diff --git a/.gitignore b/.gitignore
index c6432ad..f77ab37 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,3 +13,9 @@ test/test_xmssmt_core_XMSSMT*
 test/test_xmssmt_core_fast_XMSSMT*
 test/speed
 test/gen_testvectors
+test/xmss_keypair
+test/xmss_open
+test/xmss_sign
+test/xmssmt_keypair
+test/xmssmt_open
+test/xmssmt_sign
diff --git a/Makefile b/Makefile
index b0e9571..3ce49a3 100644
--- a/Makefile
+++ b/Makefile
@@ -1,42 +1,41 @@
 CC = /usr/bin/gcc
 CFLAGS = -Wall -g -O3 -Wextra
+LDLIBS =  -lcrypto -lm
 
-all: test/test_wots \
-test/test_xmss_core \
-test/test_xmss_core_fast \
-test/test_xmss \
-test/test_xmssmt_core_fast \
-test/test_xmssmt_core \
-test/test_xmssmt
+SOURCES = params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss.c xmss_core.c xmss_commons.c
+HEADERS = params.h hash.h fips202.h hash_address.h randombytes.h wots.h xmss.h xmss_core.h xmss_commons.h
 
-.PHONY: clean
+SOURCES_FAST = $(subst core,core_fast,$(SOURCES))
+HEADERS_FAST = $(subst core,core_fast,$(HEADERS))
 
-test/test_wots: params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_commons.c test/test_wots.c params.h hash.h fips202.h hash_address.h randombytes.h wots.h xmss_commons.h
-	$(CC) $(CFLAGS) params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_commons.c test/test_wots.c -o $@ -lcrypto -lm
+TESTS = test/test_wots \
+		test/test_xmss_core \
+		test/test_xmss_core_fast \
+		test/test_xmss \
+		test/test_xmssmt_core_fast \
+		test/test_xmssmt_core \
+		test/test_xmssmt \
 
-test/test_xmss_core: params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_core.c xmss_commons.c test/test_xmss_core.c params.h hash.h fips202.h hash_address.h randombytes.h wots.h xmss_core.h xmss_commons.h
-	$(CC) $(CFLAGS) params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_core.c xmss_commons.c test/test_xmss_core.c -o $@ -lcrypto -lm
+UI = test/xmss_keypair \
+	 test/xmss_sign \
+	 test/xmss_open \
+	 test/xmssmt_keypair \
+	 test/xmssmt_sign \
+	 test/xmssmt_open \
 
-test/test_xmss_core_fast: params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_core_fast.c xmss_commons.c test/test_xmss_core_fast.c params.h hash.h fips202.h hash_address.h randombytes.h wots.h xmss_core_fast.h xmss_commons.h
-	$(CC) $(CFLAGS) params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_core_fast.c xmss_commons.c test/test_xmss_core_fast.c -o $@ -lcrypto -lm
+all: $(TESTS) $(UI)
 
-test/test_xmssmt_core: params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_core.c xmss_commons.c test/test_xmssmt_core.c params.h hash.h fips202.h hash_address.h randombytes.h wots.h xmss_core.h xmss_commons.h
-	$(CC) $(CFLAGS) params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_core.c xmss_commons.c test/test_xmssmt_core.c -o $@ -lcrypto -lm
+.PHONY: clean
 
-test/test_xmssmt_core_fast: params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_core_fast.c xmss_commons.c test/test_xmssmt_core_fast.c params.h hash.h fips202.h hash_address.h randombytes.h wots.h xmss_core_fast.h xmss_commons.h
-	$(CC) $(CFLAGS) params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_core_fast.c xmss_commons.c test/test_xmssmt_core_fast.c -o $@ -lcrypto -lm
+test/%_fast: test/%_fast.c $(SOURCES_FAST) $(OBJS) $(HEADERS_FAST)
+	$(CC) $(CFLAGS) -o $@ $(SOURCES_FAST) $< $(LDLIBS)
 
