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authorAris Adamantiadis <aris@0xbadc0de.be>2018-10-27 23:54:56 +0200
committerAndreas Schneider <asn@cryptomilk.org>2019-01-24 09:34:18 +0100
commit43a4f86b6e14a907b3a298d10d5cd7efb59f6a09 (patch)
treeef166a4dbdd80362fcb4142dae1a02275e126265 /src/session.c
parente42a423a247c8c9f0bd58d32a8b80c522f7b43f6 (diff)
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dh: move unrelated functions out of dh.c
Signed-off-by: Aris Adamantiadis <aris@0xbadc0de.be> Reviewed-by: Jakub Jelen <jjelen@redhat.com> Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Diffstat (limited to 'src/session.c')
-rw-r--r--src/session.c234
1 files changed, 234 insertions, 0 deletions
diff --git a/src/session.c b/src/session.c
index 01a96a32..b79f4548 100644
--- a/src/session.c
+++ b/src/session.c
@@ -38,6 +38,7 @@
#include "libssh/misc.h"
#include "libssh/buffer.h"
#include "libssh/poll.h"
+#include "libssh/pki.h"
#define FIRST_CHANNEL 42 // why not ? it helps to find bugs.
@@ -949,4 +950,237 @@ void ssh_set_counters(ssh_session session, ssh_counter scounter,
}
}
+/**
+ * @deprecated Use ssh_get_publickey_hash()
+ */
+int ssh_get_pubkey_hash(ssh_session session, unsigned char **hash)
+{
+ ssh_key pubkey = NULL;
+ ssh_string pubkey_blob = NULL;
+ MD5CTX ctx;
+ unsigned char *h;
+ int rc;
+
+ if (session == NULL || hash == NULL) {
+ return SSH_ERROR;
+ }
+ *hash = NULL;
+ if (session->current_crypto == NULL ||
+ session->current_crypto->server_pubkey == NULL) {
+ ssh_set_error(session,SSH_FATAL,"No current cryptographic context");
+ return SSH_ERROR;
+ }
+
+ h = calloc(MD5_DIGEST_LEN, sizeof(unsigned char));
+ if (h == NULL) {
+ return SSH_ERROR;
+ }
+
+ ctx = md5_init();
+ if (ctx == NULL) {
+ SAFE_FREE(h);
+ return SSH_ERROR;
+ }
+
+ rc = ssh_get_server_publickey(session, &pubkey);
+ if (rc != SSH_OK) {
+ md5_final(h, ctx);
+ SAFE_FREE(h);
+ return SSH_ERROR;
+ }
+
+ rc = ssh_pki_export_pubkey_blob(pubkey, &pubkey_blob);
+ ssh_key_free(pubkey);
+ if (rc != SSH_OK) {
+ md5_final(h, ctx);
+ SAFE_FREE(h);
+ return SSH_ERROR;
+ }
+
+ md5_update(ctx, ssh_string_data(pubkey_blob), ssh_string_len(pubkey_blob));
+ ssh_string_free(pubkey_blob);
+ md5_final(h, ctx);
+
+ *hash = h;
+
+ return MD5_DIGEST_LEN;
+}
+
+/**
+ * @brief Deallocate the hash obtained by ssh_get_pubkey_hash.
+ *
+ * This is required under Microsoft platform as this library might use a
+ * different C library than your software, hence a different heap.
+ *
+ * @param[in] hash The buffer to deallocate.
+ *
+ * @see ssh_get_pubkey_hash()
+ */
+void ssh_clean_pubkey_hash(unsigned char **hash) {
+ SAFE_FREE(*hash);
+}
+
+/**
+ * @brief Get the server public key from a session.
+ *
+ * @param[in] session The session to get the key from.
+ *
+ * @param[out] key A pointer to store the allocated key. You need to free
+ * the key.
+ *
+ * @return SSH_OK on success, SSH_ERROR on errror.
