT_FUNCTION(PKCS7_ISSUER_AND_SUBJECT);
 
+DECLARE_ASN1_PRINT_FUNCTION(PKCS7_ISSUER_AND_SERIAL);
\ No newline at end of file
diff --git a/init.c b/init.c
index 621c9bb..eff856d 100644
--- a/init.c
+++ b/init.c
@@ -15,7 +15,7 @@ void
 init_config(FILE *conf) {
 	char	buff[1024];
 	char	*str1, *str2;
-	int	k, i, lines;
+	int		i, lines;
 
  	lines = 0;
 	while (fgets(buff, 1024, conf)) {
@@ -38,12 +38,11 @@ init_config(FILE *conf) {
 
 		/* fetch key and value: */
 
-		k = 0;
 		str1 = get_string(&buff[i]);
 		i += strlen(&buff[i])+1;
 		for ( ; isspace(buff[i]) ; i++ )
 			;
-		k = 1;
+
 		str2 = get_string(&buff[i]);
 
 		/* if not found... */
diff --git a/net.c b/net.c
index 2bded32..5ea60e7 100644
--- a/net.c
+++ b/net.c
@@ -197,10 +197,10 @@ send_msg(struct http_reply *http,char *msg,char *host,int port,int operation) {
 	return (0);
 
 mime_err:
-if (v_flag)
-	fprintf(stderr, "%s: wrong (or missing) MIME content type\n", pname);
-	return (1);
+	if (v_flag)
+		fprintf(stderr, "%s: wrong (or missing) MIME content type\n", pname);
 
+	return (1);
 }
 
 /* URL-encode the input and return back encoded string */
diff --git a/pkcs7.c b/pkcs7.c
index 4f66d98..3efec63 100644
--- a/pkcs7.c
+++ b/pkcs7.c
@@ -9,9 +9,15 @@
 #include "sscep.h"
 #include "ias.h"
 
+unsigned char* generate_nonce(int len) {
+	unsigned char * nonce = malloc(len);
+	RAND_bytes(nonce, len);
+	return nonce;
+}
+
 /*
  * Wrap data in PKCS#7 envelopes and base64-encode the result.
- * Data is PKCS#10 request in PKCSReq, or pkcs7_issuer_and_subject
+ * Data is PKCS#10 request in PKCSReq, or PKCS7_ISSUER_AND_SUBJECT
  * structure in GetCertInitial and PKCS7_ISSUER_AND_SERIAL in
  * GetCert and GETCrl.
  */
@@ -31,13 +37,11 @@ int pkcs7_wrap(struct scep *s) {
 	STACK_OF(X509_ATTRIBUTE) *attributes;
 	X509			*signercert = NULL;
 	EVP_PKEY		*signerkey = NULL;
-	X509_REQ *reqcsr = NULL;
 
 	/* Create a new sender nonce for all messages 
 	 * XXXXXXXXXXXXXX should it be per transaction? */
 	s->sender_nonce_len = 16;
-	s->sender_nonce = malloc(s->sender_nonce_len); 
-	RAND_bytes(s->sender_nonce, s->sender_nonce_len);
+	s->sender_nonce = generate_nonce(s->sender_nonce_len);
 
 	/* Prepare data payload */
 	switch(s->request_type) {
@@ -86,8 +90,8 @@ int pkcs7_wrap(struct scep *s) {
 
 			/* Read data in memory bio */
 			databio = BIO_new(BIO_s_mem());
-			if ((rc = i2d_pkcs7_issuer_and_subject_bio(databio,
-						s->ias_getcertinit)) <= 0) {
+			if ((rc = PKCS7_ISSUER_AND_SUBJECT_print_ctx(databio,
+						s->ias_getcertinit, 0, NULL)) <= 0) {
 				fprintf(stderr, "%s: error writing "
 					"GetCertInitial data in bio\n", pname);
 				ERR_print_errors_fp(stderr);
@@ -105,8 +109,8 @@ int pkcs7_wrap(struct scep *s) {
 
 			/* Read data in memory bio */
 			databio = BIO_new(BIO_s_mem());
-			if ((rc = i2d_PKCS7_ISSUER_AND_SERIAL_bio(databio,
-						s->ias_getcert)) <= 0) {
+			if ((rc = PKCS7_ISSUER_AND_SERIAL_print_ctx(databio,
+						s->ias_getcert, 0, NULL)) <= 0) {
 				fprintf(stderr, "%s: error writing "
 					"GetCert data in bio\n", pname);
 				ERR_print_errors_fp(stderr);
@@ -124,8 +128,8 @@ int pkcs7_wrap(struct scep *s) {
 
