|
| 1 | +package utils |
| 2 | + |
| 3 | +import ( |
| 4 | + "bytes" |
| 5 | + "context" |
| 6 | + "crypto/sha256" |
| 7 | + "encoding/hex" |
| 8 | + "fmt" |
| 9 | + "io" |
| 10 | + "net/http" |
| 11 | + "sync" |
| 12 | + "time" |
| 13 | + |
| 14 | + "github.com/aws/aws-sdk-go-v2/aws" |
| 15 | + v4 "github.com/aws/aws-sdk-go-v2/aws/signer/v4" |
| 16 | + "github.com/aws/aws-sdk-go-v2/config" |
| 17 | + "github.com/aws/aws-sdk-go-v2/credentials" |
| 18 | +) |
| 19 | + |
| 20 | +const ( |
| 21 | + emptySHA256 = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855" |
| 22 | + |
| 23 | + bedrockService = "bedrock" |
| 24 | +) |
| 25 | + |
| 26 | +type lazyCredentialsProvider struct { |
| 27 | + region string |
| 28 | + |
| 29 | + once sync.Once |
| 30 | + cp aws.CredentialsProvider |
| 31 | + err error |
| 32 | +} |
| 33 | + |
| 34 | +func NewBedrockDefaultCredentialsPreparer(region string) func(*http.Request) error { |
| 35 | + return NewSigV4Preparer(bedrockService, region, &lazyCredentialsProvider{region: region}) |
| 36 | +} |
| 37 | + |
| 38 | +func NewBedrockStaticCredentialsPreparer(region, accessKeyID, secretAccessKey, sessionToken string) func(*http.Request) error { |
| 39 | + cp := aws.NewCredentialsCache(credentials.NewStaticCredentialsProvider(accessKeyID, secretAccessKey, sessionToken)) |
| 40 | + return NewSigV4Preparer(bedrockService, region, cp) |
| 41 | +} |
| 42 | + |
| 43 | +func NewSigV4Preparer(service, region string, cp aws.CredentialsProvider) func(*http.Request) error { |
| 44 | + signer := v4.NewSigner() |
| 45 | + |
| 46 | + return func(req *http.Request) error { |
| 47 | + payloadHash, err := requestPayloadHash(req) |
| 48 | + if err != nil { |
| 49 | + return err |
| 50 | + } |
| 51 | + |
| 52 | + creds, err := cp.Retrieve(req.Context()) |
| 53 | + if err != nil { |
| 54 | + return fmt.Errorf("retrieve AWS credentials: %w", err) |
| 55 | + } |
| 56 | + |
| 57 | + if err := signer.SignHTTP(req.Context(), creds, req, payloadHash, service, region, time.Now().UTC()); err != nil { |
| 58 | + return fmt.Errorf("sign AWS request: %w", err) |
| 59 | + } |
| 60 | + |
| 61 | + return nil |
| 62 | + } |
| 63 | +} |
| 64 | + |
| 65 | +func (p *lazyCredentialsProvider) Retrieve(ctx context.Context) (aws.Credentials, error) { |
| 66 | + p.once.Do(func() { |
| 67 | + cfg, err := config.LoadDefaultConfig(ctx, config.WithRegion(p.region)) |
| 68 | + if err != nil { |
| 69 | + p.err = err |
| 70 | + return |
| 71 | + } |
| 72 | + p.cp = cfg.Credentials |
| 73 | + }) |
| 74 | + if p.err != nil { |
| 75 | + return aws.Credentials{}, p.err |
| 76 | + } |
| 77 | + return p.cp.Retrieve(ctx) |
| 78 | +} |
| 79 | + |
| 80 | +func requestPayloadHash(req *http.Request) (string, error) { |
| 81 | + if req.Body == nil { |
| 82 | + return emptySHA256, nil |
| 83 | + } |
| 84 | + |
| 85 | + if req.GetBody != nil { |
| 86 | + body, err := req.GetBody() |
| 87 | + if err != nil { |
| 88 | + return "", fmt.Errorf("clone request body: %w", err) |
| 89 | + } |
| 90 | + defer body.Close() |
| 91 | + return hashReader(body) |
| 92 | + } |
| 93 | + |
| 94 | + data, err := io.ReadAll(req.Body) |
| 95 | + if err != nil { |
| 96 | + return "", fmt.Errorf("read request body: %w", err) |
| 97 | + } |
| 98 | + |
| 99 | + req.Body = io.NopCloser(bytes.NewReader(data)) |
| 100 | + req.GetBody = func() (io.ReadCloser, error) { |
| 101 | + return io.NopCloser(bytes.NewReader(data)), nil |
| 102 | + } |
| 103 | + |
| 104 | + return hashBytes(data), nil |
| 105 | +} |
| 106 | + |
| 107 | +func hashReader(r io.Reader) (string, error) { |
| 108 | + h := sha256.New() |
| 109 | + if _, err := io.Copy(h, r); err != nil { |
| 110 | + return "", fmt.Errorf("hash request body: %w", err) |
| 111 | + } |
| 112 | + return hex.EncodeToString(h.Sum(nil)), nil |
| 113 | +} |
| 114 | + |
| 115 | +func hashBytes(data []byte) string { |
| 116 | + sum := sha256.Sum256(data) |
| 117 | + return hex.EncodeToString(sum[:]) |
| 118 | +} |
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