openssl rsa 加解密代码片段

在RSA使用过程中，公钥加密一般用来协商密钥；私钥加密一般用来签名。

 

 

 

Ø n：模数

Ø e：公钥指数

Ø d：私钥指数

 

n+e可以组成公钥

 

n+d可以组成私钥

 

代码包括

1。生成RSA的数据结构

2。用指定的n,e,d生成RSA的数据结构

3。用私钥加密

4。用公钥解密

5。SHA256报文摘要

 #include <stdio.h>#include <stdlib.h>#include <string.h>#include <openssl/sha.h>#include <openssl/rsa.h>void testRSAGen(){RSA*r;intbits=512,ret;unsigned long e=RSA_3;BIGNUM*bne;r=RSA_generate_key(bits,e,NULL,NULL);RSA_print_fp(stdout,r,11);printf("--------------------------------/n");RSA_free(r);bne=BN_new();ret=BN_set_word(bne,e);r=RSA_new();ret=RSA_generate_key_ex(r,bits,bne,NULL);if(ret!=1){printf("RSA_generate_key_ex err!/n");return -1;}//RSA_print_fp(stdout,r,11);RSA_free(r);}void testRSA(){RSA *r;BIGNUM *bne,*bnn,*bnd;int bits = 1024, ret, len, flen, padding, i;unsigned char *key, *p;BIO *b;//要加密的明文unsigned char *in = "abcef";unsigned char *encData,*decData,*tmpData;//加密后的数据/解密后的数据/临时指针//使用的密匙数据unsigned long e = 75011;const char *MODULUS="9EC7D9A2DC5B095F8E5F90295121F41262FAEFBE9AF57B772A71F1F9D9635F8769CB78DA2BCFE9B27FC1F3AD4A3D178F8C61981225EF5DEACBDC5665F12E691AA13DDD321A59CFCF376F002036612FF3C5E057A3007FF675AFA3EDE34DC23A1A2637294870EBE823F76B5CE21E25F3FA5137F5DE12437DE0118245B927B28221";const char *PRIVATE="8B26E30ECA6E8F3668F6FA78B0C55FB75A4A3FAD0667B152933A4991D7A815D1498F5E1EF44ACEF6CDF252E56F367DED5BA024DF6B267B7E36BD35552DFA0A4CC1E9D0A4BC8E7C76F98D4971441D6693745A0A76E175571BD160E4B1536A6EFF5A08EDA45236E96E7A4748CF4D031CA8B2F4CCE9F2E1286F432DE6495A535E43";//构建RSA数据结构bne = BN_new();bnd = BN_new();bnn = BN_new();ret = BN_set_word(bne, e);BN_hex2bn(&bnd, PRIVATE);BN_hex2bn(&bnn, MODULUS);r = RSA_new();r->e=bne;r->d=bnd;r->n=bnn;RSA_print_fp(stdout, r, 5);//准备输出的加密数据结构flen = RSA_size(r);// - 11;encData = (unsigned char *)malloc(flen);bzero(encData, flen);//memset(encData, 0, flen);printf("Begin RSA_private_encrypt .../n");ret = RSA_private_encrypt(flen, in, encData, r, RSA_NO_PADDING);if(ret < 0){printf("Encrypt failed!/n");return;}printf("Size:%d/n", ret);printf("ClearText:%s/n", in);printf("CipherText(Hex):/n");tmpData=encData;for (i=0; i<ret; i++){printf("0x%02x, ", *tmpData);tmpData++;}printf("end private encrypt /n");printf("------------------------/n");//准备输出的解密数据结构flen = RSA_size(r);// - 11;decData = (unsigned char *)malloc(flen);bzero(decData, flen);//memset(encData, 0, flen);printf("Begin RSA_public_decrypt .../n");ret = RSA_public_decrypt(flen, encData, decData, r, RSA_NO_PADDING);if(ret < 0){printf("RSA_public_decrypt failed!/n");return;}printf("Size:%d/n", ret);printf("ClearText:%s/n", decData);free(encData);free(decData);RSA_free(r);}void testSHA256(){unsigned char in[]="asdfwerqrewrasfaser";unsigned char out[32];size_t n;int i;n=strlen((const char*)in);SHA256(in,n,out);printf("/n/nSHA256 digest result:/n");printf("%d/n",sizeof(out));for(i=0;i<32;i++)printf("%d",out[i]);printf("/n");}int main(void) {puts("!!!Hello World!!!"); /* prints !!!Hello World!!! */testSHA256();testRSA();return EXIT_SUCCESS;}

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