imapfilter/imapfilter/passwd.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <limits.h>

#include "config.h"
#include "imapfilter.h"
#include "data.h"

#ifdef ENCRYPTED_PASSWORDS
#include <openssl/evp.h>
#endif


extern unsigned int flags;
extern account_t *accounts;

#ifdef ENCRYPTED_PASSWORDS
extern char *passphr;
#endif

/*
 * Get password from user interactively.
 */
void get_password(char *passwd, size_t pwlen)
{
    char *c;

    tty_disable_echo();
    
    if (fgets(passwd, pwlen, stdin))
        if ((c = strchr(passwd, '\n')))
            *c = 0;

    tty_restore();

    putchar('\n');
}


#ifdef ENCRYPTED_PASSWORDS
/*
 * Encrypt and Base64 encode passwords.  Append the MD5 checksum of the passwords
 * before encrypting them.
 */
int encrypt_passwords(FILE *fd, account_t *accts[])
{
    int i;    
    char *c;
    unsigned char iv[EVP_MAX_IV_LENGTH];
    unsigned char *key;
    unsigned char buf[ENCRYPTION_BUF];
    unsigned char ebuf[ENCRYPTION_BUF];
    unsigned char bbuf[ENCRYPTION_BUF];
    unsigned char mdv[EVP_MAX_MD_SIZE];
    int mdl, ebufl, bbufl;
    EVP_CIPHER_CTX ctx;
    EVP_MD_CTX mdctx;
    EVP_ENCODE_CTX bctx;
    
    key = (unsigned char *) smalloc(EVP_MAX_KEY_LENGTH);

    srandom(time(NULL));

    c = ultostr(1 + random() % 100000000, 10);
    memset(iv, '0', EVP_MAX_IV_LENGTH);
    memcpy(iv + 8 - strlen(c), c, min(8, strlen(c)));

    fprintf(fd, "%.8s\n", iv);

    EVP_CIPHER_CTX_init(&ctx);

    EVP_BytesToKey(EVP_bf_cbc(), EVP_md5(), NULL, passphr, strlen(passphr), 1,
                   key, NULL);
        
    EVP_DigestInit(&mdctx, EVP_md5());
    EVP_EncryptInit(&ctx, EVP_bf_cbc(), key, iv);
    EVP_EncodeInit(&bctx);

    for (i = 0; accts[i]; i++) {
        snprintf(buf, ENCRYPTION_BUF, "%s %s %s\n", accts[i]->server, accts[i]->username,
                 accts[i]->password);

        EVP_DigestUpdate(&mdctx, buf, strlen(buf));
        EVP_EncryptUpdate(&ctx, ebuf, &ebufl, buf, strlen(buf));
        EVP_EncodeUpdate(&bctx, bbuf, &bbufl, ebuf, ebufl);

        fwrite(bbuf, sizeof(char), bbufl, fd);
    }

    EVP_DigestFinal(&mdctx, mdv, &mdl);
    
    xstrncpy(buf, ".\n", ENCRYPTION_BUF - 1);
    
    for (i = 0; i < mdl; i++)
        snprintf(2 + buf + i * 2, ENCRYPTION_BUF - i * 2, "%02x", mdv[i]);
    
    EVP_EncryptUpdate(&ctx, ebuf, &ebufl, buf, strlen(buf));
    EVP_EncodeUpdate(&bctx, bbuf, &bbufl, ebuf, ebufl);
    fwrite(bbuf, sizeof(char), bbufl, fd);

    EVP_EncryptFinal(&ctx, ebuf, &ebufl);
    EVP_EncodeUpdate(&bctx, bbuf, &bbufl, ebuf, ebufl);
    EVP_EncodeFinal(&bctx, bbuf, &bbufl);
    
    fwrite(bbuf, sizeof(char), bbufl, fd);

