|
| 1 | +//go:build go1.18 |
| 2 | +// +build go1.18 |
| 3 | + |
| 4 | +// Copyright (c) Microsoft Corporation. All rights reserved. |
| 5 | +// Licensed under the MIT License. See License.txt in the project root for license information. |
| 6 | + |
| 7 | +package sas |
| 8 | + |
| 9 | +import ( |
| 10 | + "bytes" |
| 11 | + "errors" |
| 12 | + "fmt" |
| 13 | + "strings" |
| 14 | + "time" |
| 15 | + |
| 16 | + "github.com/Azure/azure-sdk-for-go/sdk/storage/azdatalake/internal/exported" |
| 17 | +) |
| 18 | + |
| 19 | +// SharedKeyCredential contains an account's name and its primary or secondary key. |
| 20 | +type SharedKeyCredential = exported.SharedKeyCredential |
| 21 | + |
| 22 | +// UserDelegationCredential contains an account's name and its user delegation key. |
| 23 | +type UserDelegationCredential = exported.UserDelegationCredential |
| 24 | + |
| 25 | +// AccountSignatureValues is used to generate a Shared Access Signature (SAS) for an Azure Storage account. |
| 26 | +// For more information, see https://docs.microsoft.com/rest/api/storageservices/constructing-an-account-sas |
| 27 | +type AccountSignatureValues struct { |
| 28 | + Version string `param:"sv"` // If not specified, this format to SASVersion |
| 29 | + Protocol Protocol `param:"spr"` // See the SASProtocol* constants |
| 30 | + StartTime time.Time `param:"st"` // Not specified if IsZero |
| 31 | + ExpiryTime time.Time `param:"se"` // Not specified if IsZero |
| 32 | + Permissions string `param:"sp"` // Create by initializing AccountPermissions and then call String() |
| 33 | + IPRange IPRange `param:"sip"` |
| 34 | + ResourceTypes string `param:"srt"` // Create by initializing AccountResourceTypes and then call String() |
| 35 | +} |
| 36 | + |
| 37 | +// SignWithSharedKey uses an account's shared key credential to sign this signature values to produce |
| 38 | +// the proper SAS query parameters. |
| 39 | +func (v AccountSignatureValues) SignWithSharedKey(sharedKeyCredential *SharedKeyCredential) (QueryParameters, error) { |
| 40 | + // https://docs.microsoft.com/en-us/rest/api/storageservices/Constructing-an-Account-SAS |
| 41 | + if v.ExpiryTime.IsZero() || v.Permissions == "" || v.ResourceTypes == "" { |
| 42 | + return QueryParameters{}, errors.New("account SAS is missing at least one of these: ExpiryTime, Permissions, Service, or ResourceType") |
| 43 | + } |
| 44 | + if v.Version == "" { |
| 45 | + v.Version = Version |
| 46 | + } |
| 47 | + perms, err := parseAccountPermissions(v.Permissions) |
| 48 | + if err != nil { |
| 49 | + return QueryParameters{}, err |
| 50 | + } |
| 51 | + v.Permissions = perms.String() |
| 52 | + |
| 53 | + resources, err := parseAccountResourceTypes(v.ResourceTypes) |
| 54 | + if err != nil { |
| 55 | + return QueryParameters{}, err |
| 56 | + } |
| 57 | + v.ResourceTypes = resources.String() |
| 58 | + |
| 59 | + startTime, expiryTime := formatTimesForSigning(v.StartTime, v.ExpiryTime) |
| 60 | + |
| 61 | + stringToSign := strings.Join([]string{ |
| 62 | + sharedKeyCredential.AccountName(), |
| 63 | + v.Permissions, |
| 64 | + "b", // blob service |
| 65 | + v.ResourceTypes, |
| 66 | + startTime, |
| 67 | + expiryTime, |
| 68 | + v.IPRange.String(), |
| 69 | + string(v.Protocol), |
| 70 | + v.Version, |
| 71 | + ""}, // That is right, the account SAS requires a terminating extra newline |
| 72 | + "\n") |
| 73 | + |
| 74 | + signature, err := exported.ComputeHMACSHA256(sharedKeyCredential, stringToSign) |
| 75 | + if err != nil { |
| 76 | + return QueryParameters{}, err |
| 77 | + } |
| 78 | + p := QueryParameters{ |
| 79 | + // Common SAS parameters |
| 80 | + version: v.Version, |
| 81 | + protocol: v.Protocol, |
| 82 | + startTime: v.StartTime, |
| 83 | + expiryTime: v.ExpiryTime, |
| 84 | + permissions: v.Permissions, |
| 85 | + ipRange: v.IPRange, |
| 86 | + |
| 87 | + // Account-specific SAS parameters |
| 88 | + services: "b", // will always be "b" |
| 89 | + resourceTypes: v.ResourceTypes, |
| 90 | + |
| 91 | + // Calculated SAS signature |
| 92 | + signature: signature, |
| 93 | + } |
| 94 | + |
| 95 | + return p, nil |
| 96 | +} |
| 97 | + |
| 98 | +// AccountPermissions type simplifies creating the permissions string for an Azure Storage Account SAS. |
| 99 | +// Initialize an instance of this type and then call its String method to set AccountSignatureValues' Permissions field. |
