diff --git a/src/crypto/sha256/sha256block_decl.go b/src/crypto/sha256/sha256block_decl.go
index 85374cbdbb59bbd6037819706c98009be33828de..d622c3b174482d98545d25ebca4b416444d44b0b 100644
--- a/src/crypto/sha256/sha256block_decl.go
+++ b/src/crypto/sha256/sha256block_decl.go
@@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-//go:build (386 || amd64 || s390x || ppc64le || ppc64) && !purego
+//go:build (386 || amd64 || s390x || ppc64le || ppc64 || riscv64) && !purego
package sha256
diff --git a/src/crypto/sha256/sha256block_generic.go b/src/crypto/sha256/sha256block_generic.go
index 2964255f99cc55b1feb3a8a5d09f535eaf15ec11..4d21bdffbd8125ba703cb89ef85b333cb4ebe408 100644
--- a/src/crypto/sha256/sha256block_generic.go
+++ b/src/crypto/sha256/sha256block_generic.go
@@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-//go:build (!amd64 && !386 && !s390x && !ppc64le && !ppc64 && !arm64) || purego
+//go:build (!386 && !amd64 && !arm64 && !ppc64 && !ppc64le && !riscv64 && !s390x) || purego
package sha256
diff --git a/src/crypto/sha256/sha256block_riscv64.s b/src/crypto/sha256/sha256block_riscv64.s
new file mode 100644
index 0000000000000000000000000000000000000000..f31bfb8d53d1b97e8c2f4a6530d3a463064dbf9d
--- /dev/null
+++ b/src/crypto/sha256/sha256block_riscv64.s
@@ -0,0 +1,263 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !purego
+
+#include "textflag.h"
+
+// SHA256 block routine. See sha256block.go for Go equivalent.
+//
+// The algorithm is detailed in FIPS 180-4:
+//
+// https://csrc.nist.gov/publications/fips/fips180-4/fips-180-4.pdf
+//
+// Wt = Mt; for 0 <= t <= 15
+// Wt = SIGMA1(Wt-2) + SIGMA0(Wt-15) + Wt-16; for 16 <= t <= 63
+//
+// a = H0
+// b = H1
+// c = H2
+// d = H3
+// e = H4
+// f = H5
+// g = H6
+// h = H7
+//
+// for t = 0 to 63 {
+// T1 = h + BIGSIGMA1(e) + Ch(e,f,g) + Kt + Wt
+// T2 = BIGSIGMA0(a) + Maj(a,b,c)
+// h = g
+// g = f
+// f = e
+// e = d + T1
+// d = c
+// c = b
+// b = a
+// a = T1 + T2
+// }
+//
+// H0 = a + H0
+// H1 = b + H1
+// H2 = c + H2
+// H3 = d + H3
+// H4 = e + H4
+// H5 = f + H5
+// H6 = g + H6
+// H7 = h + H7
+
+// Wt = Mt; for 0 <= t <= 15
+#define MSGSCHEDULE0(index) \
+ MOVBU ((index*4)+0)(X29), X5; \
+ MOVBU ((index*4)+1)(X29), X6; \
+ MOVBU ((index*4)+2)(X29), X7; \
+ MOVBU ((index*4)+3)(X29), X8; \
+ SLL $24, X5; \
+ SLL $16, X6; \
+ OR X5, X6, X5; \
+ SLL $8, X7; \
+ OR X5, X7, X5; \
+ OR X5, X8, X5; \
+ MOVW X5, (index*4)(X19)
+
+// Wt = SIGMA1(Wt-2) + Wt-7 + SIGMA0(Wt-15) + Wt-16; for 16 <= t <= 63
+// SIGMA0(x) = ROTR(7,x) XOR ROTR(18,x) XOR SHR(3,x)
+// SIGMA1(x) = ROTR(17,x) XOR ROTR(19,x) XOR SHR(10,x)
+#define MSGSCHEDULE1(index) \
+ MOVWU (((index-2)&0xf)*4)(X19), X5; \
+ MOVWU (((index-15)&0xf)*4)(X19), X6; \
+ MOVWU (((index-7)&0xf)*4)(X19), X9; \
+ MOVWU (((index-16)&0xf)*4)(X19), X21; \
+ RORW $17, X5, X7; \
+ RORW $19, X5, X8; \
+ SRL $10, X5; \
+ XOR X7, X5; \
+ XOR X8, X5; \
+ ADD X9, X5; \
+ RORW $7, X6, X7; \
+ RORW $18, X6, X8; \
+ SRL $3, X6; \
+ XOR X7, X6; \
+ XOR X8, X6; \
+ ADD X6, X5; \
+ ADD X21, X5; \
+ MOVW X5, ((index&0xf)*4)(X19)
+
+// Calculate T1 in X5.
