xref: /freebsd/crypto/openssl/crypto/evp/evp_key.c (revision b077aed33b7b6aefca7b17ddb250cf521f938613)
1 /*
2  * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include <stdio.h>
11 #include "internal/cryptlib.h"
12 #include <openssl/x509.h>
13 #include <openssl/objects.h>
14 #include <openssl/evp.h>
15 #include <openssl/ui.h>
16 
17 #ifndef BUFSIZ
18 # define BUFSIZ 256
19 #endif
20 
21 /* should be init to zeros. */
22 static char prompt_string[80];
23 
EVP_set_pw_prompt(const char * prompt)24 void EVP_set_pw_prompt(const char *prompt)
25 {
26     if (prompt == NULL)
27         prompt_string[0] = '\0';
28     else {
29         strncpy(prompt_string, prompt, 79);
30         prompt_string[79] = '\0';
31     }
32 }
33 
EVP_get_pw_prompt(void)34 char *EVP_get_pw_prompt(void)
35 {
36     if (prompt_string[0] == '\0')
37         return NULL;
38     else
39         return prompt_string;
40 }
41 
42 /*
43  * For historical reasons, the standard function for reading passwords is in
44  * the DES library -- if someone ever wants to disable DES, this function
45  * will fail
46  */
EVP_read_pw_string(char * buf,int len,const char * prompt,int verify)47 int EVP_read_pw_string(char *buf, int len, const char *prompt, int verify)
48 {
49     return EVP_read_pw_string_min(buf, 0, len, prompt, verify);
50 }
51 
EVP_read_pw_string_min(char * buf,int min,int len,const char * prompt,int verify)52 int EVP_read_pw_string_min(char *buf, int min, int len, const char *prompt,
53                            int verify)
54 {
55     int ret = -1;
56     char buff[BUFSIZ];
57     UI *ui;
58 
59     if ((prompt == NULL) && (prompt_string[0] != '\0'))
60         prompt = prompt_string;
61     ui = UI_new();
62     if (ui == NULL)
63         return ret;
64     if (UI_add_input_string(ui, prompt, 0, buf, min,
65                             (len >= BUFSIZ) ? BUFSIZ - 1 : len) < 0
66         || (verify
67             && UI_add_verify_string(ui, prompt, 0, buff, min,
68                                     (len >= BUFSIZ) ? BUFSIZ - 1 : len,
69                                     buf) < 0))
70         goto end;
71     ret = UI_process(ui);
72     OPENSSL_cleanse(buff, BUFSIZ);
73  end:
74     UI_free(ui);
75     return ret;
76 }
77 
EVP_BytesToKey(const EVP_CIPHER * type,const EVP_MD * md,const unsigned char * salt,const unsigned char * data,int datal,int count,unsigned char * key,unsigned char * iv)78 int EVP_BytesToKey(const EVP_CIPHER *type, const EVP_MD *md,
79                    const unsigned char *salt, const unsigned char *data,
80                    int datal, int count, unsigned char *key,
81                    unsigned char *iv)
82 {
83     EVP_MD_CTX *c;
84     unsigned char md_buf[EVP_MAX_MD_SIZE];
85     int niv, nkey, addmd = 0;
86     unsigned int mds = 0, i;
87     int rv = 0;
88     nkey = EVP_CIPHER_get_key_length(type);
89     niv = EVP_CIPHER_get_iv_length(type);
90     OPENSSL_assert(nkey <= EVP_MAX_KEY_LENGTH);
91     OPENSSL_assert(niv <= EVP_MAX_IV_LENGTH);
92 
93     if (data == NULL)
94         return nkey;
95 
96     c = EVP_MD_CTX_new();
97     if (c == NULL)
98         goto err;
99     for (;;) {
100         if (!EVP_DigestInit_ex(c, md, NULL))
101             goto err;
102         if (addmd++)
103             if (!EVP_DigestUpdate(c, &(md_buf[0]), mds))
104                 goto err;
105         if (!EVP_DigestUpdate(c, data, datal))
106             goto err;
107         if (salt != NULL)
108             if (!EVP_DigestUpdate(c, salt, PKCS5_SALT_LEN))
109                 goto err;
110         if (!EVP_DigestFinal_ex(c, &(md_buf[0]), &mds))
111             goto err;
112 
113         for (i = 1; i < (unsigned int)count; i++) {
114             if (!EVP_DigestInit_ex(c, md, NULL))
115                 goto err;
116             if (!EVP_DigestUpdate(c, &(md_buf[0]), mds))
117                 goto err;
118             if (!EVP_DigestFinal_ex(c, &(md_buf[0]), &mds))
119                 goto err;
120         }
121         i = 0;
122         if (nkey) {
123             for (;;) {
124                 if (nkey == 0)
125                     break;
126                 if (i == mds)
127                     break;
128                 if (key != NULL)
129                     *(key++) = md_buf[i];
130                 nkey--;
131                 i++;
132             }
133         }
134         if (niv && (i != mds)) {
135             for (;;) {
136                 if (niv == 0)
137                     break;
138                 if (i == mds)
139                     break;
140                 if (iv != NULL)
141                     *(iv++) = md_buf[i];
142                 niv--;
143                 i++;
144             }
145         }
146         if ((nkey == 0) && (niv == 0))
147             break;
148     }
149     rv = EVP_CIPHER_get_key_length(type);
150  err:
151     EVP_MD_CTX_free(c);
152     OPENSSL_cleanse(md_buf, sizeof(md_buf));
153     return rv;
154 }
155