-test/test_xmss: params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_core.c xmss_commons.c xmss.c test/test_xmss.c params.h hash.h fips202.h hash_address.h randombytes.h wots.h xmss_core.h xmss_commons.h xmss.h
-	$(CC) $(CFLAGS) params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_core.c xmss_commons.c xmss.c test/test_xmss.c -o $@ -lcrypto -lm
+test/%: test/%.c $(SOURCES) $(OBJS) $(HEADERS)
+	$(CC) $(CFLAGS) -o $@ $(SOURCES) $< $(LDLIBS)
 
-test/test_xmssmt: params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_core.c xmss_commons.c xmss.c test/test_xmssmt.c params.h hash.h fips202.h hash_address.h randombytes.h wots.h xmss_core.h xmss_commons.h xmss.h
-	$(CC) $(CFLAGS) params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_core.c xmss_commons.c xmss.c test/test_xmssmt.c -o $@ -lcrypto -lm
+test/test_wots: params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_commons.c test/test_wots.c params.h hash.h fips202.h hash_address.h randombytes.h wots.h xmss_commons.h
+	$(CC) $(CFLAGS) params.c hash.c fips202.c hash_address.c randombytes.c wots.c xmss_commons.c test/test_wots.c -o $@ -lcrypto -lm
 
 clean:
-	-rm test/test_wots
-	-rm test/test_xmss_core
-	-rm test/test_xmss_core_fast
-	-rm test/test_xmss
-	-rm test/test_xmssmt_core
-	-rm test/test_xmssmt_core_fast
-	-rm test/test_xmssmt
+	-$(RM) $(TESTS)
+	-$(RM) $(UI)
diff --git a/params.c b/params.c
index 1282de4..f947e70 100644
--- a/params.c
+++ b/params.c
@@ -1,6 +1,155 @@
 #include <stdint.h>
+#include <string.h>
 #include "params.h"
 
+int xmss_str_to_oid(uint32_t *oid, const char *s)
+{
+    if (!strcmp(s, "XMSS-SHA2_10_256")) {
+        *oid = 0x01000001;
+    }
+    else if (!strcmp(s, "XMSS-SHA2_16_256")) {
+        *oid = 0x02000002;
+    }
+    else if (!strcmp(s, "XMSS-SHA2_20_256")) {
+        *oid = 0x03000003;
+    }
+    else if (!strcmp(s, "XMSS-SHA2_10_512")) {
+        *oid = 0x04000004;
+    }
+    else if (!strcmp(s, "XMSS-SHA2_16_512")) {
+        *oid = 0x05000005;
+    }
+    else if (!strcmp(s, "XMSS-SHA2_20_512")) {
+        *oid = 0x06000006;
+    }
+    else if (!strcmp(s, "XMSS-SHAKE_10_256")) {
+        *oid = 0x07000007;
+    }
+    else if (!strcmp(s, "XMSS-SHAKE_16_256")) {
+        *oid = 0x08000008;
+    }
+    else if (!strcmp(s, "XMSS-SHAKE_20_256")) {
+        *oid = 0x09000009;
+    }
+    else if (!strcmp(s, "XMSS-SHAKE_10_512")) {
+        *oid = 0x0a00000a;
+    }
+    else if (!strcmp(s, "XMSS-SHAKE_16_512")) {
+        *oid = 0x0b00000b;
+    }
+    else if (!strcmp(s, "XMSS-SHAKE_20_512")) {
+        *oid = 0x0c00000c;
+    }
+    else {
+        return -1;
+    }
+    return 0;
+}
+
+int xmssmt_str_to_oid(uint32_t *oid, const char *s)
+{
+    if (!strcmp(s, "XMSSMT-SHA2_20/2_256")) {
+       *oid = 0x01000001;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_20/4_256")) {
+       *oid = 0x02000002;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_40/2_256")) {
+       *oid = 0x03000003;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_40/4_256")) {
+       *oid = 0x04000004;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_40/8_256")) {
+       *oid = 0x05000005;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_60/3_256")) {
+       *oid = 0x06000006;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_60/6_256")) {
+       *oid = 0x07000007;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_60/12_256")) {
+      *oid = 0x08000008;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_20/2_512")) {
+       *oid = 0x09000009;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_20/4_512")) {
+       *oid = 0x0a00000a;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_40/2_512")) {
+       *oid = 0x0b00000b;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_40/4_512")) {
+       *oid = 0x0c00000c;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_40/8_512")) {
+       *oid = 0x0d00000d;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_60/3_512")) {
+       *oid = 0x0e00000e;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_60/6_512")) {
+       *oid = 0x0f00000f;
+    }
+    else if (!strcmp(s, "XMSSMT-SHA2_60/12_512")) {
+      *oid = 0x01010101;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_20/2_256")) {
+      *oid = 0x02010102;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_20/4_256")) {
+      *oid = 0x03010103;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_40/2_256")) {
+      *oid = 0x04010104;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_40/4_256")) {
+      *oid = 0x05010105;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_40/8_256")) {
+      *oid = 0x06010106;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_60/3_256")) {
+      *oid = 0x07010107;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_60/6_256")) {
+      *oid = 0x08010108;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_60/12_256")) {
+     *oid = 0x09010109;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_20/2_512")) {
+      *oid = 0x0a01010a;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_20/4_512")) {
+      *oid = 0x0b01010b;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_40/2_512")) {
+      *oid = 0x0c01010c;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_40/4_512")) {
+      *oid = 0x0d01010d;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_40/8_512")) {
+      *oid = 0x0e01010e;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_60/3_512")) {
+      *oid = 0x0f01010f;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_60/6_512")) {
+      *oid = 0x01020201;
+    }
+    else if (!strcmp(s, "XMSSMT-SHAKE_60/12_512")) {
+     *oid = 0x02020202;
+    }
+    else {
+        return -1;
+    }
+    return 0;
+}
+
 int xmss_parse_oid(xmss_params *params, const uint32_t oid)
 {
     switch (oid) {
diff --git a/params.h b/params.h
index 7b6f82c..c15a80d 100644
--- a/params.h
+++ b/params.h
@@ -30,6 +30,9 @@ typedef struct {
     unsigned int bds_k;
 } xmss_params;
 