    EVP_CIPHER_CTX_cleanup(&ctx);
    
    return 0;
}


/*
 * Decode (Base64) passwords, decrypt them and verify the MD5 checksum.
 */
int decrypt_passwords(unsigned char **buf, FILE *fd)
{
    int i, j = 1;
    unsigned char iv[EVP_MAX_IV_LENGTH];
    unsigned char *key;
    unsigned char *c;
    unsigned char ebuf[LINE_MAX];
    unsigned char bbuf[LINE_MAX];
    unsigned char mdv[EVP_MAX_MD_SIZE];
    unsigned char mdc[EVP_MAX_MD_SIZE * 2 + 1];
    int mdl, bufl, ebufl;
    EVP_CIPHER_CTX *ctx;
    EVP_MD_CTX mdctx;
    EVP_ENCODE_CTX bctx;
    
    c = *buf = (unsigned char *) smalloc(DECRYPTION_BUF * sizeof(char));    
    key = (unsigned char *) smalloc(EVP_MAX_KEY_LENGTH);
    ctx = (EVP_CIPHER_CTX *) smalloc(sizeof(EVP_CIPHER_CTX));
    
    fgets(bbuf, LINE_MAX, fd);

    memcpy(iv, bbuf, EVP_MAX_IV_LENGTH);

    EVP_CIPHER_CTX_init(ctx);

    EVP_BytesToKey(EVP_bf_cbc(), EVP_md5(), NULL, passphr, strlen(passphr),
                   1, key, NULL);
    
    EVP_DecryptInit(ctx, EVP_bf_cbc(), key, iv);
    EVP_DecodeInit(&bctx);

    while (fgets(bbuf, LINE_MAX, fd)) {
        EVP_DecodeUpdate(&bctx, ebuf, &ebufl, bbuf, strlen(bbuf));
        if (!EVP_DecryptUpdate(ctx, c, &bufl, ebuf, ebufl))
            goto fail;

        c += bufl;
        *c = 0;

        if (c - *buf > DECRYPTION_BUF * j - 64) {
            i = c - *buf;
            *buf = (char *) srealloc(*buf, DECRYPTION_BUF * ++j);
            c = *buf + i;
            *c = 0;
        }
    }
    
    EVP_DecodeFinal(&bctx, ebuf, &ebufl);
    if (!EVP_DecryptFinal(ctx, c, &bufl))
        goto fail;

    c += bufl;
    *c = 0;

    if (!(c = strstr(*buf, "\n.\n")))
        goto fail;

    EVP_DigestInit(&mdctx, EVP_md5());
    EVP_DigestUpdate(&mdctx, *buf, c - *buf + 1);
    EVP_DigestFinal(&mdctx, mdv, &mdl);
    
    for (i = 0; i < mdl; i++)
        snprintf(mdc + i * 2, EVP_MAX_MD_SIZE * 2 + 1 - i * 2, "%02x", mdv[i]);
    
    c += 3;

    if (strncmp(c, mdc, 32))
        goto fail;

    EVP_CIPHER_CTX_cleanup(ctx);
    
    sfree(key);
    sfree(ctx);
    
    return 0;

fail:
    error("Wrong master passphrase.\n");
    sfree(*buf);
    sfree(key);
    sfree(ctx);
    
    return ERROR_DECRYPT;
}


/*
 * Interactive encrypted passwords editor.
 */
void password_editor(void)
{
    int i, q, n;
    char buf[LINE_MAX];
    char *c;
    char *p[2];
    account_t *a, *accts[EDITOR_PASSWORDS_MAX];
    
    if (!(flags & FLAG_BLANK_PASSWORD)) {
        error("imapfilter: no candidate passwords for encryption found\n");
        return;
    }
    
    q = 0;
    
    memset(accts, 0, EDITOR_PASSWORDS_MAX);

    for (i = 0, a = accounts; i < EDITOR_PASSWORDS_MAX - 1 && a; a = a->next) {
        if (a->passwdattr == PASSWORD_NONE ||
            a->passwdattr == PASSWORD_ENCRYPTED)
            accts[i++] = a;
    }