 			/* Read data in memory bio */
 			databio = BIO_new(BIO_s_mem());
-			if ((rc = i2d_PKCS7_ISSUER_AND_SERIAL_bio(databio,
-						s->ias_getcrl)) <= 0) {
+			if ((rc = PKCS7_ISSUER_AND_SERIAL_print_ctx(databio,
+						s->ias_getcrl, 0, NULL)) <= 0) {
 				fprintf(stderr, "%s: error writing "
 					"GetCert data in bio\n", pname);
 				ERR_print_errors_fp(stderr);
@@ -182,7 +186,7 @@ int pkcs7_wrap(struct scep *s) {
 
 	/* Create BIO for encryption  */
 	if (d_flag){
-		printf("\n %s: hexdump request payload \n", pname , i);
+		printf("\n %s: hexdump request payload\n", pname);
 		for(i=0; i < s->request_len; i++ ){
 			printf("%02x", s->request_payload[i]);
 		}
@@ -333,15 +337,10 @@ int pkcs7_verify_unwrap(struct scep *s , char * cachainfile ) {
 	BIO				*memorybio;
 	BIO				*outbio;
 	BIO				*pkcs7bio;
-	int				i, len, bytes, used;
+	int				len, bytes, used;
 	STACK_OF(PKCS7_SIGNER_INFO)	*sk;
-	PKCS7				*p7;
 	PKCS7_SIGNER_INFO		*si;
-	STACK_OF(X509_ATTRIBUTE)	*attribs;
-	char				*p;
 	unsigned char			buffer[1024];
-	X509				*recipientcert;
-	EVP_PKEY			*recipientkey;
     X509   				*signercert;
     FILE 				*fp;
 
@@ -458,19 +457,19 @@ int pkcs7_verify_unwrap(struct scep *s , char * cachainfile ) {
 	{
 
 #ifdef WIN32
-	if ((fopen_s(&fp, w_char, "w")))
+		if ((fopen_s(&fp, w_char, "w")))
 #else
-	if (!(fp = fopen(w_char, "w")))
+		if (!(fp = fopen(w_char, "w")))
 #endif
-	{
-		fprintf(stderr, "%s: cannot open cert file for writing\n",
-				w_char);
-		exit (SCEP_PKISTATUS_FILE);
-	}
-	if (v_flag)
-		printf("%s: writing cert\n", w_char);
-	if (d_flag)
-		PEM_write_X509(stdout, signercert);
+		{
+			fprintf(stderr, "%s: cannot open cert file for writing\n",
+					w_char);
+			exit (SCEP_PKISTATUS_FILE);
+		}
+		if (v_flag)
+			printf("%s: writing cert\n", w_char);
+		if (d_flag) 
+			PEM_write_X509(stdout, signercert);
 
 		if (PEM_write_X509(fp, signercert) != 1) {
 			fprintf(stderr, "%s: error while writing certificate "
@@ -625,7 +624,7 @@ int pkcs7_unwrap(struct scep *s) {
 		/* XXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 		exit (SCEP_PKISTATUS_P7); */
 	}
-	s->reply_sender_nonce = p;
+	s->reply_sender_nonce = (unsigned char *) p;
 	if (v_flag) {
 		printf("%s: senderNonce in reply: ", pname);
 		for (i = 0; i < 16; i++) {
@@ -638,7 +637,7 @@ int pkcs7_unwrap(struct scep *s) {
 		fprintf(stderr, "%s: cannot find recipientNonce\n", pname);
 		exit (SCEP_PKISTATUS_P7);
 	}
-	s->reply_recipient_nonce = p;
+	s->reply_recipient_nonce = (unsigned char *) p;
 	if (v_flag) {
 		printf("%s: recipientNonce in reply: ", pname);
 		for (i = 0; i < 16; i++) {
@@ -807,7 +806,7 @@ int add_attribute_string(STACK_OF(X509_ATTRIBUTE) *attrs, int nid, char *buffer)
 	return (0);
 
