Mime Go Reference Documentation

Mime

Current Version: 11.5.0

Chilkat.Mime

Build, parse, modify, serialize, secure, and inspect MIME and S/MIME data.

Mime provides low-level MIME and S/MIME handling for applications that need direct control over MIME structure, headers, body content, encodings, multipart relationships, attachments, and PKCS7/CMS security layers. It can load, create, inspect, modify, serialize, and save MIME messages; build multipart structures; manage headers and content-transfer encodings; extract attachments; convert MIME to and from XML; and sign, verify, encrypt, decrypt, or unwrap S/MIME content.

Create and load MIME

Build MIME content programmatically or load existing MIME from strings, files, byte data, or other application sources.

Headers and body content

Read, add, replace, or remove MIME headers, set body content, and control content types, charsets, and transfer encodings.

Multipart structures

Create and inspect multipart MIME trees such as mixed, alternative, related, signed, encrypted, and nested MIME structures.

Attachments and parts

Add, locate, extract, remove, or inspect MIME parts and attachments, including filenames and encoded body data.

S/MIME security

Sign, verify, encrypt, decrypt, unwrap, and inspect PKCS7/CMS S/MIME layers using certificates and private keys.

Serialization and XML

Emit MIME text, save MIME to files, or convert MIME to and from XML for structured inspection, transformation, or storage.

Common pattern: Use Mime when an application needs low-level control over MIME parts, headers, encodings, multipart layout, or S/MIME security. For ordinary email composition and message-level operations, use Chilkat.Email; use Mime when you need to work closer to the raw MIME structure.
Initial state: A new Mime object has no headers or child parts. Its string serialization consists only of the blank header/body separator (CRLF CRLF) until content is added.
MIME parsing is semantic, not byte-preserving. Loading and reserializing can unfold headers, normalize parameter quoting and transfer encodings, use CRLF for generated headers and multipart framing, and discard multipart preamble or epilogue text. Use byte-oriented methods such as LoadMimeBd and GetMimeBd when arbitrary 8-bit bytes or embedded NUL bytes must be preserved.

Object Creation

mime := chilkat.NewMime()
...
mime.DisposeMime()

Properties

Boundary
func (mime *Mime) Boundary() string
func (mime *Mime) SetBoundary(s string)

Gets or sets the raw boundary token used by a multipart MIME entity. Do not include surrounding quotation marks.

Content-Type: multipart/mixed; boundary="example-boundary"
For this example, Boundary is example-boundary. Chilkat automatically quotes the parameter when the token contains characters such as spaces or semicolons.
Normally automatic. Methods such as NewMultipartMixed, NewMultipartAlternative, and NewMultipartRelated generate a nonempty boundary.
Caller-supplied boundaries are not validated. Chilkat does not detect collisions with body text. An empty value is permitted but produces invalid multipart delimiters, and supplying quotation marks as part of the property value causes those quotation marks to become part of the boundary. The property can also be set on a nonmultipart entity, where it is simply added as a Content-Type parameter.

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Charset
func (mime *Mime) Charset() string
func (mime *Mime) SetCharset(s string)

Gets or sets the charset parameter of the Content-Type header field.

Content-Type: text/plain; charset=utf-8
Changing this property preserves the media type and other parameters. Setting it when no Content-Type exists creates a Content-Type field, although the media type remains empty until ContentType is set.
Charset versus transfer encoding. The charset identifies how text characters are represented as bytes. Encoding controls the MIME transport representation of those bytes.
Empty-string behavior. Setting Charset to an empty string does not remove the parameter. It selects the platform default ANSI charset; on Windows this is typically windows-1252.

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CmsOptions
func (mime *Mime) CmsOptions() string
func (mime *Mime) SetCmsOptions(s string)
Introduced in version 9.5.0.78

Gets or sets a JSON string containing advanced CMS/PKCS #7 signing and validation options. The empty string selects normal behavior. This property is intended for specialized interoperability requirements; applications should leave it empty unless a documented option is specifically needed.

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ContentType
func (mime *Mime) ContentType() string
func (mime *Mime) SetContentType(s string)

Gets or sets the MIME media type of the current part, excluding all parameters. Supply a value such as text/plain, text/html, application/pdf, or multipart/mixed; do not include charset, boundary, or other parameters in this property.

Changing the media type preserves the existing charset and unrecognized parameters, but may remove parameters that are specific to the previous media type, such as format=flowed. Setting an empty string leaves an empty media type and can therefore produce an invalid-looking header if other parameters remain.

Classification methods use this value. Methods such as IsText, IsImage, and IsMultipart classify the media type stored here. Parameters must be set through their dedicated properties or header attributes, not appended to ContentType.

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CurrentDateTime
func (mime *Mime) CurrentDateTime() string

Returns the current local date and time formatted as an Internet message date, including the numeric UTC offset. For example:

Fri, 21 Nov 1997 09:55:06 -0600

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DebugLogFilePath
func (mime *Mime) DebugLogFilePath() string
func (mime *Mime) SetDebugLogFilePath(s string)

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

  • A timeout property set to 0, indicating an infinite timeout.
  • A hang occurring within an event callback in the application code.
  • An internal bug in the Chilkat code causing the hang.

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Disposition
func (mime *Mime) Disposition() string
func (mime *Mime) SetDisposition(s string)

Gets or sets the disposition value from the Content-Disposition header field, excluding parameters such as filename.

Content-Disposition: attachment; filename="report.pdf"
Changing this property preserves an existing filename parameter. Typical values are attachment and inline.

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Encoding
func (mime *Mime) Encoding() string
func (mime *Mime) SetEncoding(s string)

Gets or sets the value of the Content-Transfer-Encoding header field for the current part. Common values include base64, quoted-printable, 7bit, 8bit, and binary.

Transfer encoding is not compression. It determines how the body bytes are represented in serialized MIME. GetBodyEncoded returns the transfer-encoded form, while GetBodyBd, GetBodyBinary, and SaveBody return or save decoded bytes.

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Filename
func (mime *Mime) Filename() string
func (mime *Mime) SetFilename(s string)

Gets or sets the filename parameter of the Content-Disposition header field. The value is a receiver-facing filename, not a local filesystem path.

Changing this property preserves the disposition value but removes other Content-Disposition parameters such as size. Setting an empty string removes the filename parameter.

International filenames. When setting a non-ASCII filename, Chilkat emits an RFC 2047 encoded-word in filename=. When reading a header containing both filename= and filename*=, this property returns filename=. Use GetHeaderFieldAttribute to retrieve the raw filename* value.

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LastErrorHtml
func (mime *Mime) LastErrorHtml() string

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorText
func (mime *Mime) LastErrorText() string

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorXml
func (mime *Mime) LastErrorXml() string

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastMethodSuccess
func (mime *Mime) LastMethodSuccess() bool
func (mime *Mime) SetLastMethodSuccess(b bool)

Indicates the success or failure of the most recent method call: true means success, false means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.

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Micalg
func (mime *Mime) Micalg() string
func (mime *Mime) SetMicalg(s string)

Gets or sets the micalg parameter of a multipart/signed Content-Type header field.

