polarssl rsa & aes 加密与解密

上周折腾加密与解密，用了openssl, crypto++, polarssl, cyassl, 说起真的让人很沮丧，只有openssl & polarssl两个库的RSA & AES 加密和解密，我用起来了，crypto++各种模板，各种多继承，看的头大，而且对各种常用的加密算法也不了解，所以这个库我在折腾了一天之后就放弃了；cyassl这个库现在没什么印象了；openssl没什么好说的，用起来很方便，尤其是使用win32openssl，都不用自己编译，下载下来安装好了就能用，着实方便；但是我是要在移动终端使用RSA & AES，研究了半天怎么只使用openssl的源代码，发现还真是麻烦；总之呢，现在我决定使用polarssl，接口简单易用，而且使用源代码进行编译，都是C文件，肯定是跨平台的了，很小，很精悍，下面帖出使用polarssl实现的RSA & AES加密和解密的过程，便于日后直接使用

  1 #include <stdio.h>
  2 #include <stdlib.h>
  3 #include <assert.h>
  4 #include <string>
  5
  6 #include "polarssl/entropy.h"
  7 #include "polarssl/ctr_drbg.h"
  8 #include "polarssl/rsa.h"
  9 #include "polarssl/aes.h"
 10
 11 const unsigned int RSA_KEY_SIZE = 1024;        // RSA 公钥的位数
 12 const unsigned int AES_KEY_SIZE = 256;
 13 const unsigned int EXPONENT = 65537;
 14 const unsigned int BUFFER_SIZE = 1024;
 15
 16 class rsa
 17 {
 18 public:
 19     rsa()
 20     {
 21         memset(rsa_n, 0, BUFFER_SIZE);
 22         memset(rsa_e, 0, BUFFER_SIZE);
 23         memset(rsa_d, 0, BUFFER_SIZE);
 24         memset(rsa_p, 0, BUFFER_SIZE);
 25         memset(rsa_q, 0, BUFFER_SIZE);
 26         memset(rsa_dp, 0, BUFFER_SIZE);
 27         memset(rsa_dq, 0, BUFFER_SIZE);
 28         memset(rsa_qp, 0, BUFFER_SIZE);
 29     }
 30
 31     unsigned char    rsa_n[BUFFER_SIZE];
 32     unsigned char    rsa_e[BUFFER_SIZE];
 33     unsigned char    rsa_d[BUFFER_SIZE];
 34     unsigned char    rsa_p[BUFFER_SIZE];
 35     unsigned char    rsa_q[BUFFER_SIZE];
 36     unsigned char    rsa_dp[BUFFER_SIZE];
 37     unsigned char    rsa_dq[BUFFER_SIZE];
 38     unsigned char    rsa_qp[BUFFER_SIZE];
 39
 40     unsigned int n_len = BUFFER_SIZE;
 41     unsigned int e_len = BUFFER_SIZE;
 42     unsigned int d_len = BUFFER_SIZE;
 43     unsigned int p_len = BUFFER_SIZE;
 44     unsigned int q_len = BUFFER_SIZE;
 45     unsigned int dp_len = BUFFER_SIZE;
 46     unsigned int dq_len = BUFFER_SIZE;
 47     unsigned int qp_len = BUFFER_SIZE;
 48 };
 49
 50 void generate_rsa(rsa& r)
 51 {
 52     // 生成RSA密钥对
 53     rsa_context    rsa;
 54     entropy_context    entropy;
 55     ctr_drbg_context    ctr_drbg;
 56
 57     entropy_init(&entropy);
 58
 59     assert(ctr_drbg_init(&ctr_drbg, entropy_func, &entropy, nullptr, 0) == 0);
 60
 61     rsa_init(&rsa, RSA_PKCS_V15, 0);
 62
 63     assert(rsa_gen_key(&rsa, ctr_drbg_random, &ctr_drbg, RSA_KEY_SIZE, EXPONENT) == 0);
 64
 65     assert(mpi_write_binary(&rsa.N, r.rsa_n, BUFFER_SIZE) == 0);
 66     assert(mpi_write_binary(&rsa.E, r.rsa_e, BUFFER_SIZE) == 0);
 67     assert(mpi_write_binary(&rsa.D, r.rsa_d, BUFFER_SIZE) == 0);
