AuthAws C Reference Documentation

AuthAws

Current Version: 9.5.0.97

Implements AWS Signature V4 for signing and authenticating AWS REST requests.

Create/Dispose

HCkAuthAws instance = CkAuthAws_Create();
// ...
CkAuthAws_Dispose(instance);
HCkAuthAws CkAuthAws_Create(void);

Creates an instance of the HCkAuthAws object and returns a handle ("void *" pointer). The handle is passed in the 1st argument for the functions listed on this page.

void CkAuthAws_Dispose(HCkAuthAws handle);

Objects created by calling CkAuthAws_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function. Also, any handle returned by a Chilkat "C" function must also be freed by the application by calling the appropriate Dispose method, such as CkAuthAws_Dispose.

Properties

AccessKey
void CkAuthAws_getAccessKey(HCkAuthAws cHandle, HCkString retval);
void CkAuthAws_putAccessKey(HCkAuthAws cHandle, const char *newVal);
const char *CkAuthAws_accessKey(HCkAuthAws cHandle);
Introduced in version 9.5.0.58

The AWS access key.

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CanonicalizedResourceV2
void CkAuthAws_getCanonicalizedResourceV2(HCkAuthAws cHandle, HCkString retval);
void CkAuthAws_putCanonicalizedResourceV2(HCkAuthAws cHandle, const char *newVal);
const char *CkAuthAws_canonicalizedResourceV2(HCkAuthAws cHandle);
Introduced in version 9.5.0.58

If AWS Signature Version V2 is used, then this property must be set. The rules for setting the canonicalized resource for the V2 signature method is described here: Constructing the CanonicalizedResource Element.

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DebugLogFilePath
void CkAuthAws_getDebugLogFilePath(HCkAuthAws cHandle, HCkString retval);
void CkAuthAws_putDebugLogFilePath(HCkAuthAws cHandle, const char *newVal);
const char *CkAuthAws_debugLogFilePath(HCkAuthAws cHandle);

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

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LastErrorHtml
void CkAuthAws_getLastErrorHtml(HCkAuthAws cHandle, HCkString retval);
const char *CkAuthAws_lastErrorHtml(HCkAuthAws cHandle);

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorText
void CkAuthAws_getLastErrorText(HCkAuthAws cHandle, HCkString retval);
const char *CkAuthAws_lastErrorText(HCkAuthAws cHandle);

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorXml
void CkAuthAws_getLastErrorXml(HCkAuthAws cHandle, HCkString retval);
const char *CkAuthAws_lastErrorXml(HCkAuthAws cHandle);

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastMethodSuccess
BOOL CkAuthAws_getLastMethodSuccess(HCkAuthAws cHandle);
void CkAuthAws_putLastMethodSuccess(HCkAuthAws cHandle, BOOL newVal);

Indicate whether the last method call succeeded or failed. A value of TRUE indicates success, a value of FALSE indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = TRUE and failure = FALSE.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to TRUE. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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PrecomputedMd5
void CkAuthAws_getPrecomputedMd5(HCkAuthAws cHandle, HCkString retval);
void CkAuthAws_putPrecomputedMd5(HCkAuthAws cHandle, const char *newVal);
const char *CkAuthAws_precomputedMd5(HCkAuthAws cHandle);
Introduced in version 9.5.0.58

This property can optionally be set for AWS requests that have a non-empty request body. This should be the base64 encoding of the 16 bytes of the MD5 hash. The most common need for this is if doing an S3 upload from a stream. (If the pre-computed MD5 is not provided, then Chilkat is forced to stream the entire file into memory so that it can calculate the MD5 for authentication.)

Note: AWS Signature Version 2 uses the MD5, whereas Signature Version 4 uses SHA256.

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PrecomputedSha256
void CkAuthAws_getPrecomputedSha256(HCkAuthAws cHandle, HCkString retval);
void CkAuthAws_putPrecomputedSha256(HCkAuthAws cHandle, const char *newVal);
const char *CkAuthAws_precomputedSha256(HCkAuthAws cHandle);
Introduced in version 9.5.0.58

This property can optionally be set for AWS requests that have a non-empty request body. This should be the lowercase hex encoding of the 32-bytes of the SHA256 hash. The most common need for this is if doing an S3 upload from a stream. (If the pre-computed SHA-256 is not provided, then Chilkat is forced to stream the entire file into memory so that it can calculate the SHA-256 for authentication.)

