First pass at an ECC key export example.

.gitignore

@@ -104,9 +104,12 @@ signature/rsa_buffer/sign
 signature/rsa_buffer/verify
 
 ecc/ecc-key-decode
+ecc/ecc-key-export
 ecc/ecc-sign
 ecc/ecc-stack
 ecc/ecc-verify
+ecc/*.der
+ecc/*.pem
 pkcs7/pkcs7-verify
 pkcs7/authEnvelopedData-kari
 pkcs7/authEnvelopedData-ktri

ecc/Makefile

@@ -12,10 +12,10 @@ DEBUG_INC_PATHS = -MD
 OPTIMIZE        = -Os
 
 # Options
-#CFLAGS+=$(DEBUG_FLAGS)
-CFLAGS+=$(OPTIMIZE)
-#LIBS+=$(STATIC_LIB)
-LIBS+=$(DYN_LIB)
+CFLAGS+=$(DEBUG_FLAGS)
+#CFLAGS+=$(OPTIMIZE)
+LIBS+=$(STATIC_LIB)
+#LIBS+=$(DYN_LIB)
 
 # build targets
 SRC=$(wildcard *.c)

ecc/ecc-key-export.c

@@ -0,0 +1,148 @@
+#include <stdio.h>
+#include <stdint.h>
+
+#ifndef WOLFSSL_USER_SETTINGS
+    #include <wolfssl/options.h>
+#endif
+#include <wolfssl/wolfcrypt/settings.h>
+#include <wolfssl/wolfcrypt/ecc.h>
+#include <wolfssl/wolfcrypt/random.h>
+#include <wolfssl/wolfcrypt/asn_public.h>
+#include <wolfssl/wolfcrypt/error-crypt.h>
+#include <wolfssl/wolfcrypt/logging.h>
+
+/* Build wolfSSL with:
+./configure --enable-ecccustcurves CFLAGS="-DWOLFSSL_DER_TO_PEM -DHAVE_ECC_KOBLITZ"
+make
+sudo make install
+*/
+
+#define MAX_CERT_SIZE       4096
+#define TEST_ECC_KEY_SZ     32
+#ifdef HAVE_ECC_KOBLITZ
+#define TEST_ECC_KEY_CURVE  ECC_SECP256K1
+#else
+#define TEST_ECC_KEY_CURVE  ECC_SECP256R1
+#endif
+
+#define XSTRINGIFY(a) STRINGIFY(a)
+#define STRINGIFY(a) #a
+
+int main(void)
+{
+    int ret;
+    byte der[MAX_CERT_SIZE];
+    word32 derSz;
+#ifdef WOLFSSL_DER_TO_PEM
+    byte pem[MAX_CERT_SIZE];
+    word32 pemSz;
+#endif
+    WC_RNG rng;
+    ecc_key key;
+    FILE *fp;
+
+    wolfSSL_Debugging_ON();
+
+    ret = wolfCrypt_Init();
+    if (ret != 0) {
+        printf("wolfCrypt_Init error %s (%d)\n", wc_GetErrorString(ret), ret);
+        return -1;
+    }
+
+    ret = wc_InitRng(&rng);
+    if (ret != 0) {
+        printf("wc_InitRng error %s (%d)\n", wc_GetErrorString(ret), ret);
+        return -1;
+    }
+
+    ret = wc_ecc_init(&key);
+    if (ret != 0) {
+        printf("wc_ecc_init error %s (%d)\n", wc_GetErrorString(ret), ret);
+        return -1;
+    }
+
+    ret = wc_ecc_make_key_ex(&rng, TEST_ECC_KEY_SZ, &key, TEST_ECC_KEY_CURVE);
+    if (ret != 0) {
+        printf("wc_ecc_make_key_ex error %s (%d)\n", wc_GetErrorString(ret), ret);
+        return -1;
+    }
+    printf("ECC Key Generated: %d bits, curve %s\n", TEST_ECC_KEY_SZ * 8, XSTRINGIFY(TEST_ECC_KEY_CURVE));
+
+    memset(der, 0, sizeof(der));
+    ret = wc_EccKeyToDer(&key, der, sizeof(der));
+    if (ret < 0) {
+        printf("wc_EccKeyToDer error %s (%d)\n", wc_GetErrorString(ret), ret);
+        return -1;
+    }
+    derSz = ret;
+
+    fp = fopen("./" XSTRINGIFY(TEST_ECC_KEY_CURVE) ".der", "wb");
+    if (!fp) {
+        printf("Error openening %s for write\n",
+            "./" XSTRINGIFY(TEST_ECC_KEY_CURVE) ".der");
+        return -1;
+    }
+    fwrite(der, derSz, 1, fp);
+    fclose(fp);
+
+#ifdef WOLFSSL_DER_TO_PEM
+    memset(pem, 0, sizeof(pem));
+    ret = wc_DerToPem(der, derSz, pem, sizeof(pem), ECC_PRIVATEKEY_TYPE);
+    if (ret < 0) {
+        printf("wc_DerToPem error %s (%d)\n", wc_GetErrorString(ret), ret);
+        return -1;
+    }
+    pemSz = ret;
+
+    fp = fopen("./" XSTRINGIFY(TEST_ECC_KEY_CURVE) ".pem", "wb");
+    if (!fp) {
+        printf("Error openening %s for write\n",
+            "./" XSTRINGIFY(TEST_ECC_KEY_CURVE) ".pem");
+        return -1;
+    }
+    fwrite(pem, pemSz, 1, fp);
+    fclose(fp);
+#endif
+
+    memset(der, 0, sizeof(der));
+    ret = wc_EccPublicKeyToDer(&key, der, sizeof(der), TEST_ECC_KEY_CURVE);
+    if (ret < 0) {
+        printf("wc_EccPublicKeyToDer error %s (%d)\n", wc_GetErrorString(ret), ret);
+        return -1;
+    }
+    derSz = ret;
+
+    fp = fopen("./" XSTRINGIFY(TEST_ECC_KEY_CURVE) "pub.der", "wb");
+    if (!fp) {
+        printf("Error openening %s for write\n",
+            "./" XSTRINGIFY(TEST_ECC_KEY_CURVE) "pub.der");
+        return -1;
+    }
+    fwrite(der, derSz, 1, fp);
+    fclose(fp);
+
+#ifdef WOLFSSL_DER_TO_PEM
+    memset(pem, 0, sizeof(pem));
+    ret = wc_DerToPem(der, derSz, pem, sizeof(pem), ECC_PUBLICKEY_TYPE);
+    if (ret < 0) {
+        printf("wc_DerToPem error %s (%d)\n", wc_GetErrorString(ret), ret);
+        return -1;
+    }
+    pemSz = ret;
+
+    fp = fopen("./" XSTRINGIFY(TEST_ECC_KEY_CURVE) "pub.pem", "wb");
+    if (!fp) {
+        printf("Error openening %s for write\n",
+            "./" XSTRINGIFY(TEST_ECC_KEY_CURVE) "pub.pem");
+        return -1;
+    }
+    fwrite(pem, pemSz, 1, fp);
+    fclose(fp);
+#endif
+
+    wc_ecc_free(&key);
+    wc_FreeRng(&rng);
+    wolfCrypt_Cleanup();
+
+    return 0;
+}