Detached encrypt/decrypt example, fix decrypt sample.

demos/cms/cms_ddec.c

@@ -0,0 +1,89 @@
+/* S/MIME detached data decrypt example: rarely done but
+ * should the need arise this is an example....
+ */
+#include <openssl/pem.h>
+#include <openssl/cms.h>
+#include <openssl/err.h>
+
+int main(int argc, char **argv)
+	{
+	BIO *in = NULL, *out = NULL, *tbio = NULL, *dcont = NULL;
+	X509 *rcert = NULL;
+	EVP_PKEY *rkey = NULL;
+	CMS_ContentInfo *cms = NULL;
+	int ret = 1;
+
+	OpenSSL_add_all_algorithms();
+	ERR_load_crypto_strings();
+
+	/* Read in recipient certificate and private key */
+	tbio = BIO_new_file("signer.pem", "r");
+
+	if (!tbio)
+		goto err;
+
+	rcert = PEM_read_bio_X509(tbio, NULL, 0, NULL);
+
+	BIO_reset(tbio);
+
+	rkey = PEM_read_bio_PrivateKey(tbio, NULL, 0, NULL);
+
+	if (!rcert || !rkey)
+		goto err;
+
+	/* Open PEM file containing enveloped data */
+
+	in = BIO_new_file("smencr.pem", "r");
+
+	if (!in)
+		goto err;
+
+	/* Parse PEM content */
+	cms = PEM_read_bio_CMS(in, NULL, 0, NULL);
+
+	if (!cms)
+		goto err;
+
+	/* Open file containing detached content */
+	dcont = BIO_new_file("smencr.out", "rb");
+
+	if (!in)
+		goto err;
+
+	out = BIO_new_file("encrout.txt", "w");
+	if (!out)
+		goto err;
+
+	/* Decrypt S/MIME message */
+	if (!CMS_decrypt(cms, rkey, rcert, dcont, out, 0))
+		goto err;
+
+	ret = 0;
+
+	err:
+
+	if (ret)
+		{
+		fprintf(stderr, "Error Decrypting Data\n");
+		ERR_print_errors_fp(stderr);
+		}
+
+	if (cms)
+		CMS_ContentInfo_free(cms);
+	if (rcert)
+		X509_free(rcert);
+	if (rkey)
+		EVP_PKEY_free(rkey);
+
+	if (in)
+		BIO_free(in);
+	if (out)
+		BIO_free(out);
+	if (tbio)
+		BIO_free(tbio);
+	if (dcont)
+		BIO_free(dcont);
+
+	return ret;
+
+	}