+// h is also used as an accumulator. Wt is passed in X5.
+// T1 = h + BIGSIGMA1(e) + Ch(e, f, g) + Kt + Wt
+// BIGSIGMA1(x) = ROTR(6,x) XOR ROTR(11,x) XOR ROTR(25,x)
+// Ch(x, y, z) = (x AND y) XOR (NOT x AND z)
+#define SHA256T1(index, e, f, g, h) \
+ MOVWU (index*4)(X18), X8; \
+ ADD X5, h; \
+ RORW $6, e, X6; \
+ ADD X8, h; \
+ RORW $11, e, X7; \
+ XOR X7, X6; \
+ RORW $25, e, X8; \
+ XOR X8, X6; \
+ ADD X6, h; \
+ AND e, f, X5; \
+ NOT e, X7; \
+ AND g, X7; \
+ XOR X7, X5; \
+ ADD h, X5
+
+// Calculate T2 in X6.
+// T2 = BIGSIGMA0(a) + Maj(a, b, c)
+// BIGSIGMA0(x) = ROTR(2,x) XOR ROTR(13,x) XOR ROTR(22,x)
+// Maj(x, y, z) = (x AND y) XOR (x AND z) XOR (y AND z)
+#define SHA256T2(a, b, c) \
+ RORW $2, a, X6; \
+ RORW $13, a, X7; \
+ XOR X7, X6; \
+ RORW $22, a, X8; \
+ XOR X8, X6; \
+ AND a, b, X7; \
+ AND a, c, X8; \
+ XOR X8, X7; \
+ AND b, c, X9; \
+ XOR X9, X7; \
+ ADD X7, X6
+
+// Calculate T1 and T2, then e = d + T1 and a = T1 + T2.
+// The values for e and a are stored in d and h, ready for rotation.
+#define SHA256ROUND(index, a, b, c, d, e, f, g, h) \
+ SHA256T1(index, e, f, g, h); \
+ SHA256T2(a, b, c); \
+ MOV X6, h; \
+ ADD X5, d; \
+ ADD X5, h
+
+#define SHA256ROUND0(index, a, b, c, d, e, f, g, h) \
+ MSGSCHEDULE0(index); \
+ SHA256ROUND(index, a, b, c, d, e, f, g, h)
+
+#define SHA256ROUND1(index, a, b, c, d, e, f, g, h) \
+ MSGSCHEDULE1(index); \
+ SHA256ROUND(index, a, b, c, d, e, f, g, h)
+
+// Note that 64 bytes of stack space is used as a circular buffer
+// for the message schedule (4 bytes * 16 entries).
