thodg/libgit2/src/transports/auth_ntlm.c

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• Hash : ebade233
  Author :
  Date : 2020-02-24T21:49:43
  

  transports: auth_ntlm: fix use of strdup/strndup In the NTLM authentication code, we accidentally use strdup(3P) and strndup(3P) instead of our own wrappers git__strdup and git__strndup, respectively. Fix the issue by using our own functions.

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• src/transports/auth_ntlm.c

• /*
   * Copyright (C) the libgit2 contributors. All rights reserved.
   *
   * This file is part of libgit2, distributed under the GNU GPL v2 with
   * a Linking Exception. For full terms see the included COPYING file.
   */
  
  #include "git2.h"
  #include "common.h"
  #include "buffer.h"
  #include "auth.h"
  #include "auth_ntlm.h"
  #include "git2/sys/credential.h"
  
  #ifdef GIT_NTLM
  
  #include "ntlm.h"
  
  typedef struct {
  	git_http_auth_context parent;
  	ntlm_client *ntlm;
  	char *challenge;
  	bool complete;
  } http_auth_ntlm_context;
  
  static int ntlm_set_challenge(
  	git_http_auth_context *c,
  	const char *challenge)
  {
  	http_auth_ntlm_context *ctx = (http_auth_ntlm_context *)c;
  
  	assert(ctx && challenge);
  
  	git__free(ctx->challenge);
  
  	ctx->challenge = git__strdup(challenge);
  	GIT_ERROR_CHECK_ALLOC(ctx->challenge);
  
  	return 0;
  }
  
  static int ntlm_set_credentials(http_auth_ntlm_context *ctx, git_credential *_cred)
  {
  	git_credential_userpass_plaintext *cred;
  	const char *sep, *username;
  	char *domain = NULL, *domainuser = NULL;
  	int error = 0;
  
  	assert(_cred->credtype == GIT_CREDENTIAL_USERPASS_PLAINTEXT);
  	cred = (git_credential_userpass_plaintext *)_cred;
  
  	if ((sep = strchr(cred->username, '\\')) != NULL) {
  		domain = git__strndup(cred->username, (sep - cred->username));
  		GIT_ERROR_CHECK_ALLOC(domain);
  
  		domainuser = git__strdup(sep + 1);
  		GIT_ERROR_CHECK_ALLOC(domainuser);
  
  		username = domainuser;
  	} else {
  		username = cred->username;
  	}
  
  	if (ntlm_client_set_credentials(ctx->ntlm,
  	    username, domain, cred->password) < 0) {
  		git_error_set(GIT_ERROR_NET, "could not set credentials: %s",
  		    ntlm_client_errmsg(ctx->ntlm));
  		error = -1;
  		goto done;
  	}
  
  done:
  	git__free(domain);
  	git__free(domainuser);
  	return error;
  }
  
  static int ntlm_next_token(
  	git_buf *buf,
  	git_http_auth_context *c,
  	git_credential *cred)
  {
  	http_auth_ntlm_context *ctx = (http_auth_ntlm_context *)c;
  	git_buf input_buf = GIT_BUF_INIT;
  	const unsigned char *msg;
  	size_t challenge_len, msg_len;
  	int error = -1;
  
  	assert(buf && ctx && ctx->ntlm);
  
  	challenge_len = ctx->challenge ? strlen(ctx->challenge) : 0;
  
  	if (ctx->complete)
  		ntlm_client_reset(ctx->ntlm);
  