Content-Type: multipart/signed;
  protocol="application/pkcs7-signature";
  micalg=sha-256;
  boundary="example-boundary"
The parameter advertises the message-integrity algorithm used by the detached signature. When creating a signature, prefer setting SigningHashAlg; Chilkat generates the corresponding micalg value.

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Name
func (mime *Mime) Name() string
func (mime *Mime) SetName(s string)

Gets or sets the name parameter of the Content-Type header field. For attachments, Filename is generally the primary receiver-facing name.

Setting a non-ASCII value causes Chilkat to emit an RFC 2047 encoded-word in the name= parameter. Setting this property when no media type exists creates a Content-Type field with an empty media type.

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NumDecryptCerts
func (mime *Mime) NumDecryptCerts() int
Introduced in version 11.0.0

Returns the number of decryption certificates recorded by the most recent call to UnwrapSecurity. Use LastDecryptCert with a zero-based index to retrieve each certificate.

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NumHeaderFields
func (mime *Mime) NumHeaderFields() int

Returns the number of header-field occurrences in the current part. Duplicate names count separately and retain their order. Valid indexes range from 0 through NumHeaderFields - 1 for use with GetHeaderFieldName and GetHeaderFieldValue.

During MIME parsing, duplicate ordinary fields are retained. Duplicate Content-Type fields are collapsed, with the last value taking effect.

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NumParts
func (mime *Mime) NumParts() int

Returns the number of direct child parts. It does not include deeper descendants. Iterate from 0 through NumParts - 1 and call PartAt to traverse the tree.

The object returned by PartAt provides live access to the stored child. Modifying that returned object modifies the parent MIME tree.

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NumSignerCerts
func (mime *Mime) NumSignerCerts() int

Returns the number of signer certificates recorded by the most recent signature-verification or security-unwrapping operation. The property is populated by UnwrapSecurity. Use LastSignerCert to retrieve a certificate by zero-based index.

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OaepHash
func (mime *Mime) OaepHash() string
func (mime *Mime) SetOaepHash(s string)
Introduced in version 9.5.0.67

Gets or sets the hash algorithm used by RSAES-OAEP when encrypting the CMS content-encryption key. Supported values are sha1, sha256, sha384, and sha512. This property is used only when OaepPadding is true.

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OaepMgfHash
func (mime *Mime) OaepMgfHash() string
func (mime *Mime) SetOaepMgfHash(s string)
Introduced in version 9.5.0.71

Gets or sets the hash algorithm used by the mask generation function (MGF1) within RSAES-OAEP. Supported values are sha1, sha256, sha384, and sha512. The default is sha1. This property is used only when OaepPadding is true.

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OaepPadding
func (mime *Mime) OaepPadding() bool
func (mime *Mime) SetOaepPadding(b bool)
Introduced in version 9.5.0.67

Selects the RSA key-transport padding used when creating encrypted MIME. The default is false, which uses RSAES-PKCS1-v1_5. Set to true to use RSAES-OAEP.

Scope. This setting protects the symmetric content-encryption key for RSA recipients; it does not change the symmetric algorithm selected by Pkcs7CryptAlg.

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Pkcs7CryptAlg
func (mime *Mime) Pkcs7CryptAlg() string
func (mime *Mime) SetPkcs7CryptAlg(s string)

Gets or sets the symmetric content-encryption algorithm used when creating CMS/PKCS #7 encrypted MIME. Supported values are aes, aes-gcm, des, 3des, and rc2. The default is aes. The aes-gcm option was added in version 10.0.0.

Hybrid encryption. S/MIME encrypts the MIME content with a symmetric content-encryption key. Each recipient certificate is then used to protect that content-encryption key. This property selects the symmetric algorithm; Pkcs7KeyLength selects its key length.

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Pkcs7KeyLength
func (mime *Mime) Pkcs7KeyLength() int
func (mime *Mime) SetPkcs7KeyLength(v int)

Gets or sets the content-encryption key length, in bits, used when creating CMS/PKCS #7 encrypted MIME. The permitted value depends on Pkcs7CryptAlg.

AlgorithmAccepted key lengths
aes or aes-gcm128, 192, or 256
3des192
des40
rc240, 56, 64, or 128

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Protocol
func (mime *Mime) Protocol() string
func (mime *Mime) SetProtocol(s string)

Gets or sets the protocol parameter of the Content-Type header field. This parameter is commonly used by multipart/signed to identify the media type of the detached signature part.

Content-Type: multipart/signed;
  protocol="application/pkcs7-signature";
  micalg=sha-256;
  boundary="example-boundary"
For this example, Protocol is application/pkcs7-signature.

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SigningAlg
func (mime *Mime) SigningAlg() string
func (mime *Mime) SetSigningAlg(s string)
Introduced in version 9.5.0.67

Gets or sets the RSA signature scheme used when creating CMS/PKCS #7 signed MIME. The default is PKCS1-v1_5. Set the property to RSASSA-PSS or pss to use RSASSA-PSS.

This setting applies only when the signing private key is RSA. It does not select the signature scheme for EC or DSA keys. The property controls signature creation and is not updated during verification; use GetLastJsonData to inspect a verified signature.

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SigningHashAlg
func (mime *Mime) SigningHashAlg() string
func (mime *Mime) SetSigningHashAlg(s string)

Gets or sets the message-digest algorithm used when creating CMS/PKCS #7 signatures. Supported values are sha1, sha256, sha384, sha512, md5, and md2.

This property controls signature creation only. It is not changed when a signature is verified. After verification, call GetLastJsonData to inspect the algorithms found in the signed data.

Security guidance. Use a SHA-2 algorithm such as sha256 unless interoperability with a legacy system requires otherwise. MD2, MD5, and SHA-1 are retained for compatibility with older signed messages.

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UncommonOptions
func (mime *Mime) UncommonOptions() string
func (mime *Mime) SetUncommonOptions(s string)
Introduced in version 9.5.0.89

Gets or sets a semicolon-delimited or implementation-specific option string used for uncommon compatibility requirements. The default is the empty string, and normal applications should leave it empty. Options placed here may be version-specific and should be used only when directed by Chilkat documentation or support.

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UnwrapExtras
func (mime *Mime) UnwrapExtras() bool
func (mime *Mime) SetUnwrapExtras(b bool)

Controls whether UnwrapSecurity adds informative header fields describing the security layers that were removed. The default behavior should normally be retained unless the application requires a minimally modified unwrapped MIME message.

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UseMmDescription
func (mime *Mime) UseMmDescription() bool
func (mime *Mime) SetUseMmDescription(b bool)

Controls whether Chilkat uses the conventional multipart preamble text This is a multi-part message in MIME format. when serializing a multipart entity. The default is false. The preamble is meaningful only when the multipart has content and is ignored by MIME-aware readers.

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UseXPkcs7
func (mime *Mime) UseXPkcs7() bool
func (mime *Mime) SetUseXPkcs7(b bool)

Controls whether newly created S/MIME media types use the historical x-pkcs7 names.