+//
+// func block(dig *digest, p []byte)
+TEXT ·block(SB),0,$64-32
+ MOV p_base+8(FP), X29
+ MOV p_len+16(FP), X30
+ SRL $6, X30
+ SLL $6, X30
+
+ ADD X29, X30, X28
+ BEQ X28, X29, end
+
+ MOV ·_K(SB), X18 // const table
+ ADD $8, X2, X19 // message schedule
+
+ MOV dig+0(FP), X20
+ MOVWU (0*4)(X20), X10 // a = H0
+ MOVWU (1*4)(X20), X11 // b = H1
+ MOVWU (2*4)(X20), X12 // c = H2
+ MOVWU (3*4)(X20), X13 // d = H3
+ MOVWU (4*4)(X20), X14 // e = H4
+ MOVWU (5*4)(X20), X15 // f = H5
+ MOVWU (6*4)(X20), X16 // g = H6
+ MOVWU (7*4)(X20), X17 // h = H7
+
+loop:
+ SHA256ROUND0(0, X10, X11, X12, X13, X14, X15, X16, X17)
+ SHA256ROUND0(1, X17, X10, X11, X12, X13, X14, X15, X16)
+ SHA256ROUND0(2, X16, X17, X10, X11, X12, X13, X14, X15)
+ SHA256ROUND0(3, X15, X16, X17, X10, X11, X12, X13, X14)
+ SHA256ROUND0(4, X14, X15, X16, X17, X10, X11, X12, X13)
+ SHA256ROUND0(5, X13, X14, X15, X16, X17, X10, X11, X12)
+ SHA256ROUND0(6, X12, X13, X14, X15, X16, X17, X10, X11)
+ SHA256ROUND0(7, X11, X12, X13, X14, X15, X16, X17, X10)
+ SHA256ROUND0(8, X10, X11, X12, X13, X14, X15, X16, X17)
+ SHA256ROUND0(9, X17, X10, X11, X12, X13, X14, X15, X16)
+ SHA256ROUND0(10, X16, X17, X10, X11, X12, X13, X14, X15)
+ SHA256ROUND0(11, X15, X16, X17, X10, X11, X12, X13, X14)
+ SHA256ROUND0(12, X14, X15, X16, X17, X10, X11, X12, X13)
+ SHA256ROUND0(13, X13, X14, X15, X16, X17, X10, X11, X12)
+ SHA256ROUND0(14, X12, X13, X14, X15, X16, X17, X10, X11)
+ SHA256ROUND0(15, X11, X12, X13, X14, X15, X16, X17, X10)
+
+ SHA256ROUND1(16, X10, X11, X12, X13, X14, X15, X16, X17)
+ SHA256ROUND1(17, X17, X10, X11, X12, X13, X14, X15, X16)
+ SHA256ROUND1(18, X16, X17, X10, X11, X12, X13, X14, X15)
+ SHA256ROUND1(19, X15, X16, X17, X10, X11, X12, X13, X14)
+ SHA256ROUND1(20, X14, X15, X16, X17, X10, X11, X12, X13)
+ SHA256ROUND1(21, X13, X14, X15, X16, X17, X10, X11, X12)
+ SHA256ROUND1(22, X12, X13, X14, X15, X16, X17, X10, X11)
+ SHA256ROUND1(23, X11, X12, X13, X14, X15, X16, X17, X10)
+ SHA256ROUND1(24, X10, X11, X12, X13, X14, X15, X16, X17)
+ SHA256ROUND1(25, X17, X10, X11, X12, X13, X14, X15, X16)
+ SHA256ROUND1(26, X16, X17, X10, X11, X12, X13, X14, X15)
+ SHA256ROUND1(27, X15, X16, X17, X10, X11, X12, X13, X14)
+ SHA256ROUND1(28, X14, X15, X16, X17, X10, X11, X12, X13)
+ SHA256ROUND1(29, X13, X14, X15, X16, X17, X10, X11, X12)
+ SHA256ROUND1(30, X12, X13, X14, X15, X16, X17, X10, X11)
+ SHA256ROUND1(31, X11, X12, X13, X14, X15, X16, X17, X10)
+ SHA256ROUND1(32, X10, X11, X12, X13, X14, X15, X16, X17)
