-- >8 --
Subject: imap-send: support CRAM-MD5 authentication
CRAM-MD5 authentication ought to be independent from SSL, but NO_OPENSSL
build will not support this because the base64 and md5 code are used from
the OpenSSL library in this implementation.
Signed-off-by: Hitoshi Mitake<mitake@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Junio C Hamano<gitster@xxxxxxxxx>
---
Documentation/git-imap-send.txt | 4 +
imap-send.c | 146 +++++++++++++++++++++++++++++++++++----
2 files changed, 135 insertions(+), 15 deletions(-)
diff --git a/Documentation/git-imap-send.txt b/Documentation/git-imap-send.txt
index 57db955..6cafbe2 100644
--- a/Documentation/git-imap-send.txt
+++ b/Documentation/git-imap-send.txt
@@ -71,6 +71,10 @@ imap.preformattedHTML::
option causes Thunderbird to send the patch as a plain/text,
format=fixed email. Default is `false`.
+imap.authMethod::
+ Specify authenticate method for authentication with IMAP server.
+ Current supported method is 'CRAM-MD5' only.
+
Examples
~~~~~~~~
diff --git a/imap-send.c b/imap-send.c
index ba72fa4..bf1cd73 100644
--- a/imap-send.c
+++ b/imap-send.c
@@ -27,6 +27,9 @@
#include "run-command.h"
#ifdef NO_OPENSSL
typedef void *SSL;
+#else
+#include<openssl/evp.h>
+#include<openssl/hmac.h>
#endif
struct store_conf {
@@ -140,6 +143,20 @@ struct imap_server_conf {
int use_ssl;
int ssl_verify;
int use_html;
+ char *auth_method;
+};
+
+static struct imap_server_conf server = {
+ NULL, /* name */
+ NULL, /* tunnel */
+ NULL, /* host */
+ 0, /* port */
+ NULL, /* user */
+ NULL, /* pass */
+ 0, /* use_ssl */
+ 1, /* ssl_verify */
+ 0, /* use_html */
+ NULL, /* auth_method */
};
struct imap_store_conf {
@@ -214,6 +231,7 @@ enum CAPABILITY {
LITERALPLUS,
NAMESPACE,
STARTTLS,
+ AUTH_CRAM_MD5,
};
static const char *cap_list[] = {
@@ -222,6 +240,7 @@ static const char *cap_list[] = {
"LITERAL+",
"NAMESPACE",
"STARTTLS",
+ "AUTH=CRAM-MD5",
};
#define RESP_OK 0
@@ -949,6 +968,87 @@ static void imap_close_store(struct store *ctx)
free(ctx);
}
+#ifndef NO_OPENSSL
+
+/*
+ * hexchar() and cram() functions are based on the code from the isync
+ * project (http://isync.sf.net/).
+ */
+static char hexchar(unsigned int b)
+{
+ return b< 10 ? '0' + b : 'a' + (b - 10);
+}
+
+#define ENCODED_SIZE(n) (4*((n+2)/3))
+static char *cram(const char *challenge_64, const char *user, const char *pass)
+{
+ int i, resp_len, encoded_len, decoded_len;
+ HMAC_CTX hmac;
+ unsigned char hash[16];
+ char hex[33];
+ char *response, *response_64, *challenge;
+
+ /*
+ * length of challenge_64 (i.e. base-64 encoded string) is a good
+ * enough upper bound for challenge (decoded result).