| 100 | +type AccountPermissions struct { |
| 101 | + Read, Write, Delete, DeletePreviousVersion, PermanentDelete, List, Add, Create, Update, Process, FilterByTags, Tag, SetImmutabilityPolicy bool |
| 102 | +} |
| 103 | + |
| 104 | +// String produces the SAS permissions string for an Azure Storage account. |
| 105 | +// Call this method to set AccountSignatureValues' Permissions field. |
| 106 | +func (p *AccountPermissions) String() string { |
| 107 | + var buffer bytes.Buffer |
| 108 | + if p.Read { |
| 109 | + buffer.WriteRune('r') |
| 110 | + } |
| 111 | + if p.Write { |
| 112 | + buffer.WriteRune('w') |
| 113 | + } |
| 114 | + if p.Delete { |
| 115 | + buffer.WriteRune('d') |
| 116 | + } |
| 117 | + if p.DeletePreviousVersion { |
| 118 | + buffer.WriteRune('x') |
| 119 | + } |
| 120 | + if p.PermanentDelete { |
| 121 | + buffer.WriteRune('y') |
| 122 | + } |
| 123 | + if p.List { |
| 124 | + buffer.WriteRune('l') |
| 125 | + } |
| 126 | + if p.Add { |
| 127 | + buffer.WriteRune('a') |
| 128 | + } |
| 129 | + if p.Create { |
| 130 | + buffer.WriteRune('c') |
| 131 | + } |
| 132 | + if p.Update { |
| 133 | + buffer.WriteRune('u') |
| 134 | + } |
| 135 | + if p.Process { |
| 136 | + buffer.WriteRune('p') |
| 137 | + } |
| 138 | + if p.FilterByTags { |
| 139 | + buffer.WriteRune('f') |
| 140 | + } |
| 141 | + if p.Tag { |
| 142 | + buffer.WriteRune('t') |
| 143 | + } |
| 144 | + if p.SetImmutabilityPolicy { |
| 145 | + buffer.WriteRune('i') |
| 146 | + } |
| 147 | + return buffer.String() |
| 148 | +} |
| 149 | + |
| 150 | +// Parse initializes the AccountPermissions' fields from a string. |
| 151 | +func parseAccountPermissions(s string) (AccountPermissions, error) { |
| 152 | + p := AccountPermissions{} // Clear out the flags |
| 153 | + for _, r := range s { |
| 154 | + switch r { |
| 155 | + case 'r': |
| 156 | + p.Read = true |
| 157 | + case 'w': |
| 158 | + p.Write = true |
| 159 | + case 'd': |
| 160 | + p.Delete = true |
| 161 | + case 'x': |
| 162 | + p.DeletePreviousVersion = true |
| 163 | + case 'y': |
| 164 | + p.PermanentDelete = true |
| 165 | + case 'l': |
| 166 | + p.List = true |
| 167 | + case 'a': |
| 168 | + p.Add = true |
| 169 | + case 'c': |
| 170 | + p.Create = true |
| 171 | + case 'u': |
| 172 | + p.Update = true |
| 173 | + case 'p': |
| 174 | + p.Process = true |
| 175 | + case 't': |
| 176 | + p.Tag = true |
| 177 | + case 'f': |
| 178 | + p.FilterByTags = true |
| 179 | + case 'i': |
| 180 | + p.SetImmutabilityPolicy = true |
| 181 | + default: |
| 182 | + return AccountPermissions{}, fmt.Errorf("invalid permission character: '%v'", r) |
| 183 | + } |
| 184 | + } |
| 185 | + return p, nil |
| 186 | +} |
| 187 | + |
| 188 | +// AccountResourceTypes type simplifies creating the resource types string for an Azure Storage Account SAS. |
| 189 | +// Initialize an instance of this type and then call its String method to set AccountSignatureValues' ResourceTypes field. |
| 190 | +type AccountResourceTypes struct { |
| 191 | + Service, Container, Object bool |
| 192 | +} |
| 193 | + |
| 194 | +// String produces the SAS resource types string for an Azure Storage account. |
| 195 | +// Call this method to set AccountSignatureValues' ResourceTypes field. |
| 196 | +func (rt *AccountResourceTypes) String() string { |
| 197 | + var buffer bytes.Buffer |
| 198 | + if rt.Service { |
| 199 | + buffer.WriteRune('s') |
| 200 | + } |
| 201 | + if rt.Container { |
| 202 | + buffer.WriteRune('c') |
| 203 | + } |
| 204 | + if rt.Object { |
| 205 | + buffer.WriteRune('o') |
| 206 | + } |
| 207 | + return buffer.String() |
| 208 | +} |
| 209 | + |
| 210 | +// parseAccountResourceTypes initializes the AccountResourceTypes' fields from a string. |
| 211 | +func parseAccountResourceTypes(s string) (AccountResourceTypes, error) { |
| 212 | + rt := AccountResourceTypes{} |
| 213 | + for _, r := range s { |
| 214 | + switch r { |
| 215 | + case 's': |
| 216 | + rt.Service = true |
| 217 | + case 'c': |
| 218 | + rt.Container = true |
| 219 | + case 'o': |
| 220 | + rt.Object = true |
| 221 | + default: |
| 222 | + return AccountResourceTypes{}, fmt.Errorf("invalid resource type character: '%v'", r) |
| 223 | + } |
| 224 | + } |
| 225 | + return rt, nil |
| 226 | +} |
0 commit comments