+ SHA256ROUND1(33, X17, X10, X11, X12, X13, X14, X15, X16)
+ SHA256ROUND1(34, X16, X17, X10, X11, X12, X13, X14, X15)
+ SHA256ROUND1(35, X15, X16, X17, X10, X11, X12, X13, X14)
+ SHA256ROUND1(36, X14, X15, X16, X17, X10, X11, X12, X13)
+ SHA256ROUND1(37, X13, X14, X15, X16, X17, X10, X11, X12)
+ SHA256ROUND1(38, X12, X13, X14, X15, X16, X17, X10, X11)
+ SHA256ROUND1(39, X11, X12, X13, X14, X15, X16, X17, X10)
+ SHA256ROUND1(40, X10, X11, X12, X13, X14, X15, X16, X17)
+ SHA256ROUND1(41, X17, X10, X11, X12, X13, X14, X15, X16)
+ SHA256ROUND1(42, X16, X17, X10, X11, X12, X13, X14, X15)
+ SHA256ROUND1(43, X15, X16, X17, X10, X11, X12, X13, X14)
+ SHA256ROUND1(44, X14, X15, X16, X17, X10, X11, X12, X13)
+ SHA256ROUND1(45, X13, X14, X15, X16, X17, X10, X11, X12)
+ SHA256ROUND1(46, X12, X13, X14, X15, X16, X17, X10, X11)
+ SHA256ROUND1(47, X11, X12, X13, X14, X15, X16, X17, X10)
+ SHA256ROUND1(48, X10, X11, X12, X13, X14, X15, X16, X17)
+ SHA256ROUND1(49, X17, X10, X11, X12, X13, X14, X15, X16)
+ SHA256ROUND1(50, X16, X17, X10, X11, X12, X13, X14, X15)
+ SHA256ROUND1(51, X15, X16, X17, X10, X11, X12, X13, X14)
+ SHA256ROUND1(52, X14, X15, X16, X17, X10, X11, X12, X13)
+ SHA256ROUND1(53, X13, X14, X15, X16, X17, X10, X11, X12)
+ SHA256ROUND1(54, X12, X13, X14, X15, X16, X17, X10, X11)
+ SHA256ROUND1(55, X11, X12, X13, X14, X15, X16, X17, X10)
+ SHA256ROUND1(56, X10, X11, X12, X13, X14, X15, X16, X17)
+ SHA256ROUND1(57, X17, X10, X11, X12, X13, X14, X15, X16)
+ SHA256ROUND1(58, X16, X17, X10, X11, X12, X13, X14, X15)
+ SHA256ROUND1(59, X15, X16, X17, X10, X11, X12, X13, X14)
+ SHA256ROUND1(60, X14, X15, X16, X17, X10, X11, X12, X13)
+ SHA256ROUND1(61, X13, X14, X15, X16, X17, X10, X11, X12)
+ SHA256ROUND1(62, X12, X13, X14, X15, X16, X17, X10, X11)
+ SHA256ROUND1(63, X11, X12, X13, X14, X15, X16, X17, X10)
+
+ MOVWU (0*4)(X20), X5
+ MOVWU (1*4)(X20), X6
+ MOVWU (2*4)(X20), X7
+ MOVWU (3*4)(X20), X8
+ ADD X5, X10 // H0 = a + H0
+ ADD X6, X11 // H1 = b + H1
+ ADD X7, X12 // H2 = c + H2
+ ADD X8, X13 // H3 = d + H3
+ MOVW X10, (0*4)(X20)
+ MOVW X11, (1*4)(X20)
+ MOVW X12, (2*4)(X20)
+ MOVW X13, (3*4)(X20)
+ MOVWU (4*4)(X20), X5
+ MOVWU (5*4)(X20), X6
+ MOVWU (6*4)(X20), X7
+ MOVWU (7*4)(X20), X8
+ ADD X5, X14 // H4 = e + H4
+ ADD X6, X15 // H5 = f + H5
+ ADD X7, X16 // H6 = g + H6
+ ADD X8, X17 // H7 = h + H7
+ MOVW X14, (4*4)(X20)
+ MOVW X15, (5*4)(X20)
+ MOVW X16, (6*4)(X20)
+ MOVW X17, (7*4)(X20)
+
+ ADD $64, X29
+ BNE X28, X29, loop
+
+end:
+ RET