  	/*
  	 * Set us complete now since it's the default case; the one
  	 * incomplete case (successfully created a client request)
  	 * will explicitly set that it requires a second step.
  	 */
  	ctx->complete = true;
  
  	if (cred && ntlm_set_credentials(ctx, cred) != 0)
  		goto done;
  
  	if (challenge_len < 4) {
  		git_error_set(GIT_ERROR_NET, "no ntlm challenge sent from server");
  		goto done;
  	} else if (challenge_len == 4) {
  		if (memcmp(ctx->challenge, "NTLM", 4) != 0) {
  			git_error_set(GIT_ERROR_NET, "server did not request NTLM");
  			goto done;
  		}
  
  		if (ntlm_client_negotiate(&msg, &msg_len, ctx->ntlm) != 0) {
  			git_error_set(GIT_ERROR_NET, "ntlm authentication failed: %s",
  				ntlm_client_errmsg(ctx->ntlm));
  			goto done;
  		}
  
  		ctx->complete = false;
  	} else {
  		if (memcmp(ctx->challenge, "NTLM ", 5) != 0) {
  			git_error_set(GIT_ERROR_NET, "challenge from server was not NTLM");
  			goto done;
  		}
  
  		if (git_buf_decode_base64(&input_buf,
  		    ctx->challenge + 5, challenge_len - 5) < 0) {
  			git_error_set(GIT_ERROR_NET, "invalid NTLM challenge from server");
  			goto done;
  		}
  
  		if (ntlm_client_set_challenge(ctx->ntlm,
  		    (const unsigned char *)input_buf.ptr, input_buf.size) != 0) {
  			git_error_set(GIT_ERROR_NET, "ntlm challenge failed: %s",
  				ntlm_client_errmsg(ctx->ntlm));
  			goto done;
  		}
  
  		if (ntlm_client_response(&msg, &msg_len, ctx->ntlm) != 0) {
  			git_error_set(GIT_ERROR_NET, "ntlm authentication failed: %s",
  				ntlm_client_errmsg(ctx->ntlm));
  			goto done;
  		}
  	}
  
  	git_buf_puts(buf, "NTLM ");
  	git_buf_encode_base64(buf, (const char *)msg, msg_len);
  
  	if (git_buf_oom(buf))
  		goto done;
  
  	error = 0;
  
  done:
  	git_buf_dispose(&input_buf);
  	return error;
  }
  
  static int ntlm_is_complete(git_http_auth_context *c)
  {
  	http_auth_ntlm_context *ctx = (http_auth_ntlm_context *)c;
  
  	assert(ctx);
  	return (ctx->complete == true);
  }
  
  static void ntlm_context_free(git_http_auth_context *c)
  {
  	http_auth_ntlm_context *ctx = (http_auth_ntlm_context *)c;
  
  	ntlm_client_free(ctx->ntlm);
  	git__free(ctx->challenge);
  	git__free(ctx);
  }
  
  static int ntlm_init_context(
  	http_auth_ntlm_context *ctx,
  	const git_net_url *url)
  {
  	GIT_UNUSED(url);
  
  	if ((ctx->ntlm = ntlm_client_init(NTLM_CLIENT_DEFAULTS)) == NULL) {
  		git_error_set_oom();
  		return -1;
  	}
  
  	return 0;
  }
  
  int git_http_auth_ntlm(
  	git_http_auth_context **out,
  	const git_net_url *url)
  {
  	http_auth_ntlm_context *ctx;
  
  	GIT_UNUSED(url);
  
  	*out = NULL;
  
  	ctx = git__calloc(1, sizeof(http_auth_ntlm_context));
  	GIT_ERROR_CHECK_ALLOC(ctx);
  
  	if (ntlm_init_context(ctx, url) < 0) {
  		git__free(ctx);
  		return -1;
  	}
  
  	ctx->parent.type = GIT_HTTP_AUTH_NTLM;
  	ctx->parent.credtypes = GIT_CREDENTIAL_USERPASS_PLAINTEXT;
  	ctx->parent.connection_affinity = 1;
  	ctx->parent.set_challenge = ntlm_set_challenge;
  	ctx->parent.next_token = ntlm_next_token;
  	ctx->parent.is_complete = ntlm_is_complete;
  	ctx->parent.free = ntlm_context_free;
  
  	*out = (git_http_auth_context *)ctx;
  
  	return 0;
  }
  
  #endif /* GIT_NTLM */
  

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