+ *
+ * @see ssh_key_free()
+ */
+int ssh_get_server_publickey(ssh_session session, ssh_key *key)
+{
+ ssh_key pubkey = NULL;
+
+ if (session == NULL ||
+ session->current_crypto == NULL ||
+ session->current_crypto->server_pubkey == NULL) {
+ return SSH_ERROR;
+ }
+
+ pubkey = ssh_key_dup(session->current_crypto->server_pubkey);
+ if (pubkey == NULL) {
+ return SSH_ERROR;
+ }
+
+ *key = pubkey;
+ return SSH_OK;
+}
+
+/**
+ * @deprecated Use ssh_get_server_publickey()
+ */
+int ssh_get_publickey(ssh_session session, ssh_key *key)
+{
+ return ssh_get_server_publickey(session, key);
+}
+
+/**
+ * @brief Allocates a buffer with the hash of the public key.
+ *
+ * This function allows you to get a hash of the public key. You can then
+ * print this hash in a human-readable form to the user so that he is able to
+ * verify it. Use ssh_get_hexa() or ssh_print_hexa() to display it.
+ *
+ * @param[in] key The public key to create the hash for.
+ *
+ * @param[in] type The type of the hash you want.
+ *
+ * @param[in] hash A pointer to store the allocated buffer. It can be
+ * freed using ssh_clean_pubkey_hash().
+ *
+ * @param[in] hlen The length of the hash.
+ *
+ * @return 0 on success, -1 if an error occured.
+ *
+ * @warning It is very important that you verify at some moment that the hash
+ * matches a known server. If you don't do it, cryptography wont help
+ * you at making things secure.
+ * OpenSSH uses SHA1 to print public key digests.
+ *
+ * @see ssh_session_update_known_hosts()
+ * @see ssh_get_hexa()
+ * @see ssh_print_hexa()
+ * @see ssh_clean_pubkey_hash()
+ */
+int ssh_get_publickey_hash(const ssh_key key,
+ enum ssh_publickey_hash_type type,
+ unsigned char **hash,
+ size_t *hlen)
+{
+ ssh_string blob;
+ unsigned char *h;
+ int rc;
+
+ rc = ssh_pki_export_pubkey_blob(key, &blob);
+ if (rc < 0) {
+ return rc;
+ }
+
+ switch (type) {
+ case SSH_PUBLICKEY_HASH_SHA1:
+ {
+ SHACTX ctx;
+
+ h = malloc(SHA_DIGEST_LEN);
+ if (h == NULL) {
+ rc = -1;
+ goto out;
+ }
+
+ ctx = sha1_init();
+ if (ctx == NULL) {
+ free(h);
+ rc = -1;
+ goto out;
+ }
+
+ sha1_update(ctx, ssh_string_data(blob), ssh_string_len(blob));
+ sha1_final(h, ctx);
+
+ *hlen = SHA_DIGEST_LEN;
+ }
+ break;
+ case SSH_PUBLICKEY_HASH_SHA256:
+ {
+ SHA256CTX ctx;
+
+ h = malloc(SHA256_DIGEST_LEN);
+ if (h == NULL) {
+ rc = -1;
+ goto out;
+ }
+
+ ctx = sha256_init();
+ if (ctx == NULL) {
+ free(h);
+ rc = -1;
+ goto out;
+ }
+
+ sha256_update(ctx, ssh_string_data(blob), ssh_string_len(blob));
+ sha256_final(h, ctx);
+
+ *hlen = SHA256_DIGEST_LEN;
+ }
+ break;
+ case SSH_PUBLICKEY_HASH_MD5:
+ {
+ MD5CTX ctx;
+
+ h = malloc(MD5_DIGEST_LEN);
+ if (h == NULL) {
+ rc = -1;
+ goto out;
+ }
+
+ ctx = md5_init();
+ if (ctx == NULL) {
+ free(h);
+ rc = -1;
+ goto out;
+ }
+
+ md5_update(ctx, ssh_string_data(blob), ssh_string_len(blob));
+ md5_final(h, ctx);
+
+ *hlen = MD5_DIGEST_LEN;
+ }
+ break;
+ default:
+ rc = -1;
+ goto out;
+ }
+
+ *hash = h;
+ rc = 0;
+out:
+ ssh_string_free(blob);
+ return rc;
+}
+
/** @} */