+ */
+ encoded_len = strlen(challenge_64);
+ challenge = xmalloc(encoded_len);
+ decoded_len = EVP_DecodeBlock((unsigned char *)challenge,
+ (unsigned char *)challenge_64, encoded_len);
+ if (decoded_len< 0)
+ die("invalid challenge %s", challenge_64);
+ HMAC_Init(&hmac, (unsigned char *)pass, strlen(pass), EVP_md5());
+ HMAC_Update(&hmac, (unsigned char *)challenge, decoded_len);
+ HMAC_Final(&hmac, hash, NULL);
+ HMAC_CTX_cleanup(&hmac);
+
+ hex[32] = 0;
+ for (i = 0; i< 16; i++) {
+ hex[2 * i] = hexchar((hash[i]>> 4)& 0xf);
+ hex[2 * i + 1] = hexchar(hash[i]& 0xf);
+ }
+
+ /* response: "<user> <digest in hex>" */
+ resp_len = strlen(user) + 1 + strlen(hex) + 1;
+ response = xmalloc(resp_len);
+ sprintf(response, "%s %s", user, hex);
+
+ response_64 = xmalloc(ENCODED_SIZE(resp_len));
+ encoded_len = EVP_EncodeBlock((unsigned char *)response_64,
+ (unsigned char *)response, resp_len);
+ if (encoded_len< 0)
+ die("EVP_EncodeBlock error");
+ response_64[encoded_len] = '\0';
+ return (char *)response_64;
+}
+
+#else
+
+static char *cram(const char *challenge_64, const char *user, const char *pass)
+{
+ die("If you want to use CRAM-MD5 authenticate method, "
+ "you have to build git-imap-send with OpenSSL library.");
+}
+
+#endif
+
+static int auth_cram_md5(struct imap_store *ctx, struct imap_cmd *cmd, const char *prompt)
+{
+ int ret;
+ char *response;
+
+ response = cram(prompt, server.user, server.pass);
+
+ ret = socket_write(&ctx->imap->buf.sock, response, strlen(response));
+ if (ret != strlen(response))
+ return error("IMAP error: sending response failed\n");
+
+ free(response);
+
+ return 0;
+}
+
static struct store *imap_open_store(struct imap_server_conf *srvc)
{
struct imap_store *ctx;
@@ -1130,9 +1230,34 @@ static struct store *imap_open_store(struct imap_server_conf *srvc)
if (!imap->buf.sock.ssl)
imap_warn("*** IMAP Warning *** Password is being "
"sent in the clear\n");
- if (imap_exec(ctx, NULL, "LOGIN \"%s\" \"%s\"", srvc->user, srvc->pass) != RESP_OK) {
- fprintf(stderr, "IMAP error: LOGIN failed\n");
- goto bail;
+
+ if (srvc->auth_method) {
+ struct imap_cmd_cb cb;
+
+ if (!strcmp(srvc->auth_method, "CRAM-MD5")) {
+ if (!CAP(AUTH_CRAM_MD5)) {
+ fprintf(stderr, "You specified"
+ "CRAM-MD5 as authentication method, "
+ "but %s doesn't support it.\n", srvc->host);
+ goto bail;
+ }
+ /* CRAM-MD5 */
+
+ memset(&cb, 0, sizeof(cb));
+ cb.cont = auth_cram_md5;
+ if (imap_exec(ctx,&cb, "AUTHENTICATE CRAM-MD5") != RESP_OK) {
+ fprintf(stderr, "IMAP error: AUTHENTICATE CRAM-MD5 failed\n");
+ goto bail;
+ }
+ } else {
+ fprintf(stderr, "Unknown authentication method:%s\n", srvc->host);
+ goto bail;
+ }
+ } else {
+ if (imap_exec(ctx, NULL, "LOGIN \"%s\" \"%s\"", srvc->user, srvc->pass) != RESP_OK) {
+ fprintf(stderr, "IMAP error: LOGIN failed\n");
+ goto bail;
+ }
}
} /* !preauth */
@@ -1310,18 +1435,6 @@ static int split_msg(struct msg_data *all_msgs, struct msg_data *msg, int *ofs)
return 1;
}
-static struct imap_server_conf server = {
- NULL, /* name */
- NULL, /* tunnel */
- NULL, /* host */
- 0, /* port */
- NULL, /* user */
- NULL, /* pass */
- 0, /* use_ssl */
- 1, /* ssl_verify */
- 0, /* use_html */
-};
-
static char *imap_folder;
static int git_imap_config(const char *key, const char *val, void *cb)
@@ -1361,6 +1474,9 @@ static int git_imap_config(const char *key, const char *val, void *cb)
server.port = git_config_int(key, val);
else if (!strcmp("tunnel", key))
server.tunnel = xstrdup(val);
+ else if (!strcmp("authmethod", key))
+ server.auth_method = xstrdup(val);
+
return 0;
}
--
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