 68     assert(mpi_write_binary(&rsa.P, r.rsa_p, BUFFER_SIZE) == 0);
 69     assert(mpi_write_binary(&rsa.Q, r.rsa_q, BUFFER_SIZE) == 0);
 70     assert(mpi_write_binary(&rsa.DP, r.rsa_dp, BUFFER_SIZE) == 0);
 71     assert(mpi_write_binary(&rsa.DQ, r.rsa_dq, BUFFER_SIZE) == 0);
 72     assert(mpi_write_binary(&rsa.QP, r.rsa_qp, BUFFER_SIZE) == 0);
 73
 74     //puts(r.rsa_n);
 75     //puts(r.rsa_e);
 76 }
 77
 78 // 加密
 79 void encrypt(
 80     const rsa &r,
 81     const unsigned char* plaintext,
 82     unsigned int plaintext_size,
 83     unsigned char *ciphertext,
 84     unsigned int &ciphertext_size)
 85 {
 86     rsa_context            rsa;
 87     entropy_context        entropy;
 88     ctr_drbg_context    ctr_drbg;
 89
 90     entropy_init(&entropy);
 91     assert(ctr_drbg_init(&ctr_drbg, entropy_func, &entropy, nullptr, 0) == 0);
 92
 93     rsa_init(&rsa, RSA_PKCS_V15, 0);
 94
 95     assert(mpi_read_binary(&rsa.N, r.rsa_n, BUFFER_SIZE) == 0);
 96     assert(mpi_read_binary(&rsa.E, r.rsa_e, BUFFER_SIZE) == 0);
 97
 98     rsa.len = (mpi_msb(&rsa.N) + 7) >> 3;
 99
100     assert(rsa_pkcs1_encrypt(&rsa, ctr_drbg_random, &ctr_drbg, RSA_PUBLIC, plaintext_size, plaintext, ciphertext) == 0);
101 }
102
103 // 解密
104 void decrypt(
105     const rsa &r,
106     const unsigned char* ciphertext,
107     unsigned int ciphertext_size,
108     unsigned char *plaintext,
109     unsigned int &plaintext_size)
110 {
111     rsa_context            rsa;
112     entropy_context        entropy;
113     ctr_drbg_context    ctr_drbg;
114
115     entropy_init(&entropy);
116     assert(ctr_drbg_init(&ctr_drbg, entropy_func, &entropy, nullptr, 0) == 0);
117
118     rsa_init(&rsa, RSA_PKCS_V15, 0);
119
120     assert(mpi_read_binary(&rsa.N, r.rsa_n, BUFFER_SIZE) == 0);
121     assert(mpi_read_binary(&rsa.E, r.rsa_e, BUFFER_SIZE) == 0);
122     assert(mpi_read_binary(&rsa.D, r.rsa_d, BUFFER_SIZE) == 0);
123     assert(mpi_read_binary(&rsa.P, r.rsa_p, BUFFER_SIZE) == 0);
124     assert(mpi_read_binary(&rsa.Q, r.rsa_q, BUFFER_SIZE) == 0);
125     assert(mpi_read_binary(&rsa.DP, r.rsa_dp, BUFFER_SIZE) == 0);
126     assert(mpi_read_binary(&rsa.DQ, r.rsa_dq, BUFFER_SIZE) == 0);
127     assert(mpi_read_binary(&rsa.QP, r.rsa_qp, BUFFER_SIZE) == 0);
128
129     rsa.len = (mpi_msb(&rsa.N) + 7) >> 3;
130
131     assert(rsa_pkcs1_decrypt(&rsa, ctr_drbg_random, &ctr_drbg, RSA_PRIVATE, &plaintext_size, ciphertext, plaintext, plaintext_size) == 0);
132 }
133
134 void test_aes()
135 {
136     // 产生随机的AES key buffer
137     ctr_drbg_context ctr_drbg;
138     entropy_context entropy;