 }
-int add_attribute_octet(STACK_OF(X509_ATTRIBUTE) *attrs, int nid, char *buffer,
+int add_attribute_octet(STACK_OF(X509_ATTRIBUTE) *attrs, int nid, unsigned char *buffer,
 		int len) {
 	ASN1_STRING     *asn1_string = NULL;
 	X509_ATTRIBUTE  *x509_a;
@@ -865,7 +864,7 @@ int get_signed_attribute(STACK_OF(X509_ATTRIBUTE) *attribs, int nid,int type, ch
 			pname);	
 		exit (SCEP_PKISTATUS_P7);
 	}
-	memcpy(*buffer, ASN1_STRING_data(asn1_type->value.asn1_string), len);
+	memcpy(*buffer, ASN1_STRING_get0_data(asn1_type->value.asn1_string), len);
 
 	/* Add null terminator if it's a PrintableString */
 	if (type == V_ASN1_PRINTABLESTRING) {
@@ -895,16 +894,14 @@ int get_attribute(STACK_OF(X509_ATTRIBUTE) *attribs, int required_nid,
 	/* Find attribute */
 	for (i = 0; i < sk_X509_ATTRIBUTE_num(attribs); i++) {
 		x509_attrib = sk_X509_ATTRIBUTE_value(attribs, i);
-		if (OBJ_cmp(x509_attrib->object, asn1_obj) == 0) {
-			if ((x509_attrib->value.set) &&
-			  (sk_ASN1_TYPE_num(x509_attrib->value.set) != 0)) {
+		if (OBJ_cmp(X509_ATTRIBUTE_get0_object(x509_attrib), asn1_obj) == 0) {
+			if (X509_ATTRIBUTE_count(x509_attrib) != 0) {
 				if (*asn1_type != NULL) {
 					fprintf(stderr, "%s: no value found",
 							pname);
 					exit (SCEP_PKISTATUS_P7);
 				}
-			*asn1_type =
-				sk_ASN1_TYPE_value(x509_attrib->value.set, 0);
+				*asn1_type = X509_ATTRIBUTE_get0_type(x509_attrib, 0);
 			}
 		}
 	}
diff --git a/sceputils.c b/sceputils.c
index a810229..29e371e 100644
--- a/sceputils.c
+++ b/sceputils.c
@@ -27,7 +27,7 @@ int new_transaction(struct scep *s) {
 	s->fail_info_str = NULL;
 
 	/* Set other variables */
-	s->ias_getcertinit = pkcs7_issuer_and_subject_new();
+	s->ias_getcertinit = PKCS7_ISSUER_AND_SUBJECT_new();
 	s->ias_getcert = PKCS7_ISSUER_AND_SERIAL_new();
 	s->ias_getcrl = PKCS7_ISSUER_AND_SERIAL_new();
 
@@ -47,7 +47,6 @@ int new_transaction(struct scep *s) {
  * Set also subjectAltName extension if found from request.
  */
 int new_selfsigned(struct scep *s) {
-	unsigned char		 *ptr;
 	X509			 *cert;
 	X509_NAME		 *subject;
 	ASN1_INTEGER		 *serial;
@@ -98,8 +97,8 @@ int new_selfsigned(struct scep *s) {
 		exit (SCEP_PKISTATUS_SS);
 	}
 	/* Get serial no from transaction id */
-	ptr = (unsigned char *)s->transaction_id;
-	if (!(serial = c2i_ASN1_INTEGER(NULL, &ptr, 32))) {
+	read_serial(&serial, (unsigned char **) &s->transaction_id, 32);
+	if (!serial) {
 		fprintf(stderr, "%s: error converting serial\n", pname);
 		ERR_print_errors_fp(stderr);
 		exit (SCEP_PKISTATUS_SS);
@@ -230,7 +229,7 @@ key_fingerprint(X509_REQ *req) {
 	MD5_CTX		ctx;
 	
 	/* Assign space for ASCII presentation of the digest */
-	str = (unsigned char *)malloc(2 * MD5_DIGEST_LENGTH + 1);
+	str = (char *)malloc(2 * MD5_DIGEST_LENGTH + 1);
 	ret = str;
 
 	/* Create new memory bio for reading the public key */
@@ -252,4 +251,17 @@ key_fingerprint(X509_REQ *req) {
 	return(ret);
 }
 
+/**
+ * c2i_ASN1_INTERNAL is not supported anymore since openssl 1.1.x. The only way to
+ * still get the ASN1_INTEGER is by using d2i_ASN1_INTERNAL instead. However, this requires
+ * the string to start with two additional octets. One for the type (integer: 0x02) and another
+ * one representing the data length (source_length).
+ */
+void read_serial(ASN1_INTEGER** target, unsigned char ** source, int source_len) {
+    const int buffer_len = source_len + 2;
+    const unsigned char * buffer = malloc(sizeof(unsigned char[buffer_len]));
+
+    snprintf((char *) buffer, buffer_len, "%c%c%s", 2, source_len, *source);
 