    do {
        printf("command: ");
        fgets(buf, LINE_MAX, stdin);
        c = buf;
        for (;; c++) {
            if (*c == ' ' || *c == '\t')
                continue;
            else if (*c == '?' || *c == 'h')
                printf("c       clear a password entry\n"
                       "e       edit a password entry\n"
                       "h       help\n"
                       "l       list entries\n"
                       "p       change master password\n"
                       "q       quit without saving\n"
                       "s       save changes\n"
                       "x       save and exit\n");
            else if (*c == 'q')
                q = 1;
            else if (*c == 'l')
                for (i = 0; accts[i]; i++)
                    printf("%d %s %s %s\n", i + 1, accts[i]->server,
                           accts[i]->username, accts[i]->password);
            else if (*c == 'e') {
                n = atoi(++c);
                if (!n || n < 1 || n > 128 || !accts[n - 1])
                    break;
                accts[n - 1]->password[0] = 0;
                printf("Enter new password: ");
                if (fgets(accts[n - 1]->password, PASSWORD_LEN, stdin))
                    if ((c = strchr(accts[n - 1]->password, '\n')))
                        *c = 0;
            } else if (*c == 'c') {
                n = atoi(++c);
                if (!n || n < 1 || n > 128 || !accts[n - 1])
                    break;
                accts[n - 1]->password[0] = 0;
            } else if (*c == 'p') {
                p[0] = (char *) smalloc(PASSPHRASE_LEN);
                p[1] = (char *) smalloc(PASSPHRASE_LEN);
                do {
                    for (i = 0; i < 2; i++) {
                        printf("Enter %snew master password: ",
                               i ? "again " : "");
                        get_password(p[i], PASSPHRASE_LEN);
                    }
                } while (strcmp(p[0], p[1]));
                xstrncpy(passphr, p[0], PASSPHRASE_LEN - 1);
                sfree(p[0]);
                sfree(p[1]);
            } else if (*c == 's') {
                store_passwords(accts);
            } else if (*c == 'x') {
                store_passwords(accts);
                q = 1;
            } else
                break;
        }
    } while (!q);
}
#endif
1	#include <stdio.h>
2	#include <string.h>
3	#include <stdlib.h>
4	#include <limits.h>
5
6	#include "config.h"
7	#include "imapfilter.h"
8	#include "data.h"
9
10	#ifdef ENCRYPTED_PASSWORDS
11	#include <openssl/evp.h>
12	#endif
13
14
15	extern unsigned int flags;
16	extern account_t *accounts;
17
18	#ifdef ENCRYPTED_PASSWORDS
19	extern char *passphr;
20	#endif
21
22	/*
23	* Get password from user interactively.
24	*/
25	void get_password(char *passwd, size_t pwlen)
26	{
27	char *c;
28
29	tty_disable_echo();
30
31	if (fgets(passwd, pwlen, stdin))
32	if ((c = strchr(passwd, '\n')))
33	*c = 0;
34
35	tty_restore();
36
37	putchar('\n');
38	}
39
40
41	#ifdef ENCRYPTED_PASSWORDS
42	/*
43	* Encrypt and Base64 encode passwords. Append the MD5 checksum of the passwords
