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#include <stdio.h> |
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#include <string.h> |
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#include <stdlib.h> |
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#include <limits.h> |
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|
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#include "config.h" |
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#include "imapfilter.h" |
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#include "data.h" |
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|
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#ifdef ENCRYPTED_PASSWORDS |
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#include <openssl/evp.h> |
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#endif |
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|
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|
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extern unsigned int flags; |
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extern account_t *accounts; |
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|
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#ifdef ENCRYPTED_PASSWORDS |
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extern char *passphr; |
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#endif |
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|
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/* |
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* Get password from user interactively. |
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*/ |
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void get_password(char *passwd, size_t pwlen) |
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{ |
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char *c; |
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|
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tty_disable_echo(); |
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|
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if (fgets(passwd, pwlen, stdin)) |
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if ((c = strchr(passwd, '\n'))) |
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*c = 0; |
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|
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tty_restore(); |
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|
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putchar('\n'); |
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} |
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|
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|
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#ifdef ENCRYPTED_PASSWORDS |
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/* |
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* Encrypt and Base64 encode passwords. Append the MD5 checksum of the passwords |
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* before encrypting them. |
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*/ |
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int encrypt_passwords(FILE * fd, account_t * accts[]) |
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{ |
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int i; |
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char *c; |
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unsigned char iv[EVP_MAX_IV_LENGTH]; |
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unsigned char *key; |
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unsigned char buf[ENCRYPTION_BUF]; |
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unsigned char ebuf[ENCRYPTION_BUF]; |
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unsigned char bbuf[ENCRYPTION_BUF]; |
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unsigned char mdv[EVP_MAX_MD_SIZE]; |
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int mdl, ebufl, bbufl; |
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EVP_CIPHER_CTX ctx; |
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EVP_MD_CTX mdctx; |
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EVP_ENCODE_CTX bctx; |
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|
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key = (unsigned char *)smalloc(EVP_MAX_KEY_LENGTH); |
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|
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srandom(time(NULL)); |
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|
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/* Initialization vector. */ |
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c = ultostr(1 + random() % 100000000, 10); |
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memset(iv, '0', EVP_MAX_IV_LENGTH); |
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memcpy(iv + 8 - strlen(c), c, min(8, strlen(c))); |
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fprintf(fd, "%.8s\n", iv); |
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|
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EVP_CIPHER_CTX_init(&ctx); |
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|
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EVP_BytesToKey(EVP_bf_cbc(), EVP_md5(), NULL, passphr, strlen(passphr), 1, |
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key, NULL); |
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|
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EVP_DigestInit(&mdctx, EVP_md5()); |
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EVP_EncryptInit(&ctx, EVP_bf_cbc(), key, iv); |
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EVP_EncodeInit(&bctx); |
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|
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for (i = 0; accts[i]; i++) { |
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snprintf(buf, ENCRYPTION_BUF, "%s %s %s\n", accts[i]->server, accts[i]->username, |
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accts[i]->password); |
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|
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EVP_DigestUpdate(&mdctx, buf, strlen(buf)); |
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EVP_EncryptUpdate(&ctx, ebuf, &ebufl, buf, strlen(buf)); |
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EVP_EncodeUpdate(&bctx, bbuf, &bbufl, ebuf, ebufl); |
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|
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fwrite(bbuf, sizeof(char), bbufl, fd); |
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} |
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|
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EVP_DigestFinal(&mdctx, mdv, &mdl); |
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|
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xstrncpy(buf, ".\n", ENCRYPTION_BUF - 1); |
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|
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/* MD5 checksum of data. */ |
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for (i = 0; i < mdl; i++) |
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snprintf(2 + buf + i * 2, ENCRYPTION_BUF - i * 2, "%02x", mdv[i]); |
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|
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EVP_EncryptUpdate(&ctx, ebuf, &ebufl, buf, strlen(buf)); |
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EVP_EncodeUpdate(&bctx, bbuf, &bbufl, ebuf, ebufl); |
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fwrite(bbuf, sizeof(char), bbufl, fd); |
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|
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EVP_EncryptFinal(&ctx, ebuf, &ebufl); |
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EVP_EncodeUpdate(&bctx, bbuf, &bbufl, ebuf, ebufl); |
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EVP_EncodeFinal(&bctx, bbuf, &bbufl); |
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|
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fwrite(bbuf, sizeof(char), bbufl, fd); |
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|
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EVP_CIPHER_CTX_cleanup(&ctx); |
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|
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return 0; |
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} |
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|
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|
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/* |
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* Decode (Base64) passwords, decrypt them and verify the MD5 checksum. |
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*/ |
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int decrypt_passwords(unsigned char **buf, FILE * fd) |
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{ |
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int i, j = 1; |
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unsigned char iv[EVP_MAX_IV_LENGTH]; |
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unsigned char *key; |
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unsigned char *c; |
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unsigned char ebuf[LINE_MAX]; |
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unsigned char bbuf[LINE_MAX]; |
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unsigned char mdv[EVP_MAX_MD_SIZE]; |
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unsigned char mdc[EVP_MAX_MD_SIZE * 2 + 1]; |
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int mdl, bufl, ebufl; |
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EVP_CIPHER_CTX *ctx; |
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EVP_MD_CTX mdctx; |
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EVP_ENCODE_CTX bctx; |
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|
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c = *buf = (unsigned char *)smalloc(DECRYPTION_BUF * sizeof(char)); |
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key = (unsigned char *)smalloc(EVP_MAX_KEY_LENGTH); |
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ctx = (EVP_CIPHER_CTX *) smalloc(sizeof(EVP_CIPHER_CTX)); |
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|
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fgets(bbuf, LINE_MAX, fd); |
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|
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memcpy(iv, bbuf, EVP_MAX_IV_LENGTH); |
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|
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EVP_CIPHER_CTX_init(ctx); |
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|
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EVP_BytesToKey(EVP_bf_cbc(), EVP_md5(), NULL, passphr, strlen(passphr), |