ValueGenerated media types
true (default)application/x-pkcs7-mime and application/x-pkcs7-signature
falseapplication/pkcs7-mime and application/pkcs7-signature
Interoperability. The x- forms are widely encountered in existing S/MIME messages. Both naming forms describe the same CMS/PKCS #7 content.

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VerboseLogging
func (mime *Mime) VerboseLogging() bool
func (mime *Mime) SetVerboseLogging(b bool)

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
func (mime *Mime) Version() string

Version of the component/library, such as "10.1.0"

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Methods

AddContentLength
func (mime *Mime) AddContentLength()

Computes the byte length of the current entity's serialized MIME body and adds or updates its Content-Length header. The count is based on the transfer-encoded serialized body, not the decoded payload.

For a multipart entity, the count includes boundary delimiter lines, child headers, child bodies, and the closing boundary. Only the current entity's header is updated; child parts do not receive Content-Length fields. Repeated calls recompute the value and leave a single header occurrence.

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AddDecryptCert
func (mime *Mime) AddDecryptCert(cert *Cert) bool
Introduced in version 9.5.0.40

Adds cert to the internal collection of certificates available for S/MIME decryption. The certificate must have access to its corresponding private key. Call this method once for each candidate certificate.

The collection is searched by decryption methods such as Decrypt and UnwrapSecurity. Other ways to provide decryption credentials include AddPfxSourceFile, AddPfxSourceBd, and UseCertVault.

Returns true for success, false for failure.

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AddDetachedSignature
func (mime *Mime) AddDetachedSignature(cert *Cert) bool

Creates an S/MIME detached signature using cert. The certificate must have access to its private key. On success, the current object becomes a multipart/signed entity with two direct children:

PartContents
FirstThe original MIME entity being signed.
SecondThe CMS/PKCS #7 signature data.

Use SigningHashAlg and, for RSA keys, SigningAlg to select the signing algorithms.

Detached signature. The original MIME content remains visible as the first multipart child. Altering its serialized bytes after signing invalidates the signature.

Returns true for success, false for failure.

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AddDetachedSignature2
func (mime *Mime) AddDetachedSignature2(cert *Cert, transferHeaderFields bool) bool

Creates the same detached multipart/signed structure as AddDetachedSignature, with transferHeaderFields controlling whether the calling object's header fields are transferred to the first, signed content part while the outer multipart wrapper is created.

cert is the signing certificate and must have access to its private key.

Returns true for success, false for failure.

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AddDetachedSignaturePk
func (mime *Mime) AddDetachedSignaturePk(cert *Cert, privateKey *PrivateKey) bool

Creates a detached S/MIME signature using cert as the signer certificate and privateKey as its associated private key. Use this method when the certificate and private key are supplied separately rather than combined in a PFX/P12 file or certificate object.

On success, the current object is transformed into the same two-part multipart/signed structure described by AddDetachedSignature.

Returns true for success, false for failure.

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AddDetachedSignaturePk2
func (mime *Mime) AddDetachedSignaturePk2(cert *Cert, privateKey *PrivateKey, transferHeaderFields bool) bool

Creates a detached S/MIME signature using the certificate in cert and the corresponding private key in privateKey. transferHeaderFields controls whether the calling object's header fields are transferred to the first, signed content part while the outer multipart/signed wrapper is created.

This is the separate-private-key counterpart of AddDetachedSignature2.

Returns true for success, false for failure.

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AddEncryptCert
func (mime *Mime) AddEncryptCert(cert *Cert) bool

Adds cert to the internal recipient-certificate list used by EncryptN. Call this method once for each intended recipient. Encryption uses the public key in each certificate, so recipient private keys are not required at encryption time.

Call ClearEncryptCerts to empty the list.

Returns true for success, false for failure.

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AddHeaderField
func (mime *Mime) AddHeaderField(name string, value string) bool

Appends a new header field named by name with the value in value. Existing fields having the same case-insensitive name are preserved. An empty value creates a legal empty-valued field.

Chilkat converts spaces in a header name to hyphens, removes embedded CR and LF characters from the value to prevent header injection, and folds long values when serializing.

Replacing versus appending. Use SetHeaderField to remove all existing occurrences and set one replacement value.

Returns true for success, false for failure.

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AddPfxSourceBd
func (mime *Mime) AddPfxSourceBd(bd *BinData, password string) bool
Introduced in version 11.0.0

Adds the PKCS #12/PFX bytes in bd to the internal collection of credential sources. password is the password protecting the PFX data. Call the method once for each PFX source that should be searched by later decryption or signing operations.

Credential source. Adding a PFX/P12 source does not immediately decrypt the message. It makes the contained certificates and private keys available to later decryption or signing operations.

Returns true for success, false for failure.

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AddPfxSourceData
func (mime *Mime) AddPfxSourceData(pfxFileData []byte, pfxPassword string) bool

Legacy byte-array method. Adds the PKCS #12/PFX data in pfxFileData to the internal collection of credential sources. pfxPassword is the password protecting the PFX. Call the method once for each PFX source that should be searched.

Prefer AddPfxSourceBd when a BinData object is available.

Credential source. Adding a PFX/P12 source does not immediately decrypt the message. It makes the contained certificates and private keys available to later decryption or signing operations.

Returns true for success, false for failure.

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AddPfxSourceFile
func (mime *Mime) AddPfxSourceFile(pfxFilePath string, password string) bool

Adds the PFX/P12 file at the local filesystem path in pfxFilePath to the internal collection of credential sources. password is the password protecting the file. Call the method once for each PFX source that should be searched.

Credential source. Adding a PFX/P12 source does not immediately decrypt the message. It makes the contained certificates and private keys available to later decryption or signing operations.

Returns true for success, false for failure.

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AppendPart
func (mime *Mime) AppendPart(mime *Mime) bool

Appends a copy of mime as the last direct child. Chilkat does not retain a reference to mime, so later changes to mime do not affect the appended part. The same source object may be appended more than once.

If the current object is not multipart, it is converted to multipart/mixed. The complete original entity, including its existing headers and body, becomes part 0; the copy of mime becomes part 1. The new outer entity contains its generated multipart Content-Type.

Editing an appended child. Retrieve it with PartAt. The object returned by PartAt is a live child, unlike the copied input to this method.

Returns true for success, false for failure.

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AppendPartFromFile
func (mime *Mime) AppendPartFromFile(filename string) bool

Reads the local file at filename, creates an attachment part, and appends it. Filename-extension matching is case-insensitive.

File kindGenerated headers
.txttext/plain; charset=windows-1252; format=flowed, 7bit, attachment filename and name
Known binary type, such as .PNGInferred media type such as image/png, base64, attachment filename and name
Unknown extensionapplication/octet-stream, base64, attachment filename and name

If the current object is not multipart, the same conversion described by AppendPart occurs. Calling this method on a new empty object therefore creates an empty part 0 and the file attachment as part 1.

Returns true for success, false for failure.

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AsnBodyToXml
func (mime *Mime) AsnBodyToXml() *string

Parses the current part's decoded body as ASN.1 DER and returns an XML representation of the ASN.1 structure. This is primarily useful for inspecting CMS/PKCS #7 bodies such as application/pkcs7-mime or application/x-pkcs7-mime.

