Azure IoT common library
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Diff: sastoken.c
- Revision:
- 0:fa2de1b79154
- Child:
- 1:9190c0f4d23a
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/sastoken.c Fri Apr 08 12:01:36 2016 -0700 @@ -0,0 +1,126 @@ +// Copyright (c) Microsoft. All rights reserved. +// Licensed under the MIT license. See LICENSE file in the project root for full license information. + +#include <stdlib.h> +#ifdef _CRTDBG_MAP_ALLOC +#include <crtdbg.h> +#endif +#include "azure_c_shared_utility/gballoc.h" + +#include <time.h> +#include <stddef.h> + +#include "azure_c_shared_utility/crt_abstractions.h" +#include "azure_c_shared_utility/sastoken.h" +#include "azure_c_shared_utility/urlencode.h" +#include "azure_c_shared_utility/hmacsha256.h" +#include "azure_c_shared_utility/base64.h" +#include "azure_c_shared_utility/agenttime.h" +#include "azure_c_shared_utility/strings.h" +#include "azure_c_shared_utility/buffer_.h" +#include "azure_c_shared_utility/iot_logging.h" + +STRING_HANDLE SASToken_Create(STRING_HANDLE key, STRING_HANDLE scope, STRING_HANDLE keyName, size_t expiry) +{ + STRING_HANDLE result = NULL; + char tokenExpirationTime[32] = { 0 }; + + /*Codes_SRS_SASTOKEN_06_001: [If key is NULL then SASToken_Create shall return NULL.]*/ + /*Codes_SRS_SASTOKEN_06_003: [If scope is NULL then SASToken_Create shall return NULL.]*/ + /*Codes_SRS_SASTOKEN_06_007: [If keyName is NULL then SASToken_Create shall return NULL.]*/ + if ((key == NULL) || + (scope == NULL) || + (keyName == NULL)) + { + LogError("Invalid Parameter to SASToken_Create. handle key: %p, handle scope: %p, handle keyName: %p\r\n", key, scope, keyName); + } + else + { + BUFFER_HANDLE decodedKey; + /*Codes_SRS_SASTOKEN_06_029: [The key parameter is decoded from base64.]*/ + if ((decodedKey = Base64_Decoder(STRING_c_str(key))) == NULL) + { + /*Codes_SRS_SASTOKEN_06_030: [If there is an error in the decoding then SASToken_Create shall return NULL.]*/ + LogError("Unable to decode the key for generating the SAS.\r\n"); + } + else + { + /*Codes_SRS_SASTOKEN_06_026: [If the conversion to string form fails for any reason then SASToken_Create shall return NULL.]*/ + if (size_tToString(tokenExpirationTime, sizeof(tokenExpirationTime), expiry) != 0) + { + LogError("For some reason converting seconds to a string failed. No SAS can be generated.\r\n"); + } + else + { + STRING_HANDLE toBeHashed = NULL; + BUFFER_HANDLE hash = NULL; + if (((hash = BUFFER_new()) == NULL) || + ((toBeHashed = STRING_new()) == NULL) || + ((result = STRING_new()) == NULL)) + { + LogError("Unable to allocate memory to prepare SAS token.\r\n"); + } + else + { + /*Codes_SRS_SASTOKEN_06_009: [The scope is the basis for creating a STRING_HANDLE.]*/ + /*Codes_SRS_SASTOKEN_06_010: [A "\n" is appended to that string.]*/ + /*Codes_SRS_SASTOKEN_06_011: [tokenExpirationTime is appended to that string.]*/ + if ((STRING_concat_with_STRING(toBeHashed, scope) != 0) || + (STRING_concat(toBeHashed, "\n") != 0) || + (STRING_concat(toBeHashed, tokenExpirationTime) != 0)) + { + LogError("Unable to build the input to the HMAC to prepare SAS token.\r\n"); + STRING_delete(result); + result = NULL; + } + else + { + STRING_HANDLE base64Signature = NULL; + STRING_HANDLE urlEncodedSignature = NULL; + /*Codes_SRS_SASTOKEN_06_013: [If an error is returned from the HMAC256 function then NULL is returned from SASToken_Create.]*/ + /*Codes_SRS_SASTOKEN_06_012: [An HMAC256 hash is calculated using the decodedKey, over toBeHashed.]*/ + /*Codes_SRS_SASTOKEN_06_014: [If there are any errors from the following operations then NULL shall be returned.]*/ + /*Codes_SRS_SASTOKEN_06_015: [The hash is base 64 encoded.]*/ + /*Codes_SRS_SASTOKEN_06_028: [base64Signature shall be url encoded.]*/ + /*Codes_SRS_SASTOKEN_06_016: [The string "SharedAccessSignature sr=" is the first part of the result of SASToken_Create.]*/ + /*Codes_SRS_SASTOKEN_06_017: [The scope parameter is appended to result.]*/ + /*Codes_SRS_SASTOKEN_06_018: [The string "&sig=" is appended to result.]*/ + /*Codes_SRS_SASTOKEN_06_019: [The string urlEncodedSignature shall be appended to result.]*/ + /*Codes_SRS_SASTOKEN_06_020: [The string "&se=" shall be appended to result.]*/ + /*Codes_SRS_SASTOKEN_06_021: [tokenExpirationTime is appended to result.]*/ + /*Codes_SRS_SASTOKEN_06_022: [The string "&skn=" is appended to result.]*/ + /*Codes_SRS_SASTOKEN_06_023: [The argument keyName is appended to result.]*/ + if ((HMACSHA256_ComputeHash(BUFFER_u_char(decodedKey), BUFFER_length(decodedKey), (const unsigned char*)STRING_c_str(toBeHashed), STRING_length(toBeHashed), hash) != HMACSHA256_OK) || + ((base64Signature = Base64_Encode(hash)) == NULL) || + ((urlEncodedSignature = URL_Encode(base64Signature)) == NULL) || + (STRING_copy(result, "SharedAccessSignature sr=") != 0) || + (STRING_concat_with_STRING(result, scope) != 0) || + (STRING_concat(result, "&sig=") != 0) || + (STRING_concat_with_STRING(result, urlEncodedSignature) != 0) || + (STRING_concat(result, "&se=") != 0) || + (STRING_concat(result, tokenExpirationTime) != 0) || + (STRING_concat(result, "&skn=") != 0) || + (STRING_concat_with_STRING(result, keyName) != 0)) + { + LogError("Unable to build the SAS token.\r\n"); + STRING_delete(result); + result = NULL; + } + else + { + /* everything OK */ + } + STRING_delete(base64Signature); + STRING_delete(urlEncodedSignature); + } + } + STRING_delete(toBeHashed); + BUFFER_delete(hash); + } + BUFFER_delete(decodedKey); + } + } + + return result; +} +