openssl.net rsa encryption working example needed

Question

Hi,

Does anybody have any working example of RSA encryption with OpenSSL.NET ? I want to encrypt some data using private key stored in PEM format.

I create a OpenSSL.Crypto.RSA object and want to use the PrivateEncrypt method, but it throws OpenSSLException with no additional data (empty Errors array, no inner exception). Before using the PrivateEncrypt method I fill all the properties (like PublicModulus, PrivateExponent etc) with data read from command openssl rsa -in private_key.pem -text -noout

Does anybody know how to read the PEM file into OpenSSL.Crypto.RSA object or has any other working encryption example?

Answer 1

This is C/C++ on linux but I found no simple examples like this until I painfully got this to work

Generate key command line

openssl genrsa -out privkey.pem 2048

HelloWord.cpp

include

include

include

int main() { char message = "Hello World"; unsigned char encrypted = (unsigned char ) malloc(500); unsigned char decrypted = (unsigned char *) malloc(500); int bufSize;

    FILE *keyfile = fopen("privkey.pem", "r");
    RSA *rsa = PEM_read_RSAPrivateKey(keyfile, NULL, NULL, NULL);
    printf("\n\nStarting Message = %s\n", message);
    if (rsa == NULL)
    {
            printf("Badness has occured! Did not read key file\n");
            return 0;
    }
    else
    {
            printf("Opened the key file OK!\n");
    }

    bufSize = RSA_public_encrypt(strlen(message), (unsigned char *) message, encrypted, rsa, RSA_PKCS1_PADDING);
    if (bufSize == -1)
    {
            printf("Badness has occured! encryption failed\n");
            RSA_free(rsa);
            return 0;
    }
    else
    {
            printf("Encrypted the message OK! = \n%s\n", encrypted );
    }

    if (RSA_private_decrypt(bufSize, encrypted, decrypted, rsa, RSA_PKCS1_PADDING) != -1)
    {
            printf("\nMessage decrypted to : %s\n", decrypted);
    }
    else
    {
            printf("Badness has occured! decryption failed\n");
            RSA_free(rsa);
            return 0;
    }

    RSA_free(rsa);
    return 1;

}

Makefile

-----------------------------------------------------------------------------

#

File : global.make

Date : 09/03/2009

Author : Tom Nortillo

#

Description: universal make definitions for development area

#

-----------------------------------------------------------------------------

----------------------------------

GENERAL

----------------------------------

CPP=g++ BASE=/home/joneil001/RSAEncryption CPPFLAGS = -c -fPIC LDFLAGS = -static BIN = ${BASE}

===================================================================

#

THIRD-PARTY LIBRARIES

#

===================================================================

-------------------

ORACLE

-------------------

ORALIB= -L${ORACLE_LIB} -lclntsh ORAINC= -I${ORACLE_HOME}/precomp/public -I${ORACLE_HOME}/rdbms/public

PROC=${ORACLE_BIN}/proc ORAEXT = -DORACA_STORAGE_CLASS=extern -DSQLCA_STORAGE_CLASS=extern

-------------------

LIBXML

-------------------

XML_INC = -I${BASE}/lib_xml/include/libxml2 XML_LIB = -L${BASE}/lib_xml/lib -lxml2

--------------------------------

GOOGLE PROTOCOL BUFFERS

--------------------------------

GOOGLE_INC = -I${BASE}/lib_google/include GOOGLE_LIB = -L${BASE}/lib_google/lib -lprotobuf GOOGLE_BIN = ${BASE}/lib_google/bin

==============================================

#

OpenSSL

#

=============================================

OPENSSL_LIB = -L/usr/lib64 -lcrypto -L/usr/lib64/openssl/engines -laep -lcswift -lchil -l4758cca -lgmp -lubsec -lsureware -lnuron -latalla

===================================================================

#

BUILD COMMAND-LINES

#

===================================================================

--------------------

LIBRARIES

--------------------

LIBLIST = -L${BASE}/lib \ ${OPENSSL_LIB}

Repeated twice because of library inter-dependencies

LIBS = ${LIBLIST} ${LIBLIST}

--------------------

INCLUDES

--------------------

LOCAL_INC = -I.

INCLUDE = ${LOCAL_INC} ${ORAINC}

===================================================================

#

RULES

#

===================================================================

.SUFFIXES: .cpp .SUFFIXES: .cc $(SUFFIXES) .SUFFIXES: .pc $(SUFFIXES) .SUFFIXES: .proto $(SUFFIXES)

.cpp.o: ${CPP} ${CPPFLAGS} ${INCLUDE} $<

.cc.o: ${CPP} ${CPPFLAGS} ${INCLUDE} $<

.pc.o: ${PROC} SYS_INCLUDE=/usr/include include=${ORAINC} code=CPP cpp_suffix=cpp parse=NONE dbms=v8 iname=$< oname=$(*F).cpp lname=$(F).lis ${CPP} ${CPPFLAGS} ${INCLUDE} ${ORAINC} ${ORAEXT} $.cpp rm -f $.cpp rm -f $.lis rm -f tp*

.proto.o: ${GOOGLE_BIN}/protoc --cpp_out=. $< ${CPP} ${CPPFLAGS} ${INCLUDE} ${ORAINC} ${ORAEXT} $*.pb.cc

===================================================================

#

TARGETS

#

===================================================================

TARGET=doit

OBJECTS = HelloWorld.o

all: ${OBJECTS} ${CPP} ${INCLUDE} -o ${BIN}/${TARGET} ${OBJECTS} ${LIBS}

clean: touch HelloWorld.o; rm *.o