Content-Type: application/pkcs7-mime; smime-type=signed-data
Content-Transfer-Encoding: base64

MII...
Diagnostic conversion. The returned XML exposes ASN.1 tags, object identifiers, and values for inspection. It is not the MIME-to-XML representation returned by GetXml.

Returns nil on failure

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ClearEncryptCerts
func (mime *Mime) ClearEncryptCerts()

Clears the internal recipient-certificate list populated by AddEncryptCert. A subsequent call to EncryptN requires certificates to be added again.

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ContainsEncryptedParts
func (mime *Mime) ContainsEncryptedParts() bool

Returns true if the currently visible MIME tree contains a CMS/PKCS #7 encrypted part.

Encrypted layers hide their contents. This method examines the MIME structure as it currently exists. It cannot report signed or encrypted entities nested inside ciphertext until UnwrapSecurity successfully decrypts the enclosing layer.

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ContainsSignedParts
func (mime *Mime) ContainsSignedParts() bool

Returns true if the currently visible MIME tree contains a detached or opaque CMS/PKCS #7 signed part.

Encrypted layers hide their contents. A signature nested inside encrypted data is not visible until the encrypted layer is successfully removed by UnwrapSecurity. After security layers are unwrapped, this method may return false because the signed wrapper has been removed.

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Convert8Bit
func (mime *Mime) Convert8Bit()

Recursively converts every part whose Content-Transfer-Encoding is 8bit or binary to base64. Both the child object's Encoding property and the serialized header are updated. Parts using 7bit or another encoding are unchanged.

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ConvertToMultipartAlt
func (mime *Mime) ConvertToMultipartAlt() bool

Wraps the current entity in a new outer multipart/alternative entity. The original entity becomes the first and initially only child.

The new outer entity retains message-level and custom headers such as MIME-Version, Date, Subject, From, To, Content-ID, Content-Location, and custom fields. The original Content-Type, Content-Transfer-Encoding, Content-Disposition, and body move to the first child. An existing charset parameter is retained on the new multipart Content-Type. Calling the method again wraps the existing multipart in another multipart layer; the operation is not idempotent.

Alternative ordering. Additional representations can be appended with AppendPart. Conventionally, alternatives are ordered from least rich to most rich, such as text/plain followed by text/html.

Returns true for success, false for failure.

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ConvertToMultipartMixed
func (mime *Mime) ConvertToMultipartMixed() bool

Wraps the current entity in a new outer multipart/mixed entity. The original entity becomes the first and initially only child.

The new outer entity retains message-level and custom headers such as MIME-Version, Date, Subject, From, To, Content-ID, Content-Location, and custom fields. The original Content-Type, Content-Transfer-Encoding, Content-Disposition, and body move to the first child. An existing charset parameter is retained on the new multipart Content-Type. Calling the method again wraps the existing multipart in another multipart layer; the operation is not idempotent.

Returns true for success, false for failure.

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ConvertToSigned
func (mime *Mime) ConvertToSigned(cert *Cert) bool

Creates an opaque (attached) S/MIME signature using cert. The certificate must have access to its private key. On success, the current MIME entity is replaced by CMS/PKCS #7 signed-data containing both the original MIME bytes and the signature.

This differs from AddDetachedSignature, which creates a visible multipart/signed wrapper with a separate signature part.

Returns true for success, false for failure.

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ConvertToSignedPk
func (mime *Mime) ConvertToSignedPk(cert *Cert, privateKey *PrivateKey) bool

Creates an opaque (attached) S/MIME signature using cert as the signer certificate and privateKey as its associated private key. Use this method when the certificate and private key are supplied separately.

The resulting CMS/PKCS #7 signed-data contains the original MIME entity and its signature. For a detached multipart/signed result, use AddDetachedSignaturePk.

Returns true for success, false for failure.

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Decrypt
func (mime *Mime) Decrypt() bool

Decrypts the current CMS/PKCS #7 encrypted MIME entity and replaces it with the recovered MIME content. Chilkat identifies the intended recipient from the CMS recipient information and searches the configured credential sources for the matching certificate and private key.

SourceHow it is supplied
Explicit certificateAddDecryptCert or DecryptUsingCert
PFX/P12AddPfxSourceFile, AddPfxSourceBd, or a DecryptUsingPfx... method
Certificate vaultUseCertVault
Platform certificate storeWindows certificate stores and the macOS Keychain are searched automatically where supported
CMS recipient information. Encrypted S/MIME normally contains recipient identifiers and encrypted content-encryption keys. The recipient private key is required to recover the content; the private key is never embedded in the message.

Returns true for success, false for failure.

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Decrypt2
func (mime *Mime) Decrypt2(cert *Cert, privateKey *PrivateKey) bool

Decrypts the current CMS/PKCS #7 encrypted MIME entity using the certificate in cert and its associated private key in privateKey. On success, the current object is replaced by the recovered MIME content.

Use this method when the certificate and private key are stored separately. Use Decrypt when Chilkat should locate the credential from configured sources.

Returns true for success, false for failure.

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DecryptUsingCert
func (mime *Mime) DecryptUsingCert(cert *Cert) bool
Introduced in version 9.5.0.40

Decrypts the current CMS/PKCS #7 encrypted MIME entity using cert. The certificate must have access to its corresponding private key. On success, the encrypted wrapper is replaced by the recovered MIME content.

Returns true for success, false for failure.

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DecryptUsingPfxData
func (mime *Mime) DecryptUsingPfxData(pfxData []byte, password string) bool

Legacy byte-array method. Decrypts the current CMS/PKCS #7 encrypted MIME entity using certificates and private keys from the PFX/P12 bytes in pfxData. password is the password protecting the PFX data.

On success, the encrypted wrapper is replaced by the recovered MIME content.

Returns true for success, false for failure.

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DecryptUsingPfxFile
func (mime *Mime) DecryptUsingPfxFile(pfxFilePath string, pfxPassword string) bool

Decrypts the current CMS/PKCS #7 encrypted MIME entity using certificates and private keys from the PFX/P12 file at the local filesystem path in pfxFilePath. pfxPassword is the password protecting the file.

On success, the encrypted wrapper is replaced by the recovered MIME content.

Returns true for success, false for failure.

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Encrypt
func (mime *Mime) Encrypt(cert *Cert) bool

Encrypts the current MIME entity for the recipient certificate in cert and replaces it with CMS/PKCS #7 encrypted S/MIME. Only the recipient's public key is needed to encrypt; the corresponding private key is required later to decrypt.

The content-encryption algorithm is selected by Pkcs7CryptAlg and Pkcs7KeyLength. For RSA recipients, OaepPadding, OaepHash, and OaepMgfHash control key transport.

Envelope encryption. The MIME content is encrypted once with a symmetric key. The recipient certificate protects that symmetric key, allowing only the holder of the matching private key to decrypt the message.

Returns true for success, false for failure.

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EncryptN
func (mime *Mime) EncryptN() bool

Encrypts the current MIME entity for every certificate previously added with AddEncryptCert. Each recipient receives independently protected access to the same encrypted content.

Add one certificate per intended recipient, call this method, and use ClearEncryptCerts before preparing a different recipient set.

