| Message ID | 20211112125928.97318-5-hare@suse.de (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | nvme: In-band authentication support | expand |
On 11/12/21 06:59, Hannes Reinecke wrote: > Add RFC4648-compliant base64 encoding and decoding routines, based on > the base64url encoding in fs/crypto/fname.c. > > Signed-off-by: Hannes Reinecke <hare@suse.de> > --- > include/linux/base64.h | 16 +++++++ > lib/Makefile | 2 +- > lib/base64.c | 103 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 120 insertions(+), 1 deletion(-) > create mode 100644 include/linux/base64.h > create mode 100644 lib/base64.c > > diff --git a/include/linux/base64.h b/include/linux/base64.h > new file mode 100644 > index 000000000000..660d4cb1ef31 > --- /dev/null > +++ b/include/linux/base64.h > @@ -0,0 +1,16 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * base64 encoding, lifted from fs/crypto/fname.c. > + */ > + > +#ifndef _LINUX_BASE64_H > +#define _LINUX_BASE64_H > + > +#include <linux/types.h> > + > +#define BASE64_CHARS(nbytes) DIV_ROUND_UP((nbytes) * 4, 3) > + > +int base64_encode(const u8 *src, int len, char *dst); > +int base64_decode(const char *src, int len, u8 *dst); > + > +#endif /* _LINUX_BASE64_H */ > diff --git a/lib/Makefile b/lib/Makefile > index 364c23f15578..ddc5cb4c6eb8 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -46,7 +46,7 @@ obj-y += bcd.o sort.o parser.o debug_locks.o random32.o \ > bust_spinlocks.o kasprintf.o bitmap.o scatterlist.o \ > list_sort.o uuid.o iov_iter.o clz_ctz.o \ > bsearch.o find_bit.o llist.o memweight.o kfifo.o \ > - percpu-refcount.o rhashtable.o \ > + percpu-refcount.o rhashtable.o base64.o \ > once.o refcount.o usercopy.o errseq.o bucket_locks.o \ > generic-radix-tree.o > obj-$(CONFIG_STRING_SELFTEST) += test_string.o > diff --git a/lib/base64.c b/lib/base64.c > new file mode 100644 > index 000000000000..60d46157da85 > --- /dev/null > +++ b/lib/base64.c > @@ -0,0 +1,103 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * base64.c - RFC4648-compliant base64 encoding > + * > + * Copyright (c) 2020 Hannes Reinecke, SUSE > + * > + * Based on the base64url routines from fs/crypto/fname.c > + * (which are using the URL-safe base64 encoding), > + * modified to use the standard coding table from RFC4648 section 4. > + */ > + > +#include <linux/kernel.h> > +#include <linux/types.h> > +#include <linux/export.h> > +#include <linux/string.h> > +#include <linux/base64.h> > + > +static const char base64_table[65] = > + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; > + > +/** > + * base64_encode() - base64-encode some binary data > + * @src: the binary data to encode > + * @srclen: the length of @src in bytes > + * @dst: (output) the base64-encoded string. Not NUL-terminated. > + * > + * Encodes data using base64 encoding, i.e. the "Base 64 Encoding" specified > + * by RFC 4648, including the '='-padding. > + * > + * Return: the length of the resulting base64url-encoded string in bytes. > + */ > +int base64_encode(const u8 *src, int srclen, char *dst) > +{ > + u32 ac = 0; > + int bits = 0; > + int i; > + char *cp = dst; > + > + for (i = 0; i < srclen; i++) { > + ac = (ac << 8) | src[i]; > + bits += 8; > + do { > + bits -= 6; > + *cp++ = base64_table[(ac >> bits) & 0x3f]; > + } while (bits >= 6); > + } > + if (bits) { > + *cp++ = base64_table[(ac << (6 - bits)) & 0x3f]; > + bits -= 6; > + } > + while (bits < 0) { > + *cp++ = '='; > + bits += 2; > + } > + return cp - dst; > +} > +EXPORT_SYMBOL_GPL(base64_encode); > + > +/** > + * base64_decode() - base64-decode a string > + * @src: the string to decode. Doesn't need to be NUL-terminated. > + * @srclen: the length of @src in bytes > + * @dst: (output) the decoded binary data > + * > + * Decodes a string using base64url encoding, i.e. the "Base 64 Encoding" > + * specified by RFC 4648, including the '='-padding. > + * > + * This implementation hasn't been optimized for performance. > + * > + * Return: the length of the resulting decoded binary data in bytes, > + * or -1 if the string isn't a valid base64 string. > + */ > +int base64_decode(const char *src, int srclen, u8 *dst) > +{ > + u32 ac = 0; > + int bits = 0; > + int i; > + u8 *bp = dst; > + > + for (i = 0; i < srclen; i++) { > + const char *p = strchr(base64_table, src[i]); > + > + if (src[i] == '=') { > + ac = (ac << 6); > + bits += 6; > + if (bits >= 8) > + bits -= 8; > + continue; > + } > + if (p == NULL || src[i] == 0) > + return -1; > + ac = (ac << 6) | (p - base64_table); > + bits += 6; > + if (bits >= 8) { > + bits -= 8; > + *bp++ = (u8)(ac >> bits); > + } > + } > + if (ac & ((1 << bits) - 1)) > + return -1; > + return bp - dst; > +} > +EXPORT_SYMBOL_GPL(base64_decode); > Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