+int xmss_str_to_oid(uint32_t *oid, const char* s);
+int xmssmt_str_to_oid(uint32_t *oid, const char* s);
+
 int xmss_parse_oid(xmss_params *params, const uint32_t oid);
 int xmssmt_parse_oid(xmss_params *params, const uint32_t oid);
 
diff --git a/test/xmss_keypair.c b/test/xmss_keypair.c
new file mode 100644
index 0000000..d36c5ba
--- /dev/null
+++ b/test/xmss_keypair.c
@@ -0,0 +1,30 @@
+#include "../params.h"
+#include "../xmss.h"
+#include <stdio.h>
+#include <stdint.h>
+
+int main(int argc, char **argv)
+{
+    xmss_params params;
+    uint32_t oid;
+
+    if (argc != 2) {
+        fprintf(stderr, "Expected parameter string (e.g. 'XMSS-SHA2_10_256')"
+                        " as only parameter.\n"
+                        "The keypair is written to stdout.\n");
+        return -1;
+    }
+
+    xmss_str_to_oid(&oid, argv[1]);
+    xmss_parse_oid(&params, oid);
+
+    unsigned char pk[XMSS_OID_LEN + params.publickey_bytes];
+    unsigned char sk[XMSS_OID_LEN + params.privatekey_bytes];
+
+    xmss_keypair(pk, sk, oid);
+
+    fwrite(pk, 1, XMSS_OID_LEN + params.publickey_bytes, stdout);
+    fwrite(sk, 1, XMSS_OID_LEN + params.privatekey_bytes, stdout);
+
+    fclose(stdout);
+}
diff --git a/test/xmss_open.c b/test/xmss_open.c
new file mode 100644
index 0000000..05ec8fe
--- /dev/null
+++ b/test/xmss_open.c
@@ -0,0 +1,47 @@
+#include "../params.h"
+#include "../xmss_core.h"
+#include <stdio.h>
+
+#define MLEN 32
+
+int main(int argc, char **argv) {
+    FILE *keypair;
+    xmss_params params;
+    uint32_t oid;
+    int ret;
+
+    if (argc != 2) {
+        fprintf(stderr, "Expected keypair filename as only parameter, "
+                        "and the message + signature via stdin.\n"
+                        "Keypair file needs only to contain the public key.\n"
+                        "The return code 0 indicates verification success.\n");
+        return -1;
+    }
+
+    keypair = fopen(argv[1], "rb");
+    if (keypair == NULL) {
+        return -1;
+    }
+
+    fread(&oid, 1, XMSS_OID_LEN, keypair);
+    xmss_parse_oid(&params, oid);
+
+    unsigned char pk[params.publickey_bytes];
+    unsigned char sm[params.bytes + MLEN];
+    unsigned char m[params.bytes + MLEN];
+    unsigned long long mlen;
+
+    fread(pk, 1, params.publickey_bytes, keypair);
+    fread(sm, 1, params.bytes + MLEN, stdin);
+
+    ret = xmss_core_sign_open(&params, m, &mlen, sm, params.bytes + MLEN, pk);
+
+    if (ret) {
+        printf("Verification failed!\n");
+    }
+    else {
+        printf("Verification succeeded.\n");
+    }
+
+    return ret;
+}
diff --git a/test/xmss_sign.c b/test/xmss_sign.c
new file mode 100644
index 0000000..13c0615
--- /dev/null
+++ b/test/xmss_sign.c
@@ -0,0 +1,52 @@
+#include "../params.h"
+#include "../xmss_core.h"
+#include <stdio.h>
+
+#define MLEN 32
+
+int main(int argc, char **argv) {