Returns true for success, false for failure.

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GetBodyBd
func (mime *Mime) GetBodyBd(binDat *BinData) bool
Introduced in version 9.5.0.67

Replaces the contents of binDat with the decoded body bytes of the current part. Existing bytes in binDat are discarded. Base64 and quoted-printable are decoded. MIME headers, multipart boundaries, and child parts are not included.

Returns true for success, false for failure.

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GetBodyBinary
func (mime *Mime) GetBodyBinary() []byte

Returns the decoded body bytes of the current part. Base64 and quoted-printable are decoded, but no MIME headers or multipart framing are included. This legacy byte-array method preserves arbitrary bytes, including embedded NUL bytes.

Returns nil on failure

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GetBodyDecoded
func (mime *Mime) GetBodyDecoded() *string

Returns the decoded body as text. Chilkat first decodes the Content-Transfer-Encoding and then interprets text according to the declared charset.

Use a byte-oriented getter for binary content. A string result cannot reliably represent arbitrary binary bytes or embedded NUL bytes. Use GetBodyBd or GetBodyBinary for binary payloads.

Returns nil on failure

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GetBodyEncoded
func (mime *Mime) GetBodyEncoded() *string

Returns the current part's transfer-encoded body text without decoding Base64 or quoted-printable. The returned value is Chilkat's normalized serialization of the body, not necessarily the exact text that appeared in the loaded MIME. For example, Base64 padding and line wrapping or quoted-printable spelling may be regenerated.

Returns nil on failure

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GetDecryptCertInfo
func (mime *Mime) GetDecryptCertInfo(certInfo *JsonObject) bool
Introduced in version 11.4.0

Examines the current encrypted S/MIME entity and writes information about the required recipient certificate or certificates to the JsonObject in certInfo. This can be used to identify which certificate and private key must be made available before calling Decrypt or UnwrapSecurity.

No private key is revealed. The encrypted message contains recipient identifiers and encrypted key material, not the recipient private keys. This method reports identifying information available from the CMS recipient records.

Returns true for success, false for failure.

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GetEntireBody
func (mime *Mime) GetEntireBody() *string

Returns the complete serialized body of the current MIME entity. For multipart MIME, this includes boundary delimiters, each child part's headers and body, and the closing boundary. The current entity's own header fields are not included.

Use GetBodyDecoded when the decoded payload of a single part is needed.

Returns nil on failure

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GetEntireHead
func (mime *Mime) GetEntireHead() *string

Returns the complete serialized header section of the current MIME entity. The body and any multipart child content are not included.

Returns nil on failure

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GetHeaderField
func (mime *Mime) GetHeaderField(fieldName string) *string

Returns the value of the first header field whose name matches fieldName case-insensitively. Duplicate later occurrences are not combined. Returns null when no matching field exists.

Returns nil on failure

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GetHeaderFieldAttribute
func (mime *Mime) GetHeaderFieldAttribute(name string, attrName string) *string

Returns an attribute value parsed from the first header field named by name. Both the header name and attrName attribute name are matched case-insensitively. Surrounding quotation marks are removed, and semicolons inside a quoted value are handled as part of the value.

Extended parameters such as filename*=utf-8''r%C3%A9sum%C3%A9.txt are returned in their raw encoded form; this method does not percent-decode or apply the declared charset. Returns null when the field or attribute is absent.

Returns nil on failure

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GetHeaderFieldName
func (mime *Mime) GetHeaderFieldName(index int) *string

Returns the name of the header-field occurrence at zero-based index. Header order and original casing are preserved for ordinary loaded headers. Use NumHeaderFields to determine the valid range.

Returns nil on failure

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GetHeaderFieldValue
func (mime *Mime) GetHeaderFieldValue(index int) *string

Returns the unfolded value of the header-field occurrence at zero-based index. Continuation lines are combined into a single value. Use NumHeaderFields to determine the valid range.

Returns nil on failure

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GetLastJsonData
func (mime *Mime) GetLastJsonData(json *JsonObject)
Introduced in version 9.5.0.69

Copies structured details from the most recent operation into json when such details are available. Many methods do not produce JSON data. Methods involving CMS/PKCS #7 security, such as UnwrapSecurity, may report algorithms, certificates, recipients, signatures, and validation results.

Read immediately. The information describes the most recent applicable call on this object and can be replaced by a later operation.

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GetMime
func (mime *Mime) GetMime() *string

Serializes and returns the complete MIME entity, including headers, body, multipart boundaries, and all descendants.

Serialization is normalized. The result is semantically equivalent MIME, not a byte-for-byte copy of loaded input. Chilkat can unfold headers, normalize parameter quoting and transfer encodings, discard multipart preamble and epilogue text, and generate CRLF for headers and multipart framing. Existing body line endings may not always be rewritten.

Returns nil on failure

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GetMimeBd
func (mime *Mime) GetMimeBd(bindat *BinData) bool
Introduced in version 9.5.0.62

Serializes the complete MIME entity and appends its bytes to bindat. Existing BinData bytes are preserved. Use this method when arbitrary binary body bytes must not pass through a text string.

Serialization is normalized. The result is semantically equivalent MIME, not a byte-for-byte copy of loaded input. Chilkat can unfold headers, normalize parameter quoting and transfer encodings, discard multipart preamble and epilogue text, and generate CRLF for headers and multipart framing. Existing body line endings may not always be rewritten.

Returns true for success, false for failure.

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GetMimeBytes
func (mime *Mime) GetMimeBytes() []byte

Returns the complete serialized MIME entity as a byte array. This preserves binary body bytes that cannot safely pass through a string.

Serialization is normalized. The result is semantically equivalent MIME, not a byte-for-byte copy of loaded input. Chilkat can unfold headers, normalize parameter quoting and transfer encodings, discard multipart preamble and epilogue text, and generate CRLF for headers and multipart framing. Existing body line endings may not always be rewritten.

Returns nil on failure

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GetMimeSb
func (mime *Mime) GetMimeSb(sb *StringBuilder) bool
Introduced in version 9.5.0.62

Serializes the complete MIME entity and appends it to sb. Existing StringBuilder content is preserved.

Serialization is normalized. The result is semantically equivalent MIME, not a byte-for-byte copy of loaded input. Chilkat can unfold headers, normalize parameter quoting and transfer encodings, discard multipart preamble and epilogue text, and generate CRLF for headers and multipart framing. Existing body line endings may not always be rewritten.

Returns true for success, false for failure.

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GetSignatureSigningTimeStr
func (mime *Mime) GetSignatureSigningTimeStr(index int) *string

Returns the CMS signingTime signed attribute for the signer at zero-based index, formatted as an RFC 822-style date string. For example:

Fri, 21 Nov 1997 09:55:06 -0600

Call HasSignatureSigningTime first because the attribute is optional. Use NumSignerCerts for the signer count.

Signing time is not a trusted timestamp. The CMS signingTime value is supplied by the signer. It is different from a timestamp token issued and signed by a trusted timestamp authority.

