pem: add passphrase-protected PEM file support for libgcrypt and wincng
Since they use our own PEM parser which did not support encrypted
PEM files, trying to use such files on these backends failed.
Fix that by augmenting the PEM parser to support encrypted PEM files.
diff --git a/src/crypt.c b/src/crypt.c
index 931ae8b..853682d 100644
--- a/src/crypt.c
+++ b/src/crypt.c
@@ -53,6 +53,7 @@
static const LIBSSH2_CRYPT_METHOD libssh2_crypt_method_none = {
"none",
+ "DEK-Info: NONE"
8, /* blocksize (SSH2 defines minimum blocksize as 8) */
0, /* iv_len */
0, /* secret_len */
@@ -119,6 +120,7 @@
#if LIBSSH2_AES_CTR
static const LIBSSH2_CRYPT_METHOD libssh2_crypt_method_aes128_ctr = {
"aes128-ctr",
+ "",
16, /* blocksize */
16, /* initial value length */
16, /* secret length -- 16*8 == 128bit */
@@ -131,6 +133,7 @@
static const LIBSSH2_CRYPT_METHOD libssh2_crypt_method_aes192_ctr = {
"aes192-ctr",
+ "",
16, /* blocksize */
16, /* initial value length */
24, /* secret length -- 24*8 == 192bit */
@@ -143,6 +146,7 @@
static const LIBSSH2_CRYPT_METHOD libssh2_crypt_method_aes256_ctr = {
"aes256-ctr",
+ "",
16, /* blocksize */
16, /* initial value length */
32, /* secret length -- 32*8 == 256bit */
@@ -157,6 +161,7 @@
#if LIBSSH2_AES
static const LIBSSH2_CRYPT_METHOD libssh2_crypt_method_aes128_cbc = {
"aes128-cbc",
+ "DEK-Info: AES-128-CBC",
16, /* blocksize */
16, /* initial value length */
16, /* secret length -- 16*8 == 128bit */
@@ -169,6 +174,7 @@
static const LIBSSH2_CRYPT_METHOD libssh2_crypt_method_aes192_cbc = {
"aes192-cbc",
+ "DEK-Info: AES-192-CBC",
16, /* blocksize */
16, /* initial value length */
24, /* secret length -- 24*8 == 192bit */
@@ -181,6 +187,7 @@
static const LIBSSH2_CRYPT_METHOD libssh2_crypt_method_aes256_cbc = {
"aes256-cbc",
+ "DEK-Info: AES-256-CBC",
16, /* blocksize */
16, /* initial value length */
32, /* secret length -- 32*8 == 256bit */
@@ -195,6 +202,7 @@
static const LIBSSH2_CRYPT_METHOD
libssh2_crypt_method_rijndael_cbc_lysator_liu_se = {
"rijndael-cbc@lysator.liu.se",
+ "DEK-Info: AES-256-CBC",
16, /* blocksize */
16, /* initial value length */
32, /* secret length -- 32*8 == 256bit */
@@ -209,6 +217,7 @@
#if LIBSSH2_BLOWFISH
static const LIBSSH2_CRYPT_METHOD libssh2_crypt_method_blowfish_cbc = {
"blowfish-cbc",
+ "",
8, /* blocksize */
8, /* initial value length */
16, /* secret length */
@@ -223,6 +232,7 @@
#if LIBSSH2_RC4
static const LIBSSH2_CRYPT_METHOD libssh2_crypt_method_arcfour = {
"arcfour",
+ "DEK-Info: RC4",
8, /* blocksize */
8, /* initial value length */
16, /* secret length */
@@ -258,6 +268,7 @@
static const LIBSSH2_CRYPT_METHOD libssh2_crypt_method_arcfour128 = {
"arcfour128",
+ "",
8, /* blocksize */
8, /* initial value length */
16, /* secret length */
@@ -272,6 +283,7 @@
#if LIBSSH2_CAST
static const LIBSSH2_CRYPT_METHOD libssh2_crypt_method_cast128_cbc = {
"cast128-cbc",
+ "",
8, /* blocksize */
8, /* initial value length */
16, /* secret length */
@@ -286,6 +298,7 @@
