RSA编程实验——使用libTomCrypt库

#include "stdlib.h" #include "stdio.h" #define LTM_DESC #include <tomcrypt.h> int main(void) { int err, hash_idx, prng_idx, res,padding,inpadding; unsigned long l1, l2; unsigned char pt[17], pt2[17], out[1024],out2[1024],out3[1024]; rsa_key key; printf("\t\t\t**************************\n"); printf(" \t\t\tRSA加解密算法"); printf("\n\t\t\t**************************\n"); printf("请输入明文s(16字节):\n"); scanf("%s",&pt); printf("选择加密机制：1---RSAES-PKCS1-V1_5 2---RSAES_OAEP\n"); scanf("%d",&inpadding); if(inpadding ==1 ) padding = LTC_LTC_PKCS_1_V1_5; else padding = LTC_LTC_PKCS_1_OAEP; /* register prng/hash */ if (register_prng(&sprng_desc) == -1) { printf("Error registering sprng"); return EXIT_FAILURE; } /* register a math library (in this case TomsFastMath)*/ ltc_mp = ltm_desc; if (register_hash(&sha1_desc) == -1) { printf("Error registering sha1"); return EXIT_FAILURE; } hash_idx = find_hash("sha1"); prng_idx = find_prng("sprng"); /* make an RSA-1024 key */ if ((err = rsa_make_key(NULL, /* PRNG state */ prng_idx, /* PRNG idx */ 1024/8, /* 1024-bit key */ 65537, /* we like e=65537 */ &key) /* where to store the key */ ) != CRYPT_OK) { printf("rsa_make_key %s", error_to_string(err)); return EXIT_FAILURE; } /* fill in pt[] with a key we want to send ... */ l1 = sizeof(out); if ((err = rsa_encrypt_key_ex(pt, /* data we wish to encrypt */ 16, /* data is 16 bytes long */ out, /* where to store ciphertext */ &l1, /* length of ciphertext */ (unsigned char*)"TestApp", /* our lparam for this program */ 7, /* lparam is 7 bytes long */ NULL, /* PRNG state */ prng_idx, /* prng idx */ hash_idx, /* hash idx */ padding, &key) /* our RSA key */ ) != CRYPT_OK) { printf("rsa_encrypt_key %s", error_to_string(err)); return EXIT_FAILURE; } printf("\n加密后的密文S1:"); for(int i=0;i<=127;i++) printf("%02x",out[i]); printf("\n"); /* now let’s decrypt the encrypted key */ l2 = sizeof(pt2); if ((err = rsa_decrypt_key_ex(out, /* encrypted data */ l1, /* length of ciphertext */ pt2, /* where to put plaintext */ &l2, /* plaintext length */ (unsigned char*)"TestApp", /* lparam for this program */ 7, /* lparam is 7 bytes long */ hash_idx, /* hash idx */ padding, &res, /* validity of data */ &key) /* our RSA key */ ) != CRYPT_OK) { printf("rsa_decrypt_key %s", error_to_string(err)); return EXIT_FAILURE; } printf("将S1解密后的明文：%s\n",pt2); int m=0; for(int i=0;i<16;i++) { if(pt[i]!=pt2[i]) { printf("解密结果与原明文不同\n"); break; } else m++; } if(m==16) printf("经比较得知：解密结果与原明文相同\n"); if ((err = rsa_encrypt_key_ex(pt, /* data we wish to encrypt */ 16, /* data is 16 bytes long */ out2, /* where to store ciphertext */ &l1, /* length of ciphertext */ (unsigned char*)"TestApp", /* our lparam for this program */ 7, /* lparam is 7 bytes long */ NULL, /* PRNG state */ prng_idx, /* prng idx */ hash_idx, /* hash idx */ padding, &key) /* our RSA key */ ) != CRYPT_OK) { printf("rsa_encrypt_key %s", error_to_string(err)); return EXIT_FAILURE; } printf("\n用相同密钥对同一个明文加密后的密文S2:"); for(int i=0;i<=127;i++) printf("%02x",out2[i]); printf("\n"); l2 = sizeof(pt2); if ((err = rsa_decrypt_key_ex(out2, /* encrypted data */ l1, /* length of ciphertext */ pt2, /* where to put plaintext */ &l2, /* plaintext length */ (unsigned char*)"TestApp", /* lparam for this program */ 7, /* lparam is 7 bytes long */ hash_idx, /* hash idx */ padding, &res, /* validity of data */ &key) /* our RSA key */ ) != CRYPT_OK) { printf("rsa_decrypt_key %s", error_to_string(err)); return EXIT_FAILURE; } printf("将S2解密后的明文：%s\n",pt2); if ((err = rsa_encrypt_key_ex(pt, /* data we wish to encrypt */ 16, /* data is 16 bytes long */ out3, /* where to store ciphertext */ &l1, /* length of ciphertext */ (unsigned char*)"TestApp", /* our lparam for this program */ 7, /* lparam is 7 bytes long */ NULL, /* PRNG state */ prng_idx, /* prng idx */ hash_idx, /* hash idx */ padding, &key) /* our RSA key */ ) != CRYPT_OK) { printf("rsa_encrypt_key %s", error_to_string(err)); return EXIT_FAILURE; } printf("\n用相同密钥对同一个明文加密后的密文S3:"); for(int i=0;i<=127;i++) printf("%02x",out3[i]); printf("\n"); l2 = sizeof(pt2); if ((err = rsa_decrypt_key_ex(out3, /* encrypted data */ l1, /* length of ciphertext */ pt2, /* where to put plaintext */ &l2, /* plaintext length */ (unsigned char*)"TestApp", /* lparam for this program */ 7, /* lparam is 7 bytes long */ hash_idx, /* hash idx */ padding, &res, /* validity of data */ &key) /* our RSA key */ ) != CRYPT_OK) { printf("rsa_decrypt_key %s", error_to_string(err)); return EXIT_FAILURE; } printf("将S3解密后的明文：%s\n",pt2); /* if all went well pt == pt2, l2 == 16, res == 1 */ system("pause"); }