Returns nil on failure

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GetStructure
func (mime *Mime) GetStructure(fmt string) *string
Introduced in version 9.5.0.56

Returns a concise MIME-tree summary. fmt is case-insensitive. The value xml selects XML output; all other values, including text, an empty string, or an unrecognized value, select the indented text format.

multipart/mixed
    text/plain
    application/octet-stream
<multipart-mixed>
    <text-plain />
    <application-octet-stream />
</multipart-mixed>

Returns nil on failure

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GetXml
func (mime *Mime) GetXml() *string

Converts the MIME tree to Chilkat's XML representation and returns it as a string. Header names become XML element names, structured header parameters become XML attributes, duplicate headers become repeated elements, multipart children are nested in subpart elements, and binary bodies are represented in an encoded textual form.

XML round-tripping is semantic. Loading this XML reconstructs an equivalent MIME tree, but it is not byte-preserving and header names are normalized to lowercase.

Returns nil on failure

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HasSignatureSigningTime
func (mime *Mime) HasSignatureSigningTime(index int) bool

Returns true if the signer at zero-based index has a CMS signingTime signed attribute. Use NumSignerCerts for the signer count and GetSignatureSigningTimeStr to retrieve the value.

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IsApplicationData
func (mime *Mime) IsApplicationData() bool

Returns true when ContentType begins with application/. It returns false for an empty or malformed media type.

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IsAttachment
func (mime *Mime) IsAttachment() bool

Returns true when the current part's disposition value is attachment, matched case-insensitively. Parameters such as filename do not affect the test. An inline part remains non-attachment even when it has a filename.

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IsAudio
func (mime *Mime) IsAudio() bool

Returns true when ContentType begins with audio/.

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IsEncrypted
func (mime *Mime) IsEncrypted() bool

Returns true when the current MIME entity is a CMS/PKCS #7 encrypted S/MIME wrapper. To search the visible MIME tree rather than only the current entity, use ContainsEncryptedParts.

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IsHtml
func (mime *Mime) IsHtml() bool

Returns true when ContentType is text/html. The ContentType property must contain only the media type; set parameters such as charset separately.

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IsImage
func (mime *Mime) IsImage() bool

Returns true when ContentType begins with image/, including values such as image/svg+xml.

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IsMultipart
func (mime *Mime) IsMultipart() bool

Returns true when ContentType begins with multipart/.

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IsMultipartAlternative
func (mime *Mime) IsMultipartAlternative() bool

Returns true when ContentType is multipart/alternative.

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IsMultipartMixed
func (mime *Mime) IsMultipartMixed() bool

Returns true when ContentType is multipart/mixed.

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IsMultipartRelated
func (mime *Mime) IsMultipartRelated() bool

Returns true when ContentType is multipart/related.

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IsPlainText
func (mime *Mime) IsPlainText() bool

Returns true when ContentType is text/plain.

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IsSigned
func (mime *Mime) IsSigned() bool

Returns true when the current MIME entity is a CMS/PKCS #7 signed S/MIME wrapper, including detached multipart/signed and opaque signed-data forms. To search the visible MIME tree, use ContainsSignedParts.

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IsText
func (mime *Mime) IsText() bool

Returns true when ContentType begins with text/.

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IsVideo
func (mime *Mime) IsVideo() bool

Returns true when ContentType begins with video/.

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IsXml
func (mime *Mime) IsXml() bool

Returns true only for text/xml or application/xml. It does not classify structured-suffix media types such as application/soap+xml, application/atom+xml, or image/svg+xml as XML.

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LastDecryptCert
func (mime *Mime) LastDecryptCert(index int, cert *Cert) bool
Introduced in version 11.0.0

Loads into cert the decryption certificate at zero-based index from the most recent security-unwrapping operation. Valid indexes range from 0 through NumDecryptCerts - 1.

Returns true for success, false for failure.

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LastSignerCert
func (mime *Mime) LastSignerCert(index int, cert *Cert) bool
Introduced in version 11.0.0

Loads into cert the signer certificate at zero-based index from the most recent signature-verification or security-unwrapping operation. Valid indexes range from 0 through NumSignerCerts - 1.

Returns true for success, false for failure.

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LoadMime
func (mime *Mime) LoadMime(mimeMsg string) bool

Parses the complete MIME text in mimeMsg and replaces the current object's headers, body, and multipart tree. A successful call always replaces the previous MIME.

If no blank line separates headers from the body, lines that appear header-like are parsed as headers and the body is empty. Data after the header/body separator belongs to the body.

Permissive parser and normalized output. Chilkat accepts many imperfect messages. Observed behavior includes ignoring malformed header lines and leading non-header text, using the last duplicate Content-Type, repairing a missing multipart closing delimiter during serialization, treating unmatched boundary-like text as an ordinary body, and tolerating malformed Base64 or quoted-printable. LF-only and CR-only input are accepted; generated headers and multipart framing use CRLF. Loading and reserializing is therefore not guaranteed to reproduce the original bytes, and multipart preamble and epilogue text are not retained.
Text input is not a raw-byte container. Use LoadMimeBd or LoadMimeBytes for arbitrary 8-bit bytes or embedded NUL bytes.

Returns true for success, false for failure.

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LoadMimeBd
func (mime *Mime) LoadMimeBd(bindat *BinData) bool
Introduced in version 9.5.0.62

Parses complete MIME bytes from bindat and replaces the current MIME on success. This is the preferred loader when the MIME can contain arbitrary 8-bit body bytes or embedded NUL bytes. Parsing tolerance and serialization normalization are the same as LoadMime.

Returns true for success, false for failure.

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LoadMimeBytes
func (mime *Mime) LoadMimeBytes(binData []byte) bool

Parses complete MIME bytes from binData and replaces the current MIME on success. This byte-oriented loader preserves arbitrary 8-bit values and embedded NUL bytes. Parsing tolerance and serialization normalization are the same as LoadMime.

Returns true for success, false for failure.

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LoadMimeFile
func (mime *Mime) LoadMimeFile(fileName string) bool

Reads and parses the complete MIME entity from the local file at fileName. A successful call replaces the current MIME. If the file cannot be opened, the method returns false and preserves the existing object unchanged.

Parsing tolerance and serialization normalization are the same as LoadMime.

Returns true for success, false for failure.

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LoadMimeSb
func (mime *Mime) LoadMimeSb(sb *StringBuilder) bool
Introduced in version 9.5.0.62

Parses complete MIME text from sb and replaces the current MIME on success. Parsing tolerance and serialization normalization are the same as LoadMime.

Use byte input for arbitrary MIME bytes. A StringBuilder is text-oriented. Use LoadMimeBd for binary MIME containing arbitrary 8-bit values or NUL bytes.

Returns true for success, false for failure.

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LoadXml
func (mime *Mime) LoadXml(xml string) bool

Reconstructs a MIME tree from Chilkat's MIME XML in xml. On success, the current object is replaced. If the XML is invalid, the method returns false and preserves the existing MIME unchanged.

The reconstructed MIME is semantically equivalent but not byte-identical to the MIME that produced the XML. Header names are normalized to lowercase.

Returns true for success, false for failure.