#if LIBSSH2_3DES
static const LIBSSH2_CRYPT_METHOD libssh2_crypt_method_3des_cbc = {
"3des-cbc",
+ "DEK-Info: DES-EDE3-CBC",
8, /* blocksize */
8, /* initial value length */
24, /* secret length */
diff --git a/src/libgcrypt.c b/src/libgcrypt.c
index 6ba13a1..5429566 100644
--- a/src/libgcrypt.c
+++ b/src/libgcrypt.c
@@ -172,8 +172,6 @@
unsigned char *n, *e, *d, *p, *q, *e1, *e2, *coeff;
unsigned int nlen, elen, dlen, plen, qlen, e1len, e2len, coefflen;
- (void) passphrase;
-
fp = fopen(filename, "r");
if (!fp) {
return -1;
@@ -182,6 +180,7 @@
ret = _libssh2_pem_parse(session,
"-----BEGIN RSA PRIVATE KEY-----",
"-----END RSA PRIVATE KEY-----",
+ passphrase,
fp, &data, &datalen);
fclose(fp);
if (ret) {
@@ -285,8 +284,6 @@
unsigned char *p, *q, *g, *y, *x;
unsigned int plen, qlen, glen, ylen, xlen;
- (void) passphrase;
-
fp = fopen(filename, "r");
if (!fp) {
return -1;
@@ -295,6 +292,7 @@
ret = _libssh2_pem_parse(session,
"-----BEGIN DSA PRIVATE KEY-----",
"-----END DSA PRIVATE KEY-----",
+ passphrase,
fp, &data, &datalen);
fclose(fp);
if (ret) {
diff --git a/src/libssh2_priv.h b/src/libssh2_priv.h
index 0dab735..0114331 100644
--- a/src/libssh2_priv.h
+++ b/src/libssh2_priv.h
@@ -884,6 +884,7 @@
struct _LIBSSH2_CRYPT_METHOD
{
const char *name;
+ const char *pem_annotation;
int blocksize;
@@ -1041,6 +1042,7 @@
int _libssh2_pem_parse(LIBSSH2_SESSION * session,
const char *headerbegin,
const char *headerend,
+ const unsigned char *passphrase,
FILE * fp, unsigned char **data, unsigned int *datalen);
int _libssh2_pem_parse_memory(LIBSSH2_SESSION * session,
const char *headerbegin,
diff --git a/src/os400qc3.c b/src/os400qc3.c
index 74fe64b..0bdf538 100644
--- a/src/os400qc3.c
+++ b/src/os400qc3.c
@@ -2005,6 +2005,7 @@
fseek(fp, 0L, SEEK_SET);
for (;;) {
ret = _libssh2_pem_parse(session, header, trailer,
+ NULL,
fp, &data, &datalen);
if (!ret) {
diff --git a/src/pem.c b/src/pem.c
index 9f51bba..523d9c5 100644
--- a/src/pem.c
+++ b/src/pem.c
@@ -37,6 +37,7 @@
*/
#include "libssh2_priv.h"
+#include <assert.h>
static int
readline(char *line, int line_size, FILE * fp)
@@ -96,16 +97,26 @@
#define LINE_SIZE 128
+const char *crypt_annotation = "Proc-Type: 4,ENCRYPTED";
+
+static unsigned char hex_decode(char digit)
+{
+ return (digit >= 'A') ? 0xA + (digit - 'A') : (digit - '0');
+}
+
int
_libssh2_pem_parse(LIBSSH2_SESSION * session,
const char *headerbegin,
const char *headerend,
+ const unsigned char *passphrase,
FILE * fp, unsigned char **data, unsigned int *datalen)
{
char line[LINE_SIZE];
+ unsigned char iv[LINE_SIZE];
char *b64data = NULL;
unsigned int b64datalen = 0;
int ret;
+ const LIBSSH2_CRYPT_METHOD *method = NULL;
do {
*line = '\0';
@@ -116,7 +127,45 @@
}
while (strcmp(line, headerbegin) != 0);
- *line = '\0';
+ if (readline(line, LINE_SIZE, fp)) {
+ return -1;
+ }
+
+ if (passphrase &&
+ memcmp(line, crypt_annotation, strlen(crypt_annotation)) == 0) {
+ const LIBSSH2_CRYPT_METHOD **all_methods, *cur_method;
+ int i;
+
