linux C实现MD5withRSA签名

#include "RSA.h" /* 对二进制数据进行base64编码 */ /* input:数组，length：数组长度,result:存储编码后的数据，size：数组大小 */ unsigned char *base64(const void *input, size_t length,char *result, size_t size) { BIO *bmem, *b64; BUF_MEM *bptr; b64 = BIO_new(BIO_f_base64()); bmem = BIO_new(BIO_s_mem()); b64 = BIO_push(b64, bmem); BIO_write(b64, input, length); BIO_flush(b64); BIO_get_mem_ptr(b64, &bptr); if(size < bptr->length-1) { printf("the size is so small\n"); return NULL; } memcpy(result, bptr->data, bptr->length-1); result[bptr->length-1] = 0; BIO_free_all(b64); return result; } /* 对base64数据进行解码 */ /* input：待解码数组，length：数组长度，result：解码后数据暂存区，暂存区大小 */ unsigned char *debase64(char *input, size_t length, char *result, size_t size) { BIO * b64 = NULL; BIO * bmem = NULL; assert(NULL != input); if (length > size) return NULL; memset(result, 0, size); b64 = BIO_new(BIO_f_base64()); bmem = BIO_new_mem_buf(input, length); BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL); if (NULL == b64 || NULL == bmem) { perror("BIO_new"); return NULL; } bmem = BIO_push(b64, bmem); BIO_read(bmem, result, length); BIO_free_all(b64); return result; } /* 生成签名函数 */ /* 1:私钥名，2：待签名的数据，3：签名后的数据存储区，4：传入指针 */ unsigned char * GetSign(char* keyFile,char* plainText,unsigned char* cipherText,unsigned int *cipherTextLen) { FILE* fp = fopen (keyFile, "r"); if (fp == NULL) return NULL; /* Read private key */ EVP_PKEY* pkey = PEM_read_PrivateKey(fp, NULL, NULL, NULL); fclose (fp); if (pkey == NULL) { ERR_print_errors_fp (stderr); return NULL; } /* Do the signature */ EVP_MD_CTX md_ctx; EVP_SignInit (&md_ctx, EVP_md5()); EVP_SignUpdate (&md_ctx, plainText, strlen(plainText)); int err = EVP_SignFinal (&md_ctx, cipherText, cipherTextLen, pkey); if (err != 1) { ERR_print_errors_fp(stderr); return NULL; } EVP_PKEY_free(pkey); return cipherText; } /* 验证签名函数 */ /* 1:公钥名，2：签名的数据，3：签名的数据大小，4：原数据 */ bool VerifySign(char* certFile,unsigned char* cipherText,unsigned int cipherTextLen,char* plainText) { FILE* fp = fopen(certFile, "r"); if (fp == NULL) return false; EVP_PKEY *pkey=PEM_read_PUBKEY(fp,NULL,NULL,NULL); if (pkey == NULL) { printf("pkey fail\n"); ERR_print_errors_fp (stderr); return false; } EVP_MD_CTX md_ctx; EVP_VerifyInit (&md_ctx, EVP_md5()); EVP_VerifyUpdate (&md_ctx, plainText, strlen((char*)plainText)); int err = EVP_VerifyFinal (&md_ctx, cipherText, cipherTextLen, pkey); EVP_PKEY_free (pkey); if (err != 1) { ERR_print_errors_fp (stderr); return false; } fclose(fp); return true; }