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1, key, NULL); |
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|
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EVP_DecryptInit(ctx, EVP_bf_cbc(), key, iv); |
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EVP_DecodeInit(&bctx); |
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|
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while (fgets(bbuf, LINE_MAX, fd)) { |
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EVP_DecodeUpdate(&bctx, ebuf, &ebufl, bbuf, strlen(bbuf)); |
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if (!EVP_DecryptUpdate(ctx, c, &bufl, ebuf, ebufl)) |
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goto fail; |
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|
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c += bufl; |
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*c = 0; |
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|
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if (c - *buf > DECRYPTION_BUF * j - 64) { |
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i = c - *buf; |
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*buf = (char *)srealloc(*buf, DECRYPTION_BUF * ++j); |
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c = *buf + i; |
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*c = 0; |
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} |
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} |
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|
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EVP_DecodeFinal(&bctx, ebuf, &ebufl); |
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if (!EVP_DecryptFinal(ctx, c, &bufl)) |
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goto fail; |
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|
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c += bufl; |
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*c = 0; |
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|
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/* Calculate the MD5 checksum and check if it is correct. */ |
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if (!(c = strstr(*buf, "\n.\n"))) |
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goto fail; |
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|
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EVP_DigestInit(&mdctx, EVP_md5()); |
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EVP_DigestUpdate(&mdctx, *buf, c - *buf + 1); |
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EVP_DigestFinal(&mdctx, mdv, &mdl); |
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|
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for (i = 0; i < mdl; i++) |
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snprintf(mdc + i * 2, EVP_MAX_MD_SIZE * 2 + 1 - i * 2, "%02x", mdv[i]); |
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|
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c += 3; |
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|
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if (strncmp(c, mdc, 32)) |
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goto fail; |
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|
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EVP_CIPHER_CTX_cleanup(ctx); |
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|
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sfree(key); |
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sfree(ctx); |
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|
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return 0; |
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|
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fail: |
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error("Wrong master passphrase.\n"); |
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EVP_CIPHER_CTX_cleanup(ctx); |
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sfree(*buf); |
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sfree(key); |
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sfree(ctx); |
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|
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return ERROR_DECRYPT; |
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} |
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|
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|
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/* |
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* Interactive encrypted passwords editor. |
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*/ |
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void password_editor(void) |
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{ |
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int i, q, n; |
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char buf[LINE_MAX]; |
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char *c; |
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char *p[2]; |
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account_t *a, *accts[EDITOR_PASSWORDS_MAX]; |
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|
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if (!(flags & FLAG_BLANK_PASSWORD)) { |
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error("imapfilter: no candidate passwords for encryption found\n"); |
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return; |
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} |
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q = 0; |
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|
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memset(accts, 0, EDITOR_PASSWORDS_MAX); |
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|
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for (i = 0, a = accounts; i < EDITOR_PASSWORDS_MAX - 1 && a; a = a->next) { |
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if (a->passwdattr == PASSWORD_NONE || |
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a->passwdattr == PASSWORD_ENCRYPTED) |
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accts[i++] = a; |
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} |
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|
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do { |
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printf("command: "); |
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fgets(buf, LINE_MAX, stdin); |
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c = buf; |
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for (;; c++) { |
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if (*c == ' ' || *c == '\t') |
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continue; |
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else if (*c == '?' || *c == 'h') |
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printf("c clear a password entry\n" |
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"e edit a password entry\n" |
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"h help\n" |
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"l list entries\n" |
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"p change master password\n" |
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"q quit without saving\n" |
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"s save changes\n" |
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"x save and exit\n"); |
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else if (*c == 'q') |
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q = 1; |
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else if (*c == 'l') |
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for (i = 0; accts[i]; i++) |
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printf("%d %s %s %s\n", i + 1, accts[i]->server, |
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accts[i]->username, accts[i]->password); |
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else if (*c == 'e') { |
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n = atoi(++c); |
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if (!n || n < 1 || n > 128 || !accts[n - 1]) |
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break; |
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accts[n - 1]->password[0] = 0; |
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printf("Enter new password: "); |
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if (fgets(accts[n - 1]->password, PASSWORD_LEN, stdin)) |
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if ((c = strchr(accts[n - 1]->password, '\n'))) |
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*c = 0; |
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} else if (*c == 'c') { |
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n = atoi(++c); |
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if (!n || n < 1 || n > 128 || !accts[n - 1]) |
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break; |
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accts[n - 1]->password[0] = 0; |
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} else if (*c == 'p') { |
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p[0] = (char *)smalloc(PASSPHRASE_LEN); |
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p[1] = (char *)smalloc(PASSPHRASE_LEN); |
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do { |
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for (i = 0; i < 2; i++) { |
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printf("Enter %snew master password: ", |
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i ? "again " : ""); |
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get_password(p[i], PASSPHRASE_LEN); |
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} |
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} while (strcmp(p[0], p[1])); |
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xstrncpy(passphr, p[0], PASSPHRASE_LEN - 1); |
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sfree(p[0]); |
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sfree(p[1]); |
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} else if (*c == 's') { |
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store_passwords(accts); |
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} else if (*c == 'x') { |
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store_passwords(accts); |
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q = 1; |
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} else |
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break; |
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} |
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} while (!q); |
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} |
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|
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#endif |