139     unsigned char aes_key_buf[AES_KEY_SIZE] = { 0 };
140
141     entropy_init(&entropy);
142     assert(ctr_drbg_init(&ctr_drbg, entropy_func, &entropy, nullptr, 0) == 0);
143     ctr_drbg_set_prediction_resistance(&ctr_drbg, CTR_DRBG_PR_OFF);
144     ctr_drbg_random(&ctr_drbg, aes_key_buf, AES_KEY_SIZE);
145
146     // 生成AES
147     aes_context    aes_enc, aes_dec;
148     aes_init(&aes_enc);
149     aes_init(&aes_dec);
150
151     assert(aes_setkey_enc(&aes_enc, aes_key_buf, AES_KEY_SIZE) == 0);
152     assert(aes_setkey_dec(&aes_dec, aes_key_buf, AES_KEY_SIZE) == 0);
153
154     // 加密 & 解密. 明文与密文的长度是固定的， 都是16bytes
155     /*
156     const unsigned int DATA_SIZE = 16;
157     unsigned char plaintext[DATA_SIZE] = { 0 };
158     unsigned char ciphertext[DATA_SIZE] = { 0 };
159     sprintf((char*)plaintext, "%s", "moyakukudi");
160
161     assert(aes_crypt_ecb(&aes_enc, AES_ENCRYPT, plaintext, ciphertext) == 0);
162     memset(plaintext, 0, DATA_SIZE);
163     assert(aes_crypt_ecb(&aes_dec, AES_DECRYPT, ciphertext, plaintext) == 0);
164     */
165
166     // 加密 & 解密. 明文与密文的长度是不固定的, 但必须是16bytes的倍数
167     const unsigned int DATA_SIZE = 1024;
168     unsigned char plaintext[DATA_SIZE] = { 0 };
169     unsigned char ciphertext[DATA_SIZE] = { 0 };
170     sprintf((char*)plaintext, "%s", "return 0 if successful, or POLARSSL_ERR_AES_INVALID_INPUT_LENGTH, assert(aes_crypt_ecb(&aes_dec, AES_DECRYPT, ciphertext, plaintext) == 0);");
171
172     const unsigned int IV_SIZE = 16;
173     unsigned char iv[IV_SIZE] = { 0 };
174     //unsigned char iv2[IV_SIZE] = { 0 };
175     //ctr_drbg_random(&ctr_drbg, iv, IV_SIZE);
176     //strcpy((char*)iv2, (const char*)iv);
177
178     assert(aes_crypt_cbc(&aes_enc, AES_ENCRYPT, DATA_SIZE, iv, plaintext, ciphertext) == 0);
179     memset(plaintext, 0, DATA_SIZE);
180     memset(iv, 0, IV_SIZE);
181     assert(aes_crypt_cbc(&aes_dec, AES_DECRYPT, DATA_SIZE, iv, ciphertext, plaintext) == 0);
182
183     puts("over");
184 }
185
186 int main()
187 {
188     goto    AES;
189
190     // RSA
191 RSA:
192     rsa    r;
193     generate_rsa(r);
194
195     unsigned char    plaintext[] = "moyakukudi";
196     unsigned char    ciphertext[BUFFER_SIZE] = { 0 };
197     unsigned int    ciphertext_len = BUFFER_SIZE;
198     encrypt(r, plaintext, sizeof(plaintext), ciphertext, ciphertext_len);
199
200     unsigned char    output[BUFFER_SIZE] = { 0 };
201     unsigned int    output_len = BUFFER_SIZE;
202     decrypt(r, ciphertext, ciphertext_len, output, output_len);
203
204     // AES
205 AES:
206
207     test_aes();
208
209     system("pause");
210     return 0;
211 }