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LoadXmlFile
func (mime *Mime) LoadXmlFile(fileName string) bool

Reads Chilkat MIME XML from the local file at fileName and reconstructs the MIME tree. On success, the current object is replaced. If the file cannot be opened or the XML is invalid, the method returns false and preserves the existing MIME unchanged. Header names are normalized to lowercase during reconstruction.

Returns true for success, false for failure.

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NewMessageRfc822
func (mime *Mime) NewMessageRfc822(mimeObject *Mime) bool

Clears the current object and initializes it as message/rfc822. Its body is a serialized copy of mimeObject at the time of the call. Later modifications to mimeObject do not change the embedded message.

Returns true for success, false for failure.

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NewMultipartAlternative
func (mime *Mime) NewMultipartAlternative() bool

Initializes an empty multipart/alternative entity. Clears all existing headers, body content, and child parts. The new object contains only a multipart Content-Type with an automatically generated boundary, has zero parts, and does not automatically add MIME-Version.

Returns true for success, false for failure.

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NewMultipartMixed
func (mime *Mime) NewMultipartMixed() bool

Initializes an empty multipart/mixed entity. Clears all existing headers, body content, and child parts. The new object contains only a multipart Content-Type with an automatically generated boundary, has zero parts, and does not automatically add MIME-Version.

Returns true for success, false for failure.

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NewMultipartRelated
func (mime *Mime) NewMultipartRelated() bool

Initializes an empty multipart/related entity. Clears all existing headers, body content, and child parts. The new object contains only a multipart Content-Type with an automatically generated boundary, has zero parts, and does not automatically add MIME-Version.

Returns true for success, false for failure.

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PartAt
func (mime *Mime) PartAt(index int, subPart *Mime) bool
Introduced in version 11.0.0

Provides live access to the direct child at zero-based index through subPart. Modifying subPart after a successful call modifies the child stored in the parent MIME tree.

Valid indexes range from 0 through NumParts - 1. An invalid index returns false and preserves subPart unchanged.

Different from AppendPart. AppendPart stores a copy of its argument. This method exposes the actual stored child.

Returns true for success, false for failure.

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PartsToFiles
func (mime *Mime) PartsToFiles(path string, st *StringTable) bool
Introduced in version 11.0.0

Recursively traverses the MIME tree and saves each part having a nonempty filename parameter to the existing directory in path. A name parameter alone is not used as a fallback. The disposition may be attachment or inline; a filename is what controls extraction.

  • Only the final path component of a MIME filename is used. Directory components, absolute paths, and .. traversal are discarded.
  • On Windows, invalid filename characters are replaced with underscores.
  • Duplicate filenames target the same path; later parts overwrite earlier parts.
  • st is appended to rather than cleared. Each added entry is the full path actually written, including any sanitized filename.
  • The destination directory is not created. If it does not exist, the method returns false, creates no files, and appends nothing to st.
Treat MIME filenames as untrusted. Use a controlled destination directory and apply any application-specific policy for file types, size limits, overwriting, and renaming.

Returns true for success, false for failure.

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RemoveHeaderField
func (mime *Mime) RemoveHeaderField(fieldName string, bAllOccurrences bool)

Removes fields whose name matches fieldName case-insensitively. If bAllOccurrences is false, only the first matching occurrence is removed. If bAllOccurrences is true, all matching occurrences are removed. Remaining fields retain their relative order.

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RemovePart
func (mime *Mime) RemovePart(index int) bool

Removes the direct child at zero-based index. Valid indexes range from 0 through NumParts - 1. An out-of-range index returns false and leaves the tree unchanged.

Returns true for success, false for failure.

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SaveBody
func (mime *Mime) SaveBody(filename string) bool

Writes the decoded body bytes of the current part to the local path in filename. Base64 and quoted-printable are decoded. MIME headers and multipart framing are not written.

File behavior. Existing files are overwritten. Parent directories are not created, and passing a directory as the destination fails. On Windows, an existing read-only file is replaced and the read-only attribute is removed.

Returns true for success, false for failure.

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SaveMime
func (mime *Mime) SaveMime(filename string) bool

Serializes the complete MIME entity and writes it to the local path in filename, including headers, body, multipart boundaries, and all descendants.

Serialization is normalized. The result is semantically equivalent MIME, not a byte-for-byte copy of loaded input. Chilkat can unfold headers, normalize parameter quoting and transfer encodings, discard multipart preamble and epilogue text, and generate CRLF for headers and multipart framing. Existing body line endings may not always be rewritten.
File behavior. Existing files are overwritten. Parent directories are not created, and passing a directory as the destination fails. On Windows, an existing read-only file is replaced and the read-only attribute is removed.

Returns true for success, false for failure.

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SaveXml
func (mime *Mime) SaveXml(filename string) bool

Writes Chilkat's MIME XML representation to the local path in filename. The file can be loaded by LoadXmlFile.

File behavior. Existing files are overwritten. Parent directories are not created, and passing a directory as the destination fails. On Windows, an existing read-only file is replaced and the read-only attribute is removed.

Returns true for success, false for failure.

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SetBody
func (mime *Mime) SetBody(str string)

Sets the current part's body from str while preserving existing content headers such as Content-Type, charset, and Content-Transfer-Encoding.

Multipart entities serialize their child parts. Calling this method on a multipart object changes what the body getter methods return, but the assigned body is not included in the serialized multipart output while child parts are present. Build multipart content through AppendPart and PartAt.

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SetBodyBd
func (mime *Mime) SetBodyBd(bd *BinData) bool
Introduced in version 11.0.0

Sets the decoded body bytes from bd, changes Content-Transfer-Encoding to base64, and preserves the bytes exactly. It does not set a Content-Type, disposition, filename, or name; set those separately when needed.

Returns true for success, false for failure.

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SetBodyFromBinary
func (mime *Mime) SetBodyFromBinary(binData []byte) bool

Legacy byte-array method. Sets the decoded body bytes from binData, changes Content-Transfer-Encoding to base64, and preserves the bytes exactly. It does not set a Content-Type, disposition, filename, or name; set those separately when needed. Prefer SetBodyBd when using BinData.

Returns true for success, false for failure.

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SetBodyFromEncoded
func (mime *Mime) SetBodyFromEncoded(encoding string, str string) bool

Sets the body from transfer-encoded text. encoding must be base64 or quoted-printable; other values, including 7bit, 8bit, binary, an unknown name, or an empty string, cause failure.

Base64 whitespace is accepted and the stored representation is normalized. Invalid Base64 causes the method to return false. On any failure, all existing headers and body content are preserved unchanged.

Do not encode twice. str must already be in the encoding named by encoding. To provide decoded bytes, use SetBodyBd or SetBodyFromBinary.

Returns true for success, false for failure.

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SetBodyFromFile
func (mime *Mime) SetBodyFromFile(fileName string) bool

Reads the local file at fileName and replaces the current part's body and content headers according to the filename extension.

File kindResult
.txttext/plain; charset=windows-1252; format=flowed, 7bit
.htmltext/html; charset=windows-1252, 7bit
Unknown extensionapplication/octet-stream, base64, attachment, and filename/name parameters based on the local filename

If the file cannot be opened, the method returns false and preserves the existing MIME unchanged.