+ if (readline(line, LINE_SIZE, fp)) {
+ ret = -1;
+ goto out;
+ }
+ all_methods = libssh2_crypt_methods();
+ while ((cur_method = *all_methods++)) {
+ if (*cur_method->pem_annotation &&
+ memcmp(line, cur_method->pem_annotation, strlen(cur_method->pem_annotation)) == 0) {
+ method = cur_method;
+ memcpy(iv, line+strlen(method->pem_annotation)+1, 2*method->iv_len);
+ }
+ }
+
+ /* None of the available crypt methods were able to decrypt this key */
+ if (method == NULL)
+ return -1;
+
+ /* Decode IV from hex */
+ for (i = 0; i < method->iv_len; ++i)
+ {
+ iv[i] = hex_decode(iv[2*i]) << 4;
+ iv[i] |= hex_decode(iv[2*i+1]);
+ }
+
+ /* skip to the next line */
+ if (readline(line, LINE_SIZE, fp)) {
+ ret = -1;
+ goto out;
+ }
+ }
do {
if (*line) {
@@ -152,6 +201,72 @@
goto out;
}
+ if (method) {
+ /* Set up decryption */
+ int free_iv = 0, free_secret = 0, len_decrypted = 0, padding = 0;
+ int blocksize = method->blocksize;
+ void *abstract;
+ unsigned char secret[2*MD5_DIGEST_LENGTH];
+ libssh2_md5_ctx fingerprint_ctx;
+
+ /* Perform key derivation (PBKDF1/MD5) */
+ if (!libssh2_md5_init(&fingerprint_ctx)) {
+ ret = -1;
+ goto out;
+ }
+ libssh2_md5_update(fingerprint_ctx, passphrase, strlen((char*)passphrase));
+ libssh2_md5_update(fingerprint_ctx, iv, 8);
+ libssh2_md5_final(fingerprint_ctx, secret);
+ if (method->secret_len > MD5_DIGEST_LENGTH) {
+ if (!libssh2_md5_init(&fingerprint_ctx)) {
+ ret = -1;
+ goto out;
+ }
+ libssh2_md5_update(fingerprint_ctx, secret, MD5_DIGEST_LENGTH);
+ libssh2_md5_update(fingerprint_ctx, passphrase, strlen((char*)passphrase));
+ libssh2_md5_update(fingerprint_ctx, iv, 8);
+ libssh2_md5_final(fingerprint_ctx, secret + MD5_DIGEST_LENGTH);
+ }
+
+ /* Initialize the decryption */
+ if (method->init(session, method, iv, &free_iv, secret,
+ &free_secret, 0, &abstract)) {
+ memset((char*)secret, 0, sizeof(secret));
+ LIBSSH2_FREE(session, data);
+ ret = -1;
+ goto out;
+ }
+
+ if (free_secret) {
+ memset((char*)secret, 0, sizeof(secret));
+ }
+
+ /* Do the actual decryption */
+ assert((*datalen % blocksize) == 0);
+
+ while (len_decrypted <= *datalen - blocksize) {
+ if (method->crypt(session, *data + len_decrypted, blocksize,
+ &abstract)) {
+ ret = LIBSSH2_ERROR_DECRYPT;
+ method->dtor(session, &abstract);
+ memset(*data, 0, *datalen);
+ LIBSSH2_FREE(session, *data);
+ goto out;
+ }
+
+ len_decrypted += blocksize;
+ }
+
+ /* Account for padding */
+ padding = (*data)[*datalen - 1];
+ memset(&(*data)[*datalen-padding],0,padding);
+ *datalen -= padding;
+
+ /* Clean up */
+ memset((char*)secret, 0, sizeof(secret));
+ method->dtor(session, &abstract);
+ }
+
ret = 0;
out:
if (b64data) {
diff --git a/src/wincng.c b/src/wincng.c
index c4b658c..e58e6ec 100755
--- a/src/wincng.c
+++ b/src/wincng.c
@@ -549,14 +549,13 @@
FILE *fp;
int ret;
- (void)passphrase;
-
fp = fopen(filename, "r");
if (!fp) {
return -1;
}
ret = _libssh2_pem_parse(session, headerbegin, headerend,
+ passphrase,
fp, data, datalen);
fclose(fp);
