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; int bits=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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