44	* before encrypting them.
45	*/
46	int encrypt_passwords(FILE fd, account_t accts[])
47	{
48	int i;
49	char *c;
50	unsigned char iv[EVP_MAX_IV_LENGTH];
51	unsigned char *key;
52	unsigned char buf[ENCRYPTION_BUF];
53	unsigned char ebuf[ENCRYPTION_BUF];
54	unsigned char bbuf[ENCRYPTION_BUF];
55	unsigned char mdv[EVP_MAX_MD_SIZE];
56	int mdl, ebufl, bbufl;
57	EVP_CIPHER_CTX ctx;
58	EVP_MD_CTX mdctx;
59	EVP_ENCODE_CTX bctx;
60
61	key = (unsigned char *) smalloc(EVP_MAX_KEY_LENGTH);
62
63	srandom(time(NULL));
64
65	c = ultostr(1 + random() % 100000000, 10);
66	memset(iv, '0', EVP_MAX_IV_LENGTH);
67	memcpy(iv + 8 - strlen(c), c, min(8, strlen(c)));
68
69	fprintf(fd, "%.8s\n", iv);
70
71	EVP_CIPHER_CTX_init(&ctx);
72
73	EVP_BytesToKey(EVP_bf_cbc(), EVP_md5(), NULL, passphr, strlen(passphr), 1,
74	key, NULL);
75
76	EVP_DigestInit(&mdctx, EVP_md5());
77	EVP_EncryptInit(&ctx, EVP_bf_cbc(), key, iv);
78	EVP_EncodeInit(&bctx);
79
80	for (i = 0; accts[i]; i++) {
81	snprintf(buf, ENCRYPTION_BUF, "%s %s %s\n", accts[i]->server, accts[i]->username,
82	accts[i]->password);
83
84	EVP_DigestUpdate(&mdctx, buf, strlen(buf));
85	EVP_EncryptUpdate(&ctx, ebuf, &ebufl, buf, strlen(buf));
86	EVP_EncodeUpdate(&bctx, bbuf, &bbufl, ebuf, ebufl);
87
88	fwrite(bbuf, sizeof(char), bbufl, fd);
89	}
90
91	EVP_DigestFinal(&mdctx, mdv, &mdl);
92
93	xstrncpy(buf, ".\n", ENCRYPTION_BUF - 1);
94
95	for (i = 0; i < mdl; i++)
96	snprintf(2 + buf + i * 2, ENCRYPTION_BUF - i * 2, "%02x", mdv[i]);
97
98	EVP_EncryptUpdate(&ctx, ebuf, &ebufl, buf, strlen(buf));
99	EVP_EncodeUpdate(&bctx, bbuf, &bbufl, ebuf, ebufl);
100	fwrite(bbuf, sizeof(char), bbufl, fd);
101
102	EVP_EncryptFinal(&ctx, ebuf, &ebufl);
103	EVP_EncodeUpdate(&bctx, bbuf, &bbufl, ebuf, ebufl);
104	EVP_EncodeFinal(&bctx, bbuf, &bbufl);
105
106	fwrite(bbuf, sizeof(char), bbufl, fd);
107
108	EVP_CIPHER_CTX_cleanup(&ctx);
109
110	return 0;
111	}
112
113
114	/*
115	* Decode (Base64) passwords, decrypt them and verify the MD5 checksum.
116	*/
117	int decrypt_passwords(unsigned char *buf, FILE fd)
118	{
119	int i, j = 1;
120	unsigned char iv[EVP_MAX_IV_LENGTH];
121	unsigned char *key;
122	unsigned char *c;
123	unsigned char ebuf[LINE_MAX];
124	unsigned char bbuf[LINE_MAX];
125	unsigned char mdv[EVP_MAX_MD_SIZE];
126	unsigned char mdc[EVP_MAX_MD_SIZE * 2 + 1];
127	int mdl, bufl, ebufl;
128	EVP_CIPHER_CTX *ctx;
129	EVP_MD_CTX mdctx;
130	EVP_ENCODE_CTX bctx;
131
132	c = buf = (unsigned char ) smalloc(DECRYPTION_BUF * sizeof(char));
133	key = (unsigned char *) smalloc(EVP_MAX_KEY_LENGTH);
134	ctx = (EVP_CIPHER_CTX *) smalloc(sizeof(EVP_CIPHER_CTX));
135
136	fgets(bbuf, LINE_MAX, fd);
137
138	memcpy(iv, bbuf, EVP_MAX_IV_LENGTH);
139
140	EVP_CIPHER_CTX_init(ctx);
141
142	EVP_BytesToKey(EVP_bf_cbc(), EVP_md5(), NULL, passphr, strlen(passphr),
143	1, key, NULL);
144
145	EVP_DecryptInit(ctx, EVP_bf_cbc(), key, iv);
146	EVP_DecodeInit(&bctx);
147
148	while (fgets(bbuf, LINE_MAX, fd)) {
149	EVP_DecodeUpdate(&bctx, ebuf, &ebufl, bbuf, strlen(bbuf));
150	if (!EVP_DecryptUpdate(ctx, c, &bufl, ebuf, ebufl))
151	goto fail;
152
153	c += bufl;
154	*c = 0;
155