+    *target = d2i_ASN1_INTEGER(NULL, &buffer, buffer_len);
+}
\ No newline at end of file
diff --git a/sscep.c b/sscep.c
index 05db853..2119d7b 100644
--- a/sscep.c
+++ b/sscep.c
@@ -76,7 +76,6 @@ main(int argc, char **argv) {
 	BIO			*bp;
 	STACK_OF(X509)		*nextcara = NULL;
 	X509 				*cert=NULL;
-	PKCS7 p7;
 	int i;
 	int required_option_space;
 	
@@ -227,7 +226,7 @@ main(int argc, char **argv) {
 					M_char = realloc(M_char, required_option_space);
 					if(!M_char)
 						error_memory();
-					strncat(M_char, "&", 1);
+					strcat(M_char, "&");
 					strncat(M_char, optarg, strlen(optarg));
 				}
 				break;
@@ -696,7 +695,6 @@ main(int argc, char **argv) {
 
 
 				/* Get certs */
-				p7 = *(scep_t.reply_p7);
 				nextcara = scep_t.reply_p7->d.sign->cert;
 
 			    if (v_flag) {
@@ -1000,7 +998,7 @@ main(int argc, char **argv) {
 
 			/* Check payload */
 			scep_t.reply_len = reply.bytes;
-			scep_t.reply_payload = (unsigned char *)reply.payload;
+			scep_t.reply_payload = reply.payload;
 			pkcs7_unwrap(&scep_t);
 			pkistatus = scep_t.pki_status;
 
diff --git a/sscep.h b/sscep.h
index bc0c444..645ab27 100644
--- a/sscep.h
+++ b/sscep.h
@@ -53,6 +53,7 @@
 #include <openssl/crypto.h>
 #include <openssl/buffer.h>
 #include <openssl/asn1.h>
+#include <openssl/asn1t.h>
 #include <openssl/x509.h>
 #include <openssl/x509v3.h>
 #include <openssl/pkcs7.h>
@@ -61,7 +62,6 @@
 #include <openssl/rand.h>
 #include <openssl/md5.h>
 #include <openssl/objects.h>
-#include <openssl/asn1_mac.h>
 #include <openssl/ssl.h>
 /* Global defines */
 
@@ -195,10 +195,10 @@ int pkistatus;
 
 /* GETCertInital data structure */
 
-typedef struct {
+typedef struct PKCS7_ISSUER_AND_SUBJECT_st {
 	X509_NAME *issuer;
 	X509_NAME *subject;
-} pkcs7_issuer_and_subject;
+} PKCS7_ISSUER_AND_SUBJECT;
 
 /* HTTP reply structure */
 struct http_reply {
@@ -249,13 +249,13 @@ struct scep {
 	PKCS7 *request_p7;
 	unsigned char *request_payload;
 	int request_len;
-	pkcs7_issuer_and_subject *ias_getcertinit;
+	PKCS7_ISSUER_AND_SUBJECT *ias_getcertinit;
 	PKCS7_ISSUER_AND_SERIAL *ias_getcert;
 	PKCS7_ISSUER_AND_SERIAL *ias_getcrl;
 
 	/* Reply */
 	PKCS7 *reply_p7;
-	unsigned char *reply_payload;	
+	char *reply_payload;	
 	int reply_len;
 
 	/* Engine */
@@ -306,6 +306,9 @@ void read_cert(X509** cert, char* filename);
 /* Read certificate request and private key */
 void read_request(void);
 
+/* reads the serialnumber from a hex encoded string */
+void read_serial(ASN1_INTEGER** target, unsigned char ** source, int source_len);
+
 /* Write CRL */
 void write_crl(struct scep *);
 
@@ -337,7 +340,7 @@ int pkcs7_unwrap(struct scep *);
 int add_attribute_string(STACK_OF(X509_ATTRIBUTE) *, int, char *);
 
 /* Add signed octet attribute */
-int add_attribute_octet(STACK_OF(X509_ATTRIBUTE) *, int, char *, int);
+int add_attribute_octet(STACK_OF(X509_ATTRIBUTE) *, int, unsigned char *, int);
 
 /* Find signed attributes */
 int get_signed_attribute(STACK_OF(X509_ATTRIBUTE) *, int, int, char **);