diff --git a/include/linux/base64.h b/include/linux/base64.h new file mode 100644 index 000000000000..660d4cb1ef31 --- /dev/null +++ b/include/linux/base64.h @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * base64 encoding, lifted from fs/crypto/fname.c. + */ + +#ifndef _LINUX_BASE64_H +#define _LINUX_BASE64_H + +#include <linux/types.h> + +#define BASE64_CHARS(nbytes) DIV_ROUND_UP((nbytes) * 4, 3) + +int base64_encode(const u8 *src, int len, char *dst); +int base64_decode(const char *src, int len, u8 *dst); + +#endif /* _LINUX_BASE64_H */ diff --git a/lib/Makefile b/lib/Makefile index 364c23f15578..ddc5cb4c6eb8 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -46,7 +46,7 @@ obj-y += bcd.o sort.o parser.o debug_locks.o random32.o \ bust_spinlocks.o kasprintf.o bitmap.o scatterlist.o \ list_sort.o uuid.o iov_iter.o clz_ctz.o \ bsearch.o find_bit.o llist.o memweight.o kfifo.o \ - percpu-refcount.o rhashtable.o \ + percpu-refcount.o rhashtable.o base64.o \ once.o refcount.o usercopy.o errseq.o bucket_locks.o \ generic-radix-tree.o obj-$(CONFIG_STRING_SELFTEST) += test_string.o diff --git a/lib/base64.c b/lib/base64.c new file mode 100644 index 000000000000..60d46157da85 --- /dev/null +++ b/lib/base64.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * base64.c - RFC4648-compliant base64 encoding + * + * Copyright (c) 2020 Hannes Reinecke, SUSE + * + * Based on the base64url routines from fs/crypto/fname.c + * (which are using the URL-safe base64 encoding), + * modified to use the standard coding table from RFC4648 section 4. + */ + +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/export.h> +#include <linux/string.h> +#include <linux/base64.h> + +static const char base64_table[65] = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + +/** + * base64_encode() - base64-encode some binary data + * @src: the binary data to encode + * @srclen: the length of @src in bytes + * @dst: (output) the base64-encoded string. Not NUL-terminated. + * + * Encodes data using base64 encoding, i.e. the "Base 64 Encoding" specified + * by RFC 4648, including the '='-padding. + * + * Return: the length of the resulting base64url-encoded string in bytes. + */ +int base64_encode(const u8 *src, int srclen, char *dst) +{ + u32 ac = 0; + int bits = 0; + int i; + char *cp = dst; + + for (i = 0; i < srclen; i++) { + ac = (ac << 8) | src[i]; + bits += 8; + do { + bits -= 6; + *cp++ = base64_table[(ac >> bits) & 0x3f]; + } while (bits >= 6); + } + if (bits) { + *cp++ = base64_table[(ac << (6 - bits)) & 0x3f]; + bits -= 6; + } + while (bits < 0) { + *cp++ = '='; + bits += 2; + } + return cp - dst; +} +EXPORT_SYMBOL_GPL(base64_encode); + +/** + * base64_decode() - base64-decode a string + * @src: the string to decode. Doesn't need to be NUL-terminated. + * @srclen: the length of @src in bytes + * @dst: (output) the decoded binary data + * + * Decodes a string using base64url encoding, i.e. the "Base 64 Encoding" + * specified by RFC 4648, including the '='-padding. + * + * This implementation hasn't been optimized for performance. + * + * Return: the length of the resulting decoded binary data in bytes, + * or -1 if the string isn't a valid base64 string. + */ +int base64_decode(const char *src, int srclen, u8 *dst) +{ + u32 ac = 0; + int bits = 0; + int i; + u8 *bp = dst; + + for (i = 0; i < srclen; i++) { + const char *p = strchr(base64_table, src[i]); + + if (src[i] == '=') { + ac = (ac << 6); + bits += 6; + if (bits >= 8) + bits -= 8; + continue; + } + if (p == NULL || src[i] == 0) + return -1; + ac = (ac << 6) | (p - base64_table); + bits += 6; + if (bits >= 8) { + bits -= 8; + *bp++ = (u8)(ac >> bits); + } + } + if (ac & ((1 << bits) - 1)) + return -1; + return bp - dst; +} +EXPORT_SYMBOL_GPL(base64_decode);
Add RFC4648-compliant base64 encoding and decoding routines, based on the base64url encoding in fs/crypto/fname.c. Signed-off-by: Hannes Reinecke <hare@suse.de> --- include/linux/base64.h | 16 +++++++ lib/Makefile | 2 +- lib/base64.c | 103 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 120 insertions(+), 1 deletion(-) create mode 100644 include/linux/base64.h create mode 100644 lib/base64.c