Note: AWS Signature Version 4 uses the SHA256 hash. (AWS Signature Version 2 uses MD5)

More Information and Examples
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Region
void CkAuthAws_getRegion(HCkAuthAws cHandle, HCkString retval);
void CkAuthAws_putRegion(HCkAuthAws cHandle, const char *newVal);
const char *CkAuthAws_region(HCkAuthAws cHandle);
Introduced in version 9.5.0.58

The AWS region, such as "us-east-1", "us-west-2", "eu-west-1", "eu-central-1", etc. The default is "us-east-1". It is only used when the SignatureVersion property is set to 4. This property is unused when the SignatureVersion property is set to 2.

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SecretKey
void CkAuthAws_getSecretKey(HCkAuthAws cHandle, HCkString retval);
void CkAuthAws_putSecretKey(HCkAuthAws cHandle, const char *newVal);
const char *CkAuthAws_secretKey(HCkAuthAws cHandle);
Introduced in version 9.5.0.58

The AWS secret key.

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ServiceName
void CkAuthAws_getServiceName(HCkAuthAws cHandle, HCkString retval);
void CkAuthAws_putServiceName(HCkAuthAws cHandle, const char *newVal);
const char *CkAuthAws_serviceName(HCkAuthAws cHandle);
Introduced in version 9.5.0.58

The AWS service namespace, such as "s3", "ses", etc. See http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html#genref-aws-service-namespaces

This property is unused when the SignatureVersion property is set to 2.

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SignatureVersion
int CkAuthAws_getSignatureVersion(HCkAuthAws cHandle);
void CkAuthAws_putSignatureVersion(HCkAuthAws cHandle, int newVal);
Introduced in version 9.5.0.58

The AWS Signature Version to be used in authentication. The default value is 4. This can optionally be set to the value 2 to use the older V2 signature version.

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Utf8
BOOL CkAuthAws_getUtf8(HCkAuthAws cHandle);
void CkAuthAws_putUtf8(HCkAuthAws cHandle, BOOL newVal);

When set to TRUE, all "const char *" arguments are interpreted as utf-8 strings. If set to FALSE (the default), then "const char *" arguments are interpreted as ANSI strings. Also, when set to TRUE, and Chilkat method returning a "const char *" is returning the utf-8 representation. If set to FALSE, all "const char *" return values are ANSI strings.

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VerboseLogging
BOOL CkAuthAws_getVerboseLogging(HCkAuthAws cHandle);
void CkAuthAws_putVerboseLogging(HCkAuthAws cHandle, BOOL newVal);

If set to TRUE, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is FALSE. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
void CkAuthAws_getVersion(HCkAuthAws cHandle, HCkString retval);
const char *CkAuthAws_version(HCkAuthAws cHandle);

Version of the component/library, such as "9.5.0.94"

More Information and Examples
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Methods

GenPresignedUrl
BOOL CkAuthAws_GenPresignedUrl(HCkAuthAws cHandle, const char *httpVerb, BOOL useHttps, const char *domain, const char *path, int numSecondsValid, const char *awsService, HCkString outStr);
const char *CkAuthAws_genPresignedUrl(HCkAuthAws cHandle, const char *httpVerb, BOOL useHttps, const char *domain, const char *path, int numSecondsValid, const char *awsService);
Introduced in version 9.5.0.85

Generates a temporary pre-signed URL for an Amazon AWS service using AWS Signature V4. Requires that the SecretKey, AccessKey, and Region properties be set to valid values prior to calling this method.

The URL that is generated has this format:

https://<domain>/<path>
?X-Amz-Algorithm=AWS4-HMAC-SHA256
&X-Amz-Credential=<AccessKey>/<currentDate>/<Region>/<awsService>/aws4_request
&X-Amz-Date=<currentDateTime>
&X-Amz-Expires=<numSecondsValid>
&X-Amz-SignedHeaders=host
&X-Amz-Signature=<signature-value>  

The httpVerb is the HTTP verb such as "GET", "PUT", "POST", "DELETE", etc. The awsService is a string naming the AWS service, such as "s3", "execute-api", etc. If useHttps is TRUE, then the returned URL begins with "https://", otherwise it begins with "http://".

Returns TRUE for success, FALSE for failure.

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