156	if (c - buf > DECRYPTION_BUF j - 64) {
157	i = c - *buf;
158	buf = (char ) srealloc(buf, DECRYPTION_BUF ++j);
159	c = *buf + i;
160	*c = 0;
161	}
162	}
163
164	EVP_DecodeFinal(&bctx, ebuf, &ebufl);
165	if (!EVP_DecryptFinal(ctx, c, &bufl))
166	goto fail;
167
168	c += bufl;
169	*c = 0;
170
171	if (!(c = strstr(*buf, "\n.\n")))
172	goto fail;
173
174	EVP_DigestInit(&mdctx, EVP_md5());
175	EVP_DigestUpdate(&mdctx, buf, c - buf + 1);
176	EVP_DigestFinal(&mdctx, mdv, &mdl);
177
178	for (i = 0; i < mdl; i++)
179	snprintf(mdc + i * 2, EVP_MAX_MD_SIZE * 2 + 1 - i * 2, "%02x", mdv[i]);
180
181	c += 3;
182
183	if (strncmp(c, mdc, 32))
184	goto fail;
185
186	EVP_CIPHER_CTX_cleanup(ctx);
187
188	sfree(key);
189	sfree(ctx);
190
191	return 0;
192
193	fail:
194	error("Wrong master passphrase.\n");
195	sfree(*buf);
196	sfree(key);
197	sfree(ctx);
198
199	return ERROR_DECRYPT;
200	}
201
202
203	/*
204	* Interactive encrypted passwords editor.
205	*/
206	void password_editor(void)
207	{
208	int i, q, n;
209	char buf[LINE_MAX];
210	char *c;
211	char *p[2];
212	account_t a, accts[EDITOR_PASSWORDS_MAX];
213
214	if (!(flags & FLAG_BLANK_PASSWORD)) {
215	error("imapfilter: no candidate passwords for encryption found\n");
216	return;
217	}
218
219	q = 0;
220
221	memset(accts, 0, EDITOR_PASSWORDS_MAX);
222
223	for (i = 0, a = accounts; i < EDITOR_PASSWORDS_MAX - 1 && a; a = a->next) {
224	if (a->passwdattr == PASSWORD_NONE \|\|
225	a->passwdattr == PASSWORD_ENCRYPTED)
226	accts[i++] = a;
227	}
228
229	do {
230	printf("command: ");
231	fgets(buf, LINE_MAX, stdin);
232	c = buf;
233	for (;; c++) {
234	if (c == ' ' \|\| c == '\t')
235	continue;
236	else if (c == '?' \|\| c == 'h')
237	printf("c clear a password entry\n"
238	"e edit a password entry\n"
239	"h help\n"
240	"l list entries\n"
241	"p change master password\n"
242	"q quit without saving\n"
243	"s save changes\n"
244	"x save and exit\n");
245	else if (*c == 'q')
246	q = 1;
247	else if (*c == 'l')
248	for (i = 0; accts[i]; i++)
249	printf("%d %s %s %s\n", i + 1, accts[i]->server,
250	accts[i]->username, accts[i]->password);
251	else if (*c == 'e') {
252	n = atoi(++c);
253	if (!n \|\| n < 1 \|\| n > 128 \|\| !accts[n - 1])
254	break;
255	accts[n - 1]->password[0] = 0;
256	printf("Enter new password: ");
257	if (fgets(accts[n - 1]->password, PASSWORD_LEN, stdin))
258	if ((c = strchr(accts[n - 1]->password, '\n')))
259	*c = 0;
260	} else if (*c == 'c') {
261	n = atoi(++c);
262	if (!n \|\| n < 1 \|\| n > 128 \|\| !accts[n - 1])
263	break;
264	accts[n - 1]->password[0] = 0;
265	} else if (*c == 'p') {
266	p[0] = (char *) smalloc(PASSPHRASE_LEN);
267	p[1] = (char *) smalloc(PASSPHRASE_LEN);
268	do {
269	for (i = 0; i < 2; i++) {
270	printf("Enter %snew master password: ",
271	i ? "again " : "");
272	get_password(p[i], PASSPHRASE_LEN);
273	}
274	} while (strcmp(p[0], p[1]));
275	xstrncpy(passphr, p[0], PASSPHRASE_LEN - 1);
276	sfree(p[0]);
277	sfree(p[1]);
278	} else if (*c == 's') {
279	store_passwords(accts);
280	} else if (*c == 'x') {
281	store_passwords(accts);
282	q = 1;
283	} else
284	break;
285	}
286	} while (!q);
287	}
288	#endif