Returns true for success, false for failure.

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SetBodyFromHtml
func (mime *Mime) SetBodyFromHtml(str string) bool

Sets str as HTML and changes the media type to text/html. For ASCII input, Chilkat uses Content-Transfer-Encoding: 7bit and does not add a charset. Existing unrelated headers are preserved.

Returns true for success, false for failure.

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SetBodyFromPlainText
func (mime *Mime) SetBodyFromPlainText(str string) bool

Sets str as plain text. For ASCII input, Chilkat sets Content-Type: text/plain; format=flowed and Content-Transfer-Encoding: 7bit without a charset. For non-ASCII UTF-8 input, it sets charset=utf-8 and uses 8bit. Existing unrelated headers are preserved.

Returns true for success, false for failure.

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SetBodyFromXml
func (mime *Mime) SetBodyFromXml(str string) bool

Sets str as XML, changes the media type to text/xml, and selects a transfer encoding appropriate for the text. For ASCII input, Chilkat uses 7bit and does not add a charset.

The XML declaration's encoding value is not copied to the MIME charset parameter.

Different from LoadXml. This method places an XML document in the MIME body. LoadXml reconstructs an entire MIME object from Chilkat MIME XML.

Returns true for success, false for failure.

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SetHeaderField
func (mime *Mime) SetHeaderField(name string, value string) bool

Sets one header field named by name. Matching is case-insensitive. All existing occurrences are removed and one replacement is inserted. If no field exists, a new one is added. Passing an empty value removes all matching occurrences rather than creating an empty-valued field.

Use AddHeaderField to append another occurrence or to create an empty-valued field.

Returns true for success, false for failure.

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SetVerifyCert
func (mime *Mime) SetVerifyCert(cert *Cert) bool

Sets cert as an explicitly supplied signer certificate for subsequent signature verification. This is useful when the CMS/PKCS #7 signature does not embed the signer certificate or when the application must require a particular certificate.

The certificate's public key is used for verification; a private key is not required.

Returns true for success, false for failure.

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UnwrapSecurity
func (mime *Mime) UnwrapSecurity() bool

Recursively removes all visible S/MIME security layers from the MIME tree. It decrypts encrypted parts and verifies detached or opaque signatures, continuing through nested layers until no additional supported security wrapper remains.

On success, the object contains the original MIME structure and content from before signing and encryption. The method returns true only when every required decryption and signature verification succeeds.

After the callUse
NumSignerCerts and LastSignerCertInspect the certificates associated with verified signatures.
NumDecryptCerts and LastDecryptCertInspect certificates associated with decryption.
GetLastJsonDataInspect algorithms and other operation details.
Order matters. For a message that was signed and then encrypted, the encrypted layer must be removed before the inner signature can be seen and verified. This method handles such nesting automatically.

Returns true for success, false for failure.

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UrlEncodeBody
func (mime *Mime) UrlEncodeBody(charset string)

Replaces the current body with an application/x-www-form-urlencoded-style representation using the character set named by charset. Spaces become +, a literal plus becomes %2B, non-ASCII bytes become %HH sequences, and separators such as & and = remain unchanged.

Input:  a b+c&d=e
Output: a+b%2Bc&d=e

The MIME content headers are not changed. If the named character set is unsupported, the body remains unchanged.

Not a MIME transfer encoding. This operation is distinct from base64 and quoted-printable.

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UseCertVault
func (mime *Mime) UseCertVault(vault *XmlCertVault) bool

Sets vault as the certificate vault used to locate certificates and private keys for S/MIME encryption, decryption, signing, and verification. Only one vault is active; each call replaces the previously configured vault.

Use XmlCertVault when credentials are maintained independently of platform certificate stores or individual PFX sources.

Returns true for success, false for failure.

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Verify
func (mime *Mime) Verify() bool

Verifies the current CMS/PKCS #7 signed MIME entity and removes the signature wrapper. Both detached multipart/signed messages and opaque CMS signed-data are supported. On success, the object is restored to the MIME structure and content that was signed.

The signer certificate is commonly embedded in the signature. If it is absent, Chilkat searches configured or platform certificate sources, or uses a certificate supplied by SetVerifyCert.

What verification proves. Cryptographic verification establishes that the signed bytes have not changed and that the signature matches the signer certificate. Application trust decisions may additionally require validating the certificate chain, identity, usage, and revocation status.

Returns true for success, false for failure.

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Deprecated

NumEncryptCerts
func (mime *Mime) NumEncryptCerts() int
This property is deprecated. It will be removed in a future version.

Deprecated. Use NumDecryptCerts instead.

Returns the number of decryption certificates recorded by the most recent S/MIME security-unwrapping operation. The property is populated by UnwrapSecurity.

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ExtractPartsToFiles
func (mime *Mime) ExtractPartsToFiles(dirPath string) *StringArray
This method is deprecated and replaced by PartsToFiles

Deprecated. Applications should call PartsToFiles.

This method recursively saves parts having a nonempty filename parameter to the existing directory in dirPath and returns a StringArray containing the created paths. See PartsToFiles for the current extraction and filename-handling rules.

Returns nil on failure

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FindIssuer
func (mime *Mime) FindIssuer(cert *Cert) *Cert
This method is deprecated.

Deprecated. Use the certificate object's GetIssuer method instead.

Finds the issuer of cert. If cert is self-issued or a root certificate, the returned object is a copy of cert.

Returns nil on failure

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GetEncryptCert
func (mime *Mime) GetEncryptCert(index int) *Cert
This method is deprecated and replaced by LastDecryptCert

Deprecated. Use LastDecryptCert instead.

Returns the certificate at zero-based index from the certificates recorded by the most recent decryption operation. Use NumDecryptCerts for the count.

Returns nil on failure

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GetPart
func (mime *Mime) GetPart(index int) *Mime
This method is deprecated and replaced by PartAt

This method is deprecated. Applications should call PartAt.

Retrieves the direct child at zero-based index. The returned object provides live access to the child stored in the parent MIME tree, so modifying it modifies the parent.

Returns nil on failure

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GetSignerCert
func (mime *Mime) GetSignerCert(index int) *Cert
This method is deprecated and replaced by LastSignerCert

Deprecated. Use LastSignerCert instead.

Returns the signer certificate at zero-based index from the most recent verification or security-unwrapping operation.

Returns nil on failure

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GetSignerCertChain
func (mime *Mime) GetSignerCertChain(index int) *CertChain
Introduced in version 9.5.0.40
This method is deprecated.

Deprecated. Retrieve the signer certificate with LastSignerCert and then obtain its certificate chain through the Cert API.

This method returns the chain associated with the signer at zero-based index.

Returns nil on failure

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LastJsonData
func (mime *Mime) LastJsonData() *JsonObject
Introduced in version 9.5.0.69
This method is deprecated.

Deprecated. Use GetLastJsonData instead.

Returns a JsonObject containing details produced by the most recent operation when that operation provides structured diagnostic data. For example, after UnwrapSecurity, the JSON may describe the signature, key-transport, content-encryption, and certificate information encountered.

Returns nil on failure

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