+    FILE *keypair;
+    xmss_params params;
+    uint32_t oid_pk;
+    uint32_t oid_sk;
+
+    if (argc != 2) {
+        fprintf(stderr, "Expected keypair filename as only parameter, "
+                        "and the message via stdin.\n"
+                        "The keypair is updated with the changed state, "
+                        "and the message + signature is output via stdout.\n");
+        return -1;
+    }
+
+    keypair = fopen(argv[1], "rb");
+    if (keypair == NULL) {
+        fprintf(stderr, "Could not open keypair file.\n");
+        return -1;
+    }
+
+    // Read the OID from the public key, as we need its length to seek past it
+    fread(&oid_pk, 1, XMSS_OID_LEN, keypair);
+    xmss_parse_oid(&params, oid_pk);
+
+    // fseek past the public key
+    fseek(keypair, params.publickey_bytes, SEEK_CUR);
+    // This is the OID we're actually going to use. Likely the same, but still.
+    fread(&oid_sk, 1, XMSS_OID_LEN, keypair);
+    xmss_parse_oid(&params, oid_sk);
+
+    unsigned char sk[params.privatekey_bytes];
+    unsigned char m[MLEN];
+    unsigned char sm[params.bytes + MLEN];
+    unsigned long long smlen;
+
+    fread(sk, 1, params.privatekey_bytes, keypair);
+    fread(m, 1, MLEN, stdin);
+    xmss_core_sign(&params, sk, sm, &smlen, m, MLEN);
+
+    fseek(keypair, -params.privatekey_bytes, SEEK_CUR);
+    fwrite(sk, 1, params.privatekey_bytes, keypair);
+    fwrite(sm, 1, params.bytes + MLEN, stdout);
+
+    fclose(keypair);
+    fclose(stdout);
+}
diff --git a/test/xmssmt_keypair.c b/test/xmssmt_keypair.c
new file mode 100644
index 0000000..6e2982f
--- /dev/null
+++ b/test/xmssmt_keypair.c
@@ -0,0 +1,30 @@
+#include "../params.h"
+#include "../xmss.h"
+#include <stdio.h>
+#include <stdint.h>
+
+int main(int argc, char **argv)
+{
+    xmss_params params;
+    uint32_t oid;
+
+    if (argc != 2) {
+        fprintf(stderr, "Expected parameter string (e.g. 'XMSS-SHA2_10_256')"
+                        " as only parameter.\n"
+                        "The keypair is written to stdout.\n");
+        return -1;
+    }
+
+    xmssmt_str_to_oid(&oid, argv[1]);
+    xmssmt_parse_oid(&params, oid);
+
+    unsigned char pk[XMSS_OID_LEN + params.publickey_bytes];
+    unsigned char sk[XMSS_OID_LEN + params.privatekey_bytes];
+
+    xmssmt_keypair(pk, sk, oid);
+
+    fwrite(pk, 1, XMSS_OID_LEN + params.publickey_bytes, stdout);
+    fwrite(sk, 1, XMSS_OID_LEN + params.privatekey_bytes, stdout);
+
+    fclose(stdout);
+}
diff --git a/test/xmssmt_open.c b/test/xmssmt_open.c
new file mode 100644
index 0000000..2636f95
--- /dev/null
+++ b/test/xmssmt_open.c
@@ -0,0 +1,47 @@
+#include "../params.h"
+#include "../xmss_core.h"
+#include <stdio.h>
+
+#define MLEN 32
+
+int main(int argc, char **argv) {
+    FILE *keypair;
+    xmss_params params;
+    uint32_t oid;
+    int ret;
+
+    if (argc != 2) {
+        fprintf(stderr, "Expected keypair filename as only parameter, "
+                        "and the message + signature via stdin.\n"
+                        "Keypair file needs only to contain the public key.\n"
+                        "The return code 0 indicates verification success.\n");
+        return -1;
+    }
+
+    keypair = fopen(argv[1], "rb");
+    if (keypair == NULL) {
+        return -1;
+    }
+
+    fread(&oid, 1, XMSS_OID_LEN, keypair);
+    xmssmt_parse_oid(&params, oid);
+
+    unsigned char pk[params.publickey_bytes];
+    unsigned char sm[params.bytes + MLEN];
+    unsigned char m[params.bytes + MLEN];
+    unsigned long long mlen;
+
+    fread(pk, 1, params.publickey_bytes, keypair);
+    fread(sm, 1, params.bytes + MLEN, stdin);
+
+    ret = xmssmt_core_sign_open(&params, m, &mlen, sm, params.bytes + MLEN, pk);
+
+    if (ret) {
+        printf("Verification failed!\n");
+    }
+    else {
+        printf("Verification succeeded.\n");
+    }
+
+    return ret;
+}
diff --git a/test/xmssmt_sign.c b/test/xmssmt_sign.c
new file mode 100644
index 0000000..f709366
--- /dev/null
+++ b/test/xmssmt_sign.c
@@ -0,0 +1,52 @@
+#include "../params.h"
+#include "../xmss_core.h"
+#include <stdio.h>
+
+#define MLEN 32
+
+int main(int argc, char **argv) {
+    FILE *keypair;
+    xmss_params params;
+    uint32_t oid_pk;
+    uint32_t oid_sk;
+
+    if (argc != 2) {
+        fprintf(stderr, "Expected keypair filename as only parameter, "
+                        "and the message via stdin.\n"
+                        "The keypair is updated with the changed state, "
+                        "and the message + signature is output via stdout.\n");
+        return -1;
+    }
+
+    keypair = fopen(argv[1], "rb");
+    if (keypair == NULL) {
+        fprintf(stderr, "Could not open keypair file.\n");
+        return -1;
+    }
+
+    // Read the OID from the public key, as we need its length to seek past it
+    fread(&oid_pk, 1, XMSS_OID_LEN, keypair);
+    xmssmt_parse_oid(&params, oid_pk);
+
+    // fseek past the public key
+    fseek(keypair, params.publickey_bytes, SEEK_CUR);
+    // This is the OID we're actually going to use. Likely the same, but still.
+    fread(&oid_sk, 1, XMSS_OID_LEN, keypair);
+    xmssmt_parse_oid(&params, oid_sk);
+
+    unsigned char sk[params.privatekey_bytes];
+    unsigned char m[MLEN];
+    unsigned char sm[params.bytes + MLEN];
+    unsigned long long smlen;
+
+    fread(sk, 1, params.privatekey_bytes, keypair);
+    fread(m, 1, MLEN, stdin);
+    xmssmt_core_sign(&params, sk, sm, &smlen, m, MLEN);
+
+    fseek(keypair, -params.privatekey_bytes, SEEK_CUR);
+    fwrite(sk, 1, params.privatekey_bytes, keypair);
+    fwrite(sm, 1, params.bytes + MLEN, stdout);
+
+    fclose(